Quarterlytics / Basic Materials / Oil & Gas Midstream / TC Pipelines, LP

TC Pipelines, LP

tcp · NASDAQ Basic Materials
Claim this profile
Ticker tcp
Exchange NASDAQ
Sector Basic Materials
Industry Oil & Gas Midstream
Employees 1-10
← All annual reports
FY2010 Annual Report · TC Pipelines, LP
Sign in to download
Loading PDF…
2
0
1
0

A
n
n
u
a

l

R
e
p
o
r
t

Delivering Value
Disciplined Investment

 
 
Financial Highlights

Year ended December 31
(millions of dollars, except per unit amounts)

Cash Flow

Partnership cash flows*

Cash distributions paid

Income Statement

Net income**

Net income prior to recast*

Balance Sheet

Total assets**

Long-term debt (including current maturities)

Partners’ equity

Common Units Statistics (per unit)

Cash distributions paid

Net income

Common Units Outstanding (millions)

Weighted average for the year

End of year

2006

2007

2008

2009

2010

67.4

 43.5 

 49.1 

44.7

123.2

 86.7 

 94.7 

89.0

143.5

 108.6 

 123.0 

107.7

 150.2 

 117.0 

 106.1 

 97.8 

 1,008.1 

 1,732.4 

 1,701.1 

 1,675.1 

 468.1 
 303.9 

 573.4 
 900.1 

 536.8 
 875.6 

 541.3 
 1,103.5 

180.1

138.7

137.1

137.1

1,650.5

513.9
1,112.5

 $ 2.325 

 $ 2.39 

$ 2.565 

$ 2.48 

$ 2.775 

$ 2.73 

$ 2.870 

$ 2.34 

$2.940

$2.91

17.5

17.5

32.3

34.9

34.9

34.9

38.7

46.2

46.2

46.2

Partnership
Cash Flows* (millions of dollars)

Cash Distributions 
Paid (dollars per unit)

Net Income 
(dollars per unit)

Total Assets
(millions of dollars)

180.1

150.2

143.5

123.2

67.4

2.940

2.870

2.775

2.565

2.325

2.91

2.73

2.48

2.39

2.34

1732.4

1701.1

1675.1

1650.5

1008.1

2006

2007

2008

2009

2010

2006

2007

2008

2009

2010

2006

2007

2008

2009

2010

2006

2007

2008

2009

2010

*Partnership cash flows and net income prior to recast are non-GAAP measures. Non-GAAP measures do not have any standarized meaning prescribed by generally accepted accounting 

principles (GAAP). For more information on non-GAAP financial measures see Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations in our Form 

10-K for the year ended December 31, 2010, filed with the SEC and included in this annual report.

**Recast as discussed in Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations in our Form 10-K for the year ended December 31, 2010, filed with 

the SEC and included in this annual report.

This annual report contains forward-looking statements relating to expectations, plans or prospects for TC PipeLines, LP. These statements are based upon the current expectations and beliefs of management and are subject to certain risks 
and uncertainties that could cause actual results to differ materially from those described in the forward-looking statements. These risks and uncertainties include market conditions and other factors beyond the company’s control. Please 

read the cautionary statements found on page 7, and the risk factors found on page 19, which discuss these factors.

TC PipeLines, LP is a United States limited partnership with a long 
history of stable and growing cash distributions which 
has delivered value to its investors while maintaining a solid cash 
distribution coverage ratio.

Through its disciplined investment philosophy, TC PipeLines has investments in four critical 
FERC regulated, low-risk energy infrastructure pipelines, capable of moving 5.6 billion 
cubic feet per day of natural gas. Revenues from these assets are derived almost entirely from 
fee-based charges.

With access to new gas supplies through support from its sponsor, TransCanada, who 
also operates our assets on our behalf, TC PipeLines’ assets are primarily connected to one of the 
largest supply basins in North America that is positioned to recover and grow over the next decade.

With a strong and conservative balance sheet, a low general partner cash take and an ample 
amount of available liquidity, we are well positioned for growth.

Growth sources have the potential to come from multiple sources: drop-down opportunities 
from our sponsor who is half-way through their C$20 billion capital program, through third party 
acquisitions and organic expansion projects on our existing pipelines, all of which could ultimately 
support TC PipeLines’ ability to provide growing and sustainable cash flows to its investors.

Northern
Border

Tuscarora

Great 
Lakes

North Baja

2010 Partnership Cash Flows*

15%

11%

33%

41%

Northern Border

Great Lakes

North Baja

Tuscarora

TC PipeLines, LP wholly & 
partially owned pipeline assets

TransCanada wholly & partially 
owned pipeline assets

*  Percentages represent the proportion of Partnership Cash Flows derived from distributions received from Great Lakes and Northern Border, and operating cash flows from North Baja and Tuscarora, before deducting Partnership costs. Refer to Part 

II, Item 7. “Management’s Discussion and Analysis of Financial Condition and Results of Operations — How We Evaluate Our Operations — Partnership Cash Flows” for additional information on Partnership Cash Flows.

PipelinesLP_ARCover2010_Inside_Feb25.indd   1

2/25/2011   4:57:13 PM

Mid-Western Interstate Pipeline Assets

California Regional Pipeline Assets

Northern Border (50% Ownership Interest)

Great Lakes (46.45% Ownership Interest)

North Baja (100% Ownership)

Tuscarora (100% Ownership)

•  1,398 miles of pipeline serving markets in 

•  2,115 miles of pipeline serving markets in Minnesota, 

•  86 mile bi-directional pipeline system serving growing 

•  305 miles of pipeline serving markets in Northern 

Minneapolis (via Ventura connection), Chicago,  

Wisconsin, Michigan and eastern Canada

demand from primarily natural gas power generation 

California and northwestern Nevada

and other mid-west markets

•  Design capacity of 2,374 million cubic feet per day

•  Key interconnections into 8 regional pipelines

•  Moving additional U.S. Rockies gas supply via the 

Bison Pipeline, wholly owned by TransCanada 

Corporation, as of January 2011

•  Percentage of revenues from Capacity Reservation 

•  Design capacity of 2,300 (summer)/ 2,500 (winter) 

million cubic feet per day

•  Strong interconnections with gas storage with a total 

regional storage capacity of 650 billion cubic feet

•  Percentage of revenues from Capacity Reservation 

Charges: 95%

in Baja, Mexico and Southern California

•  Design capacity of 600 (northbound) million cubic feet 

per day and 500 (southbound) million cubic feet per day

•  Interconnects with U.S. supply and LNG-sourced 

natural gas

Charges: 100%

•  Percentage of revenues from Capacity Reservation 

Charges: 89%

•  Contracted through October 2011

•  Long term contracts that range between 2022 and 2028

•  Substantially contracted through March 2012

•  Design capacity of 230 million cubic feet per day

•  Percentage of revenues from Capacity Reservation 

Charges: 99%

•  Contracted through 2016

PipelinesLP_ARCover2010_Inside_Feb25.indd   2-3

2/25/2011   4:57:26 PM

Mid-Western Interstate Pipeline Assets

California Regional Pipeline Assets

Northern Border (50% Ownership Interest)

Great Lakes (46.45% Ownership Interest)

North Baja (100% Ownership)

Tuscarora (100% Ownership)

•  1,398 miles of pipeline serving markets in 

•  2,115 miles of pipeline serving markets in Minnesota, 

•  86 mile bi-directional pipeline system serving growing 

•  305 miles of pipeline serving markets in Northern 

Minneapolis (via Ventura connection), Chicago,  

Wisconsin, Michigan and eastern Canada

demand from primarily natural gas power generation 

California and northwestern Nevada

•  Design capacity of 2,300 (summer)/ 2,500 (winter) 

million cubic feet per day

•  Strong interconnections with gas storage with a total 

regional storage capacity of 650 billion cubic feet

•  Percentage of revenues from Capacity Reservation 

Charges: 95%

in Baja, Mexico and Southern California

•  Design capacity of 600 (northbound) million cubic feet 

per day and 500 (southbound) million cubic feet per day

•  Interconnects with U.S. supply and LNG-sourced 

natural gas

•  Percentage of revenues from Capacity Reservation 

Charges: 100%

•  Design capacity of 230 million cubic feet per day

•  Percentage of revenues from Capacity Reservation 

Charges: 99%

•  Contracted through 2016

Charges: 89%

•  Contracted through October 2011

•  Long term contracts that range between 2022 and 2028

and other mid-west markets

•  Design capacity of 2,374 million cubic feet per day

•  Key interconnections into 8 regional pipelines

•  Moving additional U.S. Rockies gas supply via the 

Bison Pipeline, wholly owned by TransCanada 

Corporation, as of January 2011

•  Percentage of revenues from Capacity Reservation 

•  Substantially contracted through March 2012

PipelinesLP_ARCover2010_Inside_Feb25.indd   2-3

2/25/2011   4:57:26 PM

Letter to Unitholders

2010 marked a very successful year for TC PipeLines. Our strategy has been to invest in low 
risk, fee-based assets supported by strong fundamentals. These types of assets provide earnings 
and cash flow certainty due to their regulated nature. This strategy has served us well. Over the 
past ten years, we’ve outperformed the Alerian MLP Total Return Index. An original investment 
back in 2001 provided you, our unitholder, a total return of 475 per cent which was 40 per 
cent higher than the index. This impressive track record of delivering value stems from our long 
history of providing stable and growing distributions in a conservative and disciplined manner.

Year in Review
The North American economy is starting to show signs of a sustained 
recovery and appears to be slowly improving. Within this environment, 
TC PipeLines had a very successful year attributed to the strong financial 
results from all four of our pipeline assets, in particular, Northern Border. 
Several key events and accomplishments contributed to this success:

Increased cash distributions paid on a per unit basis by 2.4 per cent
1. 
2.  Reached a negotiated settlement on the Great Lakes Section 5 rate 

proceeding 

3.  Placed North Baja’s Yuma lateral into service on March 13, 2010
4.  Received Federal Energy Regulatory Commission (FERC) approval on 
November 22, 2010 for construction of the $18 million Northern 
Border Princeton lateral
In January 2011, Northern Border started moving U.S. Rockies gas via 
the interconnection with TransCanada’s Bison pipeline.

5. 

As we move forward into 2011, we look to build on our successes in 2010 
as we continue to execute our business strategy.

Stable Cash Flows and Growing Distributions
Our Partnership experienced a strong year in terms of financial performance. 
Partnership cash flows increased $30 million to $180 million. Cash 
distributions paid to unitholders increased $22 million to $139 million. 
Despite the increase in distributions paid to unitholders, we continue to 
maintain a solid distribution coverage ratio ending with 1.30 times coverage. 

$1.80

1999*

$3.00

2010**

67% Growth in Annual Cash Distributions Paid per Common 
Unit Since Inception.

*Prorated for full year 
**Fourth quarter distribution on an annualized basis

For the year, Partnership net income 
increased $31 million to $137 million, or 
$2.91 per common unit. This increase 
of 29 per cent came primarily from the 
strong performance of Northern Border.

10 Year Total Return

475%

435%

Essential Infrastructure
With interests in over 3,900 miles of 
interstate natural gas pipelines and a 
combined total deliverable capacity of 
5.6 billion cubic feet per day (bcf/d), 
our assets are essential infrastructure 
that supply approximately five per cent 
of the United States daily gas volumes 
and are well interconnected to the key 
markets that they serve. During the course of year, our assets performed 
exceptionally well, demonstrating the strong fundamentals that support 
our business. 

Alerian MLP Index

TCLP

On July 15, 2010, the FERC approved our settlement resulting from the 
Great Lakes Section 5 rate proceeding. Under the terms of the settlement, 
maximum reservation rates on Great Lakes were reduced by eight per 
cent. This rate reduction should help ensure that Great Lakes’ remains 
competitive as a key pipeline serving midwest markets. Our team did an 
outstanding job working with the FERC and our shippers on a settlement 
which provides us with greater certainty on future tolls. 

Northern Border’s strong year can be attributed to the increased demand for 
its transportation services as the temporary gas oversupply situation faced 
in 2009 corrected itself in 2010. As reduced supplies from other pipelines 
which now are serving other markets, volumes rebounded in 2010 as it 
experienced strong demand for its services and favorable basis differentials. 
In addition, Northern Border received approval to construct the $18 million 
Princeton lateral which is supported by a 10 year firm-service contract that 
will connect to a power generation facility.

Both North Baja and Tuscarora are situated in unique geographic locations 
and the profile of their long term contracts provide stable earnings and 
cash flows from year to year. As such, these two pipelines are generally 
unaffected by shifting natural gas supply and demand fundamentals and 
provide good diversification to our portfolio of pipeline assets. North Baja 
expanded its reach as it placed the Yuma lateral in south west Arizona into 

service in March 2010 to serve an expansion of a power generation facility 

Looking beyond the growth in Canadian shale gas plays, our long haul 

which is expected online in early 2011.

In a year that saw two major tragic pipeline incidents, operator safety 

and maintenance practices have been called into question. TC PipeLines 

is proud to be supported by a strong sponsor in TransCanada. As our 

general partner and the operator of our assets, TransCanada operates 

pipelines are uniquely positioned to capture volumes from other U.S. 

shale gas sources. The emerging Bakken shale play in Montana and 

North Dakota along with the Collingwood shale play in Michigan are 

future sources of gas supply that Northern Border and Great Lakes could 

potentially capture and move to market given their footprint.

North America’s largest natural gas pipeline network and is proud of its 

Positioned for Growth

operating history and maintenance practices. While it is too early to tell 

Our conservative and strong balance sheet which includes a largely 

what the potential impact of the various proposed industry regulations, 

undrawn credit facility and a low general partner cash take that is 

we will continue to monitor the situation closely. We remain confident 

amongst the lowest in the industry, provides us with the financial flexibility 

our pipeline assets are essential North American infrastructure for the 

and liquidity to pursue growth opportunities in a disciplined manner that 

markets that they serve and will continue to represent solid investments 

will benefit our unitholders over the long term.

10 year downstream contracts on Northern Border for 407 million cubic 

With access to a large pool of talent for management through our 

for TC PipeLines.

Accessing New Gas Supply 

Strong support from our sponsor, TransCanada, is one of our core 

strengths. TransCanada is in the midst of developing its large multi-year 

capital program. As part of this program, several developments are 

expected to have a positive impact on TC PipeLines.

Construction began on the Bison natural gas pipeline in July 2010 and 

became operational in January 2011. The Bison pipeline will bring gas 

from the Powder River Basin in Wyoming and interconnect with the 

Northern Border pipeline in North Dakota. Bison shippers have executed 

feet per day (mmcf/d) from the Port of Morgan, Montana, to Ventura, 

Iowa. These contracts will not only strengthen Northern Border’s contract 

portfolio, but also help to diversify its natural gas supply. The pipeline also 

has the potential for expansion through additional compression.

In November 2010, TransCanada began moving gas from the Montney 

shale gas formation in northeastern British Columbia on its newly 

constructed Groundbirch pipeline into the Alberta System. The project 

has firm transportation contracts that will reach 1.24 bcf/d by 2014. 

TransCanada’s other shale gas pipeline project will connect Horn River gas. 

The Horn River pipeline has contract commitments that will reach 634 

mmcf/d by 2014 and is expected to be operational in the second quarter 

2012. These two projects will bring approximately 1.9 bcf/d of new shale 

gas volumes onto TransCanada’s Alberta System that will be ultimately be 

available for consumption and export to downstream markets.

In addition to the committed volumes received to date, TransCanada 

also has received expressions of interest from producers for an additional 

2.3 bcf/d of transportation services from these developing shale plays. 

The continued interest from natural gas producers to develop shale gas 

plays within the Western Canadian Sedimentary Basin (WCSB) leads us 

to remain optimistic that volumes produced and exported out of the 

WCSB will stabilize in the near term and will start to increase over time 

as the potential of the Horn River and Montney shale plays are developed 

and brought on stream. Both Northern Border and Great Lakes are well 

positioned to play an integral role in this regard as producers require major 

reliable pipelines to move this gas to market. 

Growth opportunities have the potential to come from several sources. 

With TransCanada now close to half way through its C$20 billion multi-

year capital program, TC PipeLines could potentially play a key role in 

its financing needs to complete this program. While we wait for an 

opportunity to assist TransCanada with its capital needs, we continue 

to explore opportunities to acquire third party assets that would 

complement our existing asset base. As we evaluate these opportunities, 

rest assured that we will remain disciplined in our investment approach, 

only selecting those that provide the ability to grow earnings, cash flows 

and distributions in a stable low-risk manner.

affiliation with TransCanada, the strong fundamentals supporting our 

existing asset base, a promising long-term outlook for gas with the 

growth in gas supplies from new shale plays and with a sound financial 

position, I am confident the Partnership is well positioned to continue 

delivering value to its unitholders and will provide stable and growing 

cash distributions well into the future.

On behalf of TC PipeLines, LP

Steve Becker

President, TC PipeLines, LP

PipelinesLP_ARCover2010_Inside_Feb25.indd   4-5

2/25/2011   4:57:27 PM

Letter to Unitholders

2010 marked a very successful year for TC PipeLines. Our strategy has been to invest in low 

risk, fee-based assets supported by strong fundamentals. These types of assets provide earnings 

and cash flow certainty due to their regulated nature. This strategy has served us well. Over the 

past ten years, we’ve outperformed the Alerian MLP Total Return Index. An original investment 

back in 2001 provided you, our unitholder, a total return of 475 per cent which was 40 per 

cent higher than the index. This impressive track record of delivering value stems from our long 

history of providing stable and growing distributions in a conservative and disciplined manner.

Year in Review

The North American economy is starting to show signs of a sustained 

For the year, Partnership net income 

recovery and appears to be slowly improving. Within this environment, 

increased $31 million to $137 million, or 

TC PipeLines had a very successful year attributed to the strong financial 

$2.91 per common unit. This increase 

results from all four of our pipeline assets, in particular, Northern Border. 

of 29 per cent came primarily from the 

Several key events and accomplishments contributed to this success:

strong performance of Northern Border.

1. 

Increased cash distributions paid on a per unit basis by 2.4 per cent

2.  Reached a negotiated settlement on the Great Lakes Section 5 rate 

proceeding 

3.  Placed North Baja’s Yuma lateral into service on March 13, 2010

4.  Received Federal Energy Regulatory Commission (FERC) approval on 

November 22, 2010 for construction of the $18 million Northern 

Border Princeton lateral

5. 

In January 2011, Northern Border started moving U.S. Rockies gas via 

the interconnection with TransCanada’s Bison pipeline.

Essential Infrastructure

With interests in over 3,900 miles of 

interstate natural gas pipelines and a 

combined total deliverable capacity of 

5.6 billion cubic feet per day (bcf/d), 

our assets are essential infrastructure 

that supply approximately five per cent 

of the United States daily gas volumes 

and are well interconnected to the key 

10 Year Total Return

475%

435%

TCLP

Alerian MLP Index

As we move forward into 2011, we look to build on our successes in 2010 

exceptionally well, demonstrating the strong fundamentals that support 

as we continue to execute our business strategy.

our business. 

markets that they serve. During the course of year, our assets performed 

Stable Cash Flows and Growing Distributions

Our Partnership experienced a strong year in terms of financial performance. 

Partnership cash flows increased $30 million to $180 million. Cash 

distributions paid to unitholders increased $22 million to $139 million. 

Despite the increase in distributions paid to unitholders, we continue to 

maintain a solid distribution coverage ratio ending with 1.30 times coverage. 

$1.80

1999*

67% Growth in Annual Cash Distributions Paid per Common 

Unit Since Inception.

*Prorated for full year 

**Fourth quarter distribution on an annualized basis

$3.00

2010**

On July 15, 2010, the FERC approved our settlement resulting from the 

Great Lakes Section 5 rate proceeding. Under the terms of the settlement, 

maximum reservation rates on Great Lakes were reduced by eight per 

cent. This rate reduction should help ensure that Great Lakes’ remains 

competitive as a key pipeline serving midwest markets. Our team did an 

outstanding job working with the FERC and our shippers on a settlement 

which provides us with greater certainty on future tolls. 

Northern Border’s strong year can be attributed to the increased demand for 

its transportation services as the temporary gas oversupply situation faced 

in 2009 corrected itself in 2010. As reduced supplies from other pipelines 

which now are serving other markets, volumes rebounded in 2010 as it 

experienced strong demand for its services and favorable basis differentials. 

In addition, Northern Border received approval to construct the $18 million 

Princeton lateral which is supported by a 10 year firm-service contract that 

will connect to a power generation facility.

Both North Baja and Tuscarora are situated in unique geographic locations 

and the profile of their long term contracts provide stable earnings and 

cash flows from year to year. As such, these two pipelines are generally 

unaffected by shifting natural gas supply and demand fundamentals and 

provide good diversification to our portfolio of pipeline assets. North Baja 

expanded its reach as it placed the Yuma lateral in south west Arizona into 

service in March 2010 to serve an expansion of a power generation facility 
which is expected online in early 2011.

In a year that saw two major tragic pipeline incidents, operator safety 
and maintenance practices have been called into question. TC PipeLines 
is proud to be supported by a strong sponsor in TransCanada. As our 
general partner and the operator of our assets, TransCanada operates 
North America’s largest natural gas pipeline network and is proud of its 
operating history and maintenance practices. While it is too early to tell 
what the potential impact of the various proposed industry regulations, 
we will continue to monitor the situation closely. We remain confident 
our pipeline assets are essential North American infrastructure for the 
markets that they serve and will continue to represent solid investments 
for TC PipeLines.

Accessing New Gas Supply 
Strong support from our sponsor, TransCanada, is one of our core 
strengths. TransCanada is in the midst of developing its large multi-year 
capital program. As part of this program, several developments are 
expected to have a positive impact on TC PipeLines.

Construction began on the Bison natural gas pipeline in July 2010 and 
became operational in January 2011. The Bison pipeline will bring gas 
from the Powder River Basin in Wyoming and interconnect with the 
Northern Border pipeline in North Dakota. Bison shippers have executed 
10 year downstream contracts on Northern Border for 407 million cubic 
feet per day (mmcf/d) from the Port of Morgan, Montana, to Ventura, 
Iowa. These contracts will not only strengthen Northern Border’s contract 
portfolio, but also help to diversify its natural gas supply. The pipeline also 
has the potential for expansion through additional compression.

In November 2010, TransCanada began moving gas from the Montney 
shale gas formation in northeastern British Columbia on its newly 
constructed Groundbirch pipeline into the Alberta System. The project 
has firm transportation contracts that will reach 1.24 bcf/d by 2014. 
TransCanada’s other shale gas pipeline project will connect Horn River gas. 
The Horn River pipeline has contract commitments that will reach 634 
mmcf/d by 2014 and is expected to be operational in the second quarter 
2012. These two projects will bring approximately 1.9 bcf/d of new shale 
gas volumes onto TransCanada’s Alberta System that will be ultimately be 
available for consumption and export to downstream markets.

In addition to the committed volumes received to date, TransCanada 
also has received expressions of interest from producers for an additional 
2.3 bcf/d of transportation services from these developing shale plays. 
The continued interest from natural gas producers to develop shale gas 
plays within the Western Canadian Sedimentary Basin (WCSB) leads us 
to remain optimistic that volumes produced and exported out of the 
WCSB will stabilize in the near term and will start to increase over time 
as the potential of the Horn River and Montney shale plays are developed 
and brought on stream. Both Northern Border and Great Lakes are well 
positioned to play an integral role in this regard as producers require major 
reliable pipelines to move this gas to market. 

Looking beyond the growth in Canadian shale gas plays, our long haul 
pipelines are uniquely positioned to capture volumes from other U.S. 
shale gas sources. The emerging Bakken shale play in Montana and 
North Dakota along with the Collingwood shale play in Michigan are 
future sources of gas supply that Northern Border and Great Lakes could 
potentially capture and move to market given their footprint.

Positioned for Growth
Our conservative and strong balance sheet which includes a largely 
undrawn credit facility and a low general partner cash take that is 
amongst the lowest in the industry, provides us with the financial flexibility 
and liquidity to pursue growth opportunities in a disciplined manner that 
will benefit our unitholders over the long term.

Growth opportunities have the potential to come from several sources. 
With TransCanada now close to half way through its C$20 billion multi-
year capital program, TC PipeLines could potentially play a key role in 
its financing needs to complete this program. While we wait for an 
opportunity to assist TransCanada with its capital needs, we continue 
to explore opportunities to acquire third party assets that would 
complement our existing asset base. As we evaluate these opportunities, 
rest assured that we will remain disciplined in our investment approach, 
only selecting those that provide the ability to grow earnings, cash flows 
and distributions in a stable low-risk manner.

With access to a large pool of talent for management through our 
affiliation with TransCanada, the strong fundamentals supporting our 
existing asset base, a promising long-term outlook for gas with the 
growth in gas supplies from new shale plays and with a sound financial 
position, I am confident the Partnership is well positioned to continue 
delivering value to its unitholders and will provide stable and growing 
cash distributions well into the future.

On behalf of TC PipeLines, LP

Steve Becker
President, TC PipeLines, LP

PipelinesLP_ARCover2010_Inside_Feb25.indd   4-5

2/25/2011   4:57:27 PM

6

TC PIPELINES, LP

TC PIPELINES, LP

TABLE OF CONTENTS

Page No.

Business

PART I
Item 1.
Item 1A. Risk Factors
Item 1B. Unresolved Staff Comments
Item 2.
Item 3.

Properties
Legal Proceedings

PART II
Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of

Equity Securities
Selected Financial Data

Item 6.
Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations
Item 7A. Quantitative and Qualitative Disclosures About Market Risk
Financial Statements and Supplementary Data
Item 8.
Changes in and Disagreements With Accountants on Accounting and Financial Disclosure
Item 9.
Item 9A. Controls and Procedures
Item 9B. Other Information

PART III
Item 10. Directors, Executive Officers and Corporate Governance
Item 11.
Item 12.

Executive Compensation
Security Ownership of Certain Beneficial Owners and Management and Related
Stockholder Matters

Item 13. Certain Relationships and Related Transactions, and Director Independence
Item 14.

Principal Accounting Fees and Services

PART IV
Item 15.

Exhibits, Financial Statement Schedules

GLOSSARY OF TERMS

All amounts are stated in United States dollars unless otherwise indicated.

8
19
33
33
33

34
35
35
56
58
58
58
59

60
63

66
68
71

72

G-1

2010 ANNUAL REPORT

7

PART I

FORWARD-LOOKING STATEMENTS

The statements in this report that are not historical information, including statements concerning plans and objectives of
management for future operations, economic performance or related assumptions, are forward-looking statements
within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities
Exchange Act of 1934, as amended (Exchange Act). Forward-looking statements may include words such as
‘‘anticipate,’’ ‘‘estimate,’’ ‘‘expect,’’ ‘‘project,’’ ‘‘intend,’’ ‘‘plan,’’ ‘‘believe,’’ ‘‘forecast’’ and other words and terms of
similar meaning. The absence of these words, however, does not mean that the statements are not forward-looking.

These statements reflect our current views with respect to future events, based on what we believe are reasonable
assumptions. Certain factors that could cause actual results to differ materially from those contemplated in the forward-
looking statements include:

(cid:127) the ability of Great Lakes Gas Transmission Limited Partnership (Great Lakes) and Northern Border Pipeline Company

(Northern Border) to continue to make distributions at their current levels;

(cid:127) the impact of unsold capacity on Great Lakes and Northern Border being greater or less than expected;

(cid:127) the competitive conditions in our industry and the ability of Great Lakes, Northern Border, North Baja Pipeline, LLC
(North Baja) and Tuscarora Gas Transmission Company (Tuscarora, and together with Great Lakes, Northern Border
and North Baja, ‘‘our pipeline systems’’) to market pipeline capacity on favorable terms, which is affected by, among
other factors:

(cid:127) future demand for and prices of natural gas;

(cid:127) level of natural gas basis differentials;

(cid:127) competitive conditions in the overall natural gas and electricity markets;

(cid:127) availability and relative cost of supplies of Canadian and United States (U.S.) natural gas, including the discovered

shale gas resources such as the Horn River and Montney deposits in Western Canada and the Bakken formation in
the Midwestern U.S., along with U.S. Rockies, Mid-Continent and Marcellus natural gas developments;

(cid:127) competitive developments by U.S. and Canadian natural gas transmission companies;

(cid:127) the availability of additional storage capacity and current storage levels;

(cid:127) the level of liquified natural gas imports;

(cid:127) weather conditions that impact supply and demand; and

(cid:127) the ability of shippers to meet creditworthiness requirements;

(cid:127) the impact of current and future laws, rulings and governmental regulations, particularly Federal Energy Regulatory

Commission (FERC) regulations and rate proceedings, and proposed and pending legislation by Congress and
proposed and pending regulations by the U.S. Environmental Protection Agency (EPA) and other regulators in the
U.S. on us and our pipeline systems;

(cid:127) the changes in relative cost structures of natural gas producing basins, such as changes in royalty programs, that may

prejudice the development of the Western Canada Sedimentary Basin (WCSB);

(cid:127) decisions by other pipeline companies to advance projects that will affect our pipeline systems;

(cid:127) the regulatory, financing and construction risks related to construction of interstate natural gas pipelines and

additional facilities;

(cid:127) our ability and that of our pipeline systems to identify and/or consummate expansion projects and other accretive

growth opportunities;

(cid:127) the performance of contractual obligations by customers of our pipeline systems;

8

TC PIPELINES, LP

(cid:127) the imposition of entity level taxation by states on partnerships;

(cid:127) the operating hazards, natural disasters, weather-related delays, casualty losses and other matters beyond our control;

(cid:127) our ability to control operating costs, including the operations of our pipeline systems; and

(cid:127) the general economic conditions in North America, which impact:

(cid:127) the debt and equity capital markets and our ability to access these markets at reasonable costs;

(cid:127) the overall demand for natural gas by end users; and

(cid:127) natural gas prices.

Other factors described elsewhere in this document, or factors that are unknown or unpredictable, could also have
material adverse effects on future results. Please also read Item 1A. ‘‘Risk Factors.’’ All forward-looking statements
attributable to us or persons acting on our behalf are expressly qualified in their entirety by these factors. These
forward-looking statements and information are made only as of the date of the filing of this report and except as
required by applicable law, we undertake no obligation to update these forward-looking statements and information to
reflect new information, subsequent events or otherwise.

Item 1. Business

OVERVIEW

Limited Partnership

TC PipeLines, LP is a publicly traded Delaware limited partnership formed in 1998 to acquire, own and participate in the
management of energy infrastructure businesses in North America. Our common units are listed on the NASDAQ Global
Select Market under the symbol ‘‘TCLP.’’ TC PipeLines, LP’s General Partner is TC PipeLines GP, Inc., which is wholly-
owned by a subsidiary of TransCanada Corporation.

TC PipeLines, LP and its subsidiaries are collectively referred to herein as ‘‘the Partnership.’’ In this report, references to
‘‘we,’’ ‘‘us’’ or ‘‘our’’ refer to the Partnership. TransCanada Corporation, together with its subsidiaries, is referred to
as TransCanada.

The Partnership has ownership interests in four natural gas interstate pipeline systems that collectively can transport
approximately 5.6 billion cubic feet per day (Bcf/d) of natural gas, including partial ownership in Northern Border
Pipeline Company (Northern Border) and Great Lakes Gas Transmission Limited Partnership (Great Lakes), which
primarily ship Western Canadian natural gas to markets in the Midwestern U.S. and Eastern Canada, and full ownership
in North Baja Pipeline, LLC (North Baja) and Tuscarora Gas Transmission Company (Tuscarora), which transport natural
gas to markets in California and the U.S. Southwest. Distributions from Northern Border and Great Lakes provide the
largest portion of distributable cash flow available to the Partnership. Each of these pipelines is operated under
agreements with subsidiaries of TransCanada. See Part III, Item 13. ‘‘Certain Relationships and Related Transactions, and
Director Independence’’ for more information on our relationship with TransCanada.

Specifically, through our subsidiaries, we own:

(cid:127) 46.45 percent of Great Lakes, a Delaware limited partnership formed in 1990. The remaining 53.55 percent is held

by subsidiaries of TransCanada.

The Great Lakes pipeline system consists of 2,115 miles of pipeline extending from the Canadian border near
Emerson, Manitoba, Canada to St. Clair, Michigan, near Detroit, and has an average design capacity of approximately
2.4 Bcf/d at Emerson. The original construction of the Great Lakes system occurred in 1967 and 1968. Numerous
capacity system expansions have occurred since its original construction, the last one completed in 1998.

2010 ANNUAL REPORT

9

(cid:127) 50 percent of Northern Border, a Texas general partnership formed in 1978. The remaining 50 percent is held by

ONEOK Partners, L.P. (ONEOK Partners).

The Northern Border pipeline system consists of 1,398 miles of pipeline extending from the Canadian border near
Port of Morgan, Montana, to a terminus near North Hayden, Indiana, south of Chicago. Northern Border has a
design capacity of approximately 2.4 Bcf/d. Construction of Northern Border’s system was initially completed in 1982,
followed by expansions or extensions in 1991, 1992, 1998, 2001 and 2006.

(cid:127) 100 percent of North Baja, a Delaware limited liability company formed in 2000.

The North Baja pipeline system consists of 86 miles of pipeline extending from an interconnection with the El Paso
Natural Gas Company (EPNG) pipeline near Ehrenberg, Arizona, to an interconnection with the Gasoducto Bajanorte
natural gas pipeline near Ogilby, California on the Mexican border. North Baja has a design capacity of 500 million
cubic feet per day (MMcf/d) for southbound transportation and 600 MMcf/d for northbound transportation. The
North Baja pipeline system was initially placed into service in 2002. An expansion was completed in April 2008 to
allow for bi-directional natural gas flow and the Yuma Lateral, from the Mexico/Arizona border to Yuma, Arizona,
was completed in March 2010.

(cid:127) 100 percent of Tuscarora, a Nevada general partnership formed in 1993.

The Tuscarora pipeline system consists of 305 miles of pipeline extending from the Gas Transmission Northwest
Corporation (GTN) pipeline, a wholly-owned subsidiary of TransCanada, near Malin, Oregon to a terminus near
Wadsworth, Nevada. Tuscarora has a design capacity of 230 MMcf/d. The Tuscarora pipeline system was initially
placed into service in 1995, followed by expansions or extensions in 2001, 2002, 2005 and 2008.

Northern
Border

Tuscarora

Great 
Lakes

North Baja

2010 Partnership Cash Flows*

Tuscarora

North Baja

15%

11%

33%

41%

Northern Border

Great Lakes

TC PipeLines, LP wholly &
partially owned pipeline assets

TransCanada wholly & partially
owned pipeline assets

25FEB201119371069

* Percentages represent the proportion of Partnership Cash Flows derived from distributions received from Great Lakes and Northern Border,

and operating cash flows from North Baja and Tuscarora, before deducting Partnership costs. Refer to Part II, Item 7. ‘‘Management’s
Discussion and Analysis of Financial Condition and Results of Operations – How We Evaluate Our Operations – Partnership Cash Flows’’ for
additional information on Partnership Cash Flows.

10

TC PIPELINES, LP

Business Strategies

(cid:127) Our strategic approach is to invest in long-term, critical energy infrastructure that provides reliable delivery of energy

to customers in the United States.

(cid:127) Our investment approach is to develop or acquire assets that provide stable cash distributions and opportunities for
new capital additions, while maintaining a low-risk profile. We are opportunistic and disciplined in our approach
when identifying new investments.

(cid:127) Our operational approach is to maximize the utilization of our pipeline systems, with a commitment to safe and

reliable operations.

Relationship with TransCanada

One of our principal strengths is our relationship with TransCanada. TransCanada is a major energy infrastructure
company, listed on the Toronto Stock Exchange and New York Stock Exchange, with more than 50 years of experience
in the responsible development and reliable operation of energy infrastructure in North America. TransCanada is
primarily focused on natural gas and oil transmission and power generation services. Together with assets under
construction, TransCanada owns more than $46.6 billion in total assets, including 37,000 miles of wholly-owned natural
gas pipelines, interests in an additional 5,500 miles of natural gas pipelines, 2,150 miles of wholly-owned oil pipelines
and approximately 380 billion cubic feet (Bcf) of storage capacity. TransCanada also owns, controls or is developing over
10,800 megawatts of power generation.

TransCanada, through its subsidiaries, currently owns a 38.2 percent interest in the Partnership and our pipeline
systems, including an effective two percent general partner interest and a 12.3 percent limited partner interest held by
TC PipeLines GP, Inc., our General Partner. Subsidiaries of TransCanada operate our pipeline systems and one subsidiary,
TransCanada PipeLines Limited, is the largest customer on Great Lakes. We expect to have the opportunity to
participate jointly with TransCanada in reviewing potential acquisitions, including transactions that we would be unable
to pursue on our own. Additionally, we may have the opportunity to make acquisitions directly from TransCanada.
TransCanada, however, is under no obligation to allow us to participate in any of its pipeline or energy infrastructure
acquisitions, nor is TransCanada required to offer any of its assets to us.

See Part II, Item 5. ‘‘Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity
Securities’’ for more information regarding TransCanada’s ownership in us.

Interstate Natural Gas Pipeline Business

Supply
Our pipelines are a critical part of the natural gas market in the U.S. and transport natural gas from producing regions
and import facilities to market hubs and consuming markets.

Natural gas is transported from producing regions and liquified natural gas (LNG) import facilities to market hubs for
distribution to natural gas consumers. The main producing regions in North America are the Gulf of Mexico, Western
Canada Sedimentary Basin (WCSB), Mid-Continent, Rockies, Permian basin and San Juan basin. Northeastern U.S., the
Midwest and the West Coast are three large natural gas regions in the U.S. Recent increases in the development of
unconventional and shale gas have resulted in increases in overall North American natural gas production and increased
reserves. Over the past few years, significant new pipeline infrastructure has been added to move natural gas from
producing regions to market areas. This impacts the transportation value on pipelines, including our pipeline systems.
Additional pipeline projects have been proposed, including projects to move additional natural gas supply into western
market regions, which are expected to continue to impact overall North American natural gas flows. Additionally,
development of new producing regions, such as the Marcellus shale in the eastern U.S., the Montney and Horn River
shale areas in northeastern British Columbia, Canada and the Bakken shale area in North Dakota and Montana, will

2010 ANNUAL REPORT

11

also impact North American natural gas flows. In the longer term, reserves from northern natural gas also have the
potential to increase supply coming out of the WCSB.

Great Lakes primarily transports natural gas produced in the WCSB and receives it at an interconnection with the
TransCanada Mainline pipeline system (TransCanada Mainline) at the Canadian border near Emerson, Manitoba,
Canada. Great Lakes extends across Minnesota, Northern Wisconsin and Michigan and redelivers natural gas to
TransCanada at the Canadian border near Sault Ste. Marie, Ontario, Canada and St. Clair, Michigan. Great Lakes also
connects to storage centers in Michigan and, through the TransCanada Mainline, interconnects to the Dawn, Ontario
market region (Dawn). Great Lakes also interconnects with other interstate natural gas pipelines, including
TransCanada’s ANR pipeline system (ANR), that primarily source natural gas from the Gulf of Mexico and Mid-Continent
regions.

Northern Border primarily transports natural gas produced in the WCSB and receives it at an interconnection with one
of TransCanada’s pipelines at the Canadian border near Port of Morgan, Montana. Northern Border also transports
natural gas produced in the Williston Basin of Montana and North Dakota, and the Powder River Basin of Wyoming
and Montana, which together accounted for approximately 10 percent of the natural gas Northern Border transported
in 2010. In addition, synthetic natural gas produced at the Dakota Gasification plant in North Dakota accounted for
approximately six percent of the natural gas transported by Northern Border in 2010. In January 2011, TransCanada
completed the Bison pipeline, which extends from Wyoming to an interconnection with Northern Border in Morton
County, North Dakota. The Bison pipeline provides additional natural gas sourced from the Powder River Basin to
Northern Border.

North Baja receives natural gas from an interconnection with EPNG at Ehrenberg, Arizona that sources natural gas
primarily from the West Texas and Southern Rocky Mountain supply regions. Due to the bi-directional capability
modifications completed in April 2008, North Baja is also able to transport natural gas northbound at Ogilby, California,
and receives natural gas sourced from the Energia Costa Azul (Costa Azul) LNG terminal in Mexico.

Tuscarora receives natural gas from its interconnection with GTN. GTN is interconnected with WCSB supply, as well as
natural gas from the Rockies and other U.S. basins. Ruby Pipeline, LLC (Ruby), which is currently under construction, will
interconnect with GTN and Tuscarora. Ruby is projected to be in service in mid-2011 and, once completed, is expected
to increase Tuscarora’s access to natural gas from the Rockies.

Demand and Seasonality
The demand for transportation service on a pipeline depends on a number of factors, including:

(cid:127) demand for natural gas in the markets served;

(cid:127) price of natural gas at the pipeline delivery point compared to other markets;

(cid:127) availability of natural gas at the pipeline system’s receipt points;

(cid:127) transportation rates of competing pipelines;

(cid:127) weather conditions; and

(cid:127) availability and competitiveness of alternative supply sources and storage alternatives in the consuming market.

The impact on our revenues due to changes in demand for natural gas transportation services is primarily dependent
upon the extent to which capacity has been contracted under long-term firm contracts. Tuscarora and North Baja have
long-term firm contracts and do not experience revenue volatility due to seasonal changes in demand related to market
conditions, including weather related demand. Great Lakes and Northern Border, however, are subject to annual
contract renewals and can experience demand changes related to seasonal market conditions. Additionally, Northern
Border’s tariff has a seasonal rate structure providing for higher rates in the traditional peak months in the summer and
winter seasons.

12

TC PIPELINES, LP

To the extent Great Lakes’ capacity is contracted, utilization does not impact revenues significantly. In periods when
Great Lakes is not fully contracted, its revenues are affected by demand for its long-haul transportation service that is
normally at its highest when natural gas is being delivered to storage areas. The high demand period usually begins in
the spring and extends through most of the summer. During the winter, there is also strong demand for Great Lakes’
services to meet the peak winter heating demand requirements of Minnesota, northern Wisconsin and Michigan.

Northern Border’s revenues are partially affected by demand for transportation services that has traditionally been the
strongest during peak winter months to serve heating demand and peak spring/summer months to serve electric
cooling demand and storage injection.

North Baja has substantial contracts for both southbound and northbound transportation service and these reservation-
based contracts provide predictable revenues despite variability in the amount of natural gas or the direction that
natural gas may flow. Similarly, Tuscarora’s significant long-term contract profile ensures stable revenues that are not
subject to utilization risk.

Competition
Competition among natural gas pipelines is based primarily on transportation rates and proximity to natural gas supply
areas and consuming markets. Our pipeline systems compete with other pipelines that source natural gas from the
same supply regions, primarily the WCSB, and those that source natural gas from different supply regions but deliver to
the same markets as our pipelines. The WCSB, which covers over 540,000 square miles, contains one of the world’s
largest reserves of petroleum and natural gas and supplies approximately 15 percent of the demand for natural gas in
North America. ‘‘Gas exiting the WCSB’’ is the term we use to represent the net of the supply of and demand for
natural gas in the WCSB region. The West Coast and the Midwest market, particularly Chicago, are two large natural
gas consuming markets in the U.S. The Midwest market is also a major storage location and market hub for further
distribution to east, north and central U.S. markets.

Great Lakes and Northern Border both compete for natural gas transportation customers with pipelines that transport
gas exiting the WCSB. The primary competition for Great Lakes is the route from Western Canada to Dawn on the
TransCanada Mainline. Other routes from Western Canada to Ontario, Canada include the Foothills Pipeline to Northern
Border to Vector Pipeline route, and the Alliance Pipeline to Vector Pipeline route. In addition, natural gas can be
delivered to the markets served by Great Lakes by competing pipelines that have access to alternate sources of supply
from the Rockies, Mid-Continent, Gulf Coast and Marcellus shale areas.

Northern Border’s system competes for WCSB natural gas transportation customers with other pipelines that transport
WCSB supply to markets in the West, Midwest and East in North America. The pipeline systems that represent Northern
Border’s primary competition in these markets include Alliance Pipeline, Great Lakes, GTN and other pipelines that
interconnect with the TransCanada Mainline for WCSB supply. Northern Border also competes with other pipelines that
serve the same market area sourcing natural gas from storage facilities and from other supply regions in the Rockies,
Mid-Continent, Permian Basin and Gulf Coast. The pipeline systems that deliver natural gas from other supply regions
into the same market that Northern Border serves include Northern Natural Gas Company into the Ventura, Iowa
market area, and ANR, Midwestern Gas Transmission Company and Natural Gas Pipeline of America into the
Chicago market.

