TCLP TC Pipelines, LP - Common Units Representing Limited Partnership Interests (MM)

TC PipeLines, LP (NASDAQ: TCLP) today filed its Annual Report on Form 10-K for the year ended December 31, 2009, including audited financial statements, with the U.S. Securities and Exchange Commission.

A copy of the Form 10-K is available to view, print or download under the Investor Center, Regulatory Filings section, of the TC PipeLines, LP website at: www.tcpipelineslp.com/RegulatoryFilings.htm

Any unitholder wishing to receive a paper copy of the Annual Report may obtain one free of charge upon request by contacting the TC PipeLines, LP Secretary at 1.800.661.3805.

TC PipeLines, LP has interests in approximately 3,700 miles of federally regulated U.S. interstate natural gas pipelines, including Great Lakes Gas Transmission Limited Partnership (46.45 per cent ownership), Northern Border Pipeline Company (50 per cent ownership), North Baja Pipeline, LLC (100 per cent ownership) and Tuscarora Gas Transmission Company (100 per cent ownership). Great Lakes is a 2,115-mile pipeline serving markets in Minnesota, Wisconsin, Michigan and eastern Canada. The 1,249-mile Northern Border Pipeline transports natural gas from the Montana-Saskatchewan border to markets in the midwestern United States. North Baja is an 80-mile natural gas pipeline that extends from Southwestern Arizona to a point on the California/Mexico border and connects with a natural gas pipeline system in Mexico. Tuscarora owns a 240-mile pipeline system that transports natural gas from Oregon, where it interconnects TransCanada's Gas Transmission Northwest System, to markets in Oregon, Northern California, and Northwestern Nevada. TC PipeLines, LP is managed by its general partner, TC PipeLines GP, Inc., an indirect wholly owned subsidiary of TransCanada Corporation. TC PipeLines GP, Inc. also holds common units of TC PipeLines, LP. Common units of TC PipeLines, LP are quoted on the NASDAQ Stock Market and trade under the symbol "TCLP." For more information about TC PipeLines, LP, visit the Partnership's website at www.tcpipelineslp.com.

Contacts: TC PipeLines, LP Media Inquiries: Cecily Dobson/Terry Cunha (403) 920-7859 or (800) 608-7859 TC PipeLines, LP Unitholder and Analyst Inquiries: Terry Hook 1-877-290-2772 investor_relations@tcpipelineslp.com www.tcpipelineslp.com