WACO, Tex. — Attorney General Alberto R. Gonzales, whose tenure has been marred by controversy and accusations of perjury before Congress, has resigned. A senior administration official said he would announce the decision later this morning in Washington.

Mr. Gonzales, who had rebuffed calls for his resignation, submitted his to President Bush by telephone on Friday, the official said. His decision was not announced immediately announced, the official added, until after the president invited him and his wife to lunch at his ranch near here.

Mr. Bush has not yet chosen a replacement but will not leave the position open long, the official said, speaking on condition of anonymity because the resignation had not yet been made public.

Mr. Bush had repeatedly stood by Mr. Gonzales, an old friend and colleague from Texas, even as Mr. Gonzales faced increasing scrutiny for his leadership of the Justice Department, over issues including his role in