North Baja’s southbound deliveries compete with LNG deliveries from the Costa Azul terminal when supply is received at
that terminal. Shippers retain contracts on North Baja to be able to deliver natural gas to several power plants in Baja
California, Mexico at times when LNG-sourced natural gas from the Costa Azul terminal is unavailable. As well, North
Baja provides a northbound path for LNG from the Costa Azul terminal to markets in the southwestern U.S.

Tuscarora competes for deliveries into the Northern Nevada natural gas market mainly with natural gas from the Rockies
delivered by the Paiute Pipeline system.

2010 ANNUAL REPORT

13

Customers and Contracting
Our customers are generally large utilities, local distribution companies and major natural gas marketers and production
companies. Our pipelines generate revenue by charging rates for transporting natural gas. Natural gas transportation
service is provided pursuant to long-term and short-term contracts.

All of our pipeline systems are regulated by the FERC. Our pipeline systems’ transportation contracts, and accordingly,
their operating revenues, are derived from rates stated in our tariffs. Tariffs specify the maximum and minimum
transportation rates that our pipeline systems may charge their customers. Rates can be discounted to address
competition, if necessary. In addition, tariffs specify the general terms and conditions for pipeline transportation service.
Tariffs are approved by the FERC, and in most cases, are established in a FERC proceeding known as a rate case. During
a rate case, a determination is reached by the FERC, either through a hearing or a settlement, on the maximum rates
permissible for transportation service on a pipeline system that would allow it to recover its cost-based investment,
operating expenses and a reasonable return for its investors. Once maximum rates are set, a pipeline system is not
permitted to adjust the maximum rates to reflect changes in costs or contract demand until new rates are approved by
the FERC. As a result, earnings and cash flows of each pipeline system depend on costs incurred; contracted capacity
and transportation path; the volume of natural gas transported; and the ability of each system to sell capacity at
acceptable rates.

Transportation contracts mature at varying times and for varying amounts of throughput capacity. As existing contracts
on our pipeline systems approach their expiration dates, efforts are made to extend and/or renew the contracts. The
ability to extend and/or renew expiring contracts will depend upon competitive alternatives, the regulatory environment
and market and supply factors. The length of new or renegotiated contracts will be affected by current market price
spreads, transportation rates, competitive conditions, levels of available pipeline capacity and customers’ judgments
concerning future market trends and volatility. If market conditions are not favorable at the time of renewal,
transportation capacity may remain uncontracted. Capacity would be recontracted, if and when market conditions
become more favorable.

Increased competition and excess transportation capacity within the North American natural gas industry have resulted
in a trend towards shorter term contracting as customers assess and choose the transportation paths that optimize their
business.

For the year ended December 31, 2010, TransCanada, through the TransCanada Mainline and ANR, accounted for
20 percent of the Partnership’s proportionate share of our pipelines’ operating revenues.

REGULATORY ENVIRONMENT

Government Regulation

The FERC initiates regulatory changes through orders intended to create a more competitive environment in the natural
gas marketplace. Among the most important of these orders on our pipelines are:

Promotion of a More Efficient Capacity Release Market, Order 712 et seq. – In a 2008 Final Rule, the FERC permanently
lifted the maximum rate cap on capacity releases of one year or less, but retained the cap for capacity sold by pipelines.
The Interstate Natural Gas Association of America (INGAA), of which TransCanada is a member, sought rehearing and
then appealed the Capacity Release Final Rule to the U.S. Court of Appeals – D.C. Circuit, contending that rate
treatment for short-term capacity should be the same whether it is available for shippers or the pipeline. In
August 2010, the DC Circuit court denied the appeal. Under market conditions to date, this rule has not had a
significant effect on our ability to compete with capacity releases in the short-term market.

Compliance with Statutes, Orders, Rules and Regulations Docket No. PL10-4-000 – In March 2010, and further revised
in September 2010, the FERC issued a ‘‘Policy Statement on Penalty Guidelines’’ adopting a penalty guideline approach
modeled after the United States Sentencing Guidelines for the purpose of providing greater fairness, consistency and

14

TC PIPELINES, LP

transparency to the FERC’s civil penalty determinations. We are not aware of any compliance issues that would invoke
application of the penalty guidelines.

Composition of Proxy Groups for Rates of Return Determinations – The FERC uses proxy groups of publicly traded
companies with business models similar to the pipeline for which a rate determination is sought in order to determine
an appropriate return on equity (ROE) for that pipeline. In a 2008 Policy Statement, the FERC expanded the criteria for
proxy group companies, thereby permitting the inclusion of master limited partnerships (MLPs). The effect of the FERC’s
evolving policy and precedent with regard to proxy groups, and the availability of risk-appropriate companies and MLPs
for inclusion in a proxy group at the time of a rate case, may impact the ROEs for any of our pipeline systems involved
in a rate case.

Enacted Regulations
All of our pipeline systems are regulated under the Natural Gas Act of 1938 (NGA), Natural Gas Policy Act of 1978 and
Energy Policy Act of 2005, which give the FERC jurisdiction to regulate virtually all aspects of their businesses, including:

(cid:127) transportation of natural gas;

(cid:127) rates and charges;

(cid:127) terms of service and service contracts with customers, including creditworthiness requirements;

(cid:127) certification and construction of new facilities;

(cid:127) extension or abandonment of service and facilities;

(cid:127) accounts and records;

(cid:127) depreciation and amortization policies;

(cid:127) acquisition and disposition of facilities;

(cid:127) initiation and discontinuation of services; and

(cid:127) standards of conduct for business relations with certain affiliates.

FERC Rate Proceedings
Great Lakes – As a result of extensive settlement negotiations, in July 2010, the FERC approved a stipulation and
agreement (GL Settlement) without modification. As approved, the GL Settlement will apply to all current and future
shippers on Great Lakes’ system. For additional information regarding the Great Lakes rate case, see Part II, Item 7.
‘‘Management’s Discussion and Analysis of Financial Condition and Results of Operations – Regulatory Environment –
FERC Rate Proceedings – Great Lakes Rate Proceeding.’’

Northern Border – Northern Border operates pursuant to maximum long-term mileage-based rates and seasonal
short-term transportation rates approved by the FERC in a January 1, 2007 rate case settlement. A moratorium on the
filing of future rate cases under NGA Sections 4 or 5 expired on January 1, 2010. Northern Border must file a rate case
on or before December 31, 2012.

North Baja – North Baja continues to operate under the rates approved by the FERC in 2004 in connection with North
Baja’s initial construction and has no requirement to file a new rate proceeding.

Tuscarora – Tuscarora operates pursuant to maximum transportation rates approved by the FERC in a July 2006 rate case
settlement. A moratorium on the filing of future rate cases under NGA Sections 4 or 5 expired on May 31, 2010. There
is no requirement for Tuscarora to file a new rate case; however, all parties to the settlement have the ability to file a
rate case at any time.

2010 ANNUAL REPORT

15

Environmental Matters

We are subject to stringent and complex federal, state, and local laws and regulations governing environmental
protection, including air emissions, water quality, wastewater discharges and solid waste management. Such laws and
regulations generally require natural gas pipelines to obtain and comply with a wide variety of environmental
registrations, licenses, permits and other approvals. These laws and regulations can impact business operations in many
ways, such as imposing strict requirements relating to the handling, transportation, storage and disposal of wastes
requiring remedial action to mitigate pollution conditions, or requiring the installation of pollution abatement or control
equipment. Failure to comply with these laws and regulations may result in the assessment of administrative, civil and/or
criminal penalties, the imposition of remedial requirements and/or the issuance of orders enjoining future operations.
These laws include, but are not limited to:

(cid:127) Resource Conservation and Recovery Act (RCRA) – The operations of our pipeline systems generate hazardous and

non-hazardous solid wastes that are subject to RCRA and comparable state laws, which impose detailed requirements
for the handling, storage, treatment and disposal of hazardous and non-hazardous solid wastes.

(cid:127) Toxic Substances Control Act (TSCA) – The TSCA authorizes the EPA to screen existing and new chemicals used in

industry and identify potentially dangerous products or uses that should be subject to federal control.

(cid:127) Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) – CERCLA, also known as

‘‘Superfund,’’ and comparable state laws, regulate the cleanup of hazardous substances and impose liability, without
regard to fault or the legality of the original conduct, on certain classes of persons relating to the release of
hazardous substances into the environment. We currently own or lease properties that for many years have been
used for the transportation and compression of natural gas, which involves the use of hazardous substances and
other regulated materials that may be subject to CERCLA and comparable state laws. Under such laws, we could be
required to remove any previously released hazardous substances, remediate contaminated property or perform
remedial closure operations to prevent future contamination, even if the disposal or release of hazardous materials
occurred prior to our ownership or operation of the property or facility. We have not been identified as a potentially
responsible party under CERCLA or comparable state laws.

(cid:127) Clean Air Act (CAA) – The CAA and comparable state laws regulate emissions of air pollutants from various industrial
sources, including compressor stations, and impose various monitoring and reporting requirements. Such laws and
regulations may require pre-approval for the construction or modification of certain facilities expected to produce air
emissions or result in an increase of existing air emissions. Such facilities must also strictly comply with air permits
containing various emission and operational limitations, or requiring the use of emission control or abatement
technologies.

(cid:127) National Ambient Air Quality Standards (NAAQS) – The CAA requires the EPA to establish NAAQS for certain air

pollutants. When NAAQS has been established, each state must identify areas in its state that do not meet the EPA
standard (known as ‘‘non-attainment areas’’) and develop regulatory measures in its state implementation plan to
reduce or control the emissions of that air pollutant in order to meet the standard and become an ‘‘attainment area.’’
If the counties in which our pipeline systems are located are designated as non-attainment areas for one or more
pollutants, our pipeline systems’ expansion or modification plans could be affected, possibly resulting in increased
costs. In March 2008, the EPA issued final rules adopting new, more stringent NAAQS standards for ozone. The EPA
is currently in the process of reconsidering those standards and, in January 2010, the EPA published a proposed rule
to establish more stringent primary and secondary ozone NAAQS standards. EPA plans to complete the ozone
standards rulemaking by July 29, 2011. Some of our operations will likely be affected by these new standards and
the costs of compliance could be material. In January 2010, the EPA published a final rule establishing a more
stringent nitrogen dioxide NAAQS standard of 100 parts-per-billion with a one hour averaging time. The impact of
this standard is uncertain at this time, however, we could reasonably expect to incur significant costs if our pipeline
systems could not demonstrate compliance with this new standard.

(cid:127) The Clean Water Act (CWA) – The CWA and comparable state laws impose strict controls with respect to the

discharge of pollutants, including spills and leaks of oil and other substances, into waters of the U.S. The discharge of

16

TC PIPELINES, LP

pollutants into regulated waters is prohibited, except in accordance with the terms of a permit issued by the EPA or
an analogous state agency. The CWA and regulations implemented thereunder also prohibit the discharge of dredge
and fill material into regulated waters, including wetlands, unless authorized by an appropriately issued permit.
Federal and state regulatory agencies may impose administrative, civil and criminal penalties for non-compliance with
discharge permits or other requirements of the CWA and analogous state laws and regulations.

(cid:127) National Environmental Policy Act (NEPA) – Natural gas transportation activities can be subject to review under NEPA,
or comparable state laws. NEPA requires federal agencies, including the Department of the Interior or the FERC, to
evaluate major agency actions having the potential to significantly impact the environment. In the course of such
evaluations, an agency will prepare an Environmental Assessment that addresses the potential direct, indirect and
cumulative impacts of a proposed project and, if necessary, will prepare a more detailed Environmental Impact
Statement that may be made available for public review and comment. The current activities of our pipeline systems,
as well as any proposed plans for future activities, on federal lands are subject to the requirements of NEPA in
connection with any new approval that is required for construction, operation or the use of federal lands.

Climate Change
Our business is affected by existing and proposed regulation of greenhouse gases. A primary component of natural gas
is methane, which is considered to be a greenhouse gas. Additionally, the burning of natural gas produces carbon
dioxide, which is also a greenhouse gas. There are various legislative and regulatory measures proposed, and expected
to be proposed, to reduce greenhouse gas emissions and establish more aggressive targets for renewable energy
development. These climate change regulations and energy policies, if enacted, will likely impact our business. Measures
to address climate change and greenhouse gas emissions are in various phases of development at international, federal,
regional and state levels, which are outlined below:

(cid:127) International Climate Change Measures – Some members of the international community have taken actions to

address climate change issues on a global level. One such measure is the Kyoto Protocol, which is a treaty under
which signatory countries, after ratification of the treaty, committed to a reduction of their greenhouse gas emissions.
Although the U.S. has never ratified the Kyoto Protocol, Canada and Mexico both ratified the treaty. The U.S.
participated in a recent United Nations Climate Conference in Cancun, Mexico, at which it reaffirmed its pledge to
reduce greenhouse gas emissions over the next decade. The pledge made by the U.S. and other participating
countries does not mandate emission reductions, nor is it legally binding.

(cid:127) Federal Climate Change Legislation – It is possible that federal legislation to reduce greenhouse gas emissions will be
enacted in the U.S. within the next few years. Although the form such legislation might take is unknown, we believe
that a cap-and-trade or other market-based legislation that sets a price on carbon emissions could increase demand
for natural gas, because less greenhouse gas emissions are generally associated with the use of natural gas as
compared to the use of coal and oil. The actual impact on demand will, however, depend on specific legislative
provisions that are adopted, including the level of emissions caps, allowances granted, offset programs established,
cost of emissions credits and incentives provided to competing fossil fuels and lower carbon technologies like nuclear
and renewable energy sources.

(cid:127) Federal Greenhouse Gas Regulations – On January 2, 2011, the EPA’s Tailoring Rule, a regulation that addresses the

implementation of certain CAA permitting requirements for greenhouse gas emissions from certain existing or future
stationary sources, became effective. Stationary sources of greenhouse gas emissions that are subject to these
permitting requirements include engines and turbines located at compressor stations such as those operated by our
pipeline systems. The Tailoring Rule establishes emissions thresholds and a phased timetable for permitting
construction or modifications under the New Source Review Prevention of Significant Deterioration and operations
under Title V Operating Permit programs.

The EPA also issued the Mandatory Reporting of Greenhouse Gases Rule (GHG Reporting Rule), effective January 1,
2010, which requires large sources and suppliers in the U.S. to report greenhouse gas emissions. The emissions data
will be used to inform the development of climate change policy. On December 30, 2010, an EPA final rule became
effective that supplements the GHG Reporting Rule and requires, among other things, the inclusion of certain vented

2010 ANNUAL REPORT

17

and fugitive greenhouse gas emissions from petroleum and natural gas systems (including pipeline transportation of
natural gas) to be monitored and reported.

(cid:127) State and Regional Climate Change Measures – In addition to recent activity at the federal level, several states have

begun taking actions to control or reduce emissions of greenhouse gases, primarily through regional greenhouse gas
cap-and-trade programs, renewable energy portfolio standards, and/or efficiency standards. The principal effect of
such programs is likely to be limited to a reduction in demand for natural gas deliveries, if the programs, in fact,
reduce fossil fuel use. In California, there are state-imposed reporting requirements that have increased our operating
costs slightly. Additionally, the California Air Resources Board has released a cap-and-trade regulation that will
(a) require large industrial users of fossil fuels to obtain allowances authorizing greenhouse gas emissions after
January 1, 2012, and (b) impose allowance requirements upon natural gas importers commencing January 1, 2015.
The costs of allowances are not yet able to be predicted, but could result in material reductions in demand for
natural gas or in increased compliance costs for our pipeline systems.

(cid:127) Energy Legislation – There are also ongoing legislative and regulatory efforts to encourage the use of cleaner energy
technologies at the federal, state and local levels. While natural gas is a fossil fuel, it is generally associated with
lower greenhouse gas emissions as compared to other fossil fuels, such as coal or oil. Future regulatory developments
could, therefore, have a positive impact on our pipeline systems to the extent that natural gas is positioned as a
preferred fossil fuel. On the other hand, some proposals for renewable energy and efficiency standards at both the
federal and state level would require a material increase of renewable sources, such as wind and solar power
generation, and establish incentives for energy efficiency and conservation. Such proposals, if enacted, could
negatively impact natural gas demand. Although it is reasonably likely that energy policy and incentives will change
over the next few years, we cannot predict the form of any new laws and regulations and cannot yet anticipate the
precise impact on our pipelines systems or the demand for natural gas.

(cid:127) Impact of Climate Change on Our Business – The regulation or restriction of greenhouse gas emissions could result in
changes to the consumption and demand for natural gas. This could have adverse effects on our pipeline systems
and our financial position, results of operations and future prospects. The physical effects associated with climate
change may include changes in weather patterns, such as increases in storm intensity or temperature extremes, the
availability or quality of water, or sea-level rise. These effects can impact supply and distribution chains or demand for
certain products or services, or result in damage to facilities or decreased efficiency of equipment.

The impact of new or proposed greenhouse gas laws and regulations is not yet certain and we cannot estimate the
effect of proposed legislation on our future financial position, results of operations or cash flow. It is also reasonably
likely, however, that such legislation could materially increase our operating costs, including our cost of environmental
compliance by requiring us to install additional equipment and potentially purchase emissions allowances or offset
credits. Increases in costs of our pipeline systems’ suppliers to comply with greenhouse gas legislation could also
materially increase our costs of operations. Although many of these costs might be recoverable in the rates charged
to our pipeline customers, recovery through these mechanisms is uncertain.

Costs of compliance with existing environmental laws and regulations have not had, nor are they expected to have, a
material adverse effect upon our financial position, results of operations or cash flows. Environmental laws and
regulations, however, are subject to change. The trend in environmental regulation is to increase protection of the
environment and reduce instances of human exposure to hazardous materials or pollutants. There can be no
assurances as to our pipeline systems’ ability to obtain permits in the future or the amount or timing of future
expenditures for environmental compliance or remediation. Changes to environmental regulations can result in
increased compliance costs or additional operating restrictions, which could have an adverse effect on our pipeline
systems, and the Partnership’s financial position, results of operations and cash flows.

18

TC PIPELINES, LP

Safety Matters

Our pipeline systems are affected by existing and proposed pipeline safety regulations imposed by the U.S. Department
of Transportation with respect to pipeline design, installation, testing, construction, operation, replacement
and management.

The Pipeline Safety Improvement Act of 2002 (Pipeline Safety Act) requires pipeline companies to perform baseline
integrity assessments on pipeline segments that exist in densely populated areas or near specifically identified sites that
are designated as ‘‘high consequence areas’’ (HCAs). On December 29, 2006, the Pipeline Inspection, Protection,
Enforcement, and Safety Act of 2006, referred to as PIPES of 2006, was enacted, which further amended the Pipeline
Safety Act. Pipeline companies are required to perform the baseline integrity assessments within 10 years of the date of
enactment and perform reassessments on a seven-year cycle. At this time, over 90 percent of the baseline assessments
have been completed for our pipeline systems. The final baseline assessments are scheduled to be completed in 2011
and 2012. Approximately 50 percent of our pipeline systems are inspected in order to comply with the Pipeline Safety
Improvement Act requirements for HCAs. Inspection programs for the remaining 50 percent of our pipeline systems are
also developed to further manage risk.

There are various legislative and regulatory measures proposed and expected to be proposed to increase pipeline safety.
These legislative and regulatory policies, if enacted, will likely impact our business, as well as other pipelines in the
industry. While we believe that our pipeline systems are in substantial compliance with current applicable requirements,
due to the possibility of these new or amended laws and regulations, there can be no assurance that future compliance
with the requirements will not have a material adverse effect on our pipelines systems and the Partnership’s financial
position, results of operations and cash flows.

TITLE TO PROPERTIES

We believe that our pipeline systems hold all rights, titles and interests in their respective pipeline systems. With respect
to real property, our pipeline systems own sites for compressor stations, meter stations, pipeline field offices and
microwave towers. Our pipeline systems are constructed and operated on land owned by governmental authorities and
others pursuant to leases, easements, rights-of-way, permits and licenses. We believe that our pipeline systems’
properties are adequate and suitable for the conduct of their business in the future.

Great Lakes – Approximately 74 miles of Great Lakes’ pipeline system are located within the boundaries of three Indian
reservations: the Leech Lake Chippewa Indian Reservation and the Fond du Lac Chippewa Indian Reservation in
Minnesota, and the Bad River Chippewa Indian Reservation in Wisconsin. In 1968, Great Lakes obtained right-of-way
access across allotted lands located within each reservation’s boundaries. All of the allotted lands are subject to a
50-year easement granted by the Bureau of Indian Affairs (BIA) for and on behalf of the individual Indian owners or the
reservations. These tracts are subject to right-of-way permits issued by the BIA that expire in 2018. Also, the Great
Lakes pipeline crosses approximately 1,000 feet in two tracts in lower Michigan, which are located within the Chippewa
Indian Reservation under perpetual easements.

Northern Border – Approximately 90 miles of Northern Border’s pipeline system are located within the boundaries of the
Fort Peck Indian Reservation in Montana. In 1980, Northern Border entered into a pipeline right-of-way lease with the
Fort Peck Tribal Executive Board on behalf of the Assiniboine and Sioux Tribes of the Fort Peck Indian Reservation. This
pipeline right-of-way lease granted Northern Border the right to construct and operate its pipeline on certain tribal
lands. The pipeline right-of-way lease expires in 2011, with an option to renew the pipeline right-of-way lease through
2061. Northern Border exercised the option to renew on February 15, 2011. In conjunction with obtaining right-of-way
access across tribal lands located within the exterior boundaries of the Fort Peck Indian Reservation, Northern Border
also obtained right-of-way access across allotted lands located within the reservation boundaries. Most of the allotted
lands are subject to a perpetual easement granted by the BIA for and on behalf of the individual Indian owners or
obtained through condemnation. Several tracts are subject to a right-of-way grant that expires in 2015.

2010 ANNUAL REPORT

19

INSURANCE

The Partnership’s operations and activities are insured under TransCanada’s insurance programs, including property
insurance, liability, automobile liability and workers compensation, in amounts that management believes are reasonable
and appropriate.

EMPLOYEES

The Partnership does not have any employees. In addition, none of our pipeline systems directly employ any of the
persons responsible for managing or operating the pipeline systems, or for providing them with services related to their
day-to-day business affairs. Subsidiaries of TransCanada operate our pipelines systems, in addition to providing services
to the Partnership.

AVAILABLE INFORMATION

We make available free of charge, on or through our website (https://www.tcpipelineslp.com), our annual report on
Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and any amendments to those reports filed or
furnished pursuant to Section 13(a) or 15(d) of the Exchange Act, as soon as reasonably practicable after we
electronically file the material with, or furnish it to, the Securities and Exchange Commission (SEC). Information
contained on our website is not part of this report.

Item 1A. Risk Factors

Limited partner interests are inherently different from the capital stock of a corporation, although many of the business
risks to which we are subject are similar to those that would be faced by a corporation engaged in a similar business.
Each of the risks and uncertainties described below could lead to events or circumstances that may have a material
adverse effect on our business, financial condition, results of operations and cash flows, including our ability to make
distributions to our unitholders. New risks may emerge at any time, and we cannot predict such risks or estimate the
extent to which they may affect our financial performance. All of the information included in this report, including the
following discussion of risks and ‘‘Forward-Looking Statements,’’ and any subsequent reports we may file with the SEC
or make available to the public should be carefully considered and evaluated before investing in any securities issued
by us.

Risks Inherent in Our Business

The long-term financial conditions of our pipeline systems, except North Baja, are dependent on the
continued availability of natural gas exiting the WCSB and the market demand for these volumes.
Competition from pipelines that deliver natural gas from the WCSB to different market areas and
competition from pipelines that deliver natural gas from other supply areas to our pipeline systems’ market
areas could cause our pipeline systems to discount their rates or otherwise experience a reduction in
their revenues.
The development of additional natural gas reserves requires significant capital expenditures by others for exploration
and development drilling, and the installation of production, gathering, storage, transportation and other facilities that
permit natural gas to be produced and delivered to pipelines that interconnect with our pipeline systems. High
exploration and production costs, low natural gas prices, regulatory limitations and competition for capital from other
North American natural gas producing basins that have lower exploration costs have adversely affected the
development of additional reserves in Western Canada and the production in the WCSB in 2010 and may continue to
do so in 2011.

20

TC PIPELINES, LP

Gas exiting the WCSB depends, in part, on the demand for natural gas within Western Canada. Western Canadian
demand may increase as a result of increased demand for natural gas fired electricity generation and other industrial
requirements, including the development of oil sands projects, which may require substantial amounts of natural gas.
This higher Canadian demand may reduce the amount of natural gas available for downstream U.S. markets. In the
longer term, a portion of the WCSB natural gas supply may come from the development of recently discovered natural
gas shale resources such as Montney and Horn River in Western Canada and from proposed natural gas pipelines from
the North Slope of Alaska and the Mackenzie Delta of Canada. Cancellation, changes in route, and delays in the
construction of such pipelines or such projects could adversely affect gas exiting the WCSB in the long term.

If the availability of natural gas exiting the WCSB was to decline, existing shippers on our pipeline systems, except
North Baja, may be unlikely to extend their contracts and our pipeline systems may be unable to find replacement
shippers for lost capacity. Furthermore, additional natural gas reserves may not be developed in commercial quantities
and in sufficient amounts to fill the capacities of each of our pipeline systems.

Customers might not extend their contracts for transportation if the cost of delivered natural gas from other producing
regions into the markets served by our pipeline systems is more economical than the cost of natural gas delivered by
our pipeline systems.

An increase in competition in the key markets served by our pipeline systems could arise from new ventures or
expanded operations from existing competitors. For Great Lakes, the combination of growing supply from the Rockies
and shale developments reaching Dawn through both new and available pipeline capacity, as well as reduced demand
due to the economic environment has the potential to maintain competitive pressures on WCSB supply into the
Midwest. Great Lakes is fully contracted on a long-haul basis to St. Clair, Michigan, near the Dawn, Ontario storage
hub through October 2011; however, if the transport of natural gas from the Rockies and Mid-Continent shales
eastward to Dawn becomes more economical on competitive pipeline routes, then those supplies could reach the
eastern zone of Great Lakes’ market area and displace Great Lakes’ long-haul volumes.

Similarly, for Northern Border, the combination of growing supply from the Rockies and shale developments reaching
the Chicago market region through both new and available pipeline capacity, as well as reduced demand due to the
economic environment has the potential to maintain competitive pressures on WCSB supply into the Midwest markets
served by Northern Border. Northern Border is essentially fully contracted through March 2012; however, any reduction
in flows to this market will impact the supply and demand fundamentals at the Ventura market.

Our financial performance depends to a large extent on the capacity contracted on our pipeline systems. Decreases in
the volumes transported by our pipeline systems, whether caused by supply or demand factors in the markets these
pipeline systems serve, competition or otherwise, can directly and adversely affect our business, financial position, results
of operations and ability to make distributions.

Our pipeline systems may not be able to maintain existing customers or acquire new customers when the
current shipper contracts expire or customers may recontract for shorter periods or at less than
maximum rates.
The ability to extend and replace contracts on terms comparable to prior contracts or on any terms at all could be
adversely affected by various factors, including:

(cid:127) the available supply of natural gas in Canada and the U.S.;

(cid:127) competition from alternative sources of supply in the U.S.;

(cid:127) competition from other pipelines, including through their transportation rates or through their access to upstream

supplies, as well as the proposed construction by other companies of additional pipeline capacity;

(cid:127) contract expirations on competing pipelines, which can change our pipeline systems’ relative competitiveness;

(cid:127) changes in rate design upstream or downstream of our pipeline systems, which can affect our pipeline systems’

relative competitiveness in attracting volumes;

2010 ANNUAL REPORT

21

(cid:127) the price of, and demand for, natural gas in markets served by our pipeline systems;

(cid:127) the liquidity and willingness of shippers to contract for transportation services; and

(cid:127) regulatory actions.

Ongoing changes in these factors and customers’ abilities to adjust to changing market conditions may cause Great
Lakes and Northern Border to sell a significant portion of available capacity on a short-term basis. Additionally, when
the forward natural gas basis differentials do not support maximum rates, Great Lakes and Northern Border may sell
portions of their capacity at discounted rates. Great Lakes’ and Northern Border’s inability to renew existing contracts at
maximum rates, or at all, or to enter into new long-term shipper contracts for upcoming excess capacity will have an
adverse impact on their revenues and, as a result, cash distributions made to us.

Our pipeline systems are subject to regulation by agencies, including the FERC, which could have an adverse
impact on their ability to establish transportation rates that would allow recovery of the full cost of
operating our pipeline systems, including a reasonable return, which could impact our ability to make
distributions.
Under the NGA, interstate transportation rates must be just, reasonable and not unduly discriminatory. Our pipeline
systems are subject to extensive regulation by the FERC, the U.S. Department of Transportation, the EPA and other
federal, state and local regulatory agencies. Regulatory actions taken by these agencies have the potential to adversely
affect our pipeline systems’ profitability. Federal regulation extends to such matters as:

(cid:127) rates and charges;

(cid:127) operating terms and conditions of service, including creditworthiness requirements;

(cid:127) types of services our pipeline systems may offer to their customers;

(cid:127) construction of new facilities;

(cid:127) extension or abandonment of service and facilities;

(cid:127) accounts and records;

(cid:127) depreciation and amortization policies;

(cid:127) income tax allowance policies;

(cid:127) acquisition and disposition of facilities;

(cid:127) initiation and discontinuation of services;

(cid:127) standards of conduct for business relations with certain affiliates; and

(cid:127) integrity and safety of our pipeline systems and related operations.

Given the extent of regulation by regulatory agencies and potential changes to regulations, we cannot predict:

(cid:127) the federal regulations under which our pipeline systems will operate in the future;

(cid:127) the effect that regulation will have on the financial position, results of operations and cash flows of our pipeline

systems and ourselves; or

(cid:127) whether our cash flow will be adequate to make distributions to unitholders.

Action by the FERC on currently pending regulatory matters, as well as matters arising in the future, could adversely
affect our pipeline systems’ abilities to establish or charge rates that would cover future increases in their costs, such as
additional costs related to environmental matters including any climate change regulation, or increased costs of
compliance with regulations, or even to continue to collect rates that cover current costs, including a reasonable return.
We cannot assure unitholders that our pipeline systems will be able to recover all of their costs through existing or
future rates.

22

TC PIPELINES, LP

Our pipeline systems are required to comply with all applicable FERC administered statutes, rules, regulations and
orders. Under the Energy Policy Act of 2005, the FERC has civil penalty authority under the NGA to impose penalties
for current violations of up to $1 million per day for each violation.

Composition of Proxy Groups for Rates of Return Determinations – The FERC uses proxy groups of publicly traded
companies with business models similar to the pipeline for which a rate determination is sought in order to determine
an appropriate return on equity (ROE) for that pipeline. In a 2008 Policy Statement, the FERC expanded the criteria for
proxy group companies, thereby permitting the inclusion of master limited partnerships (MLPs). The effect of the FERC’s
evolving policy and precedent with regard to proxy groups, and the availability of risk-appropriate companies and MLPs
for inclusion in a proxy group at the time of a rate case, may impact the ROEs for any of our pipeline systems involved
in a rate case.

If our pipeline systems do not make additional capital expenditures sufficient to offset depreciation expense,
which would result in a declining rate base, the amount of revenue attributable to the return on the rate
base they collect from their shippers will decrease over time.
Our pipeline systems are generally allowed to collect from their customers a return on their assets or ‘‘rate base’’ as
reflected in their financial records, as well as recover that rate base through depreciation. In the absence of additions to
the rate base through capital expenditures, the amount they collect from customers, as a result of a rate case,
decreases as the rate base declines due to, among other things, depreciation and amortization.

We are dependent on our pipeline systems to generate sufficient cash to enable us to pay distributions.
The amount of cash we have on a quarterly basis to distribute to our common unitholders depends upon numerous
factors, some of which are beyond our control and the control of our General Partner, including:

(cid:127) the rates charged and the volumes under contract for the transportation services of our pipeline systems;

(cid:127) the quantities of natural gas available for transport and the demand for natural gas;

(cid:127) legislative or regulatory action affecting demand for and supply of natural gas, and the rates our pipeline systems are

allowed to charge in relation to their operating costs;

(cid:127) the level of our pipeline systems’ operating costs; and

(cid:127) the creditworthiness of our pipeline systems’ shippers.

The global economic and financial market crisis in late 2008 and into 2009 has had, and may continue to
have, a negative effect on our business.
The global economic and financial market crisis in late 2008 and into 2009 caused, among other things, a general
tightening in the credit markets, lower levels of liquidity, increases in the rates of default and bankruptcy, lower
consumer and business spending, lower consumer net worth and reduced energy demand. Although general economic
conditions have improved, recovery for certain sectors has been slower. Many natural gas producers, natural gas
marketing companies and end users have been negatively affected by current economic conditions, as evidenced by
reduced drilling and natural gas development in the WCSB, which is a critical natural gas supply source for our pipeline
systems, except North Baja. Current or potential shippers may be unable to fund contracts or meet the creditworthiness
requirements of our pipeline systems or they may reduce the amount or length of their transportation commitments on
our pipeline systems, all of which could impact demand for transportation services on our pipeline systems, and may
cause reduced revenues and increased customer payment delays or defaults. We are also limited in our ability to reduce
costs to offset the results of a prolonged or severe economic downturn given the high percentage of fixed costs
associated with our operations.

Although conditions in the credit and financial markets have largely returned to pre-crisis levels, there can be no
assurance that the recovery in market conditions will be sustained or that our results will not be materially and
adversely affected in the future. Such conditions make it difficult to forecast operating results, make business decisions
and identify and address material business risks. The foregoing conditions may also impact the valuation of certain

2010 ANNUAL REPORT

23

long-lived or intangible assets, including goodwill, that are subject to impairment testing, potentially resulting in
impairment charges, which may be material to our financial condition or results of operations.

If we do not identify opportunities for accretive growth through organic growth projects or acquisitions, or
our pipeline systems do not successfully complete expansion projects or make and integrate acquisitions that
are accretive, our future growth may be limited.
A principal focus of our strategy is to continue to grow the cash distributions on our common units by expanding our
business. Our ability to grow depends on our ability to undertake acquisitions and organic growth projects, and the
ability of our pipelines systems to complete expansion projects and make and integrate acquisitions that result in an
increase in cash per common unit generated from operations.

If any significant shipper fails to perform its contractual obligations, our pipeline systems’ respective cash
flows and financial condition could be adversely impacted.
At any time, each of our pipeline systems may have customers that account for more than ten percent of its revenue.
The loss of all or even a portion of the revenues associated with these customers, as a result of competition,
creditworthiness or otherwise, could have a material adverse effect on the financial condition, results of operations and
cash flows of our pipeline systems, unless they are able to contract for comparable volumes from other customers at
favorable rates.

Our pipeline systems’ pipeline integrity testing programs and any necessary pipeline repairs, or preventative
or remedial measures may impose significant costs and liabilities.
The U.S. Department of Transportation has adopted regulations that require pipeline operators to develop integrity
management programs to comprehensively evaluate their pipelines, and take measures to protect pipeline segments
located in HCAs, where a leak or rupture could do the most harm. The final rule resulted from the enactment of the
Pipeline Safety Act. The results of the integrity management programs could cause our pipeline systems to incur
significant and unanticipated capital and operating expenditures for repairs or upgrades deemed necessary to ensure
their continued safe and reliable operation. Additionally, the possibility of new or amended laws and regulations could
have a material adverse effect on our results of operations or financial position. Any failure to comply with the
regulations could subject our pipeline systems to penalties and fines. If these costs were significantly higher than
estimated, our cash available for distribution may be correspondingly reduced.

Our pipeline systems’ operations are regulated by federal, state and local laws and regulations that could
impose costs for compliance with environmental protection and operational safety standards.
Risks of substantial costs and liabilities are inherent in pipeline operations and each of our pipeline systems may incur
substantial costs and liabilities in the future as a result of stricter environmental and safety laws, regulations and
enforcement policies and claims for personal or property damages resulting from our pipeline systems’ operations.
Moreover, new environmental and safety laws, regulations or enforcement policies could be implemented that
significantly increase our pipeline systems’ compliance costs or the cost of any remediation of environmental
contamination that may become necessary, and these costs could be material. For instance, we may be required to
obtain and maintain permits and approvals issued by various federal, state and local governmental authorities, limit or
prevent releases of materials from our operations in accordance with these permits and approvals, or install pollution
control equipment. In addition, due to several recent third party pipeline incidents, various legislative and regulatory
reforms associated with pipeline safety and integrity issues have been proposed, including reforms that would require
increased periodic inspections. It is uncertain which proposed laws, regulations or reforms, if any, will be adopted and
what impact they might ultimately have on our operations or financial results.

Under certain environmental laws and regulations, we may be exposed to substantial liabilities for any pollution or
contamination that arises in connection with our operations. In particular, the costs of recently adopted and future
legislative and regulatory requirements related to greenhouse gas emissions and climate change may increase our
operating costs materially or adversely affect demand. If we are unable to recover or pass through a significant level of

24

TC PIPELINES, LP

our costs related to environmental matters, safety or greenhouse gas regulatory requirements, it could have a material
adverse effect on our results of operations.

On April 7, 2010, the EPA published an Advance Notice of Proposed Rulemaking to solicit comments with respect to
the EPA’s reassessment of current regulations, promulgated under TSCA, governing the authorized use of
polychlorinated biphenyls (PCBs) in certain equipment. The proposed changes could require notification to the EPA
when PCBs are discovered in any pipeline system, a phase out and eventual elimination of PCB use in pipeline systems
and air compressor systems and the immediate elimination of the storage of PCB equipment for reuse. These changes,
if finalized as proposed, could potentially have a material impact on certain of our pipeline systems.

Great Lakes Requests for Information –
(cid:127) By letter dated December 28, 2009, the EPA required Great Lakes to provide information regarding its natural gas
compressor stations in the states of Minnesota, Wisconsin and Michigan as part of the EPA’s investigation of Great
Lakes compliance with the CAA. On May 28, 2010, Great Lakes submitted its final response to the EPA. To date,
Great Lakes has received one request from EPA for clarification regarding submitted information. The potential effects
on Great Lakes that may arise as a result of this information request are not determinable at this time.

(cid:127) By letter dated July 26, 2010, the EPA required Great Lakes to provide information regarding one natural gas

compressor station located in Minnesota. The potential effects on Great Lakes that may arise as a result of this
information request are not determinable at this time.

Minnesota Pollution Control Agency (MPCA) Data Request – In November 2010, Northern Border and Great Lakes
received verbal data requests from the MPCA related to Title V operating permits for all facilities located in Minnesota.
The information was submitted to the MPCA in December 2010. The potential effects on Northern Border and Great
Lakes that may arise as a result of this information request are not determinable at this time.

We make assumptions and develop expectations about possible expenditures related to safety and environmental
matters based on current laws and regulations and current interpretations of those laws and regulations. If the laws or
regulations, or the interpretations of laws or regulations change, our assumptions may change. Our regulatory rate
structure and our contracts with customers might not necessarily allow us to recover capital costs we incur to comply
with the new environmental and safety regulations. Also, we might not be able to obtain or maintain from time to time
all required regulatory approvals for development of new projects or continued operation of existing systems. If there is
a delay in obtaining any required regulatory approvals or if we fail to obtain and comply with them, the operation of
our facilities could be prevented or become subject to additional costs, resulting in potentially material adverse
consequences to our results of operations.

Our pipeline systems’ indebtedness may limit their ability to borrow additional funds, make distributions to
us or capitalize on business opportunities.
As at December 31, 2010, Great Lakes, Northern Border and Tuscarora had $392.0 million, $541.0 million and
$30.9 million of debt outstanding, respectively. Of the debt outstanding, Great Lakes and Tuscarora have $19.0 million
and $0.8 million of debt maturing in 2011, respectively. Their respective levels of debt could have important
consequences to Great Lakes, Northern Border and Tuscarora, including the following:

(cid:127) their ability to obtain additional financing, if necessary, for working capital, capital expenditures, acquisitions or other

purposes may be impaired or such financing may not be available on favorable terms;

(cid:127) their need for a portion of their cash flow to make interest payments on the debt, reducing the funds that would
otherwise be available for operations, future business opportunities and distributions to us, which will reduce our
ability to make distributions to our unitholders;

(cid:127) their debt level may make them more vulnerable to competitive pressures or a downturn in our business or the

economy generally; and

(cid:127) their debt level may limit their flexibility in responding to changing business and economic conditions.

2010 ANNUAL REPORT

25

Our pipeline systems’ ability to service their respective debt will depend upon, among other things, future financial and
operating performance, which will be affected by prevailing economic conditions and financial, business, regulatory and
other factors, some of which are beyond their control.

In addition, under the terms of these financing arrangements, our pipeline systems are prohibited from making cash
distributions during an event of default under their debt instruments. Under Great Lakes’ debt instruments, Great Lakes
has limitations on the level of indebtedness and has other restrictions, including a general prohibition against liens on
pipeline facilities. Provisions in Northern Border’s debt instruments limit its ability to incur indebtedness and engage in
specific transactions. This could reduce its ability to capitalize on business opportunities that arise in the course of its
business. Under Tuscarora’s debt instruments, Tuscarora has granted a security interest in certain of its transportation
contracts, which is available to noteholders upon an event of default. In addition, the Partnership’s third party credit
facility requires us to maintain certain financial ratios and contains restrictions on incurring additional debt and making
distributions to unitholders.

Capital and credit market conditions may adversely affect the Partnership’s and/or our pipeline systems’ access
to capital and cost of capital.
Access to capital and credit markets is important to the Partnership to enable it to execute its business strategies, which
include seeking opportunities to undertake accretive acquisitions and organic growth projects and maximizing the value
of our existing portfolio of pipeline systems. Access to capital markets is also important to our pipeline systems’ ability
to meet liquidity and capital resource requirements. Additionally, market conditions may impact the ability of our
pipeline systems to access capital and credit markets for debt under reasonable terms.

If conditions in the U.S. capital markets and credit markets undergo a significant deterioration, the Partnership’s and our
pipeline systems’ future cost of debt and equity capital and future access to capital markets could be adversely affected.

We do not own a controlling interest in Great Lakes or Northern Border and we may be unable to cause
certain actions to take place unless the other partner agrees. As a result, we will be unable to control the
amount of cash we will receive from those operations and we could be required to contribute significant cash
to fund our share of their operations. If we fail to make these contributions our ownership interest would
be diluted.
The major policies of Great Lakes and Northern Border are established by each of their management committees.

Great Lakes’ management committee consists of up to six appointed members, half of whom are designated by us and
half of whom are designated by TransCanada. Currently, there are four members appointed to the management
committee and all decisions require unanimous consent. An executive committee consisting of two appointed
members – one Partnership committee member and one TransCanada committee member, who also serves as the
president of Great Lakes – has all of the powers of the management committee in the management of Great Lakes’
business. Because of these provisions, without the concurrence of TransCanada, we may be unable to cause Great Lakes
to take or not to take certain actions, even though those actions may be in the best interest of us or Great Lakes.

Northern Border’s management committee consists of four members, two of whom are designated by us and two of
whom are designated by an affiliate of ONEOK Partners. The management committee requires the affirmative vote of a
majority of the partners’ ownership interests to act on most activities. Certain activities require the unanimous consent
of the committee, such as the filing of the application for regulatory authority to construct and operate new facilities
and any changes to the cash distribution policy. Because of these provisions, without the concurrence of ONEOK, we
may be unable to cause Northern Border to take or not to take certain actions, even though those actions may be in
the best interest of us or Northern Border.

Great Lakes and Northern Border may require us to make additional capital contributions. Our funding of these capital
contributions would reduce the amount of cash otherwise available for distribution to our unitholders. Additionally, in
the event we elect not to, or are unable to, make a required capital contribution to Great Lakes or Northern Border, our
ownership interest would be diluted.

26

TC PIPELINES, LP

Our pipeline systems’ operations are subject to operational hazards and unforeseen interruptions, which
could adversely affect their businesses and for which they may not be adequately insured.
Our pipeline systems’ operations are subject to all of the risks and hazards typically associated with the operation of
natural gas transportation pipeline systems. Operating risks include, but are not limited to, leaks, pipeline ruptures, the
breakdown or failure of equipment or processes and the performance of pipeline facilities below expected levels of
capacity and efficiency. Other operational hazards and unforeseen interruptions include adverse weather conditions,
accidents, the collision of equipment with our pipeline systems’ facilities (which may occur if a third party were to
perform excavation or construction work near these facilities) and catastrophic events such as explosions, fires,
earthquakes, floods or other similar events beyond our pipeline systems’ control. It is also possible that our pipeline
systems’ infrastructure facilities could be direct targets or indirect casualties of an act of terrorism. A casualty occurrence
might result in injury or loss of life, extensive property damage or environmental damage. Liabilities incurred, and
interruptions to the operation of our pipeline systems’ facilities, for short or extended durations, caused by such an
event, could reduce revenues generated by our pipeline systems and increase expenses, thereby impairing their ability to
meet their obligations. Insurance proceeds may not be adequate to cover all liabilities or expenses incurred or revenues
lost. Should one of our pipeline systems experience such an event, it may have an adverse impact on our results of
operations and cash flows.

