TransCanada Corp. (TO: TRP, NYSE: TRP) closed the sale of its remaining 30% interest in Gas Transmission Northwest LLC (GTN) to TC PipeLines LP, the company said April 1.

GTN is a 2,178 kilometer (1,353 mile) pipeline that transports natural gas under long-term contracts from the Western Canada Sedimentary Basin and the Rocky Mountains to Washington, Oregon and California.

In 2014, the 30% interest in GTN generated comparable EBITDA of US$43 million.

The US$446 million transaction is comprised of US$253 million in cash, the assumption of US$98 million in proportional GTN debt and the issuance of US$95 million of new Class B units to TransCanada.

The Class B units will entitle TransCanada to a distribution based on 30% of GTN's annual cash distributions for the first five years. TransCanada will receive 100% of distributions greater than US$20 million in subsequent years.

TC PipeLines is a U.S. MLP, and TransCanada holds a 28% interest in it through subsidiaries. TC PipeLines acquires and owns U.S. natural gas pipelines and related assets.

TransCanada Corp. is based in Calgary, Alberta.