The head of the Justice Department’s antitrust unit said Thursday she is leaving the role, effective immediately, at a critical moment for corporate mergers in America.

Gail Slater, the assistant attorney general in charge of the Antitrust Division, wrote on X: ‘It is with great sadness and abiding hope that I leave my role as AAG for Antitrust today.’

Slater continued, ‘It was indeed the honor of a lifetime to serve in this role. Huge thanks to all who supported me this past year, most especially the men and women of’ the Department.

The White House referred questions to the Justice Department.

Attorney General Pam Bondi said in a statement, “On behalf of the Department of Justice, we thank Gail Slater for her service to the Antitrust Division which works to protect consumers, promote affordability, and expand economic opportunity.”

Slater is leaving just as media giants Netflix and Paramount Skydance battle for control of Warner Bros. Discovery.

President Donald Trump had said he was going to get involved in reviewing whichever Warner Bros. deal proceeds, an uncommon occurrence in antitrust matters.

But in an interview with NBC News, Trump slightly changed his tune. ‘I’ve been called by both sides, it’s the two sides, but I’ve decided I shouldn’t be involved,’ he said.

‘The Justice Department will handle it.’

Trump has met with executives from both of Warner Bros.’ bidders.

The Justice Department will also head to court in weeks in a bid to challenge concert venue manager Live Nation’s ownership of Ticketmaster.

Shares of Live Nation jumped as much as 5.8% after Slater announced her departure. By 1 p.m. ET, the rally had abated to around 2.5%.

When the Senate confirmed Slater, 78 senators from both sides of the aisle voted in her favor. Only 19 opposed her confirmation.

This week, her deputy in the Antitrust Division also departed.

Mark Hamer, deputy assistant attorney general for the Antitrust Division, wrote on LinkedIn, ‘Decided the time is right for me to return to private practice.’ He praised Slater as a ‘leader of exceptional wisdom, strength and integrity.’