Our pipeline systems do not own all of the land on which their pipelines and facilities are located, which
could disrupt their operations.
Our pipeline systems do not own all of the land on which their pipelines and facilities are located, and they are,
therefore, subject to the risk of increased costs to maintain necessary land use. They obtain the rights to construct and
operate certain of our pipelines and related facilities on land owned by third parties, governmental agencies and Indian
reservations for a specific period of time. Their loss of these rights, through their inability to renew right-of-way
contracts or otherwise, or increased costs to renew such rights, could have a material adverse effect on their financial
condition, results of operations and cash flows.

If we were to lose TransCanada’s management expertise, we would not have sufficient stand-alone resources
to operate.
TransCanada, through wholly-owned subsidiaries, is the operator of all our pipeline systems. We do not presently have
stand-alone management resources to operate without services provided by TransCanada. Should we lose the services
of TransCanada, we may not be able to replace those services for the same cost and our costs could increase.

Risks Inherent in an Investment in the Partnership

The Partnership’s indebtedness may limit its ability to borrow additional funds, make distributions or
capitalize on business opportunities. The conditions of the U.S. and international credit markets may
adversely affect our ability to obtain credit or draw on our current credit facility.
As at December 31, 2010, the Partnership had $513.9 million of debt outstanding, including the revolving credit and
term loan agreement (Senior Credit Facility) and Senior Notes. This substantial level of debt could have important
consequences to the Partnership including the following:

(cid:127) our ability to obtain additional financing, if necessary, for working capital, acquisitions or other purposes may be

impaired or such financing may not be available on favorable terms;

(cid:127) we will need a portion of our cash flow to make interest payments on the debt, reducing the funds that would
otherwise be available for operations, future business opportunities and distributions to our unitholders; and

(cid:127) our debt level may limit our flexibility in responding to changing business and economic conditions.

Our ability to service our debt will depend upon, among other things, the future financial and operating performance
of our pipeline systems, which will be affected by prevailing economic conditions and financial, business, regulatory and
other factors, some of which are beyond our control.

2010 ANNUAL REPORT

27

If the financial institutions that have extended credit commitments to us and our pipeline systems are adversely affected
by the conditions of the U.S. and international capital markets, they may become unable to fund borrowings under
their credit commitments, which could have a material and adverse impact on our financial condition and our ability to
borrow additional funds, if needed.

In addition, our credit facilities contain restrictive covenants that may prevent us from engaging in certain transactions
that are deemed beneficial. These agreements require us to comply with various affirmative and negative covenants and
maintaining certain financial ratios. There are restrictions and covenants with respect to:

(cid:127) entering into mergers, consolidations and sales of assets;

(cid:127) granting liens;

(cid:127) material amendments to the Partnership’s Second Amended and Restated Agreement of Limited Partnership

(Partnership Agreement);

(cid:127) incurring additional debt; and

(cid:127) distributions to unitholders.

Any future debt may contain similar restrictions.

Our Senior Credit Facility matures in December 2011 and we may be unable to refinance in a timely manner
or on terms acceptable to us, if at all.
Our Senior Credit Facility matures on December 12, 2011, at which time all amounts outstanding thereunder will be
due and payable. We currently expect to renew the facility, but there can be no assurance that we will be able to
refinance the Senior Credit Facility on terms and conditions acceptable to us, or at all, or on a timely basis. In addition,
credit or financial market disruptions such as those experienced in the U.S. in 2008 and 2009 may have a material
adverse effect on our ability to refinance the facility on a timely basis and on terms acceptable to us, if at all. Without a
replacement credit facility, it is likely that we would have insufficient capital to support our development and capital
expenditure plans, which could have a materially negative impact to existing common unitholders.

Cash distributions are dependent primarily on our cash flow, financial reserves and working capital
borrowings.
Cash distributions are not dependent solely on our profitability, which is affected by non-cash items. Therefore, we may
make cash distributions during periods when losses are reported and may not make cash distributions during periods
when we report profits.

Factors that affect the actual amount of cash that we will have available for distribution to our unitholders include
the following:

(cid:127) the amount of cash set aside and the adjustment in reserves made by our General Partner in its sole discretion;

(cid:127) the level of capital expenditures made by our pipeline systems;

(cid:127) the required principal and interest payments on our debt, retirement of debt and other liabilities, including cost of

acquisitions;

(cid:127) the amount of cash distributed to us by the entities in which we own a non-controlling interest;

(cid:127) our ability to borrow funds and access capital markets, including the issuance of debt and equity securities; and

(cid:127) restrictions on distributions contained in debt agreements.

Increases in interest rates and general volatility in the financial markets and economy could adversely affect
our business, our common unit price, results of operations, cash flows and financial condition.
As at December 31, 2010, the partnership had $483.0 million outstanding under the Senior Credit Facility (2009 –
$484.0 million), all of which is initially exposed to variable interest rates. As a result, our results of operations, cash
flows and financial condition could be materially adversely affected by significant increases in interest rates. From time

28

TC PIPELINES, LP

to time, we may enter into interest rate swap arrangements, which decrease our exposure to variable interest rates. At
December 31, 2010, the variable interest rate exposure related to $375.0 million of the $483.0 million outstanding debt
under the Senior Credit Facility was mitigated by fixed interest rate swap arrangements.

An increase in interest rates may also cause a corresponding decline in demand for yield-based equity investments such
as our common units. Any such reduction in demand for our common units resulting from other more attractive
investment opportunities may cause the trading price of our common units to decline.

We do not have the same flexibility as other types of organizations to accumulate cash and equity to protect
against illiquidity in the future.
Unlike a corporation, our Partnership Agreement requires us to make quarterly distributions to our unitholders of all
available cash, reduced by any amounts of reserves for commitments and contingencies, including capital and operating
costs and debt service requirements. The value of our units and other limited partner interests may decrease in direct
correlation with decreases in the amount we distribute per common unit. Accordingly, if we experience a liquidity
problem in the future, we may not be able to recapitalize by issuing more equity.

Unitholders have limited voting rights and do not control our General Partner.
The General Partner is our manager and operator. Unlike the holders of common stock in a corporation, holders of
common units have only limited voting rights on matters affecting our business. Unitholders have no right to elect our
General Partner on an annual or other continuing basis. Our General Partner may not be removed except by the vote of
the holders of at least 662⁄3 percent of the outstanding common units and upon the election of a successor General
Partner by the vote of the holders of a majority of the outstanding common units. These required votes would include
the votes of common units owned by our General Partner and its affiliates. The ownership of an aggregate of
37.0 percent of the outstanding common units by our General Partner and its affiliates has the practical effect of
making removal of our General Partner difficult.

In addition, the Partnership Agreement contains some provisions that may have the effect of discouraging a person or
group from attempting to remove our General Partner or otherwise change our management. If our General Partner is
removed as our General Partner under circumstances where cause does not exist and common units held by our
General Partner and its affiliates are not voted in favor of that removal:

(cid:127) any existing arrearages in the payment of the minimum quarterly distributions on the common units will be

extinguished; and

(cid:127) our General Partner will have the right to convert its general partner interests and its incentive distribution rights into

common units or to receive cash in exchange for those interests.

These provisions may diminish the price at which the common units will trade under some circumstances. The
Partnership Agreement also contains provisions limiting the ability of unitholders to call meetings of unitholders or to
acquire information about our operations, as well as other provisions limiting the unitholders’ ability to influence the
manner or direction of management. Further, if any person or group other than our General Partner or its affiliates or a
direct transferee of our General Partner or its affiliates acquires beneficial ownership of 20 percent or more of any class
of common units then outstanding, that person or group will lose voting rights with respect to all of its common units.
As a result, unitholders will have limited influence on matters affecting our operations, and third parties may find it
difficult to attempt to gain control of us or influence our activities.

2010 ANNUAL REPORT

29

We may issue additional common units without unitholder approval, which would dilute the existing
unitholders’ interest. In addition, issuance of additional common units may increase the risk that we will be
unable to pay the full minimum quarterly distribution on all common units.
Our General Partner can cause us to issue additional common units, without the approval of unitholders, in the
following circumstances:

(cid:127) under employee benefit plans, if any;

(cid:127) upon conversion of the general partner interests and incentive distribution rights into common units as a result of the

withdrawal of our General Partner; or

(cid:127) in connection with acquisitions or capital improvements that are accretive to our cash flow on a per common

unit basis.

In addition, we may issue an unlimited number of limited partner interests of any type without the approval of the
unitholders. Based on the circumstances of each case, the issuance of additional common units or securities ranking
senior to or on a parity with the common units may dilute the value of the interests of the then-existing holders of
common units in the net assets of the Partnership and dilute the interests of unitholders in distributions by the
Partnership. Our Partnership Agreement does not give the unitholders the right to approve the issuance by us of equity
securities ranking junior to the common units at any time.

Any increase in the number of outstanding common units will increase the percentage of the aggregate minimum
quarterly distribution payable to the common unitholders, which will in turn have the effect of increasing the risk that
we will be unable to pay the minimum quarterly distribution in full on all the common units.

Unitholders may not have limited liability in some circumstances.
The limitations on the liability of holders of limited partner interests for the obligations of a limited partnership have not
been clearly established in some states. If it were to be determined that:

(cid:127) the Partnership had been conducting business in any state without compliance with the applicable limited partnership

statute; or

(cid:127) the right or the exercise of the right by the unitholders as a group to remove or replace our General Partner, to

approve some amendments to the Partnership Agreement or to take other action under the Partnership Agreement
constituted participation in the ‘‘control’’ of the Partnership’s business,

then unitholders could be held liable in some circumstances for the Partnership’s obligations to the same extent as a
general partner. In addition, under some circumstances a unitholder may be liable to the Partnership for the amount of
a distribution for a period of three years from the date of the distribution.

Our General Partner has a limited call right that may require unitholders to sell their common units at an
undesirable time or price.
If our General Partner and its affiliates, who currently own an aggregate of approximately 37 percent of our common
units, come to own 80 percent or more of the common units, the General Partner will have the right, but not the
obligation, which it may assign to any of its affiliates or us, to acquire all of the remaining common units held by
unaffiliated persons at a price generally equal to the then current market price of the common units. As a consequence,
unitholders may be required to sell their common units at a time when they may not desire to sell them or at a price
that is less than the price they would desire to receive upon sale. Unitholders may also incur a tax liability upon a sale
of their units.

Without the consent of each unitholder, Great Lakes, Northern Border, North Baja or Tuscarora might be
converted into a corporation, which would result in Great Lakes, Northern Border, North Baja or Tuscarora, as
the case may be, being subject to corporate income taxes.
If it becomes unlawful to conduct the business of Great Lakes, Northern Border or Tuscarora as a partnership and some
other conditions are satisfied, the business and assets of Great Lakes, Northern Border or Tuscarora, as the case may be,

30

TC PIPELINES, LP

will automatically be transferred to a corporation without the vote or consent of unitholders. Therefore, unitholders
would not receive a proxy or consent solicitation statement in connection with that transaction. However, we believe
that it is unlikely that circumstances requiring an automatic transfer will occur. A transfer to corporate form would result
in Great Lakes, Northern Border, North Baja or Tuscarora being subject to corporate income taxes and would likely be
materially adverse to their, and therefore, our results of operations and financial condition.

TransCanada, through its subsidiaries, controls our General Partner, which has responsibility for conducting
our business and managing our operations. TC PipeLines GP, Inc., our General Partner, and its affiliates have
limited fiduciary responsibilities and may have conflicts of interest with respect to our partnership, and they
may favor their own interests to the detriment of our unitholders.
The directors and officers of our General Partner and its affiliates have duties to manage the General Partner in a
manner that is beneficial to its stockholders. At the same time, our General Partner has duties to manage our
partnership in a manner that is beneficial to us. Therefore, our General Partner’s duties to us may conflict with the
duties of its officers and directors to its stockholders. Such conflicts may include, among others, the following:

(cid:127) expenditures, borrowings, issuances of additional common units and reserves in any quarter may affect the level of

cash available to pay quarterly distributions to unitholders and our General Partner;

(cid:127) under our Partnership Agreement, our General Partner determines which costs incurred by it and its affiliates are

reimbursable by us;

(cid:127) affiliates of our General Partner may compete with us in certain circumstances;

(cid:127) our General Partner may limit our liability and reduce their fiduciary duties, while also restricting the remedies

available to our unitholders for actions that might, without the limitations, constitute breaches of fiduciary duty. As a
result of purchasing our units, unitholders are deemed to consent to some actions and conflicts of interest that might
otherwise constitute a breach of fiduciary or other duties under applicable law; and

(cid:127) TransCanada, through wholly-owned subsidiaries, is the operator of all of our pipeline systems. This operator role
along with its ownership interests in our pipeline systems may influence TransCanada to make decisions that may
conflict as operator and/or owner of these systems.

Cost reimbursements due to our General Partner may be substantial and could reduce our cash available for
distribution.
Prior to making any distribution on the common units, we will reimburse our General Partner and its affiliates, including
officers and directors of the General Partner, for all expenses incurred by our General Partner and its affiliates on our
behalf. During the year ended December 31, 2010, we paid fees and reimbursements to our General Partner in the
amount of $2.2 million (2009 – $2.1 million). Our General Partner in its sole discretion will determine the amount of
these expenses. In addition, our General Partner and its affiliates may provide us services for which we will be charged
reasonable fees as determined by the General Partner. The reimbursement of expenses and the payment of fees could
adversely affect our ability to make distributions.

Tax Risks to Common Unitholders

The Internal Revenue Service (IRS) could treat us as a corporation, which would substantially reduce the cash
available for distribution to unitholders.
The anticipated after-tax benefit of an investment in us depends largely on our classification as a partnership for federal
income tax purposes. We have not requested, and do not plan to request, a ruling from the IRS on this or any other tax
matter affecting us.

If we were treated as a corporation for federal income tax purposes, we would pay federal income taxes on our taxable
income at the applicable corporate tax rate, which is currently a maximum of 35 percent, and we would likely have to
pay state income tax at varying rates. Distributions would generally be taxed again to unitholders as corporate
distributions, and no income, gains, losses, deductions or credits would flow through to unitholders. Because a tax
would be imposed upon us as an entity, the cash available for distribution to unitholders would be substantially
reduced. Our treatment as a corporation would result in a material reduction in the anticipated cash flow and after-tax
return to unitholders and thus would likely result in a substantial reduction in the value of the common units.

2010 ANNUAL REPORT

31

Current laws may change so as to cause us to be taxable as a corporation for federal income tax purposes or otherwise
to be subject to entity level taxation. Our Partnership Agreement provides that, if a law is enacted or existing law is
modified or interpreted in a manner that subjects us to taxation as a corporation or otherwise subjects us to entity level
taxation for federal, state or local income tax purposes, then specified provisions of the Partnership Agreement relating
to distributions will be subject to change. These changes would include a decrease in distributions to reflect the impact
of that law on us.

The tax treatment of publicly traded partnerships or an investment in our units could be subject to potential
legislative, judicial or administrative changes and differing interpretations, possibly on a retroactive basis.
The present federal income tax treatment of publicly traded partnerships, including us, or an investment in our units,
may be modified by administrative, legislative or judicial interpretation at any time. Any modification to the federal
income tax law or interpretations thereof could make it difficult or impossible to meet the requirements for us to be
treated as a partnership for federal income tax purposes. These modifications could cause us to change our business
activities, affect the tax considerations of an investment in us, change the character or treatment of portions of our
income and adversely affect an investment in our units. We are unable to predict whether or not such changes, if any,
will ultimately occur. Any modifications to the federal income tax laws and interpretations thereof may or may not be
applied retroactively. Any such changes could negatively affect the value of an investment in our common units and the
amount of cash available for distribution to our unitholders.

If our pipeline systems were to become subject to a material amount of entity-level taxation for state tax
purposes, then our pipeline systems’ operating cash flow and cash available for distribution to us and for
other business needs would be reduced.
Our pipeline systems are held in operating partnerships, which are generally treated as flow-through entities for income
tax purposes, and as such the income from our pipeline systems generally has not been subject to income tax at the
entity level. Several states have either adopted or are evaluating a variety of ways to subject partnerships to entity level
taxation. For example, in 2010, Great Lakes recorded a Michigan business tax of $5.3 million relating to a partnership
level tax, adopted by Michigan in 2008, of which the Partnership’s share of the tax was $2.5 million. Imposition of such
taxes on our pipeline systems will reduce the cash available for distribution to us and for other business needs by our
pipeline systems, and adversely affect the amount of funds available for distribution to our unitholders.

We have not requested an IRS ruling with respect to our tax treatment.
We have not requested a ruling from the IRS with respect to any tax matter affecting us. The IRS may adopt positions
that differ from the positions we take. It may be necessary to resort to administrative or court proceedings in an effort
to sustain some or all of the positions we take. Any contest with the IRS may materially and adversely impact the
market for our common units and the price at which the common units trade. In addition, the costs of any contest
with the IRS will be borne directly or indirectly by the unitholders and the General Partner.

Unitholders may be required to pay taxes on income from us even if they receive no cash distributions.
Unitholders may be required to pay federal income taxes and, in some cases, state and local income taxes on their
allocable share of our income, whether or not they receive cash distributions from us. Unitholders may not receive cash
distributions equal to their allocable share of our taxable income or even the tax liability that results from that income.

Tax gains or losses on the disposition of common units could be different than expected.
If unitholders sell their common units, they will recognize a taxable gain or loss equal to the difference between the
amount realized and their tax basis in those common units. Prior distributions in excess of the total net taxable income
that a unitholder was allocated for a common unit which decreased the unitholder’s tax basis in that common unit will,
in effect, become taxable income if the common unit is sold at a price greater than their tax basis in that common unit,
even if the price is less than the original cost. A substantial portion of the amount realized on the sale of common
units, whether or not representing a gain, may be ordinary income to unitholders due to potential recapture of items
such as depreciation recapture. If the IRS were to successfully contest some conventions we use, unitholders could
recognize more taxable gain on the sale of common units than would be the case under those conventions without the
benefit of decreased taxable income in prior years.

32

TC PIPELINES, LP

Tax-exempt and non-U.S. investors may have adverse tax consequences from owning common units.
An investment in common units by tax-exempt entities and foreign persons raises issues unique to these persons. For
example, virtually all of our income allocated to organizations which are exempt from federal income tax, including
individual retirement accounts and other retirement plans, will be unrelated business taxable income and will be taxable
to them. Distributions to foreign persons will be reduced by withholding taxes, and foreign persons will be required to
file federal income tax returns and pay tax on their share of our taxable income.

We treat a purchaser of common units as having the same tax benefits without regard to the actual common
units purchased. A successful IRS challenge could adversely affect the value of the common units.
Because we cannot match transferors and transferees of common units, to maintain uniformity of the economic and tax
characteristics of our common units, we have adopted depreciation and amortization conventions that do not conform
to all aspects of specified Treasury Regulations. A successful challenge to those conventions by the IRS could adversely
affect the amount of tax benefits available to unitholders or could affect the timing of tax benefits or the amount of
taxable gain from the sale of common units and could have a negative impact on the value of the common units or
result in audit adjustments to unitholders’ tax returns.

We have adopted certain valuation methodologies that may result in a shift of income, gain, loss and
deduction between the General Partner and the unitholders. The IRS may challenge this treatment, which
could adversely affect the value of the common units.
For income tax purposes and pursuant to the Partnership Agreement, when we issue additional units or engage in
certain other transactions, we determine the fair market value of our assets and allocate any unrealized gain or loss
attributable to our assets to the capital accounts of our unitholders and our General Partner. If our valuation
methodology were not sustained upon an IRS challenge, there may be a shift of income, gain, loss and deduction
between certain unitholders and the General Partner, which may be unfavorable to such unitholders. Our valuation
methodology is also used in certain computations and allocations relating to tax basis adjustments and the tax
treatment of unitholders’ gain on sale of common units.

A successful IRS challenge to these methods, calculations or allocations could adversely affect the amount of taxable
income or loss being allocated to our unitholders. It also could affect the amount or character of taxable gain from our
unitholders’ sale of common units and could have a negative impact on the value of the common units or result in
audit adjustments to our unitholders’ tax returns without the benefit of additional deductions.

The sale or exchange of 50 percent or more of the total interest in our capital and profits will result in the
termination of our partnership for federal income tax purposes.
We will be considered to have terminated for federal income tax purposes if there is a sale or exchange of 50 percent
or more of the total interests in our capital and profits within a 12-month period. Our termination would, among other
things, result in the closing of our taxable year for all unitholders and could result in a deferral of depreciation
deductions allowable in computing our taxable income.

Unitholders will likely be subject to state and local taxes and return filing requirements in states where they
do not live as a result of an investment in our common units.
In addition to federal income taxes, unitholders will likely be subject to other taxes, including state and local taxes,
unincorporated business taxes and estate, inheritance or intangible taxes that are imposed by the various jurisdictions in
which we do business or own property. We may be required to withhold income taxes with respect to income allocable
or distributions made to our unitholders. In addition, unitholders may be required to file state and local income tax
returns and pay state and local income taxes in some or all of the jurisdictions in which we do business or own
property and may be subject to penalties for failure to comply with those requirements. We currently own assets and
conduct business in Arizona, California, Illinois, Indiana, Iowa, Michigan, Minnesota, Montana, Nebraska, Nevada, North
Dakota, Oregon, South Dakota, Texas and Wisconsin. Should we make acquisitions or expand our business, we may
own assets or conduct business in additional states. Most of these states currently impose personal income taxes on
individuals. Generally, these states also impose income taxes on corporations and other entities. It is the unitholders’
responsibility to file all required U.S. federal, state and local tax returns. Counsel has not rendered an opinion on the
state or local tax consequences of an investment in us.

2010 ANNUAL REPORT

33

Item 1B. Unresolved Staff Comments

None.

Item 2. Properties

A description of our properties and the properties of our pipeline systems is included in Part 1, Item 1. ‘‘Business – Title
to Properties,’’ and is incorporated herein by reference.

Item 3.

Legal Proceedings

Great Lakes v. Essar Steel Minnesota LLC, et al. (Essar) – In October 2009, Great Lakes filed suit in the U.S. District
Court, District of Minnesota, against Essar for breach of contract. Essar is a party to a transportation contract for a term
starting July 1, 2009 through March 31, 2024. The fifteen-year contract has a total approximate value of $33.0 million.
Essar has refused to honor their contractual obligations. Great Lakes is seeking recovery of all sums due, including all
future sums due under the contract. The case is currently in the discovery phase.

In addition to this proceeding, the Partnership and our pipeline systems are involved in various pending or potential
legal actions in the ordinary course of business. While management is unable to predict the ultimate outcome of these
actions, and because of the inherent uncertainty of litigation, we cannot provide assurance that the resolution of any
particular claim or proceeding will have a favorable or unfavorable material effect on the Partnership’s financial position,
results of operations or cash flows for the period in which the resolution occurs.

34

TC PIPELINES, LP

PART II

Item 5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity

Securities

The common units representing limited partner interests in the Partnership have been quoted on the NASDAQ Global
Select Market since May 1999 and trade under the symbol ‘‘TCLP.’’

The following table sets forth, for the periods indicated, the high and low sale prices per common unit, as reported by
the NASDAQ Global Select Market, and the amount of cash distributions per common unit declared with respect to the
corresponding periods. Cash distributions are paid within 45 days after the end of each quarter to unitholders of record
as of the record date.

2010
First Quarter
Second Quarter
Third Quarter
Fourth Quarter

2009
First Quarter
Second Quarter
Third Quarter
Fourth Quarter

Price Range

High

Low

Cash Distributions
Declared per
Common Unit

$38.09
$40.96
$46.50
$52.00

$30.44
$36.43
$39.14
$41.10

$34.40
$34.72
$40.35
$46.21

$23.62
$29.71
$34.82
$35.17

$0.730
$0.730
$0.750
$0.750

$0.705
$0.730
$0.730
$0.730

As at February 16, 2011, there were 71 registered holders of common units and approximately 21,500 beneficial
owners of common units, including common units held in street name.

The Partnership currently has 46,227,766 common units outstanding, of which 29,142,935 are held by the public,
11,287,725 are held by TransCan Northern Ltd., and 5,797,106 are held by our General Partner. The common units
represent an aggregate 98 percent limited partner interest and the general partner interest represents an aggregate two
percent general partner interest in the Partnership.

Cash Distributions
The General Partner receives two percent of all cash distributions in regard to its general partner interest and is also
entitled to incentive distributions as described below. The unitholders receive the remaining portion of the cash
distribution. The Partnership’s quarterly cash distributions to its unitholders comprise all of its Available Cash. Available
Cash is defined in the Partnership Agreement and generally means, with respect to any quarter of the Partnership, all
cash on hand at the end of a quarter less the amount of cash reserves that are necessary or appropriate, in the
reasonable discretion of the General Partner, to:

(cid:127) provide for the proper conduct of the business of the Partnership (including reserves for future capital expenditures

and for anticipated credit needs);

(cid:127) comply with applicable laws or any Partnership debt instrument or agreement; and

(cid:127) provide funds for cash distributions to unitholders and the General Partner in respect of any one or more of the next

four quarters.

The incentive distribution provisions were amended in July 2009. As a result, the General Partner receives 15 percent of
quarterly amounts distributed in excess of $0.81 per common unit, and a maximum of 25 percent of quarterly amounts
distributed in excess of $0.88 per common unit, provided the balance has been first distributed to unitholders on a

2010 ANNUAL REPORT

35

pro rata basis. The amounts that trigger incentive distributions at various levels are subject to adjustment in certain
events, as described in the Partnership Agreement.

In 2010, the Partnership made cash distributions to unitholders and the General Partner that amounted to
$138.7 million compared to $117.0 million in 2009. These payments represented $0.73 per common unit for the
quarters ended December 31, 2009, March 31, 2010 and June 30, 2010 and $0.75 per common unit for the quarter
ended September 30, 2010. On February 14, 2011, the Partnership paid a cash distribution of $35.4 million to
unitholders and the General Partner, representing a cash distribution of $0.75 per common unit for the quarter ended
December 31, 2010. The distribution was allocated in the following manner: $34.7 million to the unitholders as of the
close of business on January 31, 2011 (including $4.3 million to the General Partner as holder of 5,797,106 common
units and $8.5 million to TransCanada as indirect holder of 11,287,725 common units), and $0.7 million to the General
Partner in respect of its two percent general partner interest.

Item 6. Selected Financial Data

The selected financial data should be read in conjunction with the financial statements, including the notes thereto, and
Item 7. ‘‘Management’s Discussion and Analysis of Financial Condition and Results of Operations.’’

(millions of dollars, except per common unit amounts)

2010

2009(a)

2008(a)

2007(a)(b)

2006(a)(c)

Income Data (for the year ended December 31)
Equity income from investment in Great Lakes
Equity income from investment in Northern Border
Equity income from investment in Tuscarora
Transmission revenues
Financial charges and other
Net income
Basic and diluted net income per common unit

Cash Flow Data (for the year ended December 31)
Cash distribution declared per common unit

Balance Sheet Data (at December 31)
Total assets
Long-term debt (including current maturities)
Partners’ equity

58.7
67.3
–
69.1
(25.6)
137.1
$2.91

59.1
40.3
–
67.9
(29.3)
106.1
$2.34

57.3
65.3
–
64.5
(34.6)
123.0
$2.73

49.0
61.2
–
49.8
(38.7)
94.7
$2.48

–
56.6
5.9
23.0
(21.7)
49.1
$2.39

$2.960

$2.895

$2.815

$2.630

$2.350

1,650.5
513.9
1,112.5

1,675.1
541.3
1,103.5

1,701.1
536.8
875.6

1,732.4
573.4
900.1

1,008.1
468.1
303.9

(a) The acquisition of North Baja from TransCanada was accounted for as a transaction between entities under common control, similar to a
pooling of interests, whereby the assets and liabilities of North Baja were recorded at TransCanada’s carrying value and the Partnership’s
historical financial information was recast to include North Baja for all periods presented on a consolidated basis.

(b) The Partnership acquired a 46.45 percent interest in Great Lakes on February 22, 2007. The equity method is used to account for the

Partnership’s investment in Great Lakes.

(c) The Partnership acquired an additional 20 percent interest in Northern Border on April 6, 2006. The equity method is used to account for
the Partnership’s investment in Northern Border. The Partnership accounted for its 49 percent investment in Tuscarora using the equity
method until December 19, 2006 and began consolidating Tuscarora’s operations upon acquisition of the additional 49 percent general
partner interest.

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations

The following discussion of the financial condition and results of operations of the Partnership and its pipeline systems
should be read in conjunction with the financial statements and notes thereto of the Partnership, Great Lakes and
Northern Border included elsewhere in this report. See Part II, Item 8. ‘‘Financial Statements and Supplementary Data.’’
For more detailed information regarding the basis of presentation for the following financial information, see the notes

36

TC PIPELINES, LP

to the financial statements of the Partnership, Great Lakes and Northern Border. The discussion below includes forward-
looking statements that are subject to risks and uncertainties that may result in actual results differing materially from
the statements we make. These risks and uncertainties are discussed further in Part 1, Item 1A. ‘‘Risk Factors.’’

OVERVIEW

TC PipeLines, LP was formed in 1998 as a Delaware limited partnership to acquire, own and participate in the
management of energy infrastructure businesses in North America.

To date, our investments have been in interstate natural gas pipeline systems that transport natural gas to a variety of
markets in the U.S. and Eastern Canada. Our pipeline systems derive their operating revenue from the transportation of
natural gas. Our pipelines are regulated by the FERC and are operated by TransCanada. With the exception of North
Baja, these pipelines comprise critical links for the transportation of natural gas from the WCSB to U.S. markets.

Our investments are:

Ownership

System Specifications

Percentage Date Acquired

Miles Capacity (MMcf/d)

Great Lakes

46.45

February 2007

2,115

2,300 (summer design)
2,500 (winter design)

Northern Border

North Baja

Tuscarora

2010 Year in Review

30.00 May 1999
20.00 April 2006
50.00

100.00

July 2009

49.00
September 2000
49.00 December 2006
2.00 December 2007

100.00

1,398

2,374 (design)

86

500 (southbound design)
600 (northbound design)

305

230 (design)

(cid:127) Partnership Distribution – In 2010, we continued to focus on delivering stable, sustainable cash distributions to our

unitholders and finding opportunities to increase cash distributions while maintaining a low-risk profile. In
October 2010, we increased our quarterly cash distribution rate by three percent to $0.75 per common unit, or $3.00
per common unit on an annualized basis.

(cid:127) Northern Border Contract Volumes – In 2010, average daily scheduled volumes on Northern Border’s pipeline system
was 2,471 MMcf/d compared to 1,934 MMcf/d in 2009. This increase was primarily due to Northern Border being
fully contracted at the end of 2010 due to increased demand for Northern Border’s transportation services compared
to 2009. Substantially all of Northern Border’s capacity has been sold through March 2012.

(cid:127) Great Lakes Contract Volumes – Great Lakes’ largest shipper, TransCanada PipeLines Limited, has held contracts for

approximately 1.3 MMDth/d for over 40 years. Beginning November 1, 2010, TransCanada PipeLines Limited reduced
its contract demand to 961 MDth/d; however, Great Lakes resold all available long-haul capacity and remains fully
contracted through October 31, 2011.

(cid:127) Great Lakes Rate Case Settlement – As a result of extensive settlement negotiations, in July 2010, the FERC approved

a stipulation and agreement (GL Settlement) without modification. As approved, the GL Settlement resulted in a
reduction in rates and will apply to all current and future shippers on Great Lakes’ system. Please read ‘‘Regulatory
Environment – FERC Rating Proceedings – Great Lakes Rate Proceeding’’ in this section for additional information with
respect to the GL Settlement. 

2010 ANNUAL REPORT

37

(cid:127) Great Lakes Backhaul Service – In 2010, Great Lakes installed facilities to increase its ability to provide firm backhaul
(east to west) transportation. As of November 1, 2010, Great Lakes began providing an incremental 440 MDth/d of
transportation service from St. Clair, Michigan to Emerson, Manitoba, Canada.

(cid:127) North Baja Bi-directional Flow – In March 2010, North Baja transported natural gas northbound into the U.S. for the
first time since the pipeline completed its expansion to allow for bi-directional flows in April 2008. The northbound
service provides North Baja with additional market opportunities.

(cid:127) Yuma Lateral – In March 2010, the Partnership acquired the expansion facilities and contracts in place for an

expansion of the North Baja pipeline from the Mexico/Arizona border to Yuma, Arizona (Yuma Lateral). The Yuma
Lateral was placed in service in March 2010.

(cid:127) Northern Border Princeton Lateral – In December 2010, Northern Border accepted the certificate issued by the FERC
to construct the Princeton Lateral Project authorizing Northern Border to construct, own and operate 8.7 miles of
16-inch diameter pipeline and associated facilities. The project is fully subscribed for a 10-year term and is expected
to be in service by fourth quarter 2011. The total cost of the project is expected to be approximately $18 million, of
which the Partnership expects to contribute approximately $4.5 million.

(cid:127) TransCanada Mainline Interim Toll Application – Because the ability and willingness of natural gas shippers to utilize a
pipeline system over alternative pipelines can be impacted by relative transportation rates and the volume of natural
gas delivered to markets supplied by that system from other supply sources and storage facilities, the demand for
natural gas services on Great Lakes, Northern Border and Tuscarora, may be impacted by changes in TransCanada
Mainline tolls. In January 2011, TransCanada filed an application with Canada’s National Energy Board (NEB) for
approval of interim 2011 tolls calculated in accordance with TransCanada Mainline’s 2007-2011 settlement currently
in effect, and the NEB approved the application, as filed, in February 2011. An application and proceeding regarding
2011 final tolls is expected to follow.

FACTORS THAT IMPACT OUR BUSINESS

Factors that may impact demand for transportation service on any one system include the availability of natural gas
supply at the pipeline system’s receipt points, the ability and willingness of natural gas shippers to utilize that system
over alternative pipelines, transportation rates compared to other systems and the volume of natural gas delivered to
the same market from other supply sources and storage facilities.

Prevailing market conditions and dynamic competitive factors in North America (particularly reduced natural gas exiting
the WCSB, increased supply from other supply basin market areas served by our pipelines and the economic
environment affecting the demand for natural gas) will continue to impact the value of transportation on our pipeline
systems and their ability to market available capacity. Our pipeline systems actively market their available capacity and
work closely with customers, including natural gas producers and end users, to ensure our pipelines are offering
attractive services and competitive rates.

Supply

The primary source of natural gas transported by our pipeline systems, excluding North Baja, is the WCSB. Gas exiting
the WCSB is dependent upon WCSB natural gas production levels, demand for natural gas in Western Canada, and the
volume of natural gas injected into natural gas storage in Western Canada. Despite declines in drilling activity in the
WCSB in recent years, we expect drilling in the WCSB to recover over the long term as supply costs and royalty
structures become more competitive. In addition, the ultimate supply potential of the WCSB has been improving due to
improved economic access to its unconventional resources including shale gas, tight gas and coal-bed methane. In
particular, the Horn River and Montney shale plays have demonstrated encouraging results which are expected to
improve supply available from the WCSB in 2011 and 2012. In the longer term, reserves from northern natural gas may
increase the supply coming out of the WCSB.

38

TC PIPELINES, LP

Demand

Demand for natural gas is impacted by a variety of factors including weather conditions, economic conditions,
government regulations and the availability and price of alternative energy sources. North American natural gas demand
in 2010 grew compared to 2009 levels due to a rebound in economic activity and a warmer than normal summer in
our pipeline systems’ market regions which increased natural gas demand for electric generation. We expect that
demand for natural gas will improve modestly along with the economic recovery, and that most of the growth in
demand will result from increased demand for natural gas-fired electric generation.

Competition

Due to excess pipeline capacity, there is currently increased competition amongst natural gas pipelines for the
transportation of gas exiting the WCSB. Factors impacting the competition for gas exiting the WCSB include levels of
firm transportation contracts on each pipeline, demand for natural gas in the regions served by each pipeline and
relative transportation values on each pipeline.

Contracting

The majority of our pipeline systems’ natural gas transportation services are provided through firm service transportation
contracts with a reservation charge to reserve pipeline capacity, regardless of use, for the term of the contract. The
revenues associated with capacity under firm service transportation contracts are not subject to fluctuations caused by
changing supply and demand conditions, competition and customers. Customers with interruptible service
transportation agreements may utilize available capacity on a pipeline system after firm service transportation requests
are satisfied. Interruptible service customers are assessed commodity charges (or utilization fees) based on distance and
the volume of natural gas they transport.

The following table provides information with respect to the revenue composition for our pipeline systems for the year
ended December 31, 2010:

Great Lakes
Northern Border
North Baja
Tuscarora

2010 Revenue Composition

Firm Contracts

Capacity
Reservation
Charges

Variable
Usage Fees

Interruptible
Contracts &
Other Services

95%
89%
99%
100%

3%
8%
1%
0%

2%
3%
0%
0%

New major long-haul pipeline projects are typically underpinned by contracts for an original term equal to or greater
than ten years. When this original term expires, shippers typically renew on an annual basis. Terms for interruptible
transportation services range from day-to-day to multiple years. With the interconnection of the Bison pipeline to
Northern Border, terms for transportation services for related capacity on Northern Border have contract terms of ten
years. However, contract renewals for Great Lakes and the remaining Northern Border contracts are generally on an
annual basis. Tuscarora has long-term contracts for the majority of its capacity with term expiries after 2016. Similarly,
North Baja has long-term contracts for a substantial portion of its capacity with terms that mature between 2022
and 2028.

2010 ANNUAL REPORT

39

Average Daily Scheduled Volumes

The table below provides historical information on the average daily scheduled volumes for Great Lakes and Northern
Border from the past three years:

December 31 

(million cubic feet per day)

Great Lakes
Northern Border

Average Daily Scheduled Volumes(a)

2010

2,203
2,471

2009

1,992
1,934

2008

2,143
2,291

(a) Average daily scheduled volumes represent volumes of natural gas, irrespective of path or distance transported, from which variable usage
fee revenue is earned. Average daily scheduled volumes are not presented for North Baja and Tuscarora as Partnership Cash Flows and
Net Income from these investments are underpinned by long-term firm contracts and do not vary significantly with changes in utilization.

Great Lakes

Average daily scheduled volumes on Great Lakes’ pipeline system in 2010 increased to 2,203 MMcf/d compared to
1,992 MMcf/d in 2009 primarily due to higher utilization of long-term firm contracts by Great Lakes’ major shipper,
TransCanada PipeLines Limited, during the traditional summer storage-fill season. Increases in volumes related to higher
utilization of long-term firm contracts have a minimal impact on revenue earned from these contracts.

Great Lakes’ long-haul capacity contracts are generally subject to annual renewals. Contracting occurs throughout the
year; however, shippers typically contract on Great Lakes for the upcoming natural gas year starting on November 1 of
each year. As a result, Great Lakes is currently fully contracted through October 2011. Great Lakes’ largest shipper,
TransCanada PipeLines Limited has 576 MDth/d of long-haul capacity under contract expiring on October 31, 2011.
Negotiations related to these contracts are currently underway.

Northern Border

Average daily scheduled volumes on Northern Border’s pipeline system in 2010 increased to 2,471 MMcf/d compared to
1,934 MMcf/d in 2009. Demand for transportation on Northern Border improved during 2010 primarily due to an
increase in the transportation value that was available to shippers utilizing Northern Border transportation services. The
increase in transportation value was due to a number of factors, including the completion of other pipeline projects
that moved Mid-Continent natural gas supply to eastern markets and the relative economic value of Northern Border
services compared with other transportation paths and available markets, resulting in an increase in demand for
Northern Border’s transportation services.

Northern Border’s capacity is generally subject to annual contract renewals, which occur throughout the year.
Substantially all of Northern Border’s capacity has been sold through March 2012.

In January 2011, TransCanada placed in service the Bison Pipeline Project that extends from the Powder River Basin
producing region in Wyoming to an interconnection with the Northern Border system in Morton County, North Dakota.
Northern Border has secured 10-year contracts with the Bison shippers, at a discounted rate, for approximately
407 MMcf/d of capacity from Port of Morgan, Montana to Ventura, Iowa.

Outlook

Due to the relatively short-term contract profiles for Great Lakes and Northern Border, these systems may experience
operating revenue volatility. We believe Great Lakes and Northern Border to be fundamental and competitive

40

TC PIPELINES, LP

components of the natural gas pipeline infrastructure exiting the WCSB. The level of contracting and, accordingly,
revenues post-October 2011 for Great Lakes and post-March 2012 for Northern Border will depend on the factors of
supply, demand and competition described above.

North Baja and Tuscarora are expected to provide stable revenues, subject to any FERC decisions on rates, as the
capacity on both pipelines is contracted for the long-term.

REGULATORY ENVIRONMENT

FERC Rate Proceedings
Great Lakes Rate Proceeding – On November 19, 2009, the FERC issued an order in FERC Docket No. RP10-149
instituting an investigation pursuant to Section 5 of the NGA. The FERC alleged, based on a review of certain historical
information, that Great Lakes’ revenues might substantially exceed Great Lakes’ actual cost of service and therefore may
be unjust and unreasonable. As a result of extensive settlement negotiations, in July 2010, the FERC approved the GL
Settlement without modification, establishing the terms pursuant to which all matters in the GL Rate Proceeding were
resolved. The GL Settlement was effective May 1, 2010 and applies to all current and future shippers on Great Lakes’
system.

Under the terms of the GL Settlement, reservation rates on Great Lakes’ pipeline system were reduced eight percent,
Interruptible Transportation (IT) rates were increased, and the depreciation rate for Great Lakes’ transmission plant was
also reduced. IT revenue sharing was terminated by the GL Settlement, and a new limited revenue sharing provision
was agreed to for jurisdictional revenues that Great Lakes receives in excess of $500 million during the period between
November 1, 2010 and October 31, 2012.

 The GL Settlement rates will remain in effect through at least November 30, 2011. The GL Settlement includes a
moratorium on participants and customers filing any NGA Section 5 rate case to place new rates into effect prior to
November 1, 2012. There is also a moratorium on Great Lakes filing a general NGA Section 4 rate case to place new
rates into effect prior to December 1, 2011. In addition, the GL Settlement requires Great Lakes to file a NGA Section 4
general rate case no later than November 1, 2013.

Environmental Matters

Impact of Climate Change on Our Business – The regulation or restriction of greenhouse gas emissions could result in
changes to the consumption and demand for natural gas. This could have adverse effects on our pipeline systems, and
our financial position, results of operations and future prospects. The physical effects associated with climate change
may include changes in weather patterns, such as increases in storm intensity or temperature extremes, the availability
or quality of water, or sea-level rise. These effects can impact supply and distribution chains or demand for certain
products or services, or result in damage to facilities or decreased efficiency of equipment.

The impact of new or proposed greenhouse gas laws and regulations is not yet certain and we cannot estimate the
effect of proposed legislation on our future financial position, results of operations or cash flow. It is also reasonably
likely, however, that such legislation could materially increase our operating costs, including our cost of environmental
compliance by requiring us to install additional equipment and potentially purchase emission allowances or offset
credits. Increases in costs of our pipeline systems’ suppliers to comply with greenhouse gas legislation could also
materially increase our costs of operations. Although many of these costs might be recoverable in the rates charged to
our pipeline customers, recovery through these mechanisms is uncertain.

2010 ANNUAL REPORT

41

HOW WE EVALUATE OUR OPERATIONS

We evaluate our business primarily on the basis of the underlying operating results for each of our pipeline systems,
along with a measure of Partnership cash flows. This measure does not have any standardized meaning prescribed by
U.S. generally accepted accounting principles (GAAP). It is, therefore, considered to be a non-GAAP measure and is
unlikely to be comparable to similar measures presented by other entities. The Partnership calculates Partnership cash
flows as net income, less North Baja’s net income contribution prior to acquisition, plus operating cash flows from the
Partnership’s wholly-owned subsidiaries, North Baja and Tuscarora, and cash distributions received in excess of equity
income from the Partnership’s equity investments, Great Lakes and Northern Border, net of distributions declared to the
General Partner. Partnership cash flows before General Partner distributions represent Partnership cash flows prior to
distributions declared to the General Partner.

