TransCanada to Become Operator of Northern Border Pipeline.

CALGARY, Alberta -- TransCanada Corporation (TSX:TRP) (NYSE:TRP) (TransCanada) today announced that it will sell its 17.5 per cent general partner interest in Northern Border Partners, L.P., to a subsidiary of ONEOK, Inc. (ONEOK) for a net payment of US$30 million subject to certain closing adjustments. In addition, TransCanada will become the operator of Northern Border Pipeline (NBPL) in early 2007. This is part of a series of transactions that will also result in TC PipeLines, LP acquiring an additional 20 per cent interest in NBPL from Northern Border Partners, L.P., bringing its total general partnership interest in NBPL to 50 per cent. These transactions are subject to closing conditions, including regulatory approvals.

TransCanada, through its wholly owned subsidiary TC PipeLines GP, Inc., holds a 13.4 per cent interest in TC PipeLines, LP, a United States Master Limited Partnership, which was formed to acquire, own and actively participate in the management of U.S. natural gas pipelines and related assets, including NBPL.

"With capacity of 2.4 billion cubic feet per day, Northern Border is the largest natural gas pipeline connecting the Alberta Hub with growing markets in the U.S. Midwest. In 2005, more than 20 per cent of the total amount of natural gas exported from Canada to the United States was shipped on Northern Border," said Hal Kvisle, chief executive officer of TransCanada. "We look forward to becoming operator of this important pipeline which in the future is expected to play a significant role in moving northern frontier natural gas from the Alberta Hub to U.S. markets."

Northern Border Pipeline owns a 2,010-kilometre (1,249-mile) interstate pipeline system that transports natural gas from the Montana-Saskatchewan border, where it connects with TransCanada's Foothills System, to interconnecting pipelines in the upper Midwestern United States.

TransCanada is a leader in the responsible development and reliable operation of North American energy infrastructure. TransCanada's network of approximately 41,000 kilometres (25,600 miles) of pipeline transports the majority of Western Canada's natural gas production to key Canadian and U.S. markets. A growing independent power producer, TransCanada owns, or has interests in, approximately 6,700 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

Certain information in this news release is forward-looking and is subject to important risks and uncertainties. The results or events predicted in this information may differ from actual results or events. 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 availability and price of energy commodities, regulatory decisions, competitive factors in the pipeline and power industry sectors, and the current economic conditions in North America. For additional information on these and other factors, see the reports filed by TransCanada with Canadian securities regulators and with the United States Securities and Exchange Commission. TransCanada disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

TRANSCANADA (TSX:TRP) (NYSE:TRP)