UPDATE 1-U.S. House Democrats seek briefing on Acosta's role in Epstein plea deal

(Adds details, background, Justice Dept. declining commment)

WASHINGTON, July 11 (Reuters) - U.S. House Democrats on Thursday asked the Justice Department for a briefing on Labor Secretary Alexander Acosta's decision to approve a 2007 plea deal for financier Jeffrey Epstein, who was charged this week with sex trafficking in underage girls.

Acosta, who was a top U.S. prosecutor in Florida at the time, has been the target of criticism that his office approved a lenient deal for Epstein, which has received renewed attention because of the new charges.

Instead of prosecuting Epstein on a federal level, Acosta's office agreed to have the billionaire sign a plea deal with state prosecutors that resulted in a lax sentence.

"We have serious misgivings about Secretary Acosta's handling of the case and whether the department fairly administered justice," members of a House of Representatives judiciary subcommittee said in a letter to Deputy Attorney General Jeffrey Rosen.

Democrats on the crime, terrorism and homeland security subcommittee asked the Justice Department for the briefing and "any relevant documents" by July 24.

The Justice Department declined to comment.

On Wednesday, Acosta held a news conference to defend his handling of the case.

Acosta disputed that his office let Epstein get off easily and argued that had his team not stepped in, Epstein would have only faced one charge from state prosecutors and avoided any jail time.

Ultimately, Epstein served time in jail but was granted daily work release.

Acosta said that at the time, a trial would have been difficult because the witnesses would have faced intense scrutiny from a team of defense attorneys.

Epstein, 66, was arrested on Saturday evening at Teterboro Airport in New Jersey, where he had returned on his private plane from Paris. He pleaded not guilty to sex trafficking and conspiracy.

On Thursday, Epstein asked a federal judge to let him out of jail and allow him to remain under house arrest in his Manhattan mansion while he awaits trial. (Reporting by Eric Beech; Editing by Peter Cooney)