RESULTS OF OPERATIONS OF TC PIPELINES, LP

Our general partner interests in Great Lakes and Northern Border and ownership of North Baja and Tuscarora were our
only material sources of income in 2010. Therefore, our results of operations and Partnership cash flows were
influenced by and reflect the same factors that influenced the financial results of Great Lakes, Northern Border, North
Baja and Tuscarora. See Item 1. ‘‘Business.’’

NET INCOME

The Partnership uses the non-GAAP financial measure ‘‘Net income prior to recast’’ as a financial performance measure.
Net income prior to recast excludes North Baja’s net income for periods prior to July 1, 2009, the date on which the
Partnership acquired North Baja. The acquisition of North Baja from TransCanada was accounted for as a transaction
under common control, similar to a pooling of interests, whereby the Partnership’s historical financial information was
recast to include the net income of North Baja for all periods presented, which included income which did not accrue
to the Partnership’s general partner interest or to the Partnership’s common units, but rather accrued to North Baja’s
former parent.

Net income prior to recast is presented to enhance investors’ understanding of the way management analyzes the
Partnership’s financial performance. Net income prior to recast is provided as a supplement to GAAP financial results
and is not meant to be considered in isolation or as a substitute for financial results prepared in accordance with GAAP.

To supplement our financial statements, we have presented a comparison of the earnings contribution components
from each of our investments. We have presented net income in this format to enhance investors’ understanding of the
way management analyzes our financial performance. We believe this summary provides a more meaningful comparison
of our net income to prior years, as we account for our partially-owned pipeline systems using the equity method. The
presentation of this additional information is not meant to be considered in isolation or as a substitute for results
prepared in accordance with GAAP.

42

TC PIPELINES, LP

The shaded areas in the tables below disclose the results from Great Lakes and Northern Border, representing
100 percent of each entity’s operations for the given period.

Year Ended December 31, 2010
(millions of dollars)

Transmission revenues
Operating expenses
General and administrative
Depreciation
Financial charges and other
Michigan business tax

Equity income

Net income

Year Ended December 31, 2009
(millions of dollars)

Transmission revenues
Operating expenses
General and administrative
Depreciation
Financial charges and other
Michigan business tax

Equity income

Net income prior to recast

North Baja’s contribution prior to

acquisition(d)

Net income(d)

Total

Other Pipes(a)

Corporate(b)

Great Lakes

69.1
(13.0)
(4.4)
(15.0)
(25.6)
–

126.0

137.1

69.1
(13.0)
–
(15.0)
(4.2)
–

–

36.9

–
–
(4.4)
–
(21.4)
–

–

(25.8)

262.4
(59.2)
–
(40.5)
(30.9)
(5.3)

126.5

58.7

58.7

Total

Other Pipes(a)

Corporate(b)

Great Lakes

50.9
(7.9)
(6.2)
(10.9)
(27.5)
–

99.4

97.8

8.3

106.1

50.9
(7.9)
–
(10.9)
(4.1)
–

–

28.0

8.3

36.3

–
–
(6.2)
–
(23.4)
–

–

(29.6)

–

(29.6)

289.7
(66.5)
–
(58.5)
(31.9)
(5.4)

127.4

59.1

59.1

–

59.1

Northern
Border(c)

295.1
(74.0)
–
(61.5)
(23.4)
–

136.2

67.3

67.3

Northern
Border(c)

249.2
(70.8)
–
(61.9)
(34.4)
–

82.1

40.3

40.3

–

40.3

2010 ANNUAL REPORT

43

Year Ended December 31, 2008
(millions of dollars)

Transmission revenues
Operating expenses
General and administrative
Depreciation
Financial charges and other(c)
Michigan business tax

Equity income

Net income prior to recast

North Baja’s contribution prior to

acquisition(d)

Net income(d)

Total

Other Pipes(a)

Corporate(b)

Great Lakes

31.6
(5.4)
(4.1)
(6.9)
(30.1)
–

122.6

107.7

15.3

123.0

31.6
(5.4)
–
(6.9)
(4.3)
–

–

15.0

15.3

30.3

–
–
(4.1)
–
(25.8)
–

–

(29.9)

–

(29.9)

287.1
(67.1)
–
(58.5)
(32.6)
(5.5)

123.4

57.3

57.3

–

57.3

Northern
Border(c)

293.1
(78.0)
–
(61.1)
(21.8)
–

132.2

65.3

65.3

–

65.3

(a) ‘‘Other Pipes’’ includes the results of North Baja and Tuscarora.

(b) ‘‘Corporate’’ includes the costs of the Partnership, but excludes the costs of its subsidiaries.

(c) The Partnership owns a 50 percent general partner interest in Northern Border. Equity income from Northern Border includes the
twelve-year amortization of a $10.0 million transaction fee paid to the operator of Northern Border at the time of the additional
20 percent acquisition in April 2006.

(d) The acquisition of North Baja from TransCanada was accounted for as a transaction between entities under common control, similar to a
pooling of interests, whereby the assets and liabilities of North Baja were recorded at TransCanada’s carrying value and the Partnership’s
historical financial information was recast to include North Baja for all periods presented on a consolidated basis.

(e)

In 2008, Northern Border’s financial charges, net and other, included a $16.2 million gain on the sale of Bison Pipeline LLC (Bison).

Year Ended December 31, 2010 Compared with the Year Ended December 31, 2009
Net income increased $31.0 million to $137.1 million in 2010 compared to $106.1 million in 2009. Excluding the
contribution from North Baja prior to the acquisition, net income prior to recast increased $39.3 million to
$137.1 million in 2010 compared to $97.8 million in 2009. This increase was primarily due to increased equity income
from Northern Border, net income from North Baja for a full year in 2010 compared to six months in 2009 and lower
general and administrative costs and lower financial charges at the Partnership level.

Equity income from Northern Border was $67.3 million in 2010, an increase of $27.0 million compared to 2009. The
increase in equity income was primarily due to increased transmission revenues and reduced financial charges, partially
offset by higher operating expenses. Northern Border’s transmission revenues increased $45.9 million in 2010 compared
to 2009 primarily due to increased demand for transportation services on Northern Border. Financial charges decreased
$11.0 million in 2010 compared to 2009 primarily due to lower effective interest rates and lower average debt
outstanding.

Equity income from Great Lakes was $58.7 million in 2010, a decrease of $0.4 million compared to $59.1 million in
2009. The decrease in equity income was primarily due to decreased transmission revenues, partially offset by
depreciation rate reductions from the GL Settlement and lower operating expenses. Great Lakes’ transmission revenues
in 2010 decreased $27.3 million compared to 2009 due to the impact of the GL Settlement rates on long-term
revenues and decreased sales of short-term capacity. Operating expenses decreased $7.3 million in 2010 compared to
2009 primarily due to lower maintenance costs.

44

TC PIPELINES, LP

Net income prior to recast from Other Pipes, which includes results from North Baja and Tuscarora, was $36.9 million in
2010, an increase of $8.9 million compared to 2009. This increase was primarily due to the $8.3 million contribution to
net income from North Baja for a full year in 2010 compared to six months in 2009.

Costs at the Partnership level decreased $3.8 million to $25.8 million in 2010 compared to 2009. The decrease was
primarily due to costs incurred in 2009 relating to the North Baja acquisition and Incentive Distribution Rights (IDRs)
restructuring, along with lower financial charges in 2010 resulting from lower average debt outstanding.

Year Ended December 31, 2009 Compared with the Year Ended December 31, 2008
Net income decreased $16.9 million to $106.1 million in 2009 compared to $123.0 million in 2008. Excluding the
contribution from North Baja prior to the acquisition, net income prior to recast decreased $9.9 million to $97.8 million
in 2009 compared to $107.7 million in 2008. This decrease was primarily due to lower equity income from Northern
Border, partially offset by the contribution from North Baja since the acquisition. North Baja contributed $11.6 million to
the Partnership’s net income subsequent to its acquisition on July 1, 2009.

Equity income from Northern Border was $40.3 million in 2009, a decrease of $25.0 million compared to 2008. A
portion of this decrease in equity income was due to the Partnership’s $8.1 million share of Northern Border’s gain
recorded on the sale of Bison in 2008. Excluding the gain, Northern Border’s 2009 net income decreased $33.9 million
compared to 2008 primarily due to decreased transmission revenues, partially offset by lower operating expenses and
financial charges. Northern Border’s transmission revenues decreased $43.9 million due to reductions in contracted
capacity compared to 2008. In 2009, demand for Northern Border’s transportation services, and therefore ability to
contract capacity, continued to be negatively impacted by increased U.S. natural gas supplies being transported to the
Midwestern and Eastern markets from new U.S. supply sources, including the Rockies Basin and southern shale gas,
which displaced demand for natural gas from traditional natural gas sources including the WCSB. Reduced overall
demand for natural gas related to the economic environment also affected demand for Northern Border’s
transportation. Operating expenses decreased $7.2 million in 2009 compared to 2008 primarily due to decreased
property taxes and lower general and administrative costs. Excluding the gain recorded on the sale of Bison in 2008,
financial charges and other decreased $3.5 million in 2009 compared to 2008 primarily due to lower interest rates and
average debt outstanding.

Net income from Other Pipes, which includes results from North Baja and Tuscarora, was $36.3 million in 2009, an
increase of $6.0 million compared to 2008. Excluding the contribution from North Baja prior to the acquisition, net
income from Other Pipes, prior to recast, was $28.0 million, an increase of $13.0 million. This increase was primarily
due to the acquisition of North Baja which contributed $11.6 million to net income in 2009, as well as increased
transmission revenues from a full year of operation of Tuscarora’s Likely compressor station expansion that went into
service in April 2008.

Equity income from Great Lakes was $59.1 million in 2009, an increase of $1.8 million compared to $57.3 million in
2008. The increase in equity income was primarily due to increased transmission revenues and decreased operating
expenses. Transmission revenues increased primarily due to increased sales of short-term services, partially offset by
decreased reservation revenues resulting from re-negotiation of contracts at lower rates and non-renewal of services.
Operating expenses decreased primarily due to lower compressor fuel use tax, lower property taxes and lower transition
costs. These decreases in operating expenses were offset by increased repairs and overhauls.

Costs at the Partnership level were $29.6 million in 2009, a decrease of $0.3 million compared to 2008. This decrease
was primarily due to lower financial charges and other, partially offset by increased operating expenses. The decrease in
financial charges and other was a result of lower interest rates, partially offset by higher average debt outstanding and
losses on interest rate derivatives. Operating expenses increased primarily due to transaction costs relating to the North
Baja acquisition and the concurrent IDR restructuring.

2010 ANNUAL REPORT

45

PARTNERSHIP CASH FLOWS

The Partnership uses the non-GAAP financial measures ‘‘Partnership cash flows’’ and ‘‘Partnership cash flows before
General Partner distributions’’ as they provide a measure of cash generated during the period to evaluate our cash
distribution capability. As well, management uses these measures as a basis for recommendations to our General
Partner’s board of directors regarding the distribution amount to be declared each quarter. Partnership cash flow
information is presented to enhance investors’ understanding of the way that management analyzes the Partnership’s
financial performance.

The Partnership calculates Partnership cash flows as net income, less North Baja’s net income contribution prior to
acquisition, plus operating cash flows from the Partnership’s wholly-owned subsidiaries, North Baja and Tuscarora, and
cash distributions received in excess of equity income from the Partnership’s equity investments, Great Lakes and
Northern Border, net of distributions declared to the General Partner. Partnership cash flows before General Partner
distributions represent Partnership cash flows prior to distributions declared to the General Partner.

Partnership cash flows and Partnership cash flows before General Partner distributions are provided as a supplement to
GAAP financial results and are not meant to be considered in isolation or as substitutes for financial results prepared in
accordance with GAAP.

Non-GAAP Measures
Reconciliations of Net Income to Net Income Prior to Recast and Partnership Cash Flows

Year Ended December 31
(millions of dollars except per common unit amounts)

Net income(a)
North Baja’s contribution prior to acquisition(a)

Net income prior to recast

Add:
Cash distributions from Great Lakes(b)
Cash distributions from Northern Border(b)
Cash flows provided by North Baja’s operating activities
Cash flows provided by Tuscarora’s operating activities

Less:
Equity income from investment in Great Lakes
Equity income from investment in Northern Border
North Baja’s net income
Tuscarora’s net income

Partnership cash flows before General Partner distributions
General Partner distributions(c)

Partnership cash flows

Cash distributions declared
Cash distributions declared per common unit(d)
Cash distributions paid
Cash distributions paid per common unit(d)

2010

137.1
–

137.1

69.2
86.0
29.6
23.9

208.7

(58.7)
(67.3)
(20.7)
(16.2)

(162.9)

182.9
(2.8)

180.1

(139.6)
$2.960
(138.7)
$2.940

2009

106.1
(8.3)

97.8

72.5
75.7
15.7
23.7

187.6

(59.1)
(40.3)
(11.6)
(16.4)

(127.4)

158.0
(7.8)

150.2

(123.6)
$2.895
(117.0)
$2.870

2008

123.0
(15.3)

107.7

73.9
90.7
–
21.5

186.1

(57.3)
(65.3)
–
(15.0)

(137.6)

156.2
(12.7)

143.5

(110.8)
$2.815
(108.6)
$2.775

(a) The acquisition of North Baja from TransCanada was accounted for as a transaction between entities under common control, similar to a
pooling of interests, whereby the assets and liabilities of North Baja were recorded at TransCanada’s carrying value and the Partnership’s
historical financial information was recast to include North Baja for all periods presented on a consolidated basis.

46

TC PIPELINES, LP

(b)

In accordance with the cash distribution policies of the respective pipeline systems, cash distributions from Great Lakes and Northern
Border are based on their respective prior quarter financial results, except that the distribution paid by Northern Border in the third
quarter of 2008 included a special distribution of $16.4 million (Partnership share – $8.2 million) related to the sale of Bison.

(c) General Partner distributions represent the cash distributions declared to the General Partner with respect to its two percent interest plus
an amount equal to incentive distributions. Prior to 2009, General Partner distributions were based on the cash distributions paid during
the quarter to the General Partner. As a result of the retrospective application of Accounting Standards Codification 260-10-55, General
Partner distributions for the year ended December 31, 2008 increased from $11.8 million to $12.7 million.

(d) Cash distributions declared per common unit and cash distributions paid per common unit are computed by dividing cash distributions,
after the deduction of the General Partner’s allocation, by the number of common units outstanding. The General Partner’s allocation is
computed based upon the General Partner’s two percent interest plus an amount equal to incentive distributions.

Year Ended December 31, 2010 Compared with the Year Ended December 31, 2009
Partnership cash flows increased $29.9 million to $180.1 million in 2010 compared to $150.2 million in 2009. This
increase was primarily due to an additional six months of operating cash flows in the amount of $13.9 million from
North Baja, which was acquired July 1, 2009, as well as an increase in cash distributions from Northern Border of
$10.3 million and a decrease of $5.0 million in General Partner distributions resulting from the IDR restructuring on
July 1, 2009. Additionally, Partnership general and administrative costs were lower in 2010 due to costs incurred in
2009 relating to the North Baja acquisition and IDR restructuring. These positive factors were partially offset by
decreased cash distributions from Great Lakes of $3.3 million.

The Partnership paid distributions of $138.7 million in 2010, an increase of $21.7 million compared to 2009, due to an
increase in the number of common units outstanding and an increase in the distribution of $0.02 per common unit in
the third quarter 2010.

Year Ended December 31, 2009 Compared with the Year Ended December 31, 2008
Partnership cash flows increased $6.7 million to $150.2 million in 2009 compared to $143.5 million in 2008. This
increase was primarily due to $15.7 million of cash flows provided by North Baja’s operating activities since the
Partnership’s July 1, 2009 acquisition, a decrease of $4.9 million in General Partner distributions resulting from the IDR
restructuring on July 1, 2009 and an increase of cash flows provided by Tuscarora’s operating activities of $2.2 million.
These positive factors were partially offset by decreased cash distributions from Northern Border of $15.0 million.
Northern Border’s decreased cash distributions were due to a special one-time $8.2 million distribution for the proceeds
received in connection with the sale of Bison in 2008 and lower net income in 2009 as compared to 2008, partially
offset by a reduction in maintenance capital expenditures.

The Partnership paid distributions of $117.0 million in 2009, an increase of $8.4 million compared to 2008 due to an
increase in the number of common units outstanding, in addition to increases in quarterly per common unit distribution
amounts.

Other Cash Flows
In 2010, North Baja and Tuscarora made capital expenditures of $9.3 million, of which the majority was spent on the
acquisition of the Yuma Lateral expansion facilities and contracts in place on March 5, 2010, for a purchase price of
$7.6 million. The Yuma Lateral was placed into service on March 13, 2010. Also in 2010, the Partnership made an
equity contribution of $9.3 million to Great Lakes of which $4.7 million was used by Great Lakes to fund debt
repayments and $4.6 million was used by Great Lakes to fund capital expenditures.

On July 1, 2009, the Partnership acquired North Baja with proceeds from equity issuances of $80.0 million, including
the General Partner’s contribution to maintain its two percent interest, a $170.0 million draw on its revolving credit
facility and cash on hand. In 2009, the Partnership made equity contributions to Northern Border totaling $42.3 million
to partially fund the repayment of Northern Border’s $200.0 million of debt which matured on September 1, 2009 and
to complete the Des Plaines Project. In the fourth quarter of 2009, net proceeds from equity issuances of
$185.5 million, including the General Partner’s contribution to maintain its two percent interest, were used to repay
long-term debt outstanding on the Partnership’s revolving portion of its senior credit facility.

2010 ANNUAL REPORT

47

In 2008, Tuscarora made capital expenditures of $6.8 million that related primarily to the Likely compressor station
expansion.

LIQUIDITY AND CAPITAL RESOURCES OF TC PIPELINES, LP

Overview

Our principal sources of liquidity include distributions received from our investments in Great Lakes and Northern
Border, operating cash flows from North Baja and Tuscarora and our bank credit facility. The Partnership funds its
operating expenses, debt service and cash distributions primarily with operating cash flow. Long-term capital needs may
be met through the issuance of long-term debt and/or equity.

Summary of the Partnership’s Contractual Obligations

The Partnership’s contractual obligations as at December 31, 2010 included the following:

(millions of dollars)

Senior Credit Facility due 2011
6.89% Series C Senior Notes due 2012
3.82% Series D Senior Notes due 2017
Interest payments on Senior Credit Facility(a)
Interest payments on Senior Notes
Fair value of derivative contracts(b)
Operating leases

Payments Due by Period

Less than
1 Year

1-3 Years

3-5 Years

More than
5 Years

483.0
0.8
–
16.7
1.3
13.8
0.2

515.8

–
3.1
7.1
–
3.2
–
0.5

13.9

–
–
11.2
–
2.3
–
0.4

13.9

–
–
12.3
–
0.3
–
3.0

15.6

Total

483.0
3.9
27.0
16.7
6.1
13.8
3.9

554.4

(a)

Interest payments on Senior Credit Facility include the hedging effect of the derivative financial instruments placed on all of the
outstanding debt. Refer to the Interest Rate Swaps and Options section below for details of the hedges. The weighted average interest
rate incurred for the year ended December 31, 2010 of 0.91 percent was used to calculate interest payments for all unhedged debt. The
interest payment calculation assumes no principal repayments until maturity.

(b) The anticipated timing of settlement of the fair value of derivative contracts assumes no changes in interest rates from

December 31, 2010.

Yuma Lateral
The North Baja Acquisition Agreement provided that the Partnership make an additional payment of up to $2.4 million
to TransCanada in the event that any other shippers contracted for services on the Yuma Lateral before June 30, 2010.
A potential shipper signed a precedent agreement with North Baja on June 29, 2010 to enter into agreements for
service on the Yuma Lateral. Accordingly, an amendment to the Acquisition Agreement between the Partnership and
TransCanada was entered into on June 29, 2010 to allow TransCanada to continue to pursue additional contracts until
December 31, 2010. On July 28, 2010, TransCanada secured additional contracts and, as a result, an additional
payment of up to $2.4 million will be paid to TransCanada when the facilities associated with the additional contracts
go into service which is anticipated in first quarter 2011.

The Partnership’s Debt and Credit Facilities
The Partnership’s Senior Credit Facility consists of a $475.0 million senior term loan and a $250.0 million senior
revolving credit facility with a banking syndicate. At December 31, 2010, $475.0 million remained outstanding under

48

TC PIPELINES, LP

the senior term loan (2009 – $475.0 million) and $8.0 million was outstanding under the senior revolving credit facility
(2009 – $9.0 million), leaving $242.0 million available for future borrowings.

The Senior Credit Facility matures on December 12, 2011, subject to two one-year extensions at the option of the
Partnership and with the approval of a majority of the lenders thereunder. Amounts borrowed may be repaid in part, or
in full, prior to that time without penalty. However, once a senior term loan is repaid, it cannot be re-borrowed.
Borrowings under the Senior Credit Facility bear interest based, at the Partnership’s election, on the London Interbank
Offered Rate (LIBOR) or the prime rate plus, in either case, an applicable margin. There was $483.0 million outstanding
under the Senior Credit Facility at December 31, 2010 (2009 – $484.0 million). The interest rate on the Senior Credit
Facility averaged 0.91 percent for the year ended December 31, 2010 (2009 – 1.42 percent). After hedging activity, the
interest rate incurred on the Senior Credit Facility averaged 4.30 percent for the year ended December 31, 2010
(2009 – 4.10 percent). Prior to hedging activities, the interest rate was 0.83 percent at December 31, 2010 (2009 –
0.97 percent). The Partnership expects to renew its Senior Credit Facility in 2011 at market rates.

The Senior Credit Facility requires the Partnership to maintain a leverage ratio (debt to adjusted cash flow (net income
plus cash distributions received, extraordinary losses, interest expense, expense for taxes paid or accrued, depreciation
and amortization less equity earnings and extraordinary gains)) of no more than 4.75 to 1.00 at the end of any fiscal
quarter. The permitted leverage ratio will increase to 5.50 to 1.00 for the first three fiscal reporting periods during any
12-month period immediately following the consummation of specified material acquisitions. At December 31, 2010,
the Partnership was in compliance with all of its financial covenants, in addition to the other covenants which include
restrictions on entering into mergers, consolidations and sales of assets, granting liens, material amendments to the
Partnership Agreement, incurring additional debt and distributions to unitholders.

On April 22, 2010, the Partnership filed an automatic universal shelf registration statement on Form S-3 (ASR) with the
SEC, which replaced an existing shelf registration statement. The ASR allows the Partnership to issue an indeterminate
amount of securities of the Partnership, including both senior and subordinated debt securities and/or common units
representing limited partnership interests in the Partnership. The ASR expires April 22, 2013.

On December 21, 2010, Tuscarora’s Series A and B Senior Notes matured. Also on December 21, 2010, Tuscarora issued
$27.0 million of 3.82 percent Series D Senior Notes, which require principal and interest payments over approximately
seven years. The Series D Senior Notes mature on August 21, 2017. Series C and D Senior Notes are secured by
Tuscarora’s transportation contracts, supporting agreements and substantially all of Tuscarora’s property. The note
purchase agreements contain certain provisions that include, among other items, limitations on additional indebtedness
and distributions to partners.

The fair value of the Partnership’s long-term debt is estimated by discounting the future cash flows of each instrument
at estimated current borrowing rates. The estimated fair value of the Partnership’s long-term debt at December 31,
2010 was $513.9 million (2009 – $544.7 million). As at February 25, 2011, the Partnership had no outstanding
borrowings under the $250.0 million revolving portion of the Senior Credit Facility, which expires on
December 12, 2011.

Interest Rate Swaps and Options
The Partnership’s long-term debt results in exposures to changing interest rates. The Partnership uses derivatives to assist
in managing its exposure to interest rate risk.

The interest rate swaps and options are structured such that the cash flows match those of the Senior Credit Facility.
The notional amount hedged was $375.0 million at December 31, 2010 (2009 – $375.0 million). $300.0 million of
variable-rate debt is hedged by an interest rate swap through December 12, 2011, where the weighted average fixed
interest rate paid is 4.89 percent. $75.0 million of variable-rate debt is hedged by an interest rate swap through
February 28, 2011, where the fixed interest rate paid is 3.86 percent. In addition to these fixed rates, the Partnership
pays an applicable margin in accordance with the Senior Credit Facility agreement.

2010 ANNUAL REPORT

49

Financial instruments are recorded at fair value on a recurring basis and are categorized into one of three categories
based upon a fair value hierarchy. The Partnership has classified all of its derivative financial instruments as Level II for
all periods presented where the fair value is determined by using valuation techniques that refer to observable market
data or estimated market prices. At December 31, 2010, the fair value of the interest rate swaps accounted for as
hedges was negative $13.8 million (2009 – negative $23.8 million), of which $13.8 million is classified as a current
liability (2009 – $12.9 million). The fair value of the interest rate swaps was calculated using the year end interest rate;
therefore, it is expected that this fair value will fluctuate in the future as interest rates change. In 2010, the Partnership
recorded interest expense of $16.5 million on the interest rate swaps and options (2009 – $15.1 million; 2008 –
$6.9 million).

Capital Requirements

The Partnership made an equity contribution of $4.6 million to Great Lakes in 2010. This amount represents the
Partnership’s 46.45 percent share of a $10.0 million cash call issued by Great Lakes to expand backhaul capacity from
St. Clair, Michigan to Emerson, Manitoba, Canada. The Partnership also made an equity contribution of $4.7 million to
Great Lakes in 2010, which represents the Partnership’s 46.45 percent share of a $10.0 million cash call from Great
Lakes to make a scheduled debt repayment and is the result of a change in Great Lakes’ distribution policy in 2010,
whereby Great Lakes commenced funding its debt repayments with cash calls to its partners and making distributions
to its partners before deducting amounts for debt repayments. The Partnership is expected to make equity contributions
totaling $8.8 million to Great Lakes in 2011 for scheduled debt repayments.

Northern Border’s distribution policy adopted in 2006 defines minimum equity to total capitalization to be used by its
management committee to establish the timing and amount of required equity contributions. In accordance with this
policy, Northern Border did not require any contributions from its partners in 2010. In the third quarter of 2009,
Northern Border required an equity contribution of $76.0 million, of which the Partnership’s share was $38.0 million, to
partially fund the repayment of $200.0 million of debt which matured on September 1, 2009. The Partnership financed
this equity contribution with a combination of debt and operating cash flows. In the first quarter of 2009, the
Partnership made an equity contribution of $4.3 million to Northern Border, representing the Partnership’s 50 percent
share of an $8.6 million cash call issued by Northern Border to complete the Des Plaines Project. The Partnership
expects to make a required equity contribution of $54 million to Northern Border in 2011 in accordance with Northern
Border’s distribution policy and an equity contribution of approximately $4.5 million to fund capital expenditures related
to the Princeton Lateral Project.

Cash Distribution Policy of the Partnership

The following table illustrates the percentage allocations of available cash from operating surplus between the common
unitholders and our General Partner based on the specified target distribution levels. The percentage interests set forth
below for our General Partner include its two percent general partner interest and IDRs, and assume our General
Partner has contributed any additional capital necessary to maintain its two percent general partner interest. The
distribution to the General Partner illustrated below, other than in its capacity as a holder of 5,797,106 common units
that are in excess of its aggregate two percent general partner interest, represents the IDRs.

Minimum Quarterly Distribution
First Target Distribution
Second Target Distribution
Thereafter

Marginal Percentage
Interest in Distribution

Total Quarterly Distribution
per Unit Target Amount

Common
Unitholders

$0.45
above $0.45 up to $0.81
above $0.81 up to $0.88
above $0.88

98%
98%
85%
75%

General
Partner

2%
2%
15%
25%

50

TC PIPELINES, LP

On July 1, 2009, in conjunction with the North Baja acquisition, the Partnership amended the IDRs held by the General
Partner to eliminate the 50 percent distribution threshold and replaced it with a new maximum distribution threshold of
25 percent (for combined general partner interest and incentive distribution interest).

2010 Fourth Quarter Cash Distribution

On January 18, 2011, the board of directors of our General Partner declared the Partnership’s fourth quarter 2010 cash
distribution in the amount of $0.75 per common unit. The fourth quarter cash distribution, which was paid on
February 14, 2011 to unitholders of record as of January 31, 2011, totaled $35.4 million and was paid in the following
manner: $34.7 million to common unitholders (including $4.3 million to the General Partner as holder of
5,797,106 common units and $8.5 million to TransCanada as holder of 11,287,725 common units) and $0.7 million to
the General Partner in respect of its two percent general partner interest. The fourth quarter 2010 cash distribution
amount represents an annualized cash distribution of $3.00 per common unit.

LIQUIDITY AND CAPITAL RESOURCES OF OUR PIPELINE SYSTEMS

Overview

Our pipeline systems’ principal sources of liquidity are cash generated from operating activities, bank credit facilities and
equity contributions from their partners. Our pipeline systems have historically funded operating expenses, debt service
and cash distributions to partners primarily with operating cash flow. However, in fourth quarter 2010, Great Lakes
started funding its debt repayments with cash calls to its partners.

Capital expenditures are funded by a variety of sources, including cash generated from operating activities, borrowings
under bank credit facilities, issuance of senior unsecured notes or equity contributions from our pipeline systems’
partners. The ability of our pipeline systems to access the debt capital markets under reasonable terms depends on their
financial position and general market conditions.

We believe that our pipeline systems’ ability to obtain financing at reasonable rates, together with their history of
consistent cash flow from operating activities, provide a solid foundation to meet their future liquidity and capital
resource requirements. The Partnership’s pipeline systems monitor the creditworthiness of their customers and have
credit provisions included in their tariffs, which allow them to request credit support as circumstances dictate.

Summary of Great Lakes’ Contractual Obligations

Great Lakes’ contractual obligations related to debt as at December 31, 2010 included the following:

(millions of dollars)

8.74% series Senior Notes due 2011
6.73% series Senior Notes due 2011 to 2018
9.09% series Senior Notes due 2012 to 2021
6.95% series Senior Notes due 2019 to 2028
8.08% series Senior Notes due 2021 to 2030
Interest payments on debt

Payments Due by Period

Total

10.0
72.0
100.0
110.0
100.0
291.5

683.5

Less than
1 Year

1-3 Years

3-5 Years

More than
5 Years

10.0
9.0
–
–
–
29.9

48.9

–
27.0
30.0
–
–
80.7

–
27.0
30.0
–
–
71.7

137.7

128.7

–
18.0
50.0
110.0
100.0
134.6

412.6

2010 ANNUAL REPORT

51

Long-Term Financing
All of Great Lakes’ outstanding debt securities are senior unsecured notes with similar terms except for interest rates,
maturity dates and prepayment premiums.

Great Lakes is required to comply with certain financial, operational and legal covenants. Under the most restrictive
covenants in the Senior Note Agreements, approximately $211.0 million of Great Lakes’ partners’ capital was restricted
as to distributions as at December 31, 2010 (2009 – $221.0 million). Great Lakes was in compliance with all of its
financial covenants at December 31, 2010.

The aggregate estimated fair value of Great Lakes’ long-term debt was $518.2 million for 2010 (2009 – $506.2 million).
The aggregate annual required repayment of senior notes is $19.0 million for each year 2011 through 2015. In 2010,
interest expense related to Great Lakes’ senior notes was $31.4 million (2009 – $32.9 million; 2008 – $34.2 million).

Other
Great Lakes has a cash management agreement with TransCanada whereby Great Lakes’ funds are pooled with other
TransCanada affiliates. The agreement also gives Great Lakes the ability to obtain short-term borrowings to provide
liquidity for Great Lakes’ operating needs.

Summary of Northern Border’s Contractual Obligations

Northern Border’s contractual obligations related to debt, operating leases and other long-term obligations as at
December 31, 2010, included the following:

(millions of dollars)

6.24% Senior Notes due 2016
7.50% Senior Notes due 2021
$250 million Credit Agreement due 2012
Interest payments on debt
Operating leases
Other long-term obligations

Payments Due by Period

Less than
1 Year

1-3 Years

3-5 Years

More than
5 Years

–
–
–
26.0
1.9
1.1

29.0

–
–
191.0
75.3
5.7
–

272.0

–
–
–
72.9
6.0
–

78.9

100.0
250.0
–
93.8
53.2
–

497.0

Total

100.0
250.0
191.0
243.0
64.9
1.1

850.0

Interest Payments on Credit Agreement
The interest rate at December 31, 2010 of 0.54 percent was used to calculate the interest payments on the Credit
Agreement. The interest payment calculation assumes no principal repayments until maturity.

Operating Leases
Northern Border is required to make future minimum payments for office space and rights-of-way under non-cancelable
operating leases.

Other
Northern Border is required to pay $3.6 million over a five year period ending in 2011 under a transition services
agreement between ONEOK Partners GP, LLC (ONEOK Partners GP) and TransCanada, related to the reimbursement for
shared assets acquired by ONEOK Partners to support the operations of Northern Border.

In connection with the Princeton Lateral Project, Northern Border has commitments of $0.3 million at
December 31, 2010.

52

TC PIPELINES, LP

Credit Agreement
Northern Border has a $250.0 million revolving Credit Agreement with certain financial institutions. The Credit
Agreement can be used to finance permitted acquisitions, pay related fees and expenses, issue letters of credit and
provide for ongoing working capital needs and for other general business purposes, including capital expenditures. At
December 31, 2010, $191.0 million was outstanding (2009 – $215.0 million) leaving $59.0 million available for future
borrowings. Northern Border may, at its option, so long as no default or event of default has occurred and is
continuing, elect to increase the capacity under its Credit Agreement by an aggregate amount not to exceed
$100.0 million, provided that lenders are willing to commit additional amounts. At Northern Border’s option, the
interest rate on the outstanding borrowings may be the lenders’ base rate or the LIBOR plus an applicable margin that
is based on its long-term unsecured credit ratings. The Credit Agreement permits Northern Border to specify the portion
of the borrowings to be covered by specific interest rate options and to specify the interest rate period. The term of the
agreement is five years, with options for two one-year extensions.

Northern Border’s long-term debt arrangements contain covenants that restrict the incurrence of secured indebtedness
or liens upon property by Northern Border. Under the Credit Agreement, Northern Border is required to comply with
certain financial, operational and legal covenants. Among other things, Northern Border is required to maintain a
leverage ratio (total debt to EBITDA (net income plus interest expense, income taxes, depreciation and amortization and
all other non-cash charges)) of no more than 4.75 to 1. Pursuant to the Credit Agreement, if one or more specified
material acquisitions are consummated, the permitted leverage ratio is increased to 5.50 to 1 for the first three full
calendar quarters following the acquisition. At December 31, 2010, Northern Border was in compliance with all of its
financial covenants.

The fair value of Northern Border’s variable-rate debt was approximately the carrying value since the interest rates are
periodically adjusted to reflect current market conditions. The average interest rate on Northern Border’s Credit
Agreement at December 31, 2010 was 0.54 percent (2009 – 0.52 percent).

Interest Rate Collar Agreement
In 2007, Northern Border entered into a zero cost interest rate collar agreement (Collar Agreement) to limit the
variability of the interest rate on $140.0 million of variable-rate borrowings through October 30, 2009 to a range
between a floor of 4.35 percent and a cap of 5.36 percent. Northern Border designated the Collar Agreement as a
cash flow hedge. At December 31, 2009, Northern Border’s balance sheet reflected no unrealized loss and no change in
its accumulated other comprehensive loss related to the changes in fair value of the Collar Agreement since inception.
In 2009, Northern Border recorded interest expense of $3.8 million under the Collar Agreement (2008 – $1.7 million).
The hedge was effective for the years ended December 31, 2009 and 2008; therefore, it had no impact on income due
to hedge ineffectiveness.

Long-Term Financing – Debt Securities
Northern Border periodically issues long-term debt securities to meet its capital resource requirements. All of Northern
Border’s outstanding debt securities are senior unsecured notes with similar terms except for interest rates, maturity
dates and prepayment premiums. The indentures of the notes do not limit the amount of unsecured debt Northern
Border may incur, but do restrict secured indebtedness.

Under the $100.0 million of 6.24 percent Senior Notes, Northern Border may not at any time permit debt secured by
liens to exceed 20 percent of partners’ capital and may not permit total debt, at any time, to exceed 70 percent of
total capitalization. At December 31, 2010, Northern Border was in compliance with all of its financial covenants.

Northern Border’s Senior Notes issuances of $100.0 million due in 2016 and $250.0 million due in 2021 are borrowed
at fixed interest rates of 6.24 percent and 7.50 percent, respectively. Northern Border intends to maintain the current
schedule of maturities, which will result in no gains or losses on their respective repayments. At December 31, 2010,
the aggregate fair value of the outstanding senior notes was approximately $599.0 million (2009 – $397.0 million). In
2010, interest expense related to the senior notes was $25.0 million (2009 – $31.3 million; 2008 – $34.3 million).

2010 ANNUAL REPORT

53

CASH FROM OUR PIPELINE SYSTEMS

Cash Distribution Policies of Great Lakes and Northern Border

Distributions to partners are made on a pro rata basis according to each general partner’s ownership percentage,
approximately one month following the end of a quarter. Great Lakes’ and Northern Border’s respective management
committees determine the amounts and timing of cash distributions, where the amounts of such distributions are based
on available cash flow as determined by a prescribed formula. Any changes to, or suspension of, Great Lakes’ or
Northern Border’s cash distribution policy requires the unanimous approval of their respective management committee.

Great Lakes’ distribution policy is to distribute 100 percent of distributable cash flow based generally on earnings before
current income taxes and depreciation less capacity capital expenditures. This defined formula is subject to management
committee approval and can be modified to ensure minimum cash balances, equity balances and ratios are maintained.
In fourth quarter 2010, Great Lakes changed their distribution policy. Previous to fourth quarter 2010, distributable cash
flows included deductions for debt repayments. Great Lakes will now, at the option of its partners, fund its debt
repayments with equity contributions from its partners.

Northern Border’s distribution policy is to distribute 100 percent of the distributable cash flow based on earnings before
interest, taxes, depreciation and amortization less interest expense and maintenance capital expenditures and adopted
certain changes related to equity contributions. The changes defined minimum equity to total capitalization ratios to be
used by the Northern Border management committee to determine the amount of required equity contributions, timing
of the required contributions, and for any shortfall due to the inability to refinance maturing debt to be funded by
equity contributions.

On February 1, 2011, a cash distribution of $36.3 million was declared and paid by Great Lakes for the fourth quarter
of 2010, of which the Partnership’s 46.45 percent share was $16.9 million. On February 1, 2011, a cash distribution of
$51.5 million was declared and paid by Northern Border for the fourth quarter of 2010, of which the Partnership’s
50 percent share was $25.8 million.

Investing Activities for our Pipeline Systems

Capital spending for maintenance of existing facilities and growth projects were as follows for each of our investments:

Year Ended December 31 

(millions of dollars)

2010

2009

2008

Great Lakes:

Maintenance
Growth

Great Lakes’ capital spending

Northern Border:
Maintenance
Growth

Northern Border’s capital spending

North Baja:

Maintenance
Growth

North Baja’s capital spending

Tuscarora:

Maintenance
Growth

Tuscarora’s capital spending

8.0
6.0

14.0

5.4
4.5

9.9

0.2
8.9

9.1

0.2
–

0.2

5.9
2.6

8.5

6.7
4.4

11.1

0.3
0.8

1.1

0.2
0.6

0.8

12.3
–

12.3

8.4
12.1

20.5

12.8
15.0

27.8

0.1
6.7

6.8

54

TC PIPELINES, LP

Our pipeline systems fund their investing activities primarily with operating cash, issuances of new debt or additional
borrowings under existing facilities. Great Lakes and Northern Border may also fund their investing activities with equity
contributions from their general partners.

Great Lakes incurred $6.0 million and $2.6 million in growth capital expenditures in 2010 and 2009, respectively,
primarily related to an expansion project involving upgrades to facilities to increase system capabilities to provide firm
transportation services from St. Clair, Michigan to Emerson, Manitoba, Canada. The remaining expenditures of Great
Lakes in 2010 through 2008 of $8.0 million, $5.9 million and $12.3 million, respectively, were comprised of
maintenance capital projects including compressor engine overhauls and pipeline integrity program costs. In 2011, Great
Lakes expects to invest approximately $14.1 million for maintenance capital expenditures, of which the Partnership’s
share is $6.5 million. No significant growth capital expenditures are planned for 2011.

Northern Border incurred growth capital expenditures of $4.5 million in 2010 primarily related to the Princeton Lateral
Project, while growth expenditures of $4.4 million in 2009 and $12.1 million in 2008 were primarily related to spending
for the Des Plaines Project. The maintenance capital expenditures of Northern Border in 2010 through 2008 of
$5.4 million, $6.7 million and $8.4 million, respectively, are comprised of maintenance capital projects including
compressor engine overhauls. In 2011, Northern Border Pipeline expects to spend approximately $28.9 million for
capital expenditures, of which the Partnership’s share is $14.5 million. The Partnership’s share of maintenance capital
expenditures are estimated at $7.1 million and include renewals and replacements of existing facilities. In 2011,
Northern Border expects to spend approximately $14.5 million for growth capital expenditures related to the Princeton
Lateral Project, of which the Partnership expects to contribute $4.5 million.

In 2010, North Baja incurred $9.1 million of capital expenditures primarily related to the Yuma Lateral Project and
routine pipeline maintenance and integrity costs. In 2009, North Baja capital expenditures of $1.1 related to minor
growth projects. In 2011, North Baja expects to spend approximately $0.3 million for capital expenditures, primarily
related to pipe integrity program costs and system pipeline improvements. Excluding an additional payment of up to
$2.4 million for the Yuma Lateral, no significant growth capital expenditures are planned for 2011.

In 2010, Tuscarora incurred $0.2 million of capital expenditures primarily related to the replacement of meter station
regulators and batteries. Tuscarora’s 2009 and 2008 capital expenditures of $0.8 million and $6.8 million, respectively,
related to the replacement of electric system components at various compressor stations and to the Likely compressor
station expansion. In 2011, Tuscarora expects to spend approximately $0.6 million for maintenance capital expenditures,
primarily related to pipe integrity program costs and system pipeline improvements. No significant growth capital
expenditures are planned for 2011.

Critical Accounting Policies and Estimates

The preparation of financial statements in accordance with GAAP requires us to make estimates and assumptions with
respect to values or conditions which cannot be known with certainty, that affect the reported amount of assets and
liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements. Such estimates
and assumptions also affect the reported amounts of revenue and expenses during the reporting period. Although we
believe these estimates and assumptions are reasonable, actual results could differ. The following summarizes the
Partnership’s and our pipeline systems’ accounting policies and estimates, and should be read in conjunction with
Note 2 of the Partnership’s Financial Statements included elsewhere in this report.

We account for our investments in Great Lakes and Northern Border using the equity method of accounting. The equity
method of accounting is appropriate where the investor does not control an investee, but rather is able to exercise
significant influence over the operating and financial policies of an investee. We are able to exercise significant influence
over our investments in Great Lakes and Northern Border because of our ownership interests and our representation on
the Great Lakes and Northern Border management committees.

We account for our investments in North Baja and Tuscarora using the consolidation method, as we wholly-own
both entities.

2010 ANNUAL REPORT

55

Regulation
Our pipeline systems’ accounting policies conform to Accounting Standards Codification (ASC) 980 – Regulated
Operations. Our pipeline systems consider several factors to evaluate their continued application of the provisions of
ASC 980 such as potential deregulation of their pipelines; anticipated changes from cost-based ratemaking to another
form of regulation; increasing competition that limits their ability to recover costs; and regulatory actions that limit rate
relief to a level insufficient to recover costs.

Certain assets that result from the ratemaking process are reflected on Northern Border’s balance sheet as regulatory
assets. If Northern Border determines future recovery of these assets is no longer probable as a result of discontinuing
application of ASC 980 or other regulatory actions, Northern Border would be required to write off the regulatory
assets at that time. As at December 31, 2010, Northern Border reflected regulatory assets of $20.3 million on its
balance sheet (2009 – $20.1 million). These assets are being amortized as directed by the FERC in Northern Border’s
previous regulatory proceedings over varying remaining time periods up to 40 years.

As at December 31, 2010, Tuscarora has no regulatory assets (2009 – nil) and $0.5 million in regulatory liabilities
(2009 – nil).

As at December 31, 2010 and 2009, Great Lakes and North Baja did not have any regulatory assets or liabilities
recorded on their respective balance sheets.

Contingencies
Our pipeline systems’ accounting for contingencies covers a variety of business activities, including contingencies for
legal and environmental liabilities. Our pipeline systems accrue for these contingencies when their assessments indicate
that it is probable that a liability has been incurred or an asset will not be recovered and an amount can be reasonably
estimated in accordance with ASC 450 – Contingencies. Our pipeline systems base their estimates on currently available
facts and their estimates of the ultimate outcome or resolution. Actual results may differ from our pipeline systems’
estimates resulting in an impact, positive or negative, on earnings and cash flow.

