UPDATE 1-TransCanada closes Keystone XL open season after "strong" demand

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Jan 18 (Reuters) - TransCanada Corp said it received strong commercial support for its Keystone XL pipeline and closed its window for shippers to sign up for committed capacity, taking it one step closer to starting construction on the project.

TransCanada has secured firm, 20-year commitments for about 500,000 barrels per day of oil and oil equivalents as it concluded its open season for the project, the company said on Thursday.

The controversial pipeline overcame its final hurdle when Nebraska regulators approved a path for the project through the state in November.

Earlier last year, the Trump administration granted TransCanada a federal permit for the pipeline, reversing a decision by former President Barack Obama to reject the project on environmental grounds.

"Interest in the project remains strong and TransCanada will look to continue to secure additional long-term contracted volumes," the company said in a statement.

Primary construction expected to begin in 2019, TransCanada said.

The controversial pipeline has been has been a lightning rod of controversy for nearly a decade, pitting environmentalists worried about spills and global warming against business advocates who say the project will lower fuel prices, shore up national security and bring jobs. (Reporting by Nivedita Bhattacharjee; Editing by Saumyadeb Chakrabarty)