President Trump on Monday named Makan Delrahim, a former government antitrust enforcer and corporate lobbyist, to lead the Justice Department's review of mergers and acquisitions.
The appointment is being closely watched because companies across industries have been hoping that the new Republican administration will be more permissive with mergers.
The Obama administration had blocked dozens of blockbuster deals over the past eight years, including AT&T's bid for T-Mobile in 2011 and Comcast's merger with Time Warner Cable in 2015.
Mr. Delrahim, who serves as legal counsel to the president, will be quickly tested in his new position by AT&T's $85 billion bid for Time Warner, which is set to be reviewed this year. Other mergers under review include Dow Chemical's bid for Dupont and Bayer's acquisition of Monsanto.