Impairment of Long-Lived Assets and Goodwill
We assess our long-lived assets for impairment based on ASC 360-10-35 Property, Plant, and Equipment – Overall –
Subsequent Measurement whenever events or changes in circumstances indicate that the carrying value may not be
recoverable. If the total of the estimated undiscounted future cash flows is less than the carrying value of the assets, an
impairment loss is recognized for the excess of the carrying value over the fair value of the assets. Fair value is a
market-based measure of the price that would be received to sell an asset or paid to transfer a liability in an orderly
transaction between market participants at the measurement date.

We assess our goodwill for impairment annually, based on ASC 350 – Intangibles – Goodwill and Other, or more
frequently if events or changes in circumstances indicate that the asset might be impaired. An initial assessment is made
by comparing the fair value of the operations with goodwill, as determined in accordance with ASC 350, to the book
value of each operation. If the fair value is less than book value, an impairment is indicated and we must perform a
second test to measure the amount of the impairment. In the second test, we calculate the implied fair value of the
goodwill by deducting the fair value of all tangible and intangible net assets of the operations with goodwill from the
fair value determined in step one of the assessment. If the carrying value of the goodwill exceeds the calculated implied
fair value of the goodwill, an impairment charge is recorded. At December 31, 2010 and 2009, we had $130.2 million
of goodwill recorded on our balance sheet related to the North Baja and Tuscarora acquisitions. No impairment of
goodwill existed at December 31, 2010.

These valuations are based on management’s projections of future cash flows and, therefore, require estimates and
assumptions with respect to:

(cid:127) discount rates;

(cid:127) market supply and demand assumptions;

(cid:127) growth opportunities;

56

TC PIPELINES, LP

(cid:127) competition from other pipelines; and

(cid:127) regulatory changes.

Significant changes in these assumptions could affect our need to record an impairment charge.

CONTINGENCIES

Legal

Various legal actions or governmental proceedings that have arisen in the ordinary course of business are pending. Our
pipeline systems believe that the resolution of these issues will not have a material adverse impact on their results of
operations or financial position. Please read Item 3. ‘‘Legal Proceedings’’ for additional information.

Environmental

We believe that our pipeline systems are in substantial compliance with applicable environmental laws and regulations.
Please read Item 1. ‘‘Business’’ for additional information.

RELATED PARTY TRANSACTIONS

Please read Item 13. ‘‘Certain Relationships and Related Transactions, and Director Independence’’ for information
regarding related party transactions.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk

OVERVIEW

The Partnership and our pipeline systems are also exposed to other risks such as interest rate risk, credit risk, liquidity
risk and foreign exchange fluctuations. Our exposure to market risk discussed below includes forward-looking
statements and is not necessarily indicative of actual results, which may not represent the maximum possible gains and
losses that may occur, since actual gains and losses will differ from those estimated, based on actual market conditions.

Market risk is the risk of loss arising from adverse changes in market rates. Our primary risk management objective is to
protect earnings and cash flow, and ultimately, unitholder value. We do not use financial instruments for trading
purposes.

We record derivative financial instruments on the balance sheet as assets and liabilities at fair value. We estimate the
fair value of derivative financial instruments using available market information and appropriate valuation techniques.
Changes in the fair value of derivative financial instruments are recognized in earnings unless the instrument qualifies as
a hedge and meets specific hedge accounting criteria. Qualifying derivative financial instruments’ gains and losses may
offset the hedged items’ related results in earnings for a fair value hedge or be deferred in accumulated other
comprehensive income for a cash flow hedge.

MARKET RISK AND INTEREST RATE RISK

From time to time, and in order to finance our business and that of our pipeline systems, the Partnership and our
pipeline systems issue debt to invest in growth opportunities and provide for ongoing operations. The issuance of debt
exposes the Partnership and our pipeline systems to market risk from changes in interest rates which affect earnings
and the value of the financial instruments we hold.

2010 ANNUAL REPORT

57

The Partnership and our pipeline systems use derivatives as part of our overall risk management policy to manage
exposures to market risk resulting from these activities within established policies and procedures. Derivative contracts
used to manage market risk generally consist of the following:

(cid:127) Swaps – contractual agreements between two parties to exchange streams of payments over time according to

specified terms. The Partnership and our pipeline systems enter into interest rate swaps to mitigate the impact of
changes in interest rates.

(cid:127) Options – contractual agreements to convey the right, but not the obligation, for the purchaser to buy or sell a
specific amount of a financial instrument at a fixed price, either at a fixed date or at any time within a specified
period. The Partnership and our pipeline systems enter into option agreements to mitigate the impact of changes in
interest rates.

Interest rate risk is created by fluctuations in the fair values or cash flows of financial instruments due to changes in the
market interest rates. Our interest rate exposure results from our Senior Credit Facility, which is subject to variability in
LIBOR interest rates. We regularly assess the impact of interest rate fluctuations on future cash flows and evaluate
hedging opportunities to mitigate our interest rate risk.

Our interest rate swaps and options are structured such that the cash flows match those of the Senior Credit Facility.
The notional amount hedged was $375.0 million at December 31, 2010 (2009 – $375.0 million). $300.0 million of
variable-rate debt is hedged by an interest rate swap through December 12, 2011, where the weighted average fixed
interest rate paid is 4.89 percent. $75.0 million of variable-rate debt is hedged by an interest rate swap through
February 28, 2011, where the fixed interest rate paid is 3.86 percent. In addition to these fixed rates, the Partnership
pays an applicable margin in accordance with the Senior Credit Facility agreement.

At December 31, 2010, the fair value of the interest rate swaps accounted for as hedges was negative $13.8 million
(2009 – negative $23.8 million), of which $13.8 million is classified as a current liability (2009 – $12.9 million). The fair
value of the interest rate swaps was calculated using the year end interest rate; therefore, it is expected that this fair
value will fluctuate over the year as interest rates change. In 2010, the Partnership recorded interest expense of
$16.5 million on the interest rate swaps and options (2009 – $15.1 million; 2008 – $6.9 million).

At December 31, 2010, we had $483.0 million (2009 – $484.0 million) outstanding on our Senior Credit Facility.
Utilizing the conditions of the interest rate swaps, if LIBOR interest rates hypothetically increased by one percent
(100 basis points) compared to the rates in effect at December 31, 2010, our annual interest expense would have
increased and our net income would have decreased by $1.1 million; and if LIBOR interest rates hypothetically
decreased to zero percent compared to the rates in effect at December 31, 2010, our annual interest expense would
have decreased and our net income would have increased by $0.3 million. These amounts have been determined by
considering the impact of the hypothetical interest rates on unhedged debt outstanding as at December 31, 2010.

Northern Border utilizes both fixed-rate and variable-rate debt and is exposed to market risk due to the floating interest
rates on its revolving credit facility. Northern Border regularly assesses the impact of interest rate fluctuations on future
cash flows and evaluates hedging opportunities to mitigate its interest rate risk. As at December 31, 2010, 65 percent
of Northern Border’s outstanding debt was at fixed rates (2009 – 62 percent).

Standard & Poor’s (S&P) issued a report on July 20, 2010 affirming Northern Border’s issuer credit rating at ‘‘A(cid:1)’’ but
revised the outlook to ‘‘negative’’ from ‘‘stable.’’ The negative outlook was based on declining credit metrics, which S&P
believes are largely due to declining cash flows from Northern Border’s firm transportation contracts. S&P will consider
revising the outlook to ‘‘stable’’ if Northern Border is successful in recontracting capacity such that cash flows improve
for a sustained period, or S&P may lower the rating if credit metrics remain weak, which would cause Northern Border’s
interest costs to increase.

If interest rates hypothetically increased by one percent (100 basis points) compared with rates in effect at
December 31, 2010, Northern Border’s annual interest expense would increase and its net income would decrease by
approximately $1.9 million; and if interest rates hypothetically decreased to zero percent compared with rates in effect

58

TC PIPELINES, LP

at December 31, 2010, Northern Border’s annual interest expense would decrease and its net income would increase by
approximately $0.5 million.

Great Lakes and Tuscarora utilize fixed-rate debt; therefore, they are not exposed to market risk due to floating interest
rates. Interest rate risk does not apply to North Baja, as it currently does not have any debt.

OTHER RISKS

The Partnership is influenced by the same factors that influence our pipeline systems. None of our pipeline systems own
any of the natural gas they transport; therefore, they do not assume any of the related natural gas commodity price risk
with respect to transported natural gas volumes.

Counterparty credit risk represents the financial loss that the Partnership and our pipeline systems would experience if a
counterparty to a financial instrument failed to meet its obligations in accordance with the terms and conditions of its
contracts with the Partnership or its pipeline systems. Our maximum counterparty credit exposure with respect to
financial instruments at the balance sheet date consists primarily of the carrying amount, which approximates fair value,
of non-derivative financial assets, such as accounts receivable, as well as the fair value of derivative financial assets. At
December 31, 2010, the Partnership’s maximum counterparty credit exposure consisted of accounts receivable of
$7.6 million (2009 – $7.4 million).

The Partnership and our pipeline systems have significant credit exposure to financial institutions as they provide
committed credit lines and critical liquidity in the interest rate derivative market, as well as letters of credit to mitigate
exposures to non-creditworthy parties. Due to the deterioration of global financial markets in 2008 and 2009, we
continue to closely monitor the creditworthiness of our counterparties, including financial institutions. Overall, we do
not believe the Partnership and our pipeline systems have any significant concentrations of counterparty credit risk.

Liquidity risk is the risk that the Partnership and our pipeline systems will not be able to meet our financial obligations
as they become due. Our approach to managing liquidity risk is to ensure that we always have sufficient cash and credit
facilities to meet our obligations when due, under both normal and stressed conditions, without incurring unacceptable
losses or damage to our reputation. At December 31, 2010, the Partnership had a committed revolving bank line of
$250.0 million maturing in December 2011. As at December 31, 2010, the outstanding balance on this facility was
$8.0 million. In addition, at December 31, 2010, Northern Border had a committed revolving bank line of
$250.0 million maturing in April 2012. As at December 31, 2010, $191.0 million was drawn on this facility.

The Partnership does not have any material foreign exchange risks.

Item 8.

Financial Statements and Supplementary Data

The financial statements required by this item are included in Part IV, Item 15 of this report on page F-1.

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure

None.

Item 9A. Controls and Procedures

EVALUATION OF DISCLOSURE CONTROLS AND PROCEDURES

As required by Rule 13a-15(e) under the Exchange Act, the management of our General Partner, including the principal
executive officer and principal financial officer, evaluated as of the end of the period covered by this report the
effectiveness of our disclosure controls and procedures. There are inherent limitations to the effectiveness of any system
of disclosure controls and procedures, including the possibility of human error and the circumvention or overriding of

2010 ANNUAL REPORT

59

the controls and procedures. The Partnership’s disclosure controls and procedures are designed to provide reasonable
assurance of achieving their objectives. Based upon and as of the date of the evaluation, the management of our
General Partner, including the principal executive officer and principal financial officer, concluded that the Partnership’s
disclosure controls and procedures as of the end of the year covered by this annual report were effective to provide
reasonable assurance that the information required to be disclosed by the Partnership in the reports that it files or
submits under the Securities Exchange Act of 1934, as amended (the ‘‘Exchange Act’’), is (a) recorded, processed,
summarized and reported within the time periods specified in the SEC’s rules and forms and (b) accumulated and
communicated to the management of our General Partner, including the principal executive officer and principal
financial officer, to allow timely decisions regarding required disclosure.

Changes in Internal Control Over Financial Reporting

During the year ended December 31, 2010, there was no change in the Partnership’s internal control over financial
reporting that has materially affected or is reasonably likely to materially affect our internal control over financial
reporting.

MANAGEMENT’S ANNUAL REPORT ON INTERNAL CONTROL OVER FINANCIAL REPORTING

Our management is responsible for establishing and maintaining adequate internal control over financial reporting, as
such term is defined in Rule 13a-15(f) promulgated under the Securities Exchange Act of 1934. Internal control over
financial reporting, no matter how well designed, has inherent limitations and can only provide reasonable assurance
with respect to the preparation and fair presentation of published financial statements. Under the supervision and with
the participation of our management, including our principal executive officer and principal financial officer, we
conducted an evaluation of the effectiveness of our internal control over financial reporting based on the framework in
Internal Control – Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway
Commission.

Based on our assessment according to the above criteria, management has concluded that our internal control over
financial reporting was effective as at December 31, 2010 to provide reasonable assurance regarding the reliability of
financial reporting and the preparation of financial statements for external purposes in accordance with GAAP. There
were no material weaknesses.

Our independent registered public accounting firm, KPMG LLP, independently assessed the effectiveness of the
Partnership’s internal control over financial reporting. KPMG has issued an attestation report concurring with
management’s assessment, which is included on page F-2 of the financial statements included in this Form 10-K.

Item 9B. Other Information

None.

60

TC PIPELINES, LP

Part III

Item 10. Directors, Executive Officers and Corporate Governance

The Partnership is a limited partnership and as such has no officers, directors or employees. Set forth below is certain
information concerning the directors and officers of the General Partner who manage the operations of the Partnership.
Each director holds office for a one-year term or until his or her successor is earlier appointed. All officers of the
General Partner serve at the discretion of the board of directors of the General Partner which is a wholly-owned
subsidiary of TransCanada.

Name

Gregory A. Lohnes
Steven D. Becker
Jack F. Jenkins-Stark
David L. Marshall
Walentin (Val) Mirosh
James M. Baggs
Kristine L. Delkus
Stuart P. Kampel
Stephanie E. Wilson
Terry C. Ofremchuk
Rhonda L. Amundson
Donald J. DeGrandis
Robert C. Jacobucci

Age

Position with General Partner

54
60
60
71
65
49
53
42
43
60
49
62
42

Chairman and Director
President, Principal Executive Officer and Director
Independent Director
Independent Director
Independent Director
Director
Director
Vice-President, Business Development
Vice-President, Commercial
Vice-President, Taxation
Treasurer
Secretary
Controller, Principal Financial Officer

Mr. Lohnes was appointed a director of the General Partner in January 2007 and has served as Chairman of the
General Partner’s board of directors since March 2010. Mr. Lohnes’ principal occupation is President, Natural Gas
Pipelines of TransCanada, a position he has held since July 2010. Prior to July 2010, he was Executive Vice-President
and Chief Financial Officer of TransCanada, a position he held since June 2006. Prior to June 2006, he was President
and Chief Executive Officer of Great Lakes Gas Transmission Company. Mr. Lohnes has extensive senior management
experience in the oil and gas industry as a result of his service as an executive officer for TransCanada and its
subsidiaries. His day-to-day leadership as President, Natural Gas Pipelines of TransCanada and his prior roles as Chief
Financial Officer of the Partnership, Executive Vice-President and Chief Financial Officer of TransCanada and President
and Chief Executive Officer of Great Lakes provide him with an intimate knowledge of the Partnership, including its
strategies, operations, markets and financing requirements. Mr. Lohnes’ business judgment, management experience
and leadership skills are highly valuable in assessing our business strategies and accompanying risks.

Mr. Becker was appointed President of the General Partner in August 2010 and serves as the General Partner’s principal
executive officer. Mr. Becker also serves as a director of the General Partner, a position he has held since January 2007.
Mr. Becker’s principal occupation is Vice-President, Business Development, Natural Gas Pipelines of TransCanada, a
position he has held since August 2010. Mr. Becker was Vice-President, Pipeline Development for TransCanada from
June 2006 to August 2010. From April 2003 to June 2006, he was Vice-President, Gas Development of TransCanada.
As the President of the General Partner and Vice-President, Business Development, Natural Gas Pipelines for
TransCanada, Mr. Becker has intimate knowledge of the Partnership’s pipeline operations, as well as a unique
understanding of market factors and operational challenges and opportunities. Mr. Becker brings extensive project
development and operational experience to the board and his extensive experience in the natural gas industry enhances
the knowledge of the board in these areas of the industry. From his prior roles in finance, natural gas marketing,
strategy and business development at TransCanada, Mr. Becker’s breadth of executive experiences are applicable to
many of the matters routinely facing the Partnership, which assists the board in creating and executing the Partnership’s
strategic plan.

2010 ANNUAL REPORT

61

Mr. Jenkins-Stark was appointed a director of the General Partner in July 1999. Mr. Jenkins-Stark’s principal occupation
is Chief Financial Officer of BrightSource Energy Inc. (designs and builds large scale solar plants that deliver solar energy
in the form of steam and/or electricity), a position he has held since May 2007. Mr. Jenkins-Stark was Chief Financial
Officer of Silicon Valley Bancshares (offering financial products and services, including commercial, investment, merchant
and private banking and private banking and private equity services) from April 2004 to May 2007. Through his current
and prior roles as chief financial officer of numerous companies, Mr. Jenkins-Stark brings valuable financial expertise and
management experience, including extensive knowledge regarding financial operations, investor relations, energy risk
management, regulatory affairs and knowledge of the natural gas industry. Mr. Jenkin-Stark’s prior service on the audit
committee of the board of directors of another company further enhances his qualifications to serve as a member of
our board. His valuable management and financial expertise includes an understanding of the accounting and financial
matters that the Partnership and industry address on a regular basis.

Mr. Marshall was appointed a director of the General Partner in July 1999. Mr. Marshall retired as Chief Financial officer
of The Pittston Company in 1995 and served as Vice Chairman of that company from 1995 to 1998. Mr. Marshall is a
corporate director. As a former chief executive officer and chief financial officer at other public companies, Mr. Marshall
has valuable experience with many functions pertinent to our board, including financing, strategic and operational
matters and the evaluation of acquisition opportunities. Mr. Marshall contributes extensive financial acumen and an
understanding of the oil and gas services industry due to his prior experiences as a chief financial officer and director
and audit committee chairman of other public companies. His valuable management and financial expertise includes an
understanding of the accounting and financial matters that the Partnership and industry address on a regular basis.

Mr. Mirosh was appointed a director of the General Partner in September 2004. Mr. Mirosh’s principal occupation is
President of Mircan Resources Ltd., a private consulting company, a position he has held since 2009. From April 2008 to
December 2009, he was Vice-President and Special Advisor to the President and Chief Operating Officer of NOVA
Chemicals Corporation (a commodity chemicals and plastics company). From July 2003 to April 2008, Mr. Mirosh was
President of Olefins and Feedstocks, a division of NOVA Chemicals Corporation. Mr. Mirosh is also a director of Superior
Plus Income Fund. Mr. Mirosh’s extensive experience in the natural gas transmission sector enhances the knowledge of
the board in this area of the industry. As a current and former executive and director of various companies, his breadth
of experience is applicable to many of the matters routinely facing the Partnership, including making valuable
contributions to our audit committee. Moreover, Mr. Mirosh’s experience and industry knowledge, complemented by an
engineering and legal educational background, enable Mr. Mirosh to provide the board with executive counsel on a full
range of business, financial, technical and professional matters.

Mr. Baggs was appointed a director of the General Partner in March 2010. Mr. Baggs’ principal occupation is
Vice-President, Operations and Engineering for TransCanada, a position he has held since 2008. From 2006 to 2008,
Mr. Baggs was Vice-President, Field Operations and Engineering for TransCanada. He has been with TransCanada for
21 years. In his position as Vice-President, Operations and Engineering at TransCanada, Mr. Baggs has unique insight
into our operational challenges and opportunities. With a nearly 30-year career focused on providing construction,
design, operations, maintenance and commissioning experience in various industries, Mr. Baggs contributes a broad-
based understanding of the oil and gas industry and of complex operational and safety matters. Mr. Baggs’ service on
the board of directors of other energy services companies further enhances his qualifications to serve as a member of
our board.

Ms. Delkus was appointed a director of the General Partner in November 2003. Ms. Delkus’ principal occupation is
Deputy General Counsel, Pipelines and Regulatory Affairs of TransCanada, a position she has held since
September 2006. From June 2006 to September 2006, she was Vice-President, Pipeline Law and Regulatory Affairs of
TransCanada. From December 2005 to June 2006, she was Vice-President, Law, Gas Transmission of TransCanada. As
Deputy General Counsel, Pipelines and Regulatory Affairs, Ms. Delkus is responsible for, and has intimate knowledge of,
the legal aspects of all regulatory and commercial matters for TransCanada’s pipeline business in Canada and the U.S.
Ms. Delkus’ experience and industry knowledge, complemented by an extensive legal career, enable her to provide the
board with executive counsel on the full range of business, regulatory, legal and professional matters.

62

TC PIPELINES, LP

In October 2010, Mr. Kampel was appointed Vice-President, Business Development for the General Partner.
Mr. Kampel’s principal occupation is Director, Business Development at TransCanada, a position he has held since
December 2003. Since 2004, he has been responsible for identifying and pursuing natural gas pipeline and other
related energy investment opportunities in Mexico.

In October 2010, Ms. Wilson was appointed Vice-President, Commercial for the General Partner. Ms. Wilson’s principal
occupation is Director, Commercial Affiliated Pipeline, a role she has held since 2009 and which includes her work as
General Manager of the TransQu ´ebec and Maritimes Pipeline for TransCanada. From 2007 to 2009, Ms. Wilson was
Director of Project and Risk Management Systems for TransCanada, and from 2006 to 2007, she was Manager of
TransCanada’s Cartier Energy Wind Power Projects. From 2003 to 2006, Ms. Wilson held the position of Assistant
Project Manager of TransCanada’s Becancour Cogeneration Power Project.

Mr. Ofremchuk was appointed Vice-President, Taxation of the General Partner in July 2007. Mr. Ofremchuk’s principal
occupation is Manager, Corporate Taxation of TransCanada, a position he has held since 1997.

Ms. Amundson was appointed Treasurer of the General Partner in December 2008. Ms. Amundson’s principal
occupation is Manager, Capital Markets of TransCanada, a position she has held since 2005.

Mr. DeGrandis was appointed Secretary of the General Partner in April 2005. Mr. DeGrandis’ principal occupation is
Corporate Secretary of TransCanada, a position he has held since June 2006. From June 2004 to June 2006,
Mr. DeGrandis was Associate General Counsel, Corporate Secretarial of TransCanada.

Mr. Jacobucci was appointed principal financial officer of the General Partner and Controller of the General Partner in
November 2009. His principal occupation is Director of Pipeline Accounting for TransCanada. From November 2008
to November 2009, Mr. Jacobucci was Director, Energy Accounting of TransCanada. From February 2006 to
November 2008, Mr. Jacobucci was Manager, Power Accounting and Manager, U.S. Pipeline Accounting.

AUDIT COMMITTEE FINANCIAL EXPERT

The board of directors of the General Partner has determined that David Marshall and Jack Jenkins-Stark are ‘‘audit
committee financial experts,’’ are ‘‘independent’’ and are ‘‘financially sophisticated’’ as defined under applicable SEC and
NASDAQ Stock Market Corporate Governance rules. The board’s affirmative determination for both David Marshall and
Jack Jenkins-Stark was based on their respective education and extensive experience as chief financial officers for
corporations that presented a breadth and level of complexity of accounting issues that are generally comparable to
those of the Partnership.

IDENTIFICATION OF THE AUDIT COMMITTEE

The General Partner of the Partnership has a separately designated audit committee consisting of three independent
board members. The members of the committee are David Marshall, as Chair, Jack Jenkins-Stark and Walentin (Val)
Mirosh. All members of the Audit Committee meet the criteria for independence as set forth under the rules of the SEC
and those of the NASDAQ Stock Market. None of the Audit Committee members have participated in the preparation
of the financial statements of the Partnership or any of its subsidiaries at any time during the past three years. In
addition, all members of the Audit Committee are able to read and understand fundamental financial statements,
including a company’s balance sheet, income statement and cash flow statement.

CODE OF ETHICS

The Partnership believes that director, management and employee honesty and integrity are important factors in
ensuring good corporate governance. The employees of the General Partner, as employees of TransCanada, are subject
to TransCanada’s Code of Business Ethics. In addition, the General Partner has adopted a code of business ethics for its

2010 ANNUAL REPORT

63

chief executive officer, president and principal financial officer and one which applies to its independent directors, being
the Code of Business Ethics for Directors. All codes are published on its website at www.tcpipelineslp.com. If any
substantive amendments are made to the code for senior officers or if any waivers are granted, the amendment or
waiver will be published on the Partnership’s website or filed in a report on Form 8-K.

CORPORATE GOVERNANCE

The Audit Committee has adopted a charter which specifically provides that it is responsible for the appointment,
compensation, retention and oversight of the work of the independent public accountants engaged in preparing or
issuing the Partnership’s audit report, that the committee has the authority to engage independent counsel and other
advisors as it determines necessary to carry out its duties and for the committee to be responsible for establishing
procedures for the receipt, retention and treatment of complaints regarding accounting, internal accounting controls or
auditing matters, including procedures for the confidential, anonymous submission by employees of the General Partner
concerns regarding questionable accounting or auditing matters. The committee has adopted TransCanada’s Ethics
Help-Line in fulfillment of its responsibility to establish a confidential and anonymous whistle blowing process. The toll
free Ethics Help-Line number and the audit committee’s charter are published on the Partnership’s website at
www.tcpipelineslp.com.

SECTION 16(a) BENEFICIAL OWNERSHIP REPORTING COMPLIANCE

Section 16(a) of the Exchange Act, as amended, requires the Partnership’s directors and executive officers, and persons
who beneficially own more than ten percent of the common units, to file reports of ownership and changes in
ownership with the SEC and to furnish us with copies of all such reports. Based solely upon a review of the copies of
the reports received by us, we believe that all such filing requirements were satisfied during 2010, with the exception of
one late filing on Form 5 in February 2011 relating to a charitable gift by Mr. Jack Jenkins-Stark in November 2010.

Item 11. Executive Compensation

COMPENSATION DISCUSSION AND ANALYSIS

We are a master limited partnership, and we are managed by the executive officers of our General Partner. We do not
directly employ any of the individuals responsible for managing or operating our business. The executive officers of our
General Partner are compensated directly by TransCanada.

The compensation policies and philosophy of TransCanada govern the types and amount of compensation granted each
of the named executive officers. Since these policies and philosophy are those of TransCanada, we refer you to a
discussion of those items as set forth in the Executive Compensation section of the TransCanada ‘‘Management Proxy
Circular’’ on the TransCanada website at www.transcanada.com. The TransCanada ‘‘Management Proxy Circular’’ is
produced by TransCanada pursuant to Canadian securities regulations and is not incorporated into this document by
reference or deemed furnished or filed by us under the Securities Exchange Act of 1934, as amended; rather the
reference is to provide our investors with an understanding of the compensation policies and philosophy of the ultimate
parent of our General Partner.

The board of directors of our General Partner does not have a separate compensation committee, nor does it make any
determination with respect to the amount of compensation to be paid to our executive officers. The board of our
General Partner does have responsibility for evaluating and determining the reasonableness of the total amount we are
charged for managerial, administrative and operational support provided by TransCanada and its affiliates, including our
General Partner. The board specifically approves the allocation of the salary of the CEO to the Partnership on an annual
basis. Please read Item 13. ‘‘Certain Relationships and Related Transactions, and Director Independence’’ for more
information regarding this arrangement.

64

TC PIPELINES, LP

In addition to base salary, we also reimburse our General Partner for certain benefit and incentive compensation
expenses related to the officers of our General Partner and employees of an affiliate of our General Partner who
perform services on our behalf. The base salaries that are allocable to us vary for each officer or employee of an affiliate
of our General Partner performing services on our behalf and are based on the amount of time an employee devotes to
matters related to our business as compared to the amount of time such employee devotes to matters related to the
business of TransCanada and its other affiliates. We are allocated and reimburse the General Partner for each officer’s
salary expense. Other benefit and incentive compensation expenses related to our officers are reimbursed to the General
Partner based upon an agreed upon calculation.

The following table summarizes the salary allocated to and paid by us in 2010, 2009 and 2008 for our principal
executive officer, president and principal financial officer. None of the other executive officers of our General Partner
allocated to us more than $100,000 related to his or her salary.

Summary Compensation Table

Name and Principal Position

Steven D. Becker
President and Principal Executive Officer

Russell K. Girling
Former Chief Executive Officer

Mark A.P. Zimmerman
Former President

Robert C. Jacobucci
Controller and Principal Financial Officer

Base Salary Allocated to the Partnership

Year

2010
2009
2008

2010
2009
2008

2010
2009
2008

2010
2009
2008

Canadian
Dollars

US Dollar
Equivalent

29,277
–
–

14,795
75,001
68,251

44,195
110,004
108,753

26,920
3,610
–

29,424
–
–

14,869
71,663
55,733

44,416
105,109
88,808

27,054
3,450
–

Total(a)

29,424
–
–

14,869
71,663
55,733

44,416
105,109
88,808

27,054
3,450
–

(a) The compensation of executive officers of the General Partner is paid by TransCanada in Canadian dollars. The US dollar equivalents have
been calculated using the applicable December 31, 2010 noon buying rate of 1.005 as reported by the Bank of Canada (2009 – 0.9555;
2008 – 0.8166).

We reimburse our General Partner for benefit and incentive compensation expenses based on a set formula, which
expenses are attributable to additional compensation paid to each of them and other compensation and employment-
related expenses, including TransCanada’s restricted stock unit and stock option awards, retirement plans, health and
welfare plans, employer-related payroll taxes, matching contributions made under a TransCanada’s employee savings
plan, and premiums for health and life insurance. This reimbursement is determined monthly and calculated based on
total monthly base salary allocated to us multiplied by a factor of 0.30 for benefits in 2010 (2009 – factor of 0.32;
2008 – factor of 0.35) and a factor of 0.49 for incentive compensation in 2010 (2009 – factor of 0.48; 2008 – factor of
0.40). The total amount reimbursed for benefits and incentive compensation was $766,564 in 2010 for all employees
providing services to the Partnership, including the named officers in the above table (2009 – $667,059; 2008 –
$610,801).

2010 ANNUAL REPORT

65

Compensation Committee Report

Neither we, nor our General Partner, have a compensation committee. The board of directors of our General Partner
has reviewed and discussed the Compensation Discussion and Analysis set forth above and based on this review and
discussion has approved it for inclusion in this Form 10-K.

The board of directors of TC PipeLines GP, Inc:

Steven D. Becker
Jack F. Jenkins-Stark
David L. Marshall
Walentin Mirosh
Gregory A. Lohnes
Kristine L. Delkus
James M. Baggs

Independent Director Compensation

Independent Director Compensation(a)
For the year ended December 31, 2010
(in dollars)

David L. Marshall(e)
Jack F. Jenkins-Stark(f)
Walentin (Val) Mirosh

Earned or
Paid in Cash(b)

Unit
Awards(c)

All Other
Compensation(d)

53,500
54,000
49,500

30,000
30,000
30,000

7,622
14,467
7,622

Total

91,122
98,467
87,122

(a) Employee directors do not receive any additional compensation for serving on the board of directors of our General Partner; therefore, no
amounts are shown for Russell K. Girling, Gregory A. Lohnes, Kristine L. Delkus, James M. Baggs and Steven D. Becker. Amounts paid as
reimbursable business expenses to each director for attending board functions are not reflected in this table. Our General Partner does
not consider the directors’ reimbursable business expenses for attending board functions and other business expenses required to perform
board duties to have a personal benefit and thus be considered a perquisite.

(b) Pursuant to the Deferred Share Unit Plan for Non-Employee Directors, Jack F. Jenkins-Stark elected to receive half of his fees ($27,000) in
Deferred Share Units. Due to this election, 620 Deferred Share Units were credited to Mr. Jenkins-Stark’s account in 2010, all of which
were outstanding at December 31, 2010.

(c) Amounts presented reflect the compensation expense recognized related to the Deferred Share Units granted during 2010 under the

Deferred Share Unit Plan for Non-Employee Directors. On January 19, 2010, each independent director was granted 791 Deferred Share
Units, all of which were outstanding at December 31, 2010. At December 31, 2010, David L. Marshall, Jack F. Jenkins-Stark and Walentin
(Val) Mirosh held 2,990, 6,067 and 2,990 Deferred Share Units, respectively. The fair value of Deferred Share Units held by Mr. Marshall,
Mr. Jenkins-Stark and Mr. Mirosh at December 31, 2010 was $110,638, $224,499 and $110,638, respectively.

(d) Amounts presented reflect Deferred Share Units credited to each independent director’s account equal to the distributions payable on the

Deferred Share Units previously granted or credited. In this regard, David L. Marshall and Walentin (Val) Mirosh were credited
206 Deferred Share Units in 2010, while Jack F. Jenkins-Stark was credited 391 Deferred Share Units. All Deferred Share Units credited
during 2010 were outstanding at December 31, 2010.

(e) Chairman of the Audit Committee

(f) Lead Director and Chairman of the Conflicts Committee

Cash Compensation
Each director who is not an employee of TransCanada, the General Partner or its affiliates (independent director) is
entitled to a directors’ retainer fee of $60,000 per annum, of which $30,000 is automatically granted in Deferred Share
Units (see Deferred Share Units section below). The independent director appointed as Lead Director and chair of the
Conflicts Committee is entitled to an additional fee of $6,000 per annum, while the independent director appointed as
chair of the Audit Committee is entitled to an additional fee of $4,000 per annum. Each independent director is also
paid a fee of $1,500 for attendance at each meeting of the board of directors and a fee of $1,500 for attendance at

66

TC PIPELINES, LP

each meeting of a committee of the board. The independent directors are reimbursed for out-of-pocket expenses
incurred in the course of attending such meetings. All fees are paid by the Partnership on a quarterly basis. The
independent directors are permitted to elect to receive any portion of their fees in the form of Deferred Share Units
pursuant to The TC PipeLines GP, Inc. Deferred Share Unit Plan for Non-Employee Directors (2007). On October 20,
2010, the board approved an increase in the annual retainer fee of $4,000 per annum, of which $2,000 is granted in
Deferred Share Units, resulting in a retainer fee of $64,000 per annum, of which $32,000 is automatically granted in
Deferred Share Units, effective January 1, 2011.

Deferred Share Units
The TC PipeLines GP, Inc. Deferred Share Unit Plan for Non-Employee Directors (2007) was established in 2007 with the
first grant occurring in January 2008. In 2010, as part of the retainer fee, each independent director received an annual
grant of Deferred Share Units with a value of $30,000.

At the time of grant, the value of a Deferred Share Unit is equal to the market value of a common unit at the time the
independent director is credited with the units. The value of a Deferred Share Unit when redeemed is equivalent to the
market value of a common unit at the time the redemption takes place. Deferred Share Units cannot be redeemed until
the director ceases to be a member of the Board. Directors may redeem Deferred Share Units for cash or common units
at their option. Deferred Share Units redeemed for common units would be purchased by the Partnership in the
open market.

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder

Matters

The following table sets forth the beneficial ownership of the voting securities of the Partnership as at February 22,
2011 by the General Partner’s directors, officers and certain beneficial owners. Executive officers of the General Partner
own shares of TransCanada, which in the aggregate amount to less than one percent of TransCanada’s issued and
outstanding shares. Other than as set forth below, no person is known by the General Partner to own beneficially more
than five percent of the voting securities of the Partnership. 

Name and Business Address

Common Units(a) Number of DSUs(b)

Percent of Class(c)

Amount and Nature of Beneficial Ownership

Number of

TransCan Northern Ltd.(d)
450 1st Street SW
Calgary, Alberta T2P 5H1

TC Pipelines GP, Inc.(e)
450 1st Street SW
Calgary, Alberta T2P 5H1

Tortoise Capital Advisors, L.L.C.(f)
11550 Ash Street, Suite 300
Leawood, Kansas 66211

David L. Marshall
2880 Oxley Drive
Sparks, Nevada 89436

Walentin (Val) Mirosh
18 Elmont Place S.W.
Calgary, Alberta T3H 0K5

11,287,725

5,797,106

3,428,859

–

–

–

–

–

3,643

3,643

24.4

12.5

7.4

*

*

2010 ANNUAL REPORT

67

Amount and Nature of Beneficial Ownership

Number of

Common Units(a) Number of DSUs(b)

Percent of Class(c)

Name and Business Address

Jack F. Jenkins-Stark(g)
1999 Harrison Street, Suite 2150
Oakland, California 94612

Gregory A. Lohnes
450 1st Street SW
Calgary, Alberta T2P 5H1

Steven D. Becker
450 1st Street SW
Calgary, Alberta T2P 5H1

Kristine L. Delkus
450 1st Street SW
Calgary, Alberta T2P 5H1

James M. Baggs
450 1st Street SW
Calgary, Alberta T2P 5H1

Robert C. Jacobucci
450 1st Street SW
Calgary, Alberta T2P 5H1

4,888

6,764

–

–

–

–

–

–

–

–

–

–

–

–

*

–

–

–

–

–

*

Directors and Executive officers as a Group(h)(i)
(14 people)

(a) A total of 46,227,766 common units are issued and outstanding.

(b) A deferred share unit is a bookkeeping entry, equivalent to the value of a Partnership common unit, and does not entitle the holder to

voting or other shareholder rights, other than the accrual of additional deferred share units for the value of dividends. A director cannot
redeem deferred share units until the director ceases to be a member of the Board. Directors can then redeem their units for cash
or shares.

(c) Any deferred share units shall be deemed to be outstanding for the purpose of computing the percentage of outstanding common units
owned by such person, but shall not be deemed to be outstanding for the purpose of computing the percentage of common units by
any other person.

(d) TransCan Northern Ltd. is a wholly-owned indirect subsidiary of TransCanada.

(e) TC PipeLines GP, Inc. is a wholly-owned indirect subsidiary of TransCanada and owns an aggregate two percent general partner interest of

the Partnership.

(f) Based on Schedule 13D filed with the SEC on February 11, 2011 by Tortoise Capital Advisors, L.L.C. (Tortoise). In the Schedule 13D,

Tortoise reported that it has shared power to vote 3,301,612 common units and shared power to dispose of all 3,428,859 common units.

(g) 4,888 common units are held by the Jenkins-Stark Family Trust dated June 16, 1995.

(h) With the exception of the one named director above, none of the other directors and executive officers hold any common units of the

Partnership.

(i) Walentin (Val) Mirosh holds 720 shares of TransCanada; Kristine L. Delkus holds 93,479 options and 5,574 shares of TransCanada; Steven

D. Becker holds 71,499 options and 14,887 shares of TransCanada; Terry C. Ofremchuk holds 1,600 options and 6,757 shares of
TransCanada; Gregory A. Lohnes holds 184,089 options and 19,411 shares of TransCanada; Robert C. Jacobucci holds 600 shares of
TransCanada; Donald J. DeGrandis holds 10,107 options and 425 shares of TransCanada; Rhonda L. Amundson holds 1,600 options and
3,756 shares of TransCanada; Annie C. Belecki holds 1,372 shares of TransCanada; James M. Baggs holds 61,225 options and
5,055 shares of TransCanada; Stephanie E. Wilson holds 843 shares of TransCanada; and Stuart P. Kampel holds 461 shares of
TransCanada. The directors and executive officers as a group hold 423,599 options and 59,861 shares of TransCanada. All options listed
above are exercisable within 60 days from February 25, 2011.

* Less than one percent.

68

TC PIPELINES, LP

Item 13. Certain Relationships and Related Transactions, and Director Independence

At February 25, 2011, TransCanada owns 11,287,725 common units and the Partnership’s General Partner owns
5,797,106 common units, representing an aggregate 36.2 percent limited partner interest in the Partnership. In
addition, the General Partner owns an aggregate two percent general partner interest in the Partnership through which
it manages and operates the Partnership. As a result, TransCanada’s aggregate ownership interest in the Partnership is
38.2 percent by virtue of its indirect ownership of the General Partner and 36.2 percent aggregate limited partner
interest.

Distributions and Payments to Our General Partner and Its Affiliates

The following table summarizes the distributions and payments made or to be made by us to our General Partner and
its affiliates, which includes TransCanada, in connection with the ongoing operation and liquidation of the Partnership.
These distributions and payments were determined by and among affiliated entities and, consequently, are not the
result of arms-length negotiations. 

Distributions of available
cash to our general partner
and its affiliates

We will generally make cash distributions 98% to common unitholders, including
our  general  partner  and 
its  affiliates  as  holders  of  an  aggregate  of
17,084,831 common units, and the remaining 2% to our general partner.

Operational Stage

Payments to our general
partner and its affiliates

Withdrawal or removal of
our general partner

In addition, if distributions exceed the minimum quarterly distribution and other
higher target levels, our general partner will be entitled to increasing percentages of
the distributions, up to 25% of the distributions above the highest target level. We
refer to the rights to the increasing distributions as ‘‘incentive distribution rights’’.
For  further  information  about  distributions,  please  read  ‘‘Market  for  Registrant’s
Common  Equity,  Related  Stockholder  Matters  and  Issuer  Purchases  of  Equity
Securities.’’

If our general partner withdraws or is removed, its general partner interest and its
incentive distribution rights will either be sold to the new general partner for cash or
converted into common units, in each case for an amount equal to the fair market
value of those interests.

Liquidation Stage

Liquidation

Upon our liquidation, the partners, including our general partner, will be entitled to
receive  liquidating  distributions  according  to  their  particular  capital  account
balances.

Reimbursement of Operating and General and Administrative Expense

The Partnership does not have any employees. The management and operating functions are provided by the General
Partner. The General Partner does not receive a management fee in connection with its management of the Partnership.
The Partnership reimburses the General Partner for all costs of services provided, including the costs of employee, officer
and director compensation and benefits, and all other expenses necessary or appropriate to the conduct of the business
of, and allocable to, the Partnership. Such costs include (i) overhead costs (such as office space and equipment) and
(ii) out-of-pocket expenses related to the provision of such services. The Partnership Agreement provides that the
General Partner will determine the costs that are allocable to the Partnership in any reasonable manner determined by
the General Partner in its sole discretion. Total costs charged to the Partnership by the General Partner were
$2.2 million for the year ended December 31, 2010 (2009 – $2.1 million; 2008 – $2.1 million).

2010 ANNUAL REPORT

69

Operating Agreements with Our Pipeline Companies

Our pipeline systems are operated by TransCanada and its affiliates pursuant to operating agreements. Under these
agreements, our pipeline systems are required to reimburse TransCanada for their costs including payroll, employee
benefit costs, and other costs incurred on behalf of our pipeline systems. Most costs for materials, services and other
charges that are third-party charges are invoiced directly to each of our pipeline systems.

Cash Management Programs

Great Lakes has a cash management agreement with TransCanada whereby Great Lakes’ funds are pooled with other
TransCanada affiliates. The agreement also gives Great Lakes the ability to obtain short-term borrowings to provide
liquidity for Great Lakes’ operating needs.

Transportation Agreements

Great Lakes earns transportation revenues from TransCanada and its affiliates under contracts with fixed prices. The
contracts have remaining terms ranging from one to eight years. Great Lakes earned $148.5 million of transportation
revenues under these contracts in 2010 (2009 – $141.7 million; 2008 – $143.7 million). This amount represents
56.6 percent of total revenues earned by Great Lakes in 2010 (2009 – 48.9 percent; 2008 – 50.0 percent). Great Lakes
also earned $0.9 million in affiliated rental revenue in 2010 (2009 – $0.6 million; 2008 – 0.4 million).

Revenue from TransCanada and its affiliates of $69.3 million is included in the Partnership’s equity income from Great
Lakes in 2010 (2009 – $66.1 million; 2008 – $66.9 million). At December 31, 2010, $11.0 million was included in Great
Lakes’ receivables for transportation contracts with TransCanada and its affiliates (2009 – $12.9 million).

Great Lakes’ largest shipper, TransCanada PipeLines Limited, has 576 MDth/d of long-haul capacity under contract
expiring on October 31, 2011. Negotiations are currently in progress related to these contracts.

Other Agreements

Great Lakes, Northern Border, North Baja and Tuscarora currently have interconnection, operational balancing
agreements, transportation and exchange agreements and/or other inter-affiliate agreements with affiliates of
TransCanada. In addition, each of our pipeline systems currently have other routine agreements with TransCanada or
one of its subsidiaries that arise in the ordinary course of business, including agreements for services and other
transportation and exchange agreement and interconnection and balancing agreements with other TransCanada
pipelines.

