Construction continues on the Dakota Access pipeline near the town of Cannon Ball, N.D., in October. (Reuters/Josh Morgan)

President-elect Donald Trump sold off his shares of Energy Transfer Partners, the owner of the $3.7 billion Dakota Access pipeline that has become the focus of protests by Native American and environmental groups, according to his spokeswoman Hope Hicks.

Trump’s share, which in a May 2015 disclosure was listed at between $500,000 and $1 million, had fallen to less than $50,000 by the time he sold it in the summer of 2016, according to a disclosure earlier this year.

The sale would eliminate one possible conflict of interest for Trump, who has vowed to speed up permits for oil and gas pipelines in order to spur more oil and gas development in the United States. The Dakota Access pipeline, which is largely finished, would carry as many as 570,000 barrels a day of shale oil 1,170 miles from western North Dakota to pipeline connections in Illinois.

Although he has sold his stake, Trump has been the recipient of generous political contributions from Energy Transfer chief executive Kelcy Warren.

Warren this year has made $1.53 million in campaign contributions to super PACs and $252,300 to individual campaigns and the GOP, according to the Center for Responsive Politics. In June 2015, he gave $5 million to Opportunity and Freedom PAC, which supported Rick Perry’s presidential campaign. The Trump Victory Fund, a joint fundraising committee that includes Trump’s campaign, the Republican National Committee and some state parties, received a $100,000 contribution from Warren on June 29.

Hicks said she did not know why Trump sold his shares in Energy Transfer, whose stock sagged as protests intensified during the fall. Energy Transfer recently announced a $20 billion merger with Sunoco in an all-stock transaction.

Hicks could not say whether Trump had sold shares in any other companies besides Energy Transfer Partners.

Drew Harwell contributed to this post.