TransCanada to Issue $1.1 Billion of Common Shares

CALGARY, ALBERTA--(Marketwire - May 5, 2008) - TransCanada Corporation (TSX:TRP) (NYSE:TRP) (TransCanada) today announced that it has entered into an agreement with a syndicate of underwriters, led by BMO Capital Markets, RBC Capital Markets, and TD Securities Inc. under which they have agreed to purchase from TransCanada and sell to the public 30,200,000 Common Shares.

The purchase price of $36.50 per Common Share will result in gross proceeds of approximately $1.1 billion. The net proceeds of the offering will be used by TransCanada to partially fund acquisitions and capital projects of the Corporation including, amongst others, the acquisition of the Ravenswood Generating Facility, the construction of the Keystone Oil Pipeline, and for general corporate purposes.

The Common Shares will be offered to the public in Canada and the U.S. through the underwriters or their affiliates. TransCanada has also granted the underwriters an option to purchase up to an additional 4,530,000 Common Shares at a price of $36.50 per Common Share at any time up to 30 days after closing of the offering.

The Common Shares will be issued by way of a prospectus supplement that will be filed with securities regulatory authorities in Canada and the U.S. under TransCanada's short form base shelf prospectus dated January 31, 2007, which was previously filed with securities regulatory authorities across Canada and in the U.S. under the multi-jurisdictional disclosure system.

This news release does not constitute an offer to sell or the solicitation of any offer to buy nor will there be any sale of these securities in any province, state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such province, state or jurisdiction.

A written prospectus relating to the offering may be obtained from BMO Capital Markets Distribution Department at 1 First Canadian Place, B2 Level, Toronto, Ontario, M5X 1H3 (Attention: Des Raposo, tel: 416-363-6996 x224).

With more than 50 years' experience, TransCanada is a leader in the responsible development and reliable operation of North American energy infrastructure including natural gas pipelines, power generation, gas storage facilities, and projects related to oil pipelines and LNG facilities. TransCanada's network of wholly owned pipelines extends more than 59,000 kilometres (36,500 miles), tapping into virtually all major gas supply basins in North America. TransCanada is one of the continent's largest providers of gas storage and related services with approximately 355 billion cubic feet of storage capacity. A growing independent power producer, TransCanada owns, or has interests in, approximately 7,700 megawatts of power generation in Canada and the United States. TransCanada's common shares trade on the Toronto and New York stock exchanges under the symbol TRP.

Note: All financial figures are in Canadian dollars unless noted otherwise.

FORWARD-LOOKING INFORMATION

This news release may contain certain information that is forward looking and is subject to important risks and uncertainties. The words "anticipate", "expect", "may", "should", "estimate", "project", "outlook", "forecast" or other similar words are used to identify such forward looking information. All forward-looking statements reflect TransCanada's beliefs and assumptions based on information available at the time the statements were made. Actual results or events may differ from those predicted in these forward-looking statements. Factors which could cause actual results or events to differ materially from current expectations include, among other things, the ability of TransCanada to successfully implement its strategic initiatives and whether such strategic initiatives will yield the expected benefits, the operating performance of the Company's pipeline and energy assets, the availability and price of energy commodities, regulatory processes and decisions, changes in environmental and other laws and regulations, competitive factors in the pipeline and energy industry sectors, construction and completion of capital projects, labour, equipment and material costs, access to capital markets, interest and currency exchange rates, technological developments and the current economic conditions in North America. By its nature, such forward-looking information is subject to various risks and uncertainties, which could cause TransCanada's actual results and experience to differ materially from the anticipated results or expectations expressed. Additional information on these and other factors is available in the reports filed by TransCanada with Canadian securities regulators and with the U.S. Securities and Exchange Commission. Readers are cautioned not to place undue reliance on this forward-looking information, which is given as of the date it is expressed in this news release or otherwise, and to not use future-oriented information or financial outlooks for anything other than their intended purpose. TransCanada undertakes no obligation to update publicly or revise any forward-looking information, whether as a result of new information, future events or otherwise, except as required by law.

TransCanada
Media Inquiries
Shela Shapiro/Cecily Dobson
(403) 920-7859 or (800) 608-7859
or
Investor & Analyst Inquiries
David Moneta/Myles Dougan/Terry Hook
(403) 920-7911 or (800) 361-6522
Website: www.transcanada.com