70

TC PIPELINES, LP

Costs charged to our pipeline systems for the years ended December 31, 2010, 2009 and 2008 by TransCanada and its
affiliates and amounts payable to TransCanada and its affiliates at December 31, 2010 and 2009 are summarized in the
following tables:

Year ended December 31 

(millions of dollars)

Costs charged by TransCanada and its affiliates:

Great Lakes
Northern Border(a)
North Baja(b)
Tuscarora

Impact on the Partnership’s net income:

Great Lakes
Northern Border
North Baja(b)
Tuscarora

December 31 

(millions of dollars)

Amount payable to/(receivable from) TransCanada and its affiliates:

Great Lakes
Northern Border
North Baja
Tuscarora

2010

2009

2008

30.3
25.8
4.4
3.7

12.8
12.5
3.2
3.5

33.8
25.5
2.9
3.0

14.3
12.3
2.4
2.8

34.3
30.5
4.7
3.7

14.2
12.9
2.7
2.7

2010

2009

3.0
2.2
0.6
0.7

3.7
2.6
(1.6)
0.6

(a)

In 2008, Northern Border’s costs charged by TransCanada and its affiliates include $2.0 million of charges related to Bison through the
effective date of the sale.

(b) Recast as discussed in Note 2 and Note 6 to the Partnership’s financial statements included elsewhere in this report.

Relationship with our General Partner and TransCanada and Conflicts of Interest Resolution

Our Partnership Agreement contains specific provisions that address potential conflicts of interest between our General
Partner and its affiliates, including TransCanada, on one hand, and us and our subsidiaries, on the other hand.
Whenever such a conflict of interest arises, our General Partner will resolve the conflict. Our General Partner may, but is
not required to, seek the approval of such resolution from the conflicts committee of the board of directors of our
General Partner (‘‘Special Approval’’), which is comprised of independent directors.

Any conflict of interest and any resolution of such conflict of interest shall be conclusively deemed fair and reasonable if
such conflict of interest or resolution is approved by Special Approval:

(cid:127) on terms no less favorable to the Partnership than those generally being provided to or available from unrelated third

parties; or

(cid:127) fair to us, taking into account the totality of the relationships between the parties involved, including other

transactions that may be particularly favorable or advantageous to us.

The General Partner may also adopt a resolution or course of action that has not received Special Approval. In acting
for the Partnership, the General Partner is accountable to us and the unitholders as a fiduciary. Neither the Delaware
Revised Uniform Limited Partnership Act (Delaware Act) nor case law defines with particularity the fiduciary duties owed
by general partners to limited partners of a limited partnership. The Delaware Act does provide that Delaware limited
partnerships may, in their partnership agreements, restrict or expand the fiduciary duties owed by a general partner to
limited partners and the partnership.

2010 ANNUAL REPORT

71

In order to induce the General Partner to manage the business of the Partnership, the Partnership Agreement contains
various provisions restricting the fiduciary duties that might otherwise be owed by the General Partner. The following is
a summary of the material restrictions of the fiduciary duties owed by the General Partner to the limited partners:
(cid:127) The Partnership Agreement permits the General Partner to make a number of decisions in its ‘‘sole discretion.’’ This
entitles the General Partner to consider only the interests and factors that it desires and it shall have no duty or
obligation to give any consideration to any interest of, or factors affecting, the Partnership, its affiliates or any limited
partner. Other provisions of the Partnership Agreement provide that the General Partner’s actions must be made in its
reasonable discretion.

(cid:127) The Partnership Agreement generally provides that affiliated transactions and resolutions of conflicts of interest not
involving a required vote of unitholders must be ‘‘fair and reasonable’’ to the Partnership. In determining whether a
transaction or resolution is ‘‘fair and reasonable’’ the General Partner may consider interests of all parties involved,
including its own. Unless the General Partner has acted in bad faith, the action taken by the General Partner shall not
constitute a breach of its fiduciary duty.

(cid:127) The Partnership Agreement specifically provides that it shall not be a breach of the General Partner’s fiduciary duty if
its affiliates engage in business interests and activities in competition with, or in preference or to the exclusion of, the
Partnership. Further, the General Partner and its affiliates have no obligation to present business opportunities to
the Partnership.

(cid:127) The Partnership Agreement provides that the General Partner and its officers and directors will not be liable for

monetary damages to the Partnership, the limited partners or assignees for errors of judgment or for any acts or
omissions if the General Partner and those other persons acted in good faith.

The Partnership is required to indemnify the General Partner and its officers, directors, employees, affiliates, partners,
members, agents and trustees (collectively referred to hereafter as the General Partner and others), to the fullest extent
permitted by law, against liabilities, costs and expenses incurred by the General Partner and others. This indemnification
is required if the General Partner and others acted in good faith and in a manner they reasonably believed to be in, or
(in the case of a person other than the General Partner) not opposed to, the best interests of the Partnership.
Indemnification is required for criminal proceedings if the General Partner and others had no reasonable cause to
believe their conduct was unlawful. Please read Item 10. ‘‘Directors, Executive Officers and Corporate Governance’’ for
additional information.

Director Independence
Please read Item 10. ‘‘Directors, Executive Officers and Corporate Governance’’ for information about the independence
of our General Partner’s board of directors and its committees, which information is incorporated herein by reference in
its entirety.

Item 14. Principal Accounting Fees and Services
The following table sets forth, for the periods indicated, the fees billed by the principal accountants:

Year ended December 31 

(thousands of dollars)

Audit Fees(a)
Tax Fees(b)
All Other Fees(b)

Total

2010

358.8
–
–

358.8

2009

513.1
–
–

513.1

(a) Audit fees include prospectus work in connection with the Partnership’s November 2009 equity issuance and the filing of the Partnership’s
Form S-3 in April 2010. Audit fees also include services performed related to Sarbanes-Oxley Act reporting requirements, and includes
services for the statutory audit of Tuscarora and North Baja.

(b) The Partnership has not engaged its external auditors for any tax or other services in 2010 or 2009.

AUDIT FEES
Audit fees include fees for the audit of annual GAAP financial statements, reviews of the related quarterly financial
statements and related consents and comforts letters for documents filed with the SEC. Before our independent
principal accountant is engaged each year for annual audit and any non-audit services, these services and fees are
reviewed and approved by our Audit Committee.

72

TC PIPELINES, LP

PART IV

Item 15. Exhibits, Financial Statement Schedules

(a)

(1) Financial Statements

See ‘‘Index to Financial Statements’’ set forth on Page F-1.

(2)

Financial Statement Schedules

All schedules are omitted because they are either not applicable or the required information is shown in the
consolidated financial statements or notes thereto.

(3) Exhibits

No.

*2.1

*2.1.1

*3.1

*3.2

*10.1

Description

Agreement for Purchase and Sale of Membership Interest by and between Gas Transmission Northwest
Corporation and TC PipeLines Intermediate Limited Partnership dated May 19, 2009 (Exhibit 2.1
to TC PipeLines, LP’s Form 8-K filed on May 20, 2009).

First Amendment to Agreement for Purchase And Sale of Membership Interest by and between Gas
Transmission Northwest Corporation and TC PipeLines Intermediate Limited Partnership dated June 29,
2010 (Exhibit 2.1 to TC PipeLines, LP’s Form 10-Q filed on July 29, 2010).

Second Amended and Restated Agreement of Limited Partnership of TC PipeLines, LP dated July 1, 2009
(Exhibit 3.1 to TC PipeLines, LP’s Form 8-K filed on July 1, 2009).

Certificate of Limited Partnership of TC PipeLines, LP (Exhibit 3.2 to TC PipeLines, LP’s Form S-1
Registration Statement, filed on December 30, 1998).

Amended and Restated Agreement of Limited Partnership of Great Lakes Gas Transmission Limited
Partnership between TransCanada GL, Inc., TC GL Intermediate Limited Partnership and Great Lakes Gas
Transmission Company dated February 22, 2007 (Exhibit 10.9 to TC PipeLines, LP’s Form 10-Q filed on
April 30, 2007).

10.1.1

Amendment No. 1 to the Amended and Restated Agreement of Limited Partnership of Great Lakes Gas
Transmission Partnership between TransCanada GL, Inc., TC GL Intermediate Limited Partnership and
Great Lakes Gas Transmission Company dated October 25, 2010.

*10.2

*10.3

*10.4

Operating Agreement between Great Lakes Gas Transmission Limited Partnership and Great Lakes Gas
Transmission Company dated April 5, 1990 (Exhibit 10.10 to TC PipeLines, LP’s Form 10-Q filed on
April 30, 2007).

First Amended and Restated General Partnership Agreement of Northern Border Pipeline Company by
and between Northern Border Intermediate Limited Partnership and TC Pipelines Intermediate Limited
Partnership dated April 6, 2006 (Exhibit 3.1 to Northern Border Pipeline Company’s Form 8-K filed on
April 12, 2006).

Operating Agreement by and between Northern Border Pipeline Company and TransCan Northwest
Border Ltd. dated April 6, 2006 (Exhibit 10.2 to Northern Border Pipeline Company’s Form 8-K filed on
April 12, 2006).

*10.4.1

Amendment No.1 to Northern Border Pipeline Company Operating Agreement by and between Northern
Border Pipeline Company and TransCanada Northern Border Inc. dated April 22, 2008 (Exhibit 10.9.1
to TC PipeLines, LP’s Form 10-K filed on February 27, 2009).

2010 ANNUAL REPORT

73

No.

*10.4.2

*10.5

*10.5.1

*10.5.2

*10.5.3

*10.5.4

*10.6

*10.7

*10.8

*10.8.1

*10.9

Description

Second Amendment of Operating Agreement by and between Northern Border Pipeline Company and
TransCanada Northern Border Inc. dated February 10, 2010 (Exhibit 10.9.2 to TC PipeLines, LP’s
Form 10-K filed on February 26, 2010).

Operating Agreement by and between Tuscarora Gas Transmission Company and TransCan Northwest
Border Ltd. dated December 19, 2006 (Exhibit 10.11 to TC PipeLines, LP’s Form 10-K filed on
March 2, 2007).

First Amendment to Operating Agreement by and between Tuscarora Gas Transmission Company and
TransCanada Northern Border Inc. (formerly TransCan Northwest Border Ltd.) dated June 21, 2007
(Exhibit 10.10.1 to TC PipeLines, LP’s Form 10-K filed on February 27, 2009).

Second Amendment to Operating Agreement by and between Tuscarora Gas Transmission Company and
TransCanada Northern Border Inc. (formerly TransCan Northwest Border Ltd.) dated December 31, 2007
(Exhibit 10.10.2 to TC PipeLines, LP’s Form 10-K filed on February 27, 2009).

Third Amendment to Operating Agreement by and between Tuscarora Gas Transmission Company and
TransCanada Northern Border Inc. dated December 31, 2008 (Exhibit 10.10.3 to TC PipeLines, LP’s
Form 10-K filed on February 27, 2009).

Fourth Amendment to Operating Agreement by and between Tuscarora Gas Transmission Company and
TransCanada Northern Border Inc. dated December 31, 2009 (Exhibit 10.10.4 to TC PipeLines, LP’s
Form 10-K filed on February 26, 2010).

Management Services Agreement by and between Gas Transmission Service Company, LLC (formally
PG&E Gas Transmission Service Company, LLC) and North Baja Pipeline, LLC dated January 1, 2002
(Exhibit 10.2 to TC PipeLines, LP’s Form 10-Q filed on August 4, 2009).

Yuma Transfer Agreement by and between Gas Transmission Northwest Corporation and North Baja
Pipeline, LLC dated March 5, 2010 (Exhibit 10.1 to TC PipeLines, LP’s Form 10-Q filed on
April 30, 2010).

Amended and Restated Revolving Credit Agreement, dated April 27, 2007, among Northern Border
Pipeline Company, the lenders from time to time party thereto, SunTrust Bank, as Administrative Agent,
Wachovia Bank, National Association, as Syndication Agent, BMO Capital Markets, Citibank, N.A. and
Mizuho Corporate Bank, LTD., as Co-Documentation Agents, JP Morgan Chase Bank, N.A. and Export
Development Canada, as Managing Agents and SunTrust Capital Markets, Inc. and Wachovia Capital
Markets, LLC, as Co-Lead Arrangers and Book Managers (Exhibit 10.1 to TC PipeLines, LP’s Form 10-Q
filed on October 29, 2010).

First Amendment to Amended and Restated Revolving Credit Agreement, dated July 31, 2008, between
Northern Border Pipeline Company and the lenders named therein. (Exhibit 10.2 to TC PipeLines, LP’s
Form 10-Q filed on November 3, 2008).

Amended and Restated Revolving Credit and Term Loan Agreement, dated February 13, 2007, among
TC PipeLines, LP, the lenders from time to time party thereto, SunTrust Bank, as Administrative Agent,
UBS Securities LLC and Royal Bank of Canada, as Co-Documentation Agents, BMO Capital Markets
Financing Inc. and the Royal Bank of Scotland PLC, as Co-Syndication Agents, Deutsche Bank AG
New York Branch and the Bank of Tokyo-Mitsubishi UFJ, Ltd., as Managing Agents, and SunTrust Capital
Markets, Inc. as Arranger and Book Manager (Exhibit 10.2 to TC PipeLines, LP’s Form 10-Q filed on
October 29, 2010).

*10.10

Subordinated Loan Agreement between TC PipeLines, LP and TransCanada PipeLines Limited dated
February 13, 2007 (Exhibit 10.2 to TC PipeLines, LP’s Form 8-K filed on February 15, 2007).

74

TC PIPELINES, LP

No.

Description

*10.11

*10.12

*10.13

*10.14

*#10.15

*10.16

*10.17

*10.18

12.1

21.1

23.1

23.2

23.3

31.1

31.2

32.1

32.2

*99.1

*99.2

Subordination and Intercreditor Agreement by and among TransCanada PipeLines Limited,
TC PipeLines, LP, and SunTrust Bank, as Administrative Agent, dated February 13, 2007 (Exhibit 10.3
to TC PipeLines, LP’s Form 8-K filed on February 15, 2007).

Contribution, Conveyance and Assumption Agreement among TC PipeLines, LP and certain other parties
dated May 28, 1999 (Exhibit 10.2 to TC PipeLines, LP’s Form 10-K filed on March 28, 2000).

Form of Conveyance, Contribution and Assumption Agreement among Northern Plains Natural Gas
Company, Northwest Border Pipeline Company, Pan Border Gas Company, Northern Border Partners, L.P.,
and Northern Border Intermediate Limited Partnership (Exhibit 10.16 to Northern Border Pipeline
Company’s Form S-1 Registration Statement filed on July 16, 1993 (Registration No. 33-66158)).

Form of Contribution, Conveyance and Assumption Agreement by and among TransCanada Border
Pipeline Ltd., TransCan Northern Ltd., TransCanada PipeLines Limited, TC PipeLines, L.P., TC PipeLines
Intermediate Limited Partnership and TC PipeLines GP, Inc. (Exhibit 10.2 to TC PipeLines, LP’s Form S-1/A
filed on May 3, 1999).

TC PipeLines GP, Inc. Share Unit Plan for Non-Employee Directors (2007), effective as of October 18,
2007, as amended on December 10, 2008 (Exhibit 10.25 to TC PipeLines, LP’s Form 10-K filed on
February 27, 2009).

Membership Interest Purchase Agreement by and between Northern Border Pipeline Company and
TransCanada Pipeline USA Ltd. dated August 28, 2008, (Exhibit 10.1 to TC PipeLines, LP’s Form 10-Q
filed on November 3, 2008).

Common Unit Purchase Agreement by and between TC PipeLines, LP and TransCan Northern Ltd. dated
July 1, 2009 (Exhibit 10.1 to TC PipeLines, LP’s Form 8-K filed on July 1, 2009).

Exchange Agreement by and between TC PipeLines, LP and TC PipeLines GP, Inc. dated July 1, 2009
(Exhibit 10.2 to TC PipeLines, LP’s Form 8-K filed on July 1, 2009).

Computation of Ratio of Earnings to Fixed Charges.

Subsidiaries of the Registrant.

Consent of KPMG LLP with respect to the financial statements of TC PipeLines, LP.

Consent of KPMG LLP with respect to the financial statements of Great Lakes Gas Transmission Limited
Partnership.

Consent of KPMG LLP with respect to the financial statements of Northern Border Pipeline Company.

Certification of Principal Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

Certification of Principal Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

Certification of Principal Executive Officer pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

Certification of Principal Financial Officer pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

Transportation Service Agreement FT5840 between Great Lakes Gas Transmission Limited Partnership and
TransCanada PipeLines Limited, dated December 1, 2005. (Exhibit 10.6 to TC PipeLines, LP’s Form 10-Q
filed on April 30, 2007).

Transportation Service Agreement FT 8742 between Great Lakes Gas Transmission Limited Partnership
and TransCanada PipeLines Limited, dated December 6, 2007. (Exhibit 10.21 to TC PipeLines, LP’s
Form 10-K filed on February 28, 2008).

2010 ANNUAL REPORT

75

No.

*99.3

*99.4

*99.5

*99.6

*99.7

*99.8

*99.9

Description

Transportation Service Agreement FT9141 between Great Lakes Gas Transmission Limited Partnership and
ANR Pipeline Company, dated March 12, 2008. (Exhibit 10.1 to TC PipeLines, LP’s Form 10-Q filed on
August 5, 2008).

Transportation Service Agreement FT9158 between Great Lakes Gas Transmission Limited Partnership and
ANR Pipeline Company, dated March 14, 2008. (Exhibit 10.2 to TC PipeLines, LP’s Form 10-Q filed on
August 5, 2008).

Transportation Service Agreement FT11701 between Great Lakes Gas Transmission Limited Partnership
and TransCanada PipeLines Limited, dated November 26, 2008. (Exhibit 10.21 to TC PipeLines, LP’s
Form 10-K filed on February 27, 2009).

Transportation Service Agreement IT11986 between Great Lakes Gas Transmission Limited Partnership
and TransCanada Gas Storage USA Inc., dated February 27, 2009. (Exhibit 10.2 to TC PipeLines, LP’s
Form 10-Q filed on April 30, 2009).

Transportation Service Agreement FT4760 between Great Lakes Transmission Limited Partnership and
TransCanada PipeLines Limited, dated November 1, 2009 (Exhibit 99.11 to TC PipeLines, LP’s Form 10-K
filed on February 26, 2010).

Transportation Service Agreement FT4761 between Great Lakes Transmission Limited Partnership and
TransCanada PipeLines Limited, dated November 1, 2009 (Exhibit 99.12 to TC PipeLines, LP’s Form 10-K
filed on February 26, 2010).

Transportation Service Agreement FT14131 between Great Lakes Transmission Limited Partnership and
TransCanada PipeLines Limited, dated November 1, 2009 (Exhibit 99.13 to TC PipeLines, LP’s Form 10-K
filed on February 26, 2010).

*99.10

Transportation Service Agreement FT14132 between Great Lakes Transmission Limited Partnership and
TransCanada PipeLines Limited, dated November 1, 2009 (Exhibit 99.14 to TC PipeLines, LP’s Form 10-K
filed on February 26, 2010).

101.INS

XBRL Instance Document.

101.SCH

XBRL Taxonomy Extension Schema Document.

101.CAL

XBRL Taxonomy Extension Calculation Linkbase Document.

101.DEF

XBRL Taxonomy Definition Linkbase Document.

101.LAB

XBRL Taxonomy Extension Label Linkbase Document.

101.PRE

XBRL Taxonomy Extension Presentation Linkbase Document.

* Indicates exhibits incorporated by reference.

+ Pursuant to item 601(b)(2) of Regulation S-K, the registrant agrees to furnish supplementally a copy of any omitted

exhibit or schedule to the SEC upon request.

# Management contract or compensatory plan or arrangement.

76

TC PIPELINES, LP

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly
caused this report to be signed on its behalf by the undersigned, thereunto duly authorized on this 25th day of
February 2011.

TC PIPELINES, LP
(A Delaware Limited Partnership)
by its General Partner, TC PipeLines GP, Inc.

By: /s/ STEVEN D. BECKER

Steven D. Becker
President
TC PipeLines GP, Inc. (Principal Executive Officer)

By: /s/ ROBERT C. JACOBUCCI

Robert C. Jacobucci
Controller
TC PipeLines GP, Inc. (Principal Financial Officer)

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the
following persons in the capacities and on the dates indicated.

Signature

/s/ GREGORY A. LOHNES

Gregory A. Lohnes

/s/ STEVEN D. BECKER

Steven D. Becker

/s/ ROBERT C. JACOBUCCI

Robert C. Jacobucci

/s/ JAMES M. BAGGS

James M. Baggs

/s/ KRISTINE L. DELKUS

Kristine L. Delkus

/s/ WALENTIN (VAL) MIROSH

Walentin (Val) Mirosh

/s/ JACK F. JENKINS-STARK

Jack F. Jenkins-Stark

/s/ DAVID L. MARSHALL

David L. Marshall

Title

Chairman,

Date

February 25, 2011

President and Principal Executive Officer

February 25, 2011

Controller and Principal Financial Officer

February 25, 2011

Director

Director

Director

Director

Director

February 25, 2011

February 25, 2011

February 25, 2011

February 25, 2011

February 25, 2011

2010 ANNUAL REPORT

F-1

TC PIPELINES, LP
INDEX TO FINANCIAL STATEMENTS

FINANCIAL STATEMENTS OF TC PIPELINES, LP

Report of Independent Registered Public Accounting Firm

Balance Sheet – December 31, 2010 and 2009

Statement of Income – Years Ended December 31, 2010, 2009 and 2008

Statement of Comprehensive Income – Years Ended December 31, 2010, 2009 and 2008

Statement of Cash Flows – Years Ended December 31, 2010, 2009 and 2008

Statement of Changes in Partners’ Equity – Years Ended December 31, 2010, 2009 and 2008

Notes to Financial Statements

FINANCIAL STATEMENTS OF GREAT LAKES GAS TRANSMISSION LIMITED PARTNERSHIP

Report of Independent Registered Public Accounting Firm

Balance Sheet – December 31, 2010 and 2009

Statement of Income and Partners’ Capital – Years Ended December 31, 2010, 2009 and 2008

Statement of Cash Flows – Years Ended December 31, 2010, 2009 and 2008

Notes to Financial Statements

FINANCIAL STATEMENTS OF NORTHERN BORDER PIPELINE COMPANY

Report of Independent Registered Public Accounting Firm

Balance Sheet – December 31, 2010 and 2009

Statement of Income – Years Ended December 31, 2010, 2009 and 2008

Statement of Comprehensive Income – Years Ended December 31, 2010, 2009 and 2008

Statement of Cash Flows – Years Ended December 31, 2010, 2009 and 2008

Statement of Changes in Partners’ Equity – Years Ended December 31, 2010, 2009 and 2008

Notes to Financial Statements

Page No.

F-2

F-3

F-4

F-4

F-5

F-6

F-7

F-19

F-20

F-21

F-22

F-23

F-29

F-30

F-31

F-31

F-32

F-33

F-34

F-2

TC PIPELINES, LP

REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The Board of Directors of TC PipeLines GP, Inc., General Partner of TC PipeLines, LP:

We have audited the accompanying consolidated balance sheets of TC PipeLines, LP (a Delaware limited partnership)
and subsidiaries as of December 31, 2010 and 2009, and the related consolidated statements of income,
comprehensive income, cash flows and changes in partners’ equity for each of the years in the three-year period ended
December 31, 2010. We also have audited TC PipeLines, LP internal control over financial reporting as of December 31,
2010, based on criteria established in Internal Control – Integrated Framework issued by the Committee of Sponsoring
Organizations of the Treadway Commission (COSO). Management of the General Partner of TC PipeLines, LP is
responsible for these consolidated financial statements, for maintaining effective internal control over financial reporting,
and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying
Management’s Annual Report on Internal Controls over Financial Reporting. Our responsibility is to express an opinion
on these consolidated financial statements and an opinion on the Partnership’s internal control over financial reporting
based on our audits.

We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board
(United States). Those standards require that we plan and perform the audits to obtain reasonable assurance about
whether the financial statements are free of material misstatement and whether effective internal control over financial
reporting was maintained in all material respects. Our audits of the consolidated financial statements included
examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements, assessing the
accounting principles used and significant estimates made by management, and evaluating the overall financial
statement presentation. Our audit of internal control over financial reporting included obtaining an understanding of
internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating
the design and operating effectiveness of internal control based on the assessed risk. Our audits also included
performing such other procedures as we considered necessary in the circumstances. We believe that our audits provide
a reasonable basis for our opinions.

An entity’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the
reliability of financial reporting and the preparation of financial statements for external purposes in accordance with
generally accepted accounting principles. An entity’s internal control over financial reporting includes those policies and
procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the
transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are
recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting
principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of
management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely
detection of unauthorized acquisition, use, or disposition of the entity’s assets that could have a material effect on the
financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements.
Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become
inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may
deteriorate.

In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the
financial position of TC PipeLines, LP and subsidiaries as of December 31, 2010 and 2009, and the results of its
operations and its cash flows for each of the years in the three-year period ended December 31, 2010, in conformity
with U.S. generally accepted accounting principles. Also in our opinion, TC PipeLines, LP maintained, in all material
respects, effective internal control over financial reporting as of December 31, 2010, based on criteria established in
Internal Control – Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway
Commission.

/s/ KPMG LLP

Calgary, Canada
February 24, 2011

2010 ANNUAL REPORT

F-3

TC PIPELINES, LP
CONSOLIDATED BALANCE SHEET

December 31 (millions of dollars)

2010

2009

Assets
Current Assets

Cash and cash equivalents
Accounts receivable and other (Note 16)

Investment in Great Lakes (Note 3)
Investment in Northern Border (Note 4)
Plant, property and equipment (Note 5)
Goodwill
Other assets

Liabilities and Partners’ Equity
Current Liabilities

Accounts payable and accrued liabilities
Accrued interest
Current portion of long-term debt (Note 7)
Current portion of fair value of derivative contracts (Note 15)

Long-term debt (Note 7)
Fair value of derivative contracts and other (Note 15)

Partners’ Equity (Note 8)

Common units
General partner
Accumulated other comprehensive loss

3.6
8.7

12.3

690.0
504.8
312.6
130.2
0.6

3.1
8.6

11.7

691.2
523.0
318.0
130.2
1.0

1,650.5

1,675.1

7.7
1.3
483.8
13.8

506.6
30.1
1.3

538.0

1,104.2
23.5
(15.2)

1,112.5

1,650.5

4.5
1.3
53.4
12.9

72.1
487.9
11.6

571.6

1,105.6
23.6
(25.7)

1,103.5

1,675.1

Subsequent events (Note 17)

The accompanying notes are an integral part of these consolidated financial statements.

F-4

TC PIPELINES, LP

TC PIPELINES, LP
CONSOLIDATED STATEMENT OF INCOME

Year ended December 31 (millions of dollars except per common unit amounts)

Equity income from investment in Great Lakes (Note 3)
Equity income from investment in Northern Border (Note 4)
Transmission revenues
Operating expenses
General and administrative
Depreciation (Note 5)
Financial charges and other (Note 9)

Net income

Net income allocation (Note 10)
Common units
General partner

Net income per common unit (Note 10)

Weighted average common units outstanding (millions)

Common units outstanding, end of year (millions)

(a) Recast as discussed in Notes 2 and 6.

TC PIPELINES, LP
CONSOLIDATED STATEMENT OF COMPREHENSIVE INCOME

Year ended December 31 (millions of dollars)

Net income(a)
Other comprehensive income/(loss)

Change associated with current period hedging transactions

(Note 15)

Change associated with current period hedging transactions

of investees

Total comprehensive income

(a) Recast as discussed in Notes 2 and 6.

2010

58.7
67.3
69.1
(13.0)
(4.4)
(15.0)
(25.6)

137.1

134.4
2.7

137.1

$2.91

46.2

46.2

2010

137.1

10.0

0.5

10.5

147.6

2009(a)

2008(a)

59.1
40.3
67.9
(11.0)
(6.2)
(14.7)
(29.3)

106.1

90.6
7.2

97.8

$2.34

38.7

46.2

2009

106.1

7.9

1.3

9.2

115.3

57.3
65.3
64.5
(11.5)
(4.1)
(13.9)
(34.6)

123.0

95.1
12.6

107.7

$2.73

34.9

34.9

2008

123.0

(22.0)

(1.6)

(23.6)

99.4

The accompanying notes are an integral part of these consolidated financial statements.

2010 ANNUAL REPORT

F-5

TC PIPELINES, LP
CONSOLIDATED STATEMENT OF CASH FLOWS

Year ended December 31 (millions of dollars)

2010

2009(a)

2008(a)

Cash Generated From Operations
Net income
Depreciation (Note 5)
Amortization of other assets (Note 9)
Increase in other long-term liabilities
Equity allowance for funds used during construction
Decrease/(increase) in operating working capital (Note 12)

Investing Activities
Cumulative distributions in excess of equity earnings:

Great Lakes
Northern Border

Investment in Great Lakes (Note 3)
Investment in Northern Border (Notes 4)
Acquisition of North Baja, net of cash acquired (Note 6)
Capital expenditures
Other assets
Increase in investing working capital (Note 12)

Financing Activities
Distributions paid (Note 11)
Equity issuances, net
Long-term debt issued (Note 7)
Long-term debt repaid (Note 7)
Due to North Baja’s former parent (Note 6)

Increase/(decrease) in cash and cash equivalents
Cash and cash equivalents, beginning of year

Cash and cash equivalents, end of year

Interest payments made

(a) Recast as discussed in Notes 2 and 6.

137.1
15.0
0.5
0.7
(0.3)
3.1

156.1

10.5
18.7
(9.3)
–
–
(9.3)
(0.1)
–

10.5

(138.7)
–
74.0
(101.4)
–

(166.1)

0.5
3.1

3.6

8.5

106.1
14.7
0.4
0.2
(0.5)
2.5

123.4

13.4
35.4
(0.1)
(42.3)
(271.4)
(1.9)
0.1
(2.9)

(269.7)

(117.0)
265.6
208.0
(203.5)
(12.1)

141.0

(5.3)
8.4

3.1

16.5

123.0
13.9
0.5
0.1
(1.1)
(4.2)

132.2

16.6
25.4
–
–
–
(34.6)
–
(3.7)

3.7

(108.6)
–
4.0
(40.6)
10.2

(135.0)

0.9
7.5

8.4

30.3

The accompanying notes are an integral part of these consolidated financial statements.

F-6

TC PIPELINES, LP

TC PIPELINES, LP
CONSOLIDATED STATEMENT OF CHANGES IN PARTNERS’ EQUITY

Common Units
(millions
(millions
of dollars)
of units)

General
Partner
(millions
of dollars)

Accumulated
Other
Comprehensive
Loss(a
(millions
of dollars)

Partners’ equity at December 31, 2007
Net income(b)
Net income attributed to former North Baja owner
Distributions paid
Other comprehensive loss

Partners’ equity at December 31, 2008
Net income(b)
Net income attributed to former North Baja owner
Equity issuances, net (Notes 6 and 8)
Distributions paid
Excess purchase price over net acquired assets(c)
Other comprehensive income

Partners’ equity at December 31, 2009
Net income
Distributions paid
Assets acquired in excess of purchase price(c)
Other comprehensive income

Partners’ equity at December 31, 2010

34.9
–
–
–
–

34.9
–
–
11.3
–
–
–

46.2
–
–
–
–

46.2

892.3
110.9
(15.0)
(96.8)
–

891.4
98.8
(8.2)
260.2
(109.4)
(27.2)
–

1,105.6
134.4
(135.9)
0.1
–

1,104.2

19.1
12.1
(0.3)
(11.8)
–

19.1
7.3
(0.1)
5.4
(7.6)
(0.5)
–

23.6
2.7
(2.8)
–
–

23.5

(11.3)
–
–
–
(23.6)

(34.9)
–
–
–
–
–
9.2

(25.7)
–
–
–
10.5

(15.2)

Partners’ Equity
(millions
(millions
of dollars)
of units)

34.9
–
–
–
–

34.9
–
–
11.3
–
–
–

46.2
–
–
–
–

46.2

900.1
123.0
(15.3)
(108.6)
(23.6)

875.6
106.1
(8.3)
265.6
(117.0)
(27.7)
9.2

1,103.5
137.1
(138.7)
0.1
10.5

1,112.5

(a) The Partnership uses derivatives to assist in managing its exposure to interest rate risk. Based on interest rates at December 31, 2010, the
amount of losses related to cash flow hedges reported in accumulated other comprehensive income that is expected to be reclassified to
net income in the next 12 months is $13.8 million, which will be offset by a reduction to interest expense of a similar amount.

(b) Recast as discussed in Notes 2 and 6.

(c) Accounting adjustment for common control transaction. See Note 6 for details.

The accompanying notes are an integral part of these consolidated financial statements.

2010 ANNUAL REPORT

F-7

TC PIPELINES, LP
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

NOTE 1 ORGANIZATION

TC PipeLines, LP and its subsidiaries are collectively referred to herein as the Partnership. The Partnership was formed by TransCanada PipeLines
Limited, a wholly-owned subsidiary of TransCanada Corporation (collectively referred to herein as TransCanada), to acquire, own and
participate in the management of energy infrastructure assets in North America.

The Partnership owns the following interests in natural gas pipeline systems:

(cid:127) a 46.45 percent general partner interest in Great Lakes Gas Transmission Limited Partnership (Great Lakes), a Delaware limited partnership.

Great Lakes owns a 2,115-mile pipeline that transports natural gas serving markets in Minnesota, Wisconsin, Michigan and Eastern Canada;

(cid:127) a 50 percent general partner interest in Northern Border Pipeline Company (Northern Border), a Texas general partnership. Northern Border
owns a 1,398-mile U.S. interstate pipeline system that transports natural gas from the Montana-Saskatchewan border to markets in the
Midwestern U.S.;

(cid:127) a 100 percent interest in North Baja Pipeline, LLC (North Baja), a Delaware limited liability company. North Baja owns an 86-mile

U.S. interstate pipeline system that transports natural gas between an interconnection with El Paso Natural Gas Company pipeline near
Ehrenberg, Arizona and an interconnection near Ogilby, California on the California/Mexico border with the Gasoducto Bajanorte natural
gas pipeline system; and

(cid:127) a 100 percent interest in Tuscarora Gas Transmission Company (Tuscarora), a Nevada general partnership. Tuscarora owns a 305-mile

U.S. interstate pipeline system that transports natural gas from Oregon, where it interconnects with facilities of Gas Transmission Northwest
Corporation, a wholly-owned subsidiary of TransCanada, to a terminus in Northern Nevada.

The Partnership is managed by its General Partner, TC PipeLines GP, Inc. (TC PipeLines GP), a wholly-owned subsidiary of TransCanada. The
General Partner provides management and operating services for the Partnership and is reimbursed for its costs and expenses. In addition to
its aggregate two percent general partner interest in the Partnership, the General Partner owns 5,797,106 common units, representing an
effective 14.3 percent interest in the Partnership at December 31, 2010. TransCanada also indirectly holds 11,287,725 common units
representing an effective 23.9 percent limited partner interest in the Partnership at December 31, 2010.

NOTE 2 SIGNIFICANT ACCOUNTING POLICIES

(a) Basis of Presentation
The accompanying financial statements and related notes present the financial position of the Partnership as at December 31, 2010 and 2009
and the results of its operations, cash flows and changes in partners’ equity for the years ended December 31, 2010, 2009 and 2008. The
Partnership uses the equity method of accounting for its investments in Great Lakes and Northern Border, over which it is able to exercise
significant influence. The Partnership consolidates its investments in North Baja and Tuscarora.

On July 1, 2009, the Partnership acquired a 100 percent interest in North Baja from TransCanada. The acquisition was accounted for as a
transaction between entities under common control, similar to a pooling of interests, whereby the assets and liabilities of North Baja were
recorded at TransCanada’s carrying value and the Partnership’s historical financial information was recast to include North Baja for all periods
presented on a consolidated basis. Refer to Note 6 for additional disclosure regarding the North Baja acquisition.

Amounts are stated in U.S. dollars. Certain comparative figures have been reclassified to conform to the current year’s presentation.

(b) Use of Estimates
The preparation of financial statements in conformity with United States of America (U.S.) generally accepted accounting principles (GAAP)
requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of
contingent assets and liabilities as at the date of the financial statements and the reported amounts of revenues and expenses during the
reporting period. Although management believes these estimates are reasonable, actual results could differ from these estimates. In the
opinion of management, these consolidated financial statements have been properly prepared within reasonable limits of materiality and
include all adjustments (consisting of normal recurring accruals) necessary for a fair presentation of the financial results for the periods
presented.

(c) Cash and Cash Equivalents
The Partnership’s short-term investments with original maturities of three months or less are considered to be cash equivalents and are
recorded at cost, which approximates market value.

F-8

TC PIPELINES, LP

(d) Plant, Property and Equipment
Plant, property and equipment of North Baja and Tuscarora is stated at original cost. Costs of restoring the land above and around the
pipeline are capitalized to pipeline facilities and depreciated over the remaining life of the related pipeline facilities. Depreciation of pipeline
facilities and compression equipment is provided on a straight-line composite basis over the estimated useful life of the pipeline and
compression equipment of 25 to 30 years. Metering and other is depreciated on a straight-line basis over the estimated useful lives of the
equipment, which range from 3 to 30 years. Repair and maintenance costs are expensed as incurred. Costs that are considered a betterment
are capitalized. An allowance for funds used during construction, using the rate of return on rate base approved by the Federal Energy
Regulatory Commission (FERC), is capitalized and included in the cost of plant, property and equipment. Amounts included in construction
work in progress are not amortized until transferred into service.

The Partnership tests its long-lived assets for impairment whenever events or changes in circumstances indicate that its carrying amount may
exceed the undiscounted cash flows expected to be generated by the asset. If the carrying amount exceeds the undiscounted cash flows,
impairment is recognized to the extent the carrying amount exceeds its fair value.

(e) Partners’ Equity
Costs incurred in connection with the issuance of units are deducted from the proceeds received.

(f) Revenue Recognition
Transmission revenues relate to North Baja and Tuscarora operations and are recognized in the period in which the service is provided. When a
rate case is pending final FERC approval, a portion of the revenue collected is subject to possible refund. As at December 31, 2010, 2009 and
2008, the Partnership has not recognized any transmission revenue that is subject to possible refund.

Income Taxes

(g)
The Partnership is not subject to federal or state income tax. The tax effect of the Partnership’s activities accrues to its partners. The
Partnership’s taxable income or loss, which may vary substantially from the net income or loss reported in the consolidated statement of
income, is includable in the federal income tax returns of each partner. The aggregate difference in the basis of the Partnership’s net assets for
financial and income tax purposes cannot be readily determined because all information regarding each partner’s tax attributes related to the
partnership is not available.

(h) Acquisitions and Goodwill
The Partnership accounts for business acquisitions from third parties using the purchase method of accounting and, accordingly, the assets and
liabilities of the acquired entities are recorded at their estimated fair values at the date of acquisition. The excess of the purchase price over
the fair value of net assets acquired is attributed to goodwill. Goodwill is not amortized for accounting purposes; however, it is tested on an
annual basis for impairment, or more frequently if any indicators of impairment are evident.

The Partnership accounts for business acquisitions between entities under common control using a method similar to a pooling of interests,
whereby the assets and liabilities of the acquired entities are recorded at TransCanada’s carrying value and the Partnership’s historical financial
information is recast to include the acquired entities for all periods presented. If the fair market value paid for the acquired entities is greater
than the recorded net assets of the acquired entities, the excess purchase price paid is recorded as a reduction to Partners’ Equity. Similarly, if
the fair market value paid for the acquired entities is less than the recorded net assets of the acquired entities, the excess of assets acquired is
recorded as an increase to Partners’ Equity.

(i) Derivative Financial Instruments and Hedging Activities
The Partnership utilizes derivative and other financial instruments to manage its exposure to changes in interest rates. Derivatives and other
hedging instruments must be designated as hedges and be effective to qualify for hedge accounting. For cash flow hedges, unrealized gains
or losses relating to derivatives are recognized as other comprehensive income. In the event that a derivative does not meet the designation or
effectiveness criteria, any unrealized gain or loss on the instrument is recognized immediately in earnings.

If a derivative that previously qualified as a hedge is settled, de-designated or ceases to be effective, the gain or loss at that date is recognized
in the same period and in the same financial statement category as the corresponding hedged transactions. If a hedged anticipated
transaction is no longer probable to occur, related gains or losses are immediately recognized in earnings and amounts previously recognized
in other comprehensive income are reclassified to earnings prospectively. Costs associated with the purchase of certain hedging instruments
are deferred and amortized against interest expense.

2010 ANNUAL REPORT

F-9

(j) Asset Retirement Obligation
The Partnership recognizes and measures liabilities associated with the retirement of tangible long-lived assets at fair value as incurred and
capitalize them as part of the cost of the related tangible long-lived assets. Accretion of the liabilities due to the passage of time is classified
as an operating expense. Retirement obligations associated with relevant long-lived are those for which a legal obligation exists under enacted
laws, statutes, ordinances, or written or oral contracts, including obligations arising under the doctrine of promissory estoppel.

No amount is recorded for asset retirement obligations relating to the assets as it is not possible to make a reasonable estimate of the fair
value of the liability due to the inability to determine the scope and timing of the asset retirements.

(k) Government Regulation
North Baja and Tuscarora, the Partnership’s wholly-owned pipeline systems, are subject to regulation by the FERC. Under regulatory accounting
principles, certain assets or liabilities that result from the regulated ratemaking process may be recorded that would not be recorded under
GAAP for non-regulated entities. The Partnership regularly evaluates the continued applicability of regulatory accounting, considering such
factors as regulatory changes, the impact of competition, and the ability to recover regulatory assets. As at December 31, 2010, Tuscarora has
no regulatory assets (2009 – nil) and $0.5 million in regulatory liabilities (2009 – nil). North Baja has no regulatory assets or liabilities as at
December 31, 2010 and 2009. Allowance for funds used during construction is capitalized and included in plant, property and equipment.

(l) Debt Issuance Costs
Costs related to the issuance of debt are deferred and amortized using the effective interest rate method over the term of the related debt.

NOTE 3 INVESTMENT IN GREAT LAKES

The Partnership owns a 46.45 percent general interest in Great Lakes. TransCanada owns the other 53.55 percent partnership interest and is
also the operator of Great Lakes. Great Lakes is regulated by the FERC.

TC GL Intermediate Limited Partnership, as one of the general partners, may be exposed to the commitments and contingencies of Great
Lakes. The Partnership holds a 98.9899 percent limited partnership interest in TC GL Intermediate Limited Partnership.

On November 19, 2009, the FERC issued an order in FERC Docket No. RP10-149 (November 2009 Order) instituting an investigation pursuant
to Section 5 of the Natural Gas Act (GL Rate Proceeding). The FERC alleged, based on a review of certain historical information, that Great
Lakes’ revenues might substantially exceed Great Lakes’ actual cost of service and therefore may be unjust and unreasonable. As a result of
extensive settlement negotiations, in July 2010, the FERC approved the settlement without modification, establishing the terms pursuant to
which all matters in the GL Rate Proceeding were resolved. The settlement was effective May 1, 2010 and applies to all current and future
shippers on Great Lakes’ system.

The Partnership uses the equity method of accounting for its investment in Great Lakes. The Partnership’s equity income from its investment in
Great Lakes amounted to $58.7 million for the year ended December 31, 2010 (2009 – $59.1 million; 2008 – $57.3). Great Lakes had no
undistributed earnings for the years ended December 31, 2010, 2009, and 2008.

At December 31, 2010 and 2009, the partnership had a $458.4 million difference between the carrying value of Great Lakes and the
underlying equity in the net assets primarily resulting from the recognition of goodwill as part of the Partnership’s investment in Great Lakes
relating to the Partnership’s February 2007 acquisition of a 46.45 percent general interest in Great Lakes.

The Partnership made an equity contribution of $4.6 million to Great Lakes in 2010. This amount represents the Partnership’s 46.45 percent
share of a $10.0 million cash call issued by Great Lakes to expand backhaul capacity from St. Clair, Michigan, U.S. to Emerson, Manitoba,
Canada. The Partnership also made an equity contribution of $4.7 million to Great Lakes in 2010, which represents the Partnership’s
46.45 percent share of a $10.0 million cash call from Great Lakes to make a scheduled debt repayment and is the result of a change in Great
Lakes’ distribution policy in 2010, whereby Great Lakes commenced funding its debt repayments with cash calls to its partners and making
distributions to its partners before deducting amounts for debt repayments.

F-10

TC PIPELINES, LP

The following tables contain summarized financial information of Great Lakes as at December 31, 2010 and 2009 and for the years ended
December 31, 2010, 2009 and 2008:

Summarized Consolidated Great Lakes Balance Sheet

December 31 (millions of dollars)

Assets
Cash and cash equivalents
Other current assets
Plant, property and equipment, net
Other assets

Liabilities and Partners’ Equity
Current liabilities
Deferred credits
Long-term debt, including current maturities
Partners’ capital

Summarized Consolidated Great Lakes Income Statement

Year ended December 31 (millions of dollars)

Transmission revenues
Operating expenses
Depreciation
Financial charges and other
Michigan business tax

Net income

2010

262.4
(59.2)
(40.5)
(30.9)
(5.3)

126.5

2010

–
83.7
846.9
0.6

931.2

34.9
5.6
392.0
498.7

931.2

2009

289.7
(66.5)
(58.5)
(31.9)
(5.4)

127.4

2009

0.1
82.3
873.3
0.7

956.4

40.3
3.8
411.0
501.3

956.4

2008

287.1
(67.1)
(58.5)
(32.6)
(5.5)

123.4

NOTE 4 INVESTMENT IN NORTHERN BORDER

The Partnership owns a 50 percent general partner interest in Northern Border. The other 50 percent partnership interest in Northern Border is
held by ONEOK Partners, L.P., a publicly traded limited partnership. Northern Border is regulated by the FERC. Northern Border is operated
by TransCanada.

TC PipeLines Intermediate Limited Partnership, as one of the general partners, may be exposed to the commitments and contingencies of
Northern Border. The Partnership holds a 98.9899 percent limited partnership interest in TC PipeLines Intermediate Limited Partnership.

The Partnership uses the equity method of accounting for its investment in Northern Border. The Partnership’s equity income from its
investment in Northern Border amounted to $67.3 million for the year ended December 31, 2010 (2009 – $40.3 million; 2008 –
$65.3 million). Equity income from Northern Border includes a twelve-year amortization of a $10.0 million transaction fee paid to the operator
of Northern Border as an inducement to become operator at the time of the additional 20 percent acquisition in April 2006. Northern Border
had no undistributed earnings for the years ended December 31, 2010, 2009 and 2008.

At December 31, 2010, the Partnership had a $120.8 million (2009 – $121.2 million) difference between the carrying value of Northern Border
and the underlying equity in the net assets primarily resulting from the recognition of goodwill as part of the Partnership’s investment in
Northern Border relating to the Partnership’s April 2006 acquisition of an additional 20 percent general partnership interest in Northern Border.

The following tables contain summarized financial information of Northern Border as at December 31, 2010 and 2009 and for the years
ended December 31, 2010, 2009 and 2008:

2010 ANNUAL REPORT

F-11

Summarized Northern Border Balance Sheet

December 31 (millions of dollars)

Assets
Cash and cash equivalents
Other current assets
Plant, property and equipment, net
Other assets

Liabilities and Partners’ Equity
Current liabilities
Deferred credits and other
Long-term debt, including current maturities
Partners’ equity

Partners’ capital
Accumulated other comprehensive loss

Summarized Northern Border Income Statement

Year ended December 31 (millions of dollars)

Transmission revenues
Operating expenses
Depreciation
Financial charges and other (Note 13)

Net income

NOTE 5 PLANT, PROPERTY AND EQUIPMENT

2010

2009

10.2
37.1
1,294.8
22.9

1,365.0

46.7
9.7
540.6

770.9
(2.9)

1,365.0

2009

249.2
(70.8)
(61.9)
(34.4)

82.1

16.9
30.2
1,343.1
24.2

1,414.4

38.0
8.3
564.6

806.6
(3.1)

1,414.4

2008

293.1
(78.0)
(61.1)
(21.8)

132.2

2010

295.1
(74.0)
(61.5)
(23.4)

136.2

December 31 (millions of dollars)

Pipeline
Compression
Metering and other
Under construction

2010

Accumulated
Depreciation

Net Book
Value

100.6
24.5
8.2
–

133.3

189.5
88.9
34.0
0.2

312.6

Cost

290.1
113.4
42.2
0.2

445.9

Cost

279.6
113.4
37.5
5.8

436.3

2009

Accumulated
Depreciation

90.7
20.5
7.1
–

118.3

Net Book
Value

188.9
92.9
30.4
5.8

318.0

F-12

TC PIPELINES, LP

NOTE 6 ACQUISITIONS AND REVISED INCENTIVE DISTRIBUTION RIGHTS

On July 1, 2009, the Partnership acquired a 100 percent interest in North Baja, a Delaware limited liability company, from TransCanada. The
North Baja pipeline system extends from an interconnection with EPNG near Ehrenberg, Arizona to a point near Ogilby, California on the
California/Mexico border where it connects with the Gasoducto Bajanorte natural gas pipeline system owned by Sempra Energy International.
North Baja is regulated by the FERC and is operated by TransCanada.

The purchase price of $271.4 million was financed through a combination of (i) a draw of $170.0 million on the Partnership’s $250.0 million
revolving portion of its revolving credit and term loan agreement (Senior Credit Facility), (ii) issuance of 2,609,680 common units at $30.042
per common unit to TransCanada for gross proceeds of $78.4 million, (iii) issuance of additional general partner interest to the General
Partner of $1.6 million, which was required to maintain the General Partner’s two percent general partner interest in the Partnership, and
(iv) approximately $21.4 million of cash on hand.

The acquisition of North Baja was accounted for as a transaction between entities under common control, similar to a pooling of interests,
whereby the assets and liabilities of North Baja were recorded at TransCanada’s carrying value and the Partnership’s historical financial
information was recast to include North Baja for all periods presented. The purchase price was recorded as follows: Working capital of
$2.0 million; Plant, property and equipment of $193.5 million; Goodwill of $48.5 million; Other assets of $0.1 million; and Other long-term
liabilities of $0.4 million. As the fair value paid for North Baja was greater than the recorded net assets of North Baja, the excess purchase
price paid of $27.7 million was recorded as a reduction to Partners’ Equity. The effect of recasting the Partnership’s consolidated financial
statements to account for the common control transaction increased the Partnership’s net income by $8.3 million and $15.3 million for the
years ended December 31, 2009 and 2008, respectively, from amounts previously reported.

Concurrent with the acquisition of North Baja, the Partnership entered into an exchange agreement with its General Partner whereby the
Partnership issued 3,762,000 common units to the General Partner and provided for revised incentive distribution rights (Revised IDRs) in
exchange for the cancellation of the incentive distribution rights available to the General Partner (Old IDRs) under the Amended and Restated
Agreement of Limited Partnership of the Partnership.

Under the terms of the Revised IDRs, the distributions to the General Partner were reset to two percent, down from the General Partner
distribution levels of the Old IDRs at 50 percent (for combined general partner interest and incentive distribution interest). The incentive
distribution levels of the Revised IDRs will result in increased combined distributions to the General Partner (for general partner interest and
incentive distribution interest) of 15 percent and a maximum of 25 percent when quarterly distributions increase to $0.81 and $0.88 per
common unit or $3.24 and $3.52 per common unit on an annualized basis, respectively.

At the time of the July 1, 2009 acquisition of North Baja, TransCanada had begun an expansion project of the North Baja pipeline from the
Mexico/Arizona border to Yuma, Arizona (Yuma Lateral). The Partnership agreed to acquire the expansion facilities and contracts for an
additional sum up to $10.0 million, if TransCanada completed the project by June 30, 2010. On March 5, 2010, the Partnership acquired the
expansion facilities and contracts in place at that time for a purchase price of $7.6 million. The Yuma Lateral was placed into service on
March 13, 2010. The North Baja Acquisition Agreement provided that an additional payment of up to $2.4 million be made to TransCanada in
the event that any other shippers contracted for services on the Yuma Lateral before June 30, 2010. A potential shipper signed a precedent
agreement with North Baja on June 29, 2010 to enter into agreements for service on the Yuma Lateral. Accordingly, an amendment to the
Acquisition Agreement between the Partnership and TransCanada was entered into on June 29, 2010 to allow TransCanada to continue to
pursue additional contracts until December 31, 2010. On July 28, 2010, TransCanada secured additional contracts and, as a result, an
additional payment of up to $2.4 million will be paid to TransCanada when the facilities associated with the additional contracts go into
service which is anticipated in first quarter 2011.

The Yuma Lateral asset purchase was accounted for as a transaction between entities under common control, similar to a pooling of interests,
whereby the assets acquired were recorded at TransCanada’s carrying value. As the fair value paid for the Yuma Lateral assets of $7.6 million
was less than the $7.7 million recorded as plant, property and equipment, the excess amount of assets acquired of $0.1 million was recorded
as an increase to Partners’ Equity at December 31, 2010.

NOTE 7 CREDIT FACILITIES AND LONG-TERM DEBT

December 31 (millions of dollars)

Senior Credit Facility due 2011
7.13% Series A Senior Notes due 2010
7.99% Series B Senior Notes due 2010
6.89% Series C Senior Notes due 2012
3.82% Series D Senior Notes due 2017

Less: current portion of long-term debt

2010 ANNUAL REPORT

F-13

2010

483.0
–
–
3.9
27.0

513.9
483.8

30.1

2009

484.0
48.2
4.4
4.7
–

541.3
53.4

487.9

The Partnership’s Senior Credit Facility consists of a $475.0 million senior term loan and a $250.0 million senior revolving credit facility with a
banking syndicate. At December 31, 2010, $475.0 million remained outstanding under the senior term loan (2009 – $475.0 million) and
$8.0 million was outstanding under the senior revolving credit facility (2009 – $9.0 million), leaving $242.0 million available for future
borrowings.

The Senior Credit Facility matures on December 12, 2011, subject to two one-year extensions at the option of the Partnership and with the
approval of a majority of the lenders thereunder. Amounts borrowed may be repaid in part, or in full, prior to that time without penalty.
However, once a senior term loan is repaid, it cannot be re-borrowed. Borrowings under the Senior Credit Facility bear interest based, at the
Partnership’s election, on the London Interbank Offered Rate (LIBOR) or the prime rate plus, in either case, an applicable margin. There was
$483.0 million outstanding under the Senior Credit Facility at December 31, 2010 (2009 – $484.0 million). The interest rate on the Senior
Credit Facility averaged 0.91 percent for the year ended December 31, 2010 (2009 – 1.42 percent). After hedging activity, the interest rate
incurred on the Senior Credit Facility averaged 4.30 percent for the year ended December 31, 2010 (2009 – 4.10 percent). Prior to hedging
activities, the interest rate was 0.83 percent at December 31, 2010 (2009 – 0.97 percent).

At December 31, 2010, the Partnership was in compliance with its financial covenants, in addition to the other covenants which include
restrictions on entering into mergers, consolidations and sales of assets, granting liens, material amendments to the Partnership Agreement,
incurring additional debt and distributions to unitholders.

On December 21, 2010, Tuscarora’s Series A and B Senior Notes matured. Also on December 21, 2010, Tuscarora issued $27.0 million of
3.82 percent Series D Senior Notes, which require principal and interest payments over approximately seven years. The Series D Senior Notes
mature on August 21, 2017.

Series C and D Senior Notes are secured by Tuscarora’s transportation contracts, supporting agreements and substantially all of Tuscarora’s
property. The note purchase agreements contain certain provisions that include, among other items, limitations on additional indebtedness and
distributions to partners.

The principal repayments required on the long-term debt are as follows:

(millions of dollars)

2011
2012
2013
2014
2015
Thereafter

483.8
3.1
3.5
3.6
3.7
16.2

513.9

On April 22, 2010, the Partnership filed an automatic universal shelf registration statement on Form S-3 (ASR) with the Securities and
Exchange Commission, which replaced the universal shelf registration filed in December 2008. The ASR will allow the Partnership to issue an
indeterminate amount of securities of the Partnership, including both senior and subordinated debt securities and/or common units
representing limited partnership interests in the Partnership. The ASR was effective immediately upon filing and will expire April 22, 2013.

F-14

TC PIPELINES, LP

NOTE 8 PARTNERS’ EQUITY

At December 31, 2010, Partners’ equity includes 46,227,766 common units (2009 – 46,227,766 common units) representing an aggregate
98 percent limited partner interest in the Partnership (including 5,797,106 common units held by the General Partner and
11,287,725 common units held indirectly by TransCanada) and an aggregate two percent general partner interest. In aggregate, the General
Partner’s interests represent an effective 14.3 percent ownership in the Partnership at December 31, 2010 (December 31, 2009 –
14.3 percent).

On November 18, 2009, the Partnership completed a public offering of 5,000,000 common units at $38.00 per common unit for gross
proceeds of $190.0 million and net proceeds of $181.8 million after unit issuance costs. TC PipeLines GP maintained its two percent general
partner interest in the Partnership by contributing $3.8 million to the Partnership in connection with the offering.

Refer to Note 6 for disclosure regarding the equity issuance in connection with the acquisition of North Baja in 2009.

NOTE 9 FINANCIAL CHARGES AND OTHER

Year ended December 31 (millions of dollars)

Interest expense on long-term debt
Interest expense on short-term debt(a)
Capitalized interest(a)
Loss on interest rate swaps and options
Interest income(a)
Amortization of other assets
Other

(a) Recast as discussed in Notes 2 and 6.

NOTE 10 NET INCOME PER COMMON UNIT

2010

8.4
–
(0.2)
16.5
–
0.5
0.4

25.6

2009

12.5
2.1
(0.4)
15.1
(0.4)
0.4
–

29.3

2008

23.4
6.0
(1.4)
6.9
(0.8)
0.5
–

34.6

Net income per common unit is computed by dividing net income, after deduction of the General Partner’s allocation, by the weighted
average number of common units outstanding. The General Partner’s allocation is equal to an amount based upon the General Partner’s two
percent interest, plus an amount equal to incentive distributions. Incentive distributions are paid to the General Partner if quarterly cash
distributions on the common units exceed levels specified in the Partnership Agreement.

Net income per common unit was determined as follows:

(millions of dollars except per unit)

Net income(a)
North Baja’s contribution prior to acquisition

Net income allocated to partners(b)
Net income allocated to general partner:

General partner interest
Incentive distribution income allocation

Net income allocable to common units

Weighted average common units outstanding (millions)
Net income per common unit

(a) Recast as discussed in Notes 2 and 6.

2010

137.1
–

137.1

(2.7)
–

(2.7)

134.4

46.2
$2.91

2009

106.1
(8.3)

97.8

(1.9)
(5.3)

(7.2)

90.6

38.7
$2.34

2008

123.0
(15.3)

107.7

(2.2)
(10.4)

(12.6)

95.1

34.9
$2.73

(b) Net income allocated to partners excludes North Baja’s earnings prior to the Partnership’s acquisition of North Baja on July 1, 2009, as the

earnings of North Baja prior to that date were allocated to TransCanada and were not allocable to either the General Partner or
common units.

2010 ANNUAL REPORT

F-15

NOTE 11 CASH DISTRIBUTIONS

The Partnership makes cash distributions to its partners with respect to each calendar quarter within 45 days after the end of each quarter.
Distributions are based on Available Cash, as defined in the Partnership Agreement, which includes all cash and cash equivalents of the
Partnership and working capital borrowings less reserves established by the General Partner. The Unitholders currently receive a quarterly
distribution of $0.75 per common unit if and to the extent there is sufficient Available Cash.

As an incentive, the General Partner’s percentage interest in quarterly distributions is increased after certain specified target levels are met.
Prior to July 1, 2009, the combined general partner interest and incentive distribution interest payable to the General Partner were 15 percent,
25 percent, and 50 percent of all quarterly distributions of Available Cash that exceed target levels of $0.45, $0.5275 and $0.69 per common
unit, respectively. On July 1, 2009, the incentive distributions were revised under the Second Amended and Restated Agreement of Limited
Partnership of the Partnership. Currently, the combined general partner interest and incentive distribution interest payable to the General
Partner are 15 percent and a maximum of 25 percent of all quarterly distributions of Available Cash that exceed target levels of $0.81 and
$0.88, respectively, per common unit.

For the year ended December 31, 2010, the Partnership distributed $2.94 per common unit (2009 – $2.87 per common unit; 2008 – $2.75
per common unit). The distributions paid for the year ended December 31, 2010 included no incentive distributions to the General Partner
(2009 – $5.3 million; 2008 – $9.7 million). Partnership income is allocated to the General Partner and the limited partners in accordance with
their respective partnership percentages, after giving effect to any priority income allocations for incentive distributions that are allocated
100 percent to the General Partner.

NOTE 12 CHANGE IN WORKING CAPITAL

Year Ended December 31 (millions of dollars)

2010

2009(a)

2008(a)

(Increase)/decrease in accounts receivable and other
Decrease in bank indebtedness
Increase/(decrease) in accounts payable and accrued liabilities
Decrease in accrued interest

Increase in investing working capital

Decrease/(increase) in operating working capital

(a) Recast as discussed in Notes 2 and 6.

NOTE 13 RELATED PARTY TRANSACTIONS

(0.1)
–
3.2
–

3.1
–

3.1

2.8
–
(0.8)
(2.4)

(0.4)
(2.9)

2.5

(0.6)
(1.4)
(5.0)
(0.9)

(7.9)
(3.7)

(4.2)

The Partnership does not have any employees. The management and operating functions are provided by the General Partner. The General
Partner does not receive a management fee in connection with its management of the Partnership. The Partnership reimburses the General
Partner for all costs of services provided, including the costs of employee, officer and director compensation and benefits, and all other
expenses necessary or appropriate to the conduct of the business of, and allocable to, the Partnership. Such costs include (i) overhead costs
(such as office space and equipment) and (ii) out-of-pocket expenses related to the provision of such services. The Partnership Agreement
provides that the General Partner will determine the costs that are allocable to the Partnership in any reasonable manner determined by the
General Partner in its sole discretion. Total costs charged to the Partnership by the General Partner were $2.2 million for the year ended
December 31, 2010 (2009 – $2.1 million; 2008 – $2.1 million).

As operator, TransCanada and its affiliates provide capital and operating services to Great Lakes, Northern Border, North Baja and Tuscarora
(together, ‘‘our pipeline systems’’). TransCanada and its affiliates incur costs on behalf of our pipeline systems, including, but not limited to,
employee salary and benefit costs, and property and liability insurance costs.

F-16

TC PIPELINES, LP

Costs charged to our pipeline systems for the years ended December 31, 2010, 2009 and 2008 by TransCanada and its affiliates and amounts
payable to TransCanada and its affiliates at December 31, 2010 and 2009 are summarized in the following tables:

Year ended December 31 (millions of dollars)

Costs charged by TransCanada and its affiliates:

Great Lakes
Northern Border(a)
North Baja(b)
Tuscarora

Impact on the Partnership’s net income:

Great Lakes
Northern Border
North Baja(b)
Tuscarora

2010

2009

2008

30.3
25.8
4.4
3.7

12.8
12.5
3.2
3.5

33.8
25.5
2.9
3.0

14.3
12.3
2.4
2.8

34.3
30.5
4.7
3.7

14.2
12.9
2.7
2.7

December 31 (millions of dollars)

2010

2009

Amount payable to/(receivable from) TransCanada and its affiliates:

Great Lakes
Northern Border
North Baja
Tuscarora

3.0
2.2
0.6
0.7

3.7
2.6
(1.6)
0.6

(a)

In 2008, Northern Border’s costs charged by TransCanada and its affiliates include $2.0 million of charges related to Bison Pipeline LLC
through the effective date of the sale.

(b) Recast as discussed in Notes 2 and 6.

Great Lakes earns transportation revenues from TransCanada and its affiliates under contracts with fixed prices. The contracts have remaining
terms ranging from one to eight years. Great Lakes earned $148.5 million of transportation revenues under these contracts in 2010 (2009 –
$141.7 million; 2008 – $143.7 million). This amount represents 56.6 percent of total revenues earned by Great Lakes in 2010 (2009 –
48.9 percent; 2008 – 50.0 percent). Great Lakes also earned $0.9 million in affiliated rental revenue in 2010 (2009 – $0.6 million; 2008 –
$0.4 million).

Revenue from TransCanada and its affiliates of $69.3 million is included in the calculation of the Partnership’s equity income from Great Lakes
in 2010 (2009 – $66.1 million; 2008 – $66.9 million). At December 31, 2010, $11.0 million was included in Great Lakes’ receivables for
transportation contracts with TransCanada and its affiliates (2009 – $12.9 million).

In August 2008, Northern Border sold its wholly-owned subsidiary, Bison Pipeline LLC, to TransCanada for $20.0 million. In connection with
this transaction, Northern Border recorded a gain on sale of $16.2 million, of which the Partnership’s share is $8.1 million. In the Summarized
Northern Border Income Statement provided in Note 4, the gain on sale is included in Financial charges, net and other.

Northern Border’s Des Plaines Project consists of the construction, ownership and operation of interconnect facilities near Joliet, Illinois. In
June 2008, in connection with the Des Plaines Project, Northern Border and ANR Pipeline Company (ANR), a wholly-owned subsidiary of
TransCanada, entered into an Interconnect Agreement, which provided that Northern Border would reimburse ANR for the cost of the
interconnect facilities to be owned by ANR. In June 2008, Northern Border paid ANR $0.5 million.

2010 ANNUAL REPORT

F-17

NOTE 14 QUARTERLY FINANCIAL DATA (unaudited)

The following sets forth selected unaudited financial data for the four quarters in 2010 and 2009:

Quarter ended (millions of dollars except per common unit amounts)

Mar 31

Jun 30

Sep 30

Dec 31

2010
Equity income
Transmission revenues
Net income
Net income per common unit
Cash distributions paid

2009
Equity income
Transmission revenues(a)
Net income(a)
Net income per common unit
Cash distributions paid

(a) Recast as discussed in Notes 2 and 6.

NOTE 15 FINANCIAL INSTRUMENTS

30.9
17.4
33.7
$0.71
34.4

35.1
16.8
35.9
$0.82
27.7

25.3
17.0
27.7
$0.59
34.4

18.3
16.8
17.9
$0.31
27.8

35.6
17.4
38.6
$0.82
34.4

23.7
17.5
27.4
$0.65
30.8

34.2
17.3
37.1
$0.79
35.4

22.3
16.8
24.9
$0.56
30.7

The carrying value of cash and cash equivalents, accounts receivable and other, accounts payable and accrued liabilities, and accrued interest
approximate their fair values because of the short maturity or duration of these instruments, or because the instruments carry a variable rate
of interest or a rate that approximates current rates. The fair value of the Partnership’s long-term debt is estimated by discounting the future
cash flows of each instrument at estimated current borrowing rates.

The estimated fair values of the Partnership’s and its subsidiary’s long-term debt as at December 31, 2010 and 2009 are as follows:

December 31 (millions of dollars)

Carrying Value

Fair Value

Carrying Value

Fair Value

2010

2009

Senior Credit Facility
Series A Senior Notes
Series B Senior Notes
Series C Senior Notes
Series D Senior Notes

483.0
–
–
3.9
27.0

513.9

483.0
–
–
4.3
26.6

513.9

484.0
48.2
4.4
4.7
–

541.3

484.0
50.8
4.7
5.2
–

544.7

The Partnership’s long-term debt results in exposures to changing interest rates. The Partnership uses derivatives to assist in managing its
exposure to interest rate risk.

The interest rate swaps and options are structured such that the cash flows match those of the Senior Credit Facility. The notional amount
hedged was $375.0 million at December 31, 2010 (2009 – $375.0 million). $300.0 million of variable-rate debt is hedged by an interest rate
swap through December 12, 2011, where the weighted average fixed interest rate paid is 4.89 percent. $75.0 million of variable-rate debt is
hedged by an interest rate swap through February 28, 2011, where the fixed interest rate paid is 3.86 percent. $100.0 million of variable-rate
debt was hedged by an interest rate option through May 22, 2009 at an interest rate range between a weighted average floor of
4.09 percent and a cap of 5.35 percent. In addition to these fixed rates, the Partnership pays an applicable margin in accordance with the
Senior Credit Facility agreement.

Financial instruments are recorded at fair value on a recurring basis and are categorized into one of three categories based upon a fair value
hierarchy. The Partnership has classified all of its derivative financial instruments as Level II for all periods presented where the fair value is
determined by using valuation techniques that refer to observable market data or estimated market prices. At December 31, 2010, the fair
value of the interest rate swaps accounted for as hedges was negative $13.8 million (2009 – negative $23.8 million), of which $13.8 million is
classified as a current liability (2009 – $12.9 million). The fair value of the interest rate swaps was calculated using the year end interest rate;
therefore, it is expected that this fair value will fluctuate over the year as interest rates change. In 2010, the Partnership recorded interest
expense of $16.5 million on the interest rate swaps and options (2009 – $15.1 million; 2008 – $6.9 million).

F-18

TC PIPELINES, LP

NOTE 16 ACCOUNTS RECEIVABLE AND OTHER

December 31 (millions of dollars)

2010

2009

Accounts receivable
Inventory
Prepayments
Other assets

(a) Recast as discussed in Notes 2 and 6.

NOTE 17 SUBSEQUENT EVENTS

7.6
0.7
0.4
–

8.7

7.4
0.6
0.5
0.1

8.6

On January 18, 2011, the board of directors of our General Partner declared the Partnership’s fourth quarter 2010 cash distribution in the
amount of $0.75 per common unit. The fourth quarter cash distribution, which was paid on February 14, 2011 to unitholders of record as of
January 31, 2011, totaled $35.4 million and was paid in the following manner: $34.7 million to common unitholders (including $4.3 million
to the General Partner as holder of 5,797,106 common units and $8.5 million to TransCanada as holder of 11,287,725 common units) and
$0.7 million to the General Partner in respect of its two percent general partner interest. The fourth quarter 2010 cash distribution represents
an annual cash distribution of $2.96 per common unit.

Great Lakes declared and paid its fourth quarter 2010 distribution of $36.3 million on February 1, 2011, of which the Partnership received its
46.45 percent share or $16.9 million.

Northern Border declared and paid its fourth quarter 2010 distribution of $51.5 million on February 1, 2011, of which the Partnership
received its 50 percent share or $25.8 million.

2010 ANNUAL REPORT

F-19

GREAT LAKES GAS TRANSMISSION LIMITED PARTNERSHIP
INDEPENDENT AUDITORS’ REPORT

The Partners and Management Committee
Great Lakes Gas Transmission Limited Partnership:

We have audited the accompanying consolidated balance sheets of Great Lake Gas Transmission Limited Partnership
and subsidiary (the Partnership) as of December 31, 2010 and 2009, and the related consolidated statements of
income, partners’ capital, and cash flows for each of the years in the three-year period ended December 31, 2010.
These consolidated financial statements are the responsibility of the Partnership’s management. Our responsibility is to
express an opinion on these consolidated financial statements based on our audits.

We conducted our audits in accordance with auditing standards generally accepted in the United States of America.
Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the
financial statements are free of material misstatement. An audit includes consideration of internal control over financial
reporting as a basis for designing audit procedures that are appropriate in the circumstances, but not for the purpose of
expressing an opinion on the effectiveness of the Partnership’s internal control over financial reporting. Accordingly, we
express no such opinion. An audit also includes examining, on a test basis, evidence supporting the amounts and
disclosures in the financial statements, assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a
reasonable basis for our opinion.

In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the
consolidated financial position of Great Lakes Gas Transmission Limited Partnership and subsidiary as of December 31,
2010 and 2009, and the results of their operations and their cash flows for each of the years in the three-year period
ended December 31, 2010, in conformity with U.S. generally accepted accounting principles.

/s/ KPMG LLP

Houston, Texas
February 10, 2011

F-20

TC PIPELINES, LP

GREAT LAKES GAS TRANSMISSION LIMITED PARTNERSHIP
CONSOLIDATED BALANCE SHEETS

December 31 (In thousands)

ASSETS
Current assets:

Cash and cash equivalents
Demand loan receivable from affiliate
Accounts receivable:

Trade, net of allowance of $250 in 2009
Affiliates

Materials and supplies
Other

Total current assets

Property, plant, and equipment:

Property, plant, and equipment
Construction work in progress

Less accumulated depreciation and amortization

Total property, plant, and equipment, net

Other assets

Total assets

LIABILITIES AND PARTNERS’ CAPITAL
Current liabilities:

Accounts payable:

Trade
Affiliates

Current maturities of long-term debt
Partnership income taxes payable
Taxes payable (other than income)
Accrued interest
Other

Total current liabilities

Long-term debt, net of current maturities

Other liabilities:

Deferred partnership income taxes
Other

Total other liabilities

Partners’ capital

Total liabilities and partners’ capital

See accompanying notes to consolidated financial statements.

2010

2009

$

40
44,924

14,610
11,286
10,824
1,990

83,674

125
33,974

22,980
12,922
10,235
2,137

82,373

2,064,641
1,875

2,066,516
(1,219,579)

2,051,274
3,034

2,054,308
(1,181,042)

846,937

873,266

638

719

$

931,249

956,358

$

11,660
2,976
19,000
3,729
8,194
8,384
38

53,981

14,355
3,674
19,000
2,887
10,541
8,690
140

59,287

373,000

392,000

5,169
436

5,605

498,663

$

931,249

3,337
436

3,773

501,298

956,358

2010 ANNUAL REPORT

F-21

GREAT LAKES GAS TRANSMISSION LIMITED PARTNERSHIP
CONSOLIDATED STATEMENTS OF INCOME AND PARTNERS’ CAPITAL

Years ended December 31 (In thousands)

2010

2009

2008

Operating revenues
Operating expenses:

Operation and maintenance
Depreciation and amortization
Taxes, other than income

Total operating expenses

Operating income

Other income, net
Interest and debt expense
Affiliated interest income

Income before partnership income taxes

Partnership income taxes

Net income

Partners’ capital:

Balance at beginning of year
Net income
Distributions to partners
Contributions from partners

Balance at end of year

See accompanying notes to consolidated financial statements.

$ 262,391

289,693

287,130

41,558
40,488
17,694

99,740

162,651
238
(31,339)
205

131,755
(5,290)

$ 126,465

$ 501,298
126,465
(149,100)
20,000

$ 498,663

48,760
58,503
17,729

124,992

164,701
595
(32,916)
449

132,829
(5,417)

127,412

529,886
127,412
(156,000)
–

501,298

46,276
58,522
20,788

125,586

161,544
1,300
(34,358)
453

128,939
(5,503)

123,436

565,650
123,436
(159,200)
–

529,886

F-22

TC PIPELINES, LP

GREAT LAKES GAS TRANSMISSION LIMITED PARTNERSHIP
CONSOLIDATED STATEMENTS OF CASH FLOWS

Years ended December 31 (In thousands)

Cash flows from operating activities:

Net Income
Adjustments to reconcile net income to net cash provided by

operating activities:
Depreciation and amortization
Deferred partnership income taxes
Allowance for funds used during construction, equity
Asset and liability changes:

Accounts receivable
Other current assets
Noncurrent assets
Accounts payable
Partnership income taxes payable
Other current liabilities
Noncurrent liabilities

2010

2009

2008

$ 126,465

127,412

123,436

40,488
1,816
(187)

10,006
(442)
97
(3,393)
842
(2,755)
–

58,503
1,410
(78)

3,775
1,967
24
(4,084)
2,887
(1,530)
19

58,522
1,927
(195)

1,159
(539)
138
(6,226)
–
(1,451)
21

Net cash provided by operating activities

172,937

190,305

176,792

Cash flows from investing activities:

Additions to property, plant, and equipment
Net change in demand loan receivable from affiliate

Net cash used in investing activities

Cash flows from financing activities:

Payments for retirement of long-term debt
Distributions to partners
Contributions from partners

Net cash used in financing activities

Net decrease in cash and cash equivalents
Cash and cash equivalents at beginning of year

Cash and cash equivalents at end of year

Supplemental cash flow information:

Cash activities:

Interest paid, net of capitalized interest
Partnership income taxes paid

See accompanying notes to consolidated financial statements.

(13,972)
(10,950)

(24,922)

(8,310)
(8,507)

(16,817)

(12,448)
(25,467)

(37,915)

(19,000)
(149,100)
20,000

(19,000)
(156,000)
–

(10,000)
(159,200)
–

(148,100)

(175,000)

(169,200)

(85)
125

40

$

(1,512)
1,637

125

(30,323)
31,960

1,637

$ 31,582
2,873

33,159
–

34,440
2,574

2010 ANNUAL REPORT

F-23

GREAT LAKES GAS TRANSMISSION LIMITED PARTNERSHIP
NOTES TO CONSOLIDATED FINANCIAL STATEMENTS

1. DESCRIPTION OF BUSINESS

Great Lakes Gas Transmission Limited Partnership (Partnership) is a Delaware limited partnership that owns and operates an interstate natural
gas pipeline system. The Partnership transports natural gas for delivery to wholesale customers in the midwestern and northeastern
United States (U.S.) and eastern Canada. The partners and partnership ownership percentages at December 31, 2010 and 2009 are as follows:

General Partners:

TransCanada GL, Inc.
TC GL Intermediate Limited Partnership

Limited Partner:

Great Lakes Gas Transmission Company

Ownership %

46.45
46.45

7.10

Great Lakes Gas Transmission Company (the Company) and TransCanada GL, Inc. are wholly owned indirect subsidiaries of TransCanada
Corporation (TransCanada). TC GL Intermediate Limited Partnership is a direct subsidiary of TC PipeLines, LP of which TransCanada indirectly
owns a 38.2% interest.

The consolidated financial statements include the accounts of the Partnership and GLGT Aviation Company, a wholly owned subsidiary. GLGT
Aviation Company owned a fractional interest in a transport aircraft used principally for pipeline operations until October 2009 when its
interest in the aircraft was sold. In December 2009, GLGT Aviation Company was liquidated.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

(a) Use of Estimates

The preparation of the consolidated financial statements in accordance with U.S. generally accepted accounting principles (GAAP) requires
management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and
accompanying notes. Actual results could differ from those estimates.

(b) Reclassifications

Prior year amounts have been reclassified where necessary to conform to the 2010 presentation.

(c) Cash and Cash Equivalents

The Partnership considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents.

(d) Accounting for Regulated Operations

The Partnership’s natural gas pipeline is subject to the jurisdiction of the Federal Energy Regulatory Commission (FERC) under the Natural
Gas Act (NGA) of 1938 and the Natural Gas Policy Act of 1978. Financial Accounting Standards Board Accounting Standards Codification
(FASB ASC) 980, Regulated Operations, provides that rate regulated enterprises account for and report assets and liabilities consistent with
the economic effect of the way in which regulators establish rates, if the rates are designed to recover the costs of providing the
regulated service and if the competitive environment makes it probable that such rates can be charged and collected. As of December 31,
2010 and 2009, there are no significant regulatory assets or liabilities reflected in these consolidated financial statements.

(e) Trade Accounts Receivable

Trade accounts receivable are recorded at the invoiced amount and do not bear interest. The Partnership maintains an allowance for
doubtful accounts for estimated losses on accounts receivable and for natural gas imbalances due from shippers and operators if it is
determined the Partnership will not collect all or part of the outstanding receivable balance. The Partnership regularly reviews its
allowance for doubtful accounts and establishes or adjusts the allowance as necessary using the specific-identification method. Account
balances are written off against the allowance after all means of collection have been exhausted and the potential for recovery is
considered remote. Accounts written off for 2010 and 2009 were not material to the Partnership’s consolidated financial statements.

F-24

TC PIPELINES, LP

(f) Natural Gas Imbalances

Natural gas imbalances occur when the actual amount of natural gas delivered to or received from a pipeline system differs from the
amount of natural gas scheduled to be delivered or received. The Partnership values these imbalances due to or from shippers and
operators at current index prices. Imbalances are settled in-kind, subject to the terms of the Partnership’s tariff.

Imbalances due from others are reported on the consolidated balance sheets as trade accounts receivable or accounts receivable from
affiliates. Imbalances owed to others are reported on the consolidated balance sheets as trade accounts payable or accounts payable to
affiliates. In addition, the Partnership classifies all imbalances as current as the Partnership expects to settle them within a year.

(g) Material and Supplies

The Partnership’s inventory consists of materials and supplies. The materials and supplies are valued at cost with cost determined using
the average cost method.

On December 1, 2010, the Partnership changed its method of valuing its materials and supplies to the average cost method from the
lower of cost or market value method as used in prior periods. The Partnership believes the average cost method is a better
representation of accounting for materials and supplies inventory described in the FERC Code of Federal Regulations. The change resulted
in a $1.2 million decrease to operations and maintenance expense in 2010 on the Partnership’s consolidated statements of income. There
was no impact to the Partnership’s cash flows.

(h) Property, Plant, and Equipment

Property, plant, and equipment are recorded at their original cost of construction. For assets the Partnership constructs, direct costs are
capitalized, such as labor and materials, and indirect costs, such as overhead and interest. The Partnership capitalizes major units of
property replacements or improvements and expenses minor items.

The Partnership uses the composite (group) method to depreciate property, plant, and equipment. Under this method, assets with similar
lives and characteristics are grouped and depreciated as one asset. The depreciation rate is applied to the total cost of the group until its
net book value equals its salvage value. All asset groups are depreciated using the FERC depreciation rates. Effective May 1, 2010 the
Partnership’s principal operating assets, which comprise approximately 94.30% of total property, plant, and equipment, are depreciated at
an annual rate of 1.48%. The remaining assets are depreciated at annual rates ranging from 2.30% to 20.00%. Using these rates, the
remaining depreciable life of these assets ranges from 1 to 42 years.

When property, plant, and equipment are retired, the Partnership charges accumulated depreciation and amortization for the original cost
of the assets in addition to the cost to remove, sell, or dispose of the assets, less their salvage value. The Partnership does not recognize
a gain or loss unless an entire operating unit is sold or retired. The Partnership includes gains or losses on dispositions of operating units
in income.

The Partnership capitalizes a carrying cost on funds invested in the construction of long-lived assets. This carrying cost includes a return
on the investment financed by debt and equity allowance for funds used during construction (AFUDC). AFUDC is calculated based on the
Partnership’s average cost of debt and equity. Debt amounts capitalized were $0.1 million for each of the years 2010 and 2009. These
amounts are included as a reduction of interest and debt expense in the consolidated statements of income. Equity amounts capitalized
during the years ended December 31, 2010 and 2009 were $0.2 million and $0.1 million, respectively. Capitalized carrying costs for
AFUDC debt and equity are reflected as an increase in the cost of the asset on the consolidated balance sheets.

(i) Revenue Recognition

The Partnership’s revenues are primarily generated from transportation services. Revenues for all services are based on the quantity of gas
delivered or subscribed at a price specified in the contract. For the Partnership’s transportation services, reservation revenues are
recognized on firm contracted capacity ratably over the contract period regardless of the amount of natural gas that is transported. For
interruptible or volumetric-based services, the Partnership records revenues when physical deliveries of natural gas and other commodities
are made at the agreed-upon delivery point. The Partnership does not take ownership of the gas that it transports. The Partnership is
subject to FERC regulations, and as a result, revenues the Partnership collects may be subject to refund in a rate proceeding. The
Partnership establishes reserves for these potential refunds.

(j) Commitments and Contingencies

Accounting for Asset Retirement Obligations

To the extent a legal obligation exists, the Partnership records a liability associated with the removal and retirement of its long-lived assets.
Asset retirement liabilities are based on an estimate of the timing and amount of their settlement. They are recorded at their estimated

2010 ANNUAL REPORT

F-25

fair value with a corresponding increase to property, plant, and equipment. This increase in property, plant, and equipment is then
depreciated over the useful life of the long-lived asset to which the liability relates. An ongoing expense is also recognized for changes in
the value of the liability as a result of the passage of time, which is recorded as accretion expense in the consolidated statements
of income.

Other Contingencies

The Partnership recognizes liabilities for contingencies when it has an exposure that, when fully analyzed, indicates it is both probable
that a liability has been incurred and the amount of loss can be reasonably estimated. Where the most likely outcome of a contingency
can be reasonably estimated, the Partnership accrues a liability for that amount. Where the most likely outcome cannot be estimated, a
range of potential losses is established and if no one amount in that range is more likely than any other, the lower end of the range
is accrued.

(k)

Income Taxes

The Michigan Business Tax (MBT), effective January 1, 2008, is an income tax levied at the Partnership level. Income taxes, other than the
MBT, are the responsibility of our partners and are not reflected in these consolidated financial statements.

3. MICHIGAN BUSINESS TAX

The Partnership files the MBT return on a combined basis with certain TransCanada affiliates. A tax payment agreement between the
Partnership and TransCanada affiliates provides that the Partnership’s MBT liability is determined as if a separate return was filed. Under the
agreement, the Partnership remits its current MBT liability to an affiliate.

MBT for the years ended December 31, 2010, 2009, and 2008 consists of the following:

(In Thousands)

Current
Deferred

The deferred tax liabilities as of December 31, 2010 and 2009 are as follows:

(In Thousands)

Deferred tax liabilities – utility plant
Deferred tax liabilities – other

Net deferred tax liability

As of December 31, 2010 and 2009, no valuation allowance is required.

4. COMMITMENTS AND CONTINGENCIES

(a)

Legal Proceedings

2010

$3,474
1,816

$5,290

2009

4,007
1,410

5,417

2010

$5,041
128

$5,169

2008

3,576
1,927

5,503

2009

3,280
57

3,337

The Partnership and its affiliates are named as defendants in legal proceedings that arise in the ordinary course of the Partnership’s
business. For each of the Partnership’s legal matters, the Partnership evaluates the merits of the case, the Partnership’s exposure to the
matter, possible legal or settlement strategies, and the likelihood of an unfavorable outcome. If the Partnership determines that an
unfavorable outcome is probable and can be estimated, the Partnership establishes the necessary accruals. As further information
becomes available, or other relevant developments occur, the Partnership may accrue amounts accordingly. While there are still
uncertainties related to the ultimate costs the Partnership may incur, based upon the Partnership’s evaluation and experience to date, the
Partnership had no accruals for its outstanding legal matters at December 31, 2010.

(b) Regulatory Matters

On November 19, 2009, the FERC issued an order in FERC Docket No. RP10-149 (November 2009 Order) instituting an investigation
pursuant to Section 5 of the NGA (GL Rate Proceeding). The FERC alleged, based on a review of certain historical information, that the

F-26

TC PIPELINES, LP

Partnership’s revenues might substantially exceed the Partnership’s actual cost of service and, therefore, may be unjust and unreasonable.
On February 4, 2010, the Partnership filed a cost and revenue study in response to the November 2009 Order.

On May 21, 2010, the Partnership filed a stipulation and agreement (GL Settlement) establishing the terms pursuant to which all matters
in the GL Rate Proceeding would be resolved. On June 17, 2010, the Administrative Law Judge certified the GL Settlement as
uncontested to the FERC for its approval. On July 15, 2010, the FERC approved the GL Settlement without modification. The GL
Settlement was reached among the Partnership, active participants, and the FERC trial staff. As approved, the GL Settlement applies to all
current and future shippers on the Partnership’s system.

Under the terms of the GL Settlement, reservation rates on the Partnership’s pipeline system were reduced by 8.00%, effective May 1,
2010. In addition, depreciation expense for the Partnership’s transmission plant decreased from 2.75% to 1.48% per year. Other
depreciation rates for the plant either decreased or remained unchanged. Long-haul reservation rates from the Partnership’s western zone
to its eastern zone declined by 8.00% from $0.338 per dekatherm to $0.311 per dekatherm and various short-haul firm paths
experienced similar reductions. Effective June 1, 2010, rates for long-haul interruptible transportation services increased from $0.252 per
dekatherm to $0.322 per dekatherm with similar increases occurring on various short-haul paths. All other terms of the GL Settlement
were effective May 1, 2010.

The Partnership’s obligation to share interruptible transportation revenues as established under the September 24, 1992 Stipulation and
Agreement in Partial Settlement of Rate Proceedings in FERC Docket No. RP91-143 was eliminated under the GL Settlement, effective
May 1, 2010. On July 1, 2010, the Partnership paid out the interruptible transportation revenue sharing accumulated prior to May 1,
2010 and filed its final interruptible transportation revenue sharing report with the FERC in Docket No. RP91-143-061. Under the GL
Settlement, the Partnership has agreed to a new revenue sharing provision with respect to jurisdictional revenues, including firm and
interruptible transportation revenues, it receives in excess of $500 million during the period between November 1, 2010 and October 31,
2012. The Partnership will share with qualifying shippers 50% of any qualifying revenues collected during this period in excess of the
$500 million threshold.

The GL Settlement rates will remain in effect through at least November 30, 2011. The GL Settlement includes a moratorium on
participants and customers filing any NGA Section 5 rate case to place new rates into effect prior to November 1, 2012. There is also a
moratorium on the Partnership filing a general NGA Section 4 rate case prior to June 1, 2011 to place new rates into effect prior to
December 1, 2011. These moratoria are subject to conditions detailed in the GL Settlement. In addition, the GL Settlement requires the
Partnership to file a NGA Section 4 general rate case no later than November 1, 2013.

(c) Environmental Matters

By letter dated December 28, 2009, the U.S. Environmental Protection Agency (EPA) required the Partnership to provide information
regarding its natural gas compressor stations in the states of Minnesota, Wisconsin, and Michigan as part of the EPA’s review of the
Partnership’s compliance with the Clean Air Act. On May 28, 2010, the Partnership submitted its final response to the EPA. To date, the
Partnership has received one request from the EPA for clarification regarding submitted information. The potential effects on the
Partnership that may arise as a result of this information request are not determinable at this time.

(d) Asset Retirement Obligations

The Partnership has determined it has legal obligations associated with its natural gas pipelines and related transmission facilities. The
obligations relate primarily to purging and sealing the pipelines if they are abandoned. The Partnership is also required to operate and
maintain its natural gas pipeline system, and intends to do so as long as supply and demand for natural gas exists, which the Partnership
expects for the foreseeable future. Therefore, the Partnership believes its natural gas pipeline system assets have indeterminate lives and,
accordingly, has recorded no asset retirement liabilities as of December 31, 2010 and 2009. The Partnership continues to evaluate its asset
retirement obligations and future developments that could impact amounts it records.

(e) Other Commercial Commitments

The Partnership holds cancelable easements or rights-of-way arrangements from landowners permitting the use of land for the
construction and operation of the Partnership’s pipeline system. Currently, the Partnership’s obligations under these easements are not
material to its results of operations.

5. LONG-TERM DEBT

The Partnership’s long-term debt outstanding consisted of the following at December 31:

(In Thousands)

8.74% series Senior Notes due 2011
6.73% series Senior Notes due 2011 to 2018
9.09% series Senior Notes due 2012 to 2021
6.95% series Senior Notes due 2019 to 2028
8.08% series Senior Notes due 2021 to 2030

Less current maturities

Total long-term debt less current maturities

2010 ANNUAL REPORT

F-27

2010

$10,000
72,000
100,000
110,000
100,000

392,000
19,000

$373,000

2009

20,000
81,000
100,000
110,000
100,000

411,000
19,000

392,000

The aggregate annual required repayment of long-term debt is $19.0 million for each year from 2011 through 2015.

The Partnership is required to comply with certain financial, operational, and legal covenants. Under the most restrictive covenants in the
Senior Note Agreements, approximately $211.0 million of partners’ capital was restricted as to distributions as of December 31, 2010. As of
December 31, 2010, management of the Partnership believes the Partnership was in compliance with all of its financial covenants.

6. FAIR VALUE MEASUREMENTS

(a)

Fair Value of Financial Instruments

The following table presents the carrying amounts and estimated fair values of the Partnership’s financial instruments that are measured
on a recurring basis at December 31, 2010 and 2009. The fair value of a financial instrument is the amount that would be received to
sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date.

(In Thousands)

Financial assets:

Cash and cash equivalents

Financial liabilities:
Long-term debt

2010

Carrying
amount

Fair value

2009

Carrying
amount

Fair value

$40

40

125

125

$392,000

518,199

411,000

506,248

The following methods and assumptions were used to estimate the fair value of each class of financial instruments measured on a
recurring basis:

Cash and cash equivalents – The carrying amount of cash and cash equivalents approximates fair value due to the short maturity of these
investments.

Long-term debt – The fair value of senior notes was estimated based on quoted market prices for the same or similar debt instruments
with similar terms and remaining maturities, which is classified as Level 2 in the fair value hierarchy, where the fair value is determined by
using valuation techniques that refer to observable market data. The Partnership presently intends to maintain the current schedule of
maturities for the note, which will result in no gains or losses on its repayment.

(b)

Fair Value Hierarchy

Under FASB ASC 820, Fair Value Measurements and Disclosures, fair value measurements are characterized in one of three levels based
upon the input used to arrive at the measurement. The three levels of the fair value hierarchy are as follows:

(cid:127) Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that the Partnership has the ability to

access at the measurement date.

(cid:127) Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly

or indirectly.

(cid:127) Level 3 inputs are unobservable inputs for the asset or liability.

F-28

TC PIPELINES, LP

When appropriate, valuations are adjusted for various factors including credit considerations. Such adjustments are generally based on
available market evidence. In the absence of such evidence, management’s best estimate is used.

7. TRANSACTIONS WITH AFFILIATED COMPANIES

(a) Cash Management Program

The Partnership participates in TransCanada’s cash management program, which matches short-term cash surpluses and needs of
participating affiliates, thus minimizing total borrowings from outside sources. Monies advanced under the agreement are considered to
be a loan, accruing interest and repayable on demand. At December 31, 2010 and 2009, the Partnership had a cash pool receivable from
TransCanada PipeLine USA Ltd. of $44.9 million and $34.0 million, respectively. The interest rate on the cash pool at December 31, 2010
and 2009 was 0.51% and 0.40%, respectively.

(b) Affiliate Revenues and Expenses

The Partnership provides natural gas transportation services to TransCanada affiliates in the normal course of business. Affiliated
transportation revenues are primarily provided under fixed priced contracts with remaining terms ranging from one to eight years.

The Partnership’s largest shipper, TransCanada PipeLines Limited, has 576 MDth/d of long haul capacity under contract expiring on
October 31, 2011. Negotiations are currently in progress related to these contracts.

Pursuant to the Partnership’s Operating Agreement, day-to-day operation of partnership activities is the responsibility of the Company. The
Partnership is charged by the Company and affiliates for services such as legal, tax, treasury, human resources, other administrative
functions, and for other costs incurred on its behalf. These include, but are not limited to, employee benefit costs and property and
liability insurance costs. These costs are based on direct assignment to the extent practicable, or by using allocation methods that are
reasonable reflections of the utilization of services provided to or for the benefits received by the Partnership. In addition, the Partnership
charges rent to affiliates for use of office space in Troy, Michigan.

The following table shows revenues and charges from the Partnerships’ affiliates for the periods ended December 31:

(In Thousands)

Transportation revenues from affiliates
Rental revenue from affiliate
Costs charged from affiliates

8. DISTRIBUTIONS

2010

$148,464
884
30,282

2009

141,721
643
33,765

2008

143,705
432
34,261

The Partnership’s distribution policy generally results in a quarterly cash distribution equal to 100% of distributable cash flow based upon
earnings before income taxes, depreciation, and AFUDC, less capital expenditures and debt repayments not funded with cash calls to its
partners, and current MBT. The resulting distribution amount and timing are subject to Management Committee modification and approval
after considering business risks as well as ensuring minimum cash balances, equity balances, and ratios are maintained.

In September 2010, the Partnership’s distribution policy was changed to allow distributable cash flow to include debt repayments funded with
partner cash calls. Previous distributable cash flow included a deduction for debt repayments without considering partner cash call funding.

On January 11, 2011, the Management Committee of the Partnership declared a cash distribution in the amount of $36.3 million to the
partners. The distribution was paid on February 1, 2011.

9. SUBSEQUENT EVENTS

Subsequent events have been assessed through February 10, 2011, which is the date the consolidated financial statements were issued, and
we concluded there were no events or transactions during this period that would require recognition or disclosure in the consolidated financial
statements other than those already reflected.

2010 ANNUAL REPORT

F-29

NORTHERN BORDER PIPELINE COMPANY
Independent Auditors’ Report

Management Committee
Northern Border Pipeline Company:

We have audited the accompanying balance sheets of Northern Border Pipeline Company (the Company) as of
December 31, 2010 and 2009, and the related statements of income, comprehensive income, cash flows, and changes
in partners’ equity for each of the years in the three-year period ended December 31, 2010. These financial statements
are the responsibility of the Company’s management. Our responsibility is to express an opinion on these financial
statements based on our audits.

We conducted our audits in accordance with auditing standards generally accepted in the United States of America.
Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the
financial statements are free of material misstatement. An audit includes consideration of internal control over financial
reporting as a basis for designing audit procedures that are appropriate in the circumstances, but not for the purpose of
expressing an opinion on the effectiveness of the Company’s internal control over financial reporting. Accordingly, we
express no such opinion. An audit also includes examining, on a test basis, evidence supporting the amounts and
disclosures in the financial statements, assessing the accounting principles used and significant estimates made by
management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a
reasonable basis for our opinion.

In our opinion, the financial statements referred to above present fairly, in all material respects, the financial position of
Northern Border Pipeline Company as of December 31, 2010 and 2009, and the results of its operations and its cash
flows for each of the years in the three-year period ended December 31, 2010 in conformity with U.S. generally
accepted accounting principles.

/s/ KPMG LLP

Houston, Texas
February 10, 2011

F-30

TC PIPELINES, LP

NORTHERN BORDER PIPELINE COMPANY
BALANCE SHEETS

December 31, (In thousands)

ASSETS
Current assets:

Cash and cash equivalents
Accounts receivable
Related party receivables
Materials and supplies, at cost
Prepaid expenses and other

Total current assets

Property, plant and equipment:

In service natural gas transmission plant
Construction work in progress

Total property, plant and equipment
Less: Accumulated provision for depreciation and amortization

Property, plant and equipment, net

Other assets:

Regulatory assets
Unamortized debt expense
Other

Total other assets

Total assets

LIABILITIES AND PARTNERS’ EQUITY
Current liabilities:

Accounts payable
Related party payables
Accrued taxes other than income
Accrued interest
Other

Total current liabilities

Long-term debt, net of current maturities

Deferred credits and other liabilities:

Related party payables
Regulatory liabilities
Other

Total deferred credits and other liabilities

Commitments and contingencies
Partners’ equity:

Partners’ capital
Accumulated other comprehensive loss

Total partners’ equity

Total liabilities and partners’ equity

The accompanying notes are an integral part of these financial statements.

2010

2009

$

10,231
31,129
276
4,310
1,307

47,253

2,508,512
8,567

2,517,079
1,222,259

1,294,820

20,315
2,573
22

22,910

$

16,864
23,843
391
4,471
1,572

47,141

2,513,825
813

2,514,638
1,171,544

1,343,094

20,027
2,791
1,339

24,157

$1,364,983

$1,414,392

$10,525
3,015
22,976
7,044
3,178

46,738

540,574

–
9,649
–

9,649

3,409
3,390
22,713
7,058
1,389

37,959

564,549

753
7,189
396

8,338

770,905
(2,883)

768,022

806,600
(3,054)

803,546

$1,364,983

$1,414,392

NORTHERN BORDER PIPELINE COMPANY
STATEMENTS OF INCOME

Years Ended December 31, (In thousands)

Operating revenue

Operating expenses:

Operations and maintenance
Depreciation and amortization
Taxes other than income

Operating expenses

Operating income

Interest expense:

Interest expense
Interest expense capitalized

Interest expense, net

Other income (expense):

Allowance for equity funds used during construction
Gain on sale of assets
Other income
Other expense

Other income, net

Net income to partners

NORTHERN BORDER PIPELINE COMPANY
STATEMENTS OF COMPREHENSIVE INCOME

Years Ended December 31, (In thousands)

Net income to partners
Other comprehensive income:

2010 ANNUAL REPORT

F-31

2010

2009

2008

$295,069

$249,217

$293,105

49,720
61,470
24,268

135,458

159,611

26,649
(60)

26,589

148
–
3,165
(86)

3,227

48,695
61,870
22,103

132,668

116,549

36,750
(137)

36,613

235
–
2,309
(348)

2,196

51,260
61,081
26,765

139,106

153,999

40,974
(182)

40,792

323
16,166
2,932
(426)

18,995

$136,249

$ 82,132

$132,202

2010

2009

2008

$136,249

$82,132

$132,202

Changes associated with hedging transactions

171

2,654

(3,267)

Total comprehensive income

$136,420

$84,786

$128,935

The accompanying notes are an integral part of these financial statements.

F-32

TC PIPELINES, LP

NORTHERN BORDER PIPELINE COMPANY
STATEMENTS OF CASH FLOWS

Years Ended December 31, (In thousands)

CASH FLOW FROM OPERATING ACTIVITIES

Net income to partners

2010

2009

2008

$136,249

$ 82,132

$ 132,202

Adjustments to reconcile net income to partners to net cash

provided by operating activities:
Depreciation and amortization
Allowance for equity funds used during construction
Changes in components of working capital
Gain on sale of assets
Other

Total adjustments

61,556
(148)
2,034
–
(519)

62,923

62,218
(235)
(25)
–
(4,084)

57,874

61,464
(323)
(4,827)
(16,166)
(2,940)

37,208

Net cash provided by operating activities

199,172

140,006

169,410

CASH FLOW FROM INVESTING ACTIVITIES

Capital expenditures for property, plant and equipment, net
Investments in other assets
Proceeds from sale of assets

Net cash used in investing activities

CASH FLOW FROM FINANCING ACTIVITIES

Equity contributions from partners
Distributions to partners
Issuance of debt
Retirement of debt
Debt financing costs

Net cash used in financing activities

Net change in cash and cash equivalents
Cash and cash equivalents at beginning of year

(9,861)
–
–

(9,861)

–
(171,944)
97,000
(121,000)
–

(195,944)

(6,633)
16,864

(11,090)
–
–

(11,090)

84,550
(151,458)
214,000
(280,000)
(799)

(133,707)

(4,791)
21,655

(20,538)
(3,834)
20,000

(4,372)

–
(181,320)
145,000
(130,000)
–

(166,320)

(1,282)
22,937

Cash and cash equivalents at end of year

$ 10,231

$ 16,864

$ 21,655

Supplemental disclosure for cash flow information:
Cash paid for interest, net of amount capitalized

Changes in components of working capital:

Accounts receivable
Related party receivables
Materials and supplies
Prepaid expenses and other
Accounts payable
Related party payables
Accrued taxes other than income
Accrued interest
Other current liabilities

Total

$ 26,137

$ 40,987

$ 41,868

$ (7,286)
115
161
265
7,116
(375)
263
(14)
1,789

$

8,938
(5)
91
1,735
(2,687)
(462)
(3,567)
(4,002)
(66)

$ (1,474)
2,368
(357)
(680)
(1,084)
(2,000)
(1,345)
(223)
(32)

$

2,034

$

(25)

$ (4,827)

The accompanying notes are an integral part of these financial statements.

NORTHERN BORDER PIPELINE COMPANY
STATEMENTS OF CHANGES IN PARTNERS’ EQUITY

(In thousands)

Partners’ equity at December 31, 2007

Net income to partners
Changes associated with hedging

transactions
Distributions paid

Partners’ equity at December 31, 2008

Net income to partners
Changes associated with hedging

transactions

Equity contributions received
Distributions paid

Partners’ equity at December 31, 2009

Net income to partners
Changes associated with hedging

transactions
Distributions paid

TC PipeLines
Intermediate
Limited
Partnership

$420,247
66,101

–
(90,660)

395,688
41,066

–
42,275
(75,729)

403,300
68,124

–
(85,972)

2010 ANNUAL REPORT

F-33

Total Partners’
Equity

ONEOK
Partners
Intermediate

Accumulated
Other
Limited Comprehensive
Income (Loss)

Partnership

$420,247
66,101

$(2,441)
–

$ 838,053
132,202

–
(90,660)

395,688
41,066

–
42,275
(75,729)

403,300
68,125

–
(85,972)

(3,267)
–

(5,708)
–

2,654
–
–

(3,054)
–

171
–

(3,267)
(181,320)

785,668
82,132

2,654
84,550
(151,458)

803,546
136,249

171
(171,944)

Partners’ equity at December 31, 2010

$385,452

$385,453

$(2,883)

$ 768,022

The accompanying notes are an integral part of these financial statements.

F-34

TC PIPELINES, LP

NORTHERN BORDER PIPELINE COMPANY
NOTES TO FINANCIAL STATEMENTS

1. ORGANIZATION AND MANAGEMENT

In this report, references to ‘‘we,’’ ‘‘us’’ or ‘‘our’’ collectively refer to Northern Border Pipeline Company.

We are a Texas general partnership formed in 1978. We own a 1,398-mile natural gas transmission pipeline system, which includes an
additional 149 pipeline miles parallel to the original system, extending from the United States-Canadian border near Port of Morgan,
Montana, to a terminus near North Hayden, Indiana.

The ownership and voting percentages of our partners at December 31, 2010 and 2009 are as follows:

Partner

ONEOK Partners Intermediate Limited Partnership (ONEOK Partners)
TC PipeLines Intermediate Limited Partnership (TC PipeLines)

Ownership

50%
50%

We are managed by a Management Committee that consists of four members. Each partner designates two members, and TC PipeLines
designates one of its members as chairman.

2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Use of Estimates

The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make
assumptions and use estimates that affect the reported amounts of assets, liabilities, revenue and expenses as well as the disclosure of
contingent assets and liabilities during the reporting period. Actual results could differ from these estimates if the underlying assumptions
are incorrect.

Government Regulation

We are subject to regulation by the Federal Energy Regulatory Commission (FERC). Our accounting policies conform to Financial Accounting
Standards Board Accounting Standards Codification (ASC) 980, Regulated Operations. Accordingly, certain assets and liabilities that result from
the regulated ratemaking process are reflected on the balance sheets as regulatory assets and regulatory liabilities.

The following table presents a summary of regulatory assets, net of amortization, at December 31, 2010 and 2009:

Fort Peck lease option
Pipeline extension project
Unamortized loss on reacquired debt
Deferred rate case expenditures

Total regulatory assets

Remaining
recovery/
settlement
period

(Years)
40
11
–
2

December 31,

2010

2009

(In thousands)

$14,457
5,075
–
783

$13,273
5,536
44
1,174

$20,315

$20,072

At December 31, 2010 and 2009, respectively, we have reflected a regulatory liability of $9.6 million and $7.2 million on the balance sheets,
related to negative salvage accrued for estimated net costs of removal of transmission plant. The settlement period for negative salvage value
is related to the estimated life of the assets. See the Property, Plant and Equipment and Related Depreciation and Amortization policy in this
note for further discussion of negative salvage.

We assess the recoverability of costs recognized as regulatory assets and liabilities and the ability to continue to account for our activities
based on the criteria set forth in ASC 980, which includes such factors as regulatory changes and the impact of competition. Our review of

2010 ANNUAL REPORT

F-35

these criteria currently supports the continuing application of ASC 980. If we cease to meet the criteria of ASC 980, a write-off of related
regulatory assets and liabilities could be required.

Revenue Recognition

Our revenues are primarily generated from transportation services. Revenues for all services are based on the quantity of gas delivered or
subscribed at a price specified in the contract. For our transportation services, reservation revenues are recognized on firm contracted capacity
ratably over the contract period regardless of the amount of natural gas that is transported. We do not take ownership of the gas that is
transported. For interruptible or volumetric-based services, we record revenues when physical deliveries of natural gas and other commodities
are made at the agreed-upon delivery point. We are subject to FERC regulations, and as a result, revenues we collect may be subject to refund
in a rate proceeding. We establish reserves for these potential refunds.

Income Taxes

Income taxes are the responsibility of our partners and are not reflected in these financial statements.

Cash and Cash Equivalents

Cash equivalents consist of highly liquid investments with original maturities of three months or less.

Materials and Supplies

Materials and supplies are valued at cost with cost determined using the average cost method.

Property, Plant and Equipment and Related Depreciation and Amortization

Property, plant and equipment are stated at original cost. During periods of construction, we are permitted to capitalize an allowance for
funds used during construction, which represents the estimated costs of funds used for construction purposes. The original cost of property
retired is charged to accumulated depreciation and amortization. No retirement gain or loss is included in income except in the case of
retirements or sales of entire regulated operating units or systems.

Maintenance and repairs are charged to operations in the period incurred. The provision for depreciation and amortization of the transmission
line is an integral part of our FERC tariff. As a result of the settlement of our 2005 rate case, the effective depreciation rate applied to our
transmission plant is 2.40 percent. The transmission plant depreciation rate of 2.40 percent is comprised of two components: one based on
economic service life or capital recovery and one based on cost of removal, net of salvage value received or negative salvage. We accrue the
estimated net costs of removal of transmission plant as a regulatory liability, which does not represent an existing legal obligation. The net
cost of removal incurred on retirements of transmission plant is recorded as a reduction to the regulatory liability. Composite rates are applied
to all other functional groups of property having similar economic characteristics.

Asset Retirement Obligation

The fair value of a liability for an asset retirement obligation is recorded during the period in which the liability is incurred, if a reasonable
estimate of fair value can be made. We have determined that asset retirement obligations exist for certain of our transmission assets; however,
the fair value of the obligations cannot be determined because the end of the transmission system life is not determinable with the degree of
accuracy necessary to currently establish a liability for the obligations.

Natural Gas Imbalances

Natural gas imbalances occur when the actual amount of natural gas delivered or received by a pipeline system differs from the amount of
natural gas scheduled to be delivered or received. We value these imbalances due to or from shippers and interconnecting parties at current
index price. Imbalances are made up in-kind, subject to the terms of our tariff.

Imbalances due from others are reported on the balance sheets as accounts receivable. Imbalances owed to others are reported on the
balance sheets as accounts payable. In addition, we classify all imbalances as current as we expect to settle them within a year.

F-36

TC PIPELINES, LP

Risk Management

We utilize financial instruments to reduce our market risk exposure to interest rate fluctuations and achieve a more predictable cash flow. We
follow established policies and procedures to assess risk and approve, monitor and report our financial instrument activities. We do not use
these instruments for trading purposes. All derivative instruments (including certain derivative instruments embedded in other contracts) are
recorded on the balance sheets as either an asset or liability measured at their fair value (see Note 7). We record changes in the derivative’s
fair value currently in earnings unless specific hedge accounting criteria are met. Accounting for qualifying hedges allows a derivative’s gains
and losses to offset related results on the hedged item in the income statement, and requires us to formally document, designate and assess
the effectiveness of transactions that receive hedge accounting (see Note 6).

Unamortized Debt Premium, Discount and Expense

We amortize premiums, discounts and expenses incurred in connection with the issuance of debt consistent with the terms of the respective
debt instrument.

Operating Leases

We have non-cancelable operating leases for office space and rights-of-way. We record rent expense over the lease term as it becomes
payable.

Contingencies

Our accounting for contingencies covers a variety of business activities including contingencies for legal exposures and environmental
exposures. We accrue these contingencies when our assessments indicate that it is probable that a liability has been incurred or an asset will
not be recovered and an amount can be reasonably estimated. We base our estimates on currently available facts and our estimates of the
ultimate outcome or resolution. Actual results may differ from our estimates resulting in an impact, positive or negative, on earnings.

Reclassifications

Certain reclassifications have been made to the financial statements for prior years to conform to the current year presentation. These
reclassifications did not impact previously reported net income or partners’ equity.

3. RATES AND REGULATORY ISSUES

The FERC regulates the rates and charges for transportation of natural gas in interstate commerce. Natural gas companies may not charge
rates that have been determined to be unjust and unreasonable by the FERC. Generally, rates for interstate pipelines are based on the cost of
service, including recovery of and a return on the pipeline’s actual prudent historical cost investment. The rates and terms and conditions for
service are found in each pipeline’s FERC-approved tariff. Under its tariff, an interstate pipeline is allowed to charge for its services on the basis
of stated transportation rates. Transportation rates are established periodically in FERC proceedings known as rate cases. The tariff also allows
the interstate pipeline to provide services under negotiated and discounted rates.

Effective January 1, 2007, we implemented new rates as a result of the settlement of our 2005 rate case. For the full transportation route
from Port of Morgan, Montana to the Chicago area, our transportation rate is approximately $0.44 per Dekatherm (Dth), which is comprised
of a reservation rate, commodity rate and a compressor usage surcharge. The settlement also provided for seasonal rates for short-term
transportation services. Seasonal maximum rates vary on a monthly basis from approximately $0.54 per Dth to approximately $0.29 per Dth
for the full transportation route from Port of Morgan, Montana to the Chicago area. The settlement included a three-year moratorium on
filing rate cases and participants challenging these rates, and requires that we file a rate case within six years from the date the new rates
went into effect.

The compressor usage surcharge rate is designed to recover the actual costs of electricity at our electric compressors and any compressor fuel
use taxes imposed on our pipeline system. Any difference between the compressor usage surcharge collected and the actual costs for
electricity and compressor fuel use taxes is recorded as either an increase to expense for an over recovery of actual costs or as a decrease to
expense for an under recovery of actual costs, and is included in operations and maintenance expense on the income statement and as either
an other current liability or a current asset classified as prepaid expense and other, respectively, on the balance sheets. The compressor usage
surcharge rate is adjusted annually. The current liability or current asset will reflect the net over or under recovery of actual compressor usage
related costs at the date of the balance sheet. As of December 31, 2010, we had recorded $2.3 million as another current liability on the

2010 ANNUAL REPORT

F-37

accompanying balance sheet for the net over recovery of compressor usage related costs. As of December 31, 2009, $0.1 million as prepaid
expense and other assets on the accompanying balance sheet for the net under recovery of compressor usage related costs.

4. MAJOR CUSTOMERS

For the year ended December 31, 2010, shippers providing significant operating revenues were Tenaska Marketing Ventures and BP Canada
Energy Marketing Corp. (BP Canada) with revenues of $43.3 million and $41.2 million, respectively. For the year ended December 31, 2009,
shippers providing significant operating revenues were BP Canada and Tenaska Marketing Ventures with revenues of $41.9 million and
$26.7 million, respectively. For the year ended December 31, 2008, shippers providing significant operating revenues were BP Canada and
Cargill Inc. (Cargill) with revenues of $38.8 million and $32.4 million, respectively.

5. CREDIT FACILITIES AND LONG-TERM DEBT

Detailed information on long-term debt is as follows:

December 31, (In thousands)

2010

2009

2007 Credit Agreement – average interest rate of 0.54% and 0.52%

at December 31, 2010 and 2009, respectively, due 2012

2001 Senior Notes – 7.50%, due 2021
2009 Senior Notes – 6.24%, due 2016
Unamortized debt discount

Subtotal

Current maturities

Long-term debt

$191,000
250,000
100,000
(426)

540,574
–

$540,574

$215,000
250,000
100,000
(451)

564,549
–

$564,549

On August 26, 2009, we issued $100 million of 6.24 percent Senior Notes due August 26, 2016. The proceeds of the 6.24 percent Senior
Notes along with equity contributions, borrowings under the revolving credit agreement and cash generated by operating activity was used to
repay $200 million of 7.75 percent Senior Notes due September 1, 2009.

At December 31, 2010, based on the principal commitment amount of $250 million, available capacity under the 2007 Credit Agreement was
$59 million. We may, at our option, so long as no default or event of default has occurred and is continuing, elect to increase the capacity
under our 2007 Credit Agreement by an aggregate amount not to exceed $100 million, provided that lenders are willing to commit additional
amounts. At our option, the interest rate on the outstanding borrowings may be the lenders’ base rate or the London Interbank Offered Rate
plus an applicable margin that is based on our long-term unsecured credit ratings. The 2007 Credit Agreement permits us to specify the
portion of the borrowings to be covered by specific interest rate options and to specify the interest rate period. We are required to pay a
facility fee of 0.05 percent based on the principal amount of the commitment of $250 million. The term of the agreement is five years, with
options for two one-year extensions.

Certain of our long-term debt arrangements contain covenants that restrict the incurrence of secured indebtedness or liens upon property by
us. Under the 2007 Credit Agreement, we are required to comply with certain financial, operational and legal covenants. Among other things,
we are required to maintain a leverage ratio (total debt to EBITDA (net income plus interest expense, income taxes, depreciation and
amortization and all other non-cash charges)) of no more than 4.75 to 1. Pursuant to the 2007 Credit Agreement, if one or more specified
material acquisitions are consummated, the permitted leverage ratio is increased to 5.50 to 1 for the first three full calendar quarters following
the acquisition. Upon any breach of these covenants, amounts outstanding under the 2007 Credit Agreement may become immediately due
and payable. Under the 2009 Senior Notes, we may not at any time permit debt secured by liens to exceed 20 percent of partners capital and
may not permit total debt, at any time, to exceed 70 percent of total capitalization. At December 31, 2010, we were in compliance with all of
our financial covenants.

Aggregate required repayment of long-term debt for the next five years is $191 million in 2012. Aggregate required repayments of long-term
debt thereafter total $350 million. There are no required repayment obligations for 2011, 2013, 2014 or 2015.

6. DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES

We record in long-term debt amounts received or paid related to terminated interest rate swap agreements for fair value hedges and amortize
these amounts to interest expense over the remaining original term of the interest rate swap agreements.

F-38

TC PIPELINES, LP

In August 2007, we entered into a zero cost interest rate collar agreement (the ‘‘Collar Agreement’’) to limit the variability of the interest rate
on $140 million of variable-rate borrowings during the period from October 30, 2007 through October 30, 2009 to a range between a floor
of 4.35 percent and a cap of 5.36 percent. We have designated the Collar Agreement as a cash flow hedge. No amounts were recognized in
income due to hedge ineffectiveness of the Collar Agreement.

The following table represents the unrealized (gains) losses recorded in accumulated other comprehensive income (loss) on the statements of
changes in partners’ equity:

Derivatives under Cash Flow Hedging Relationships

Cash flow hedges

Years Ended December 31,

2010

2009

2008

(In thousands)
–

$(3,633) $1,781

$

We record in accumulated other comprehensive income (loss) amounts received or paid related to terminated interest rate swap agreements
for cash flow hedges and amortize these amounts to interest expense. The following table represents the effective portion of realized gains,
net of realized losses, that have been reclassified from accumulated other comprehensive income (loss) and recognized as a reduction
(increase) to interest expense on the statements of income:

Net Gain Reclassified from AOCI into Income (Effective Portion)

Statements of Income Caption

2010

2009

2008

Years Ended
December 31,

Cash flow hedges

Interest expense

(In thousands)
$979

$(171)

1,486

At December 31, 2010, we have realized losses recorded in accumulated other comprehensive loss of approximately $2.9 million. We expect
to reclassify approximately $0.2 million from accumulated other comprehensive loss as an increase to interest expense in 2011.

7. FAIR VALUE MEASUREMENTS

Fair Value of Financial Instruments

The following table presents the carrying amounts and estimated fair values of our financial instruments at December 31, 2010 and 2009. The
fair value of a financial instrument is the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction
between market participants at the measurement date.

(In thousands)

Financial assets:

Cash and cash equivalents

Financial liabilities:
Long-term debt

2010

Carrying
Amount

Fair
Value

2009

Carrying
Amount

Fair
Value

$10,231

$10,231

$16,864

$16,864

$540,574

$599,381

$564,549

$612,009

The following methods and assumptions were used to estimate the fair value of each class of financial instruments:

Cash and cash equivalents – The carrying amount of cash and cash equivalents approximates fair value due to the short maturity of these
investments.

Long-term debt – The fair value of our senior notes were estimated based on quoted market prices for similar debt instruments with similar
terms and remaining maturities, which is classified as Level 2 in ‘‘Fair Value Hierarchy,’’ where the fair value is determined by using valuation
technique that refers to observable market data. We presently intend to maintain the current schedule of maturities for the 2001 and 2009
Senior Notes, which will result in no gains or losses on their respective repayments. The fair value of the 2007 Credit Agreement approximates
the carrying value since the interest rates are periodically adjusted to reflect current market conditions.

2010 ANNUAL REPORT

F-39

Fair Value Hierarchy

Under ASC 820, Fair Value Measurements and Disclosures, fair value measurements are characterized in one of three levels based upon the
input used to arrive at the measurement. The three levels of the fair value hierarchy are as follows:

(cid:127) Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities that we have the ability to access at the

measurement date.

(cid:127) Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly

or indirectly.

(cid:127) Level 3 inputs are unobservable inputs for the asset or liability.

When appropriate, valuations are adjusted for various factors including credit considerations. Such adjustments are generally based on
available market evidence. In the absence of such evidence, management’s best estimate is used.

8. COMMITMENTS AND CONTINGENCIES

Operating Leases

We make lease payments under non-cancelable operating leases on office space and rights-of-way. Expenses incurred related to these lease
obligations for the years ended December 31, 2010, 2009 and 2008 were $1.4 million, $1.4 million and $2.5 million, respectively. Our future
minimum lease payments, which assume we have exercised the option to renew a pipeline right-of-way lease in April 2011 for a term of
25 years (discussed below), are as follows:

Year ending December 31, (In thousands)

2011
2012
2013
2014
2015
Thereafter

$1,917
1,918
1,896
1,889
1,889
55,406

$64,915

In August 2004, we signed an Option Agreement and Expanded Facilities Lease (Option Agreement) with the Assiniboine and Sioux Tribes of
the Fort Peck Indian Reservation. The Option Agreement grants to us, among other things: (i) an option to renew the pipeline right-of-way
lease upon agreed terms and conditions on or before April 1, 2011, for a term of 25 years with a renewal right for an additional 25 years;
(ii) a right to use additional tribal lands for expanded facilities; and (iii) release and satisfaction of all tribal taxes against us. In consideration of
this option and other benefits, we paid a lump sum amount of $7.4 million and will make additional annual option payments through
March 31, 2036.

Transition Related Costs
We are required to pay $3.6 million over a five-year period under a transition services agreement between ONEOK Partners GP and
TransCanada Northern Border, related to the reimbursement for shared equipment and furnishings acquired by ONEOK Partners and previously
used or currently in use for our operations. Amounts related to this obligation are included in related party payables on the balance sheets.
Future remaining payments for this obligation are as follows:

Year ending December 31, (In thousands)

2011

Environmental Matters

$753

On February 2, 2009, we received a Notice of Violation (NOV) from the U.S. Environmental Protection Agency (EPA) alleging that we were in
violation of certain regulations pursuant to the Clean Air Act (CAA) regarding a compressor station on our system. On April 1, 2010, we
received indication from the EPA that it does not intend to file a complaint against us with respect to the NOV. We expect no further action
from the EPA regarding this NOV.

F-40

TC PIPELINES, LP

Other

As of December 31, 2010, we have made commitments of $0.3 million in connection with construction of the Princeton Lateral Project.

Various legal actions that have arisen in the ordinary course of business are pending. We believe that the resolution of these issues will not
have a material adverse impact on our results of operations or financial position.

9. CASH DISTRIBUTION POLICY

Our General Partnership Agreement provides that distributions to our partners are to be made on a pro rata basis according to each partner’s
capital account balance. Our Management Committee determines the amount and timing of the distributions to our partners including equity
contributions and the funding of growth capital expenditures. In addition, any inability to refinance maturing debt will be funded by equity
contributions. Any changes to, or suspension of, our cash distribution policy requires the unanimous approval of the Management Committee.
Our cash distributions are equal to 100 percent of our distributable cash flow as determined from our financial statements based upon
earnings before interest, taxes, depreciation and amortization less interest expense and maintenance capital expenditures.

For the years ended December 31, 2010, 2009 and 2008, we paid distributions to our general partners of $171.9 million, $151.5 million and
$181.3 million, respectively. In 2009, we received contributions from our general partners in the amount of $84.6 million. During the first
quarter of 2009, we received $8.6 million, which was used to fund 50 percent of the costs of construction of the Des Plaines Project. During
the third quarter of 2009, we received $76 million, which was used for the retirement of the 7.75 percent Senior Notes due
September 1, 2009.

Northern Border’s distribution policy adopted in 2006 defines minimum equity to total capitalization to be used by its Management
Committee to establish the timing and amount of required equity contributions. In accordance with this policy, we currently estimate an equity
contribution in 2011 of approximately $107.5 million.

10. RELATED PARTY TRANSACTIONS

The day-to-day management of our affairs is the responsibility of TransCanada Northern Border, Inc., (TransCanada Northern Border) pursuant
to an operating agreement between TransCanada Northern Border and us effective April 1, 2007. TransCanada Northern Border utilizes the
services of TransCanada Corporation (TransCanada) and its affiliates for management services related to us. We are charged for the salaries,
benefits and expenses of TransCanada and its affiliates attributable to our operations. For the years ended December 31, 2010, 2009 and
2008, our charges from TransCanada and its affiliates totaled approximately $25.8 million, $25.5 million and $28.6 million, respectively.

For the years ended December 31, 2010, 2009 and 2008, we had contracted firm capacity held by one shipper affiliated with one of our
general partners. Revenue from ONEOK Energy Services Company, LP (ONEOK Energy), a subsidiary of ONEOK, for 2010, 2009 and 2008 was
$4.1 million, $4.2 million and $5.0 million, respectively. At December 31, 2010 and 2009, we had outstanding receivables from ONEOK
Energy of $0.3 million and $0.4 million, respectively.

In March 2008, we formed a wholly-owned subsidiary, Bison Pipeline LLC (Bison) to develop the Bison Project. The Bison Project is a pipeline
system that extends from natural gas gathering facilities located in the Powder River Basin in Wyoming to a point of interconnection with our
pipeline system in Morton County, North Dakota. The Bison Pipeline was placed into service in January 2011.

In August 2008, we sold Bison to TransCanada Pipeline USA Ltd., a wholly-owned subsidiary of TransCanada, for $20.0 million. In connection
with this transaction, we recorded a gain on sale of $16.2 million. Through the effective date of the sale, Bison received services from
TransCanada and its affiliates totaling approximately $2.0 million in 2008.

In June 2008, in connection with the Des Plaines Project, we entered into an interconnect agreement with ANR Pipeline Company (ANR), a
wholly-owned subsidiary of TransCanada. The interconnect agreement provides that we will reimburse ANR for the cost of certain of the
interconnect facilities to be owned by ANR. In 2008, we paid ANR $0.5 million.

In April 2010, Northern Border and Bison entered into an Interconnect Agreement in which Bison paid $1.4 million for the estimated costs of
the interconnect at Northern Border Compressor Station No. 6. The project was completed in the fourth quarter of 2010.

11. SUBSEQUENT EVENTS

We make distributions to our general partners approximately one month following the end of the quarter. A cash distribution of approximately
$51.5 million was declared and paid on February 1, 2011 for the fourth quarter of 2010.

We have evaluated subsequent events through February 10, 2011, which represents the date the financial statements were issued and
concluded there were no events or transactions during this period that would require recognition or disclosure in the financial statements
other than those already reflected.

2010 ANNUAL REPORT

G-1

Glossary

The abbreviations, acronyms, and industry terminology used in this annual report are defined as follows:

Acquisition Agreement

Agreement for Purchase and Sale of Membership Interest for the Partnership’s purchase
of North Baja

ANR

ASC

Bcf

Bcf/d

BIA

Bison

CAA

ANR Pipeline Company

Accounting Standards Codification

Billion cubic feet

Billion cubic feet per day

Bureau of Indian Affairs

Bison Pipeline LLC

Clean Air Act

CERCLA

Comprehensive Environmental Response, Compensation and Liability Act

Collar Agreement

Northern Border’s interest rate collar agreement

Costa Azul

CWA

Delaware Act

Design capacity

Dth

EBITDA

EPNG

EPA

Essar

Exchange Agreement

FERC

GAAP

Gas exiting the WCSB

Energia Costa Azul

Clean Water Act

Delaware Revised Uniform Limited Partnership Act

Pipeline capacity available to transport natural gas based on system facilities and design
conditions

Dekatherms

Net income plus interest expense, income taxes, depreciation and amortization and all
other non-cash charges

El Paso Natural Gas Company

U.S. Environmental Protection Agency

Essar Steel Minnesota LLC

Agreement with the General Partner pursuant to which the Partnership issued new
common units to the General Partner and provided for Revised IDRs in exchange for the
cancellation of the Old IDRs

Federal Energy Regulatory Commission

U.S. generally accepted accounting principles

Net of the supply of and demand for natural gas in the WCSB region that is available for
transportation to downstream markets; where supply represents WCSB production
adjusted for injections into and withdrawals from WCSB storage

General Partner

TC PipeLines GP, Inc.

GL Rate Proceeding

FERC investigation into Great Lakes’ rates pursuant to Section 5 of the NGA

Great Lakes

Great Lakes Gas Transmission Limited Partnership

GTN

HCAs

IDRs

INGAA

IRS

Gas Transmission Northwest Corporation

High consequence areas

Incentive Distribution Rights

Interstate Natural Gas Association of America

Internal Revenue Service

G-2

TC PIPELINES, LP

IT

LIBOR

LNG

MDth/d

MLP

MMcf/d

MMDth/d

NEB

NEPA

NGA

North Baja

Northern Border

November 2009 Order

Offering

Old IDRs

Interruptible Transportation

London Interbank Offered Rate

Liquified Natural Gas

Thousand dekatherms per day

Master Limited Partnership

Million cubic feet per day

Million dekatherms per day

National Energy Board of Canada

National Environmental Policy Act

Natural Gas Act

North Baja Pipeline, LLC

Northern Border Pipeline Company

FERC order issued in FERC Docket No. RP10-149 on November 19, 2009 instituting GL
Rate Proceeding

The sale of 2,609,680 newly issued, unregistered common units representing limited
partner interests in the Partnership to TransCan Northern at a price per common unit of
$30.042 for an aggregate amount of approximately $78.4 million

IDRs available to the General Partner under the Amended and Restated Agreement of
Limited Partnership

ONEOK Partners

ONEOK Partners, L.P.

ONEOK Partners GP

ONEOK Partners GP, LLC

Other Pipes

North Baja and Tuscarora

Our pipeline systems

Great Lakes, Northern Border, North Baja and Tuscarora

Partnership

TC PipeLines, LP and its subsidiaries

Partnership Agreement

Second Amended and Restated Agreement of Limited Partnership

PCBs

Polychlorinated biphenyls

Pipeline Safety Act

The Pipeline Safety Improvement Act of 2002

RCRA

Revised IDRs

ROE

Ruby

S&P

SEC

Resource Conservation and Recovery Act

IDRs available to the General Partner under the Second Amended and Restated
Agreement of Limited Partnership

Return on equity

Ruby Pipeline LLC

Standard & Poor’s

Securities and Exchange Commission

Senior Credit Facility

TC PipeLines, LP’s revolving credit and term loan agreement

Tortoise

Tortoise Capital Advisors, L.L.C.

TransCan Northern

TransCan Northern Ltd.

TransCanada

Tuscarora

U.S.

WCSB

Yuma Lateral

TransCanada Corporation and its subsidiaries

Tuscarora Gas Transmission Company

United States of America

Western Canada Sedimentary Basin

An expansion of the North Baja pipeline from the Mexico/Arizona border to Yuma City,
Arizona

Board of Directors of the General Partner of  
TC PipeLines, LP

Executive Officers of the General  
Partner of TC PipeLines, LP

Gregory A. Lohnes, Chairman, TC PipeLines GP, Inc.
President, Natural Gas Pipelines 
TransCanada Corporation 
Calgary, Alberta

Steven D. Becker, President, and Director TC PipeLines GP, Inc
Vice-President, Business Development, Natural Gas Pipelines 
TransCanada Corporation 
Calgary, Alberta

Kristine L. Delkus
Deputy General Counsel, Pipelines and Regulatory Affairs,  
Pipelines Division 
TransCanada Corporation 
Calgary, Alberta

Jack F. Jenkins-Stark (1) (2) (3)
Chief Financial Officer 
BrightSource Energy, Inc. 
Oakland, California

James (Jim) M. Baggs
Vice-President, Operations and Engineering 
TransCanada Corporation 
Calgary, Alberta

David L. Marshall (4) (5)
Retired Vice-Chairman and Chief Financial Officer 
The Pittston Company 
Sparks, Nevada

Walentin (Val) Mirosh (3) (5)
President 
Mircan Resources Ltd. 
Calgary, Alberta

(1) Lead Director 
(2) Chair, Conflicts Committee 
(3) Member, Audit Committee 
(4) Chair, Audit Committee 
(5) Member, Conflicts Committee

Gregory A. Lohnes 
Chairman

Steven D. Becker 
President

Terry C. Ofremchuk 
Vice-President, Taxation

Rhonda L. Amundson  
Treasurer

Robert C. Jacobucci 
Principal Financial Officer and Controller

Donald J. DeGrandis 
Secretary

Annie C. Belecki 
Assistant Secretary

Stephanie E. Wilson 
Vice-President, Commercial

Stuart P. Kampel 
Vice-President, Business Development

TC PipeLines, LP
13710 FNB Parkway  
Omaha, NE 68154-5200 
Telephone 877.290.2772  Facsimile 508.871.7047

450 First Street SW 
Calgary, Alberta, Canada T2P 5H1 
Telephone 877.290.2772  Facsimile 403.920.2457

Investor Relations
Lee Evans  
Manager, Investor Relations 

Telephone 877.290.2772  Facsimile 403.920.2457 
E-mail: investor_relations@tcpipelineslp.com

Website
www.tcpipelineslp.com

K-1 Information
Telephone 877.699.1091

Stock Exchange Listing
NASDAQ Global Market: TCLP

Auditors 
KPMG LLP, Calgary, Alberta, Canada

Transfer Agent
BNY Mellon Shareowner Services 
Telephone 800.756.3353

Mailing Address 
P.O Box 358015 
Pittsburgh, PA 15252-8015

Courier Address
500 Ross Street, 6th Floor 
Pittsburgh, PA 15262

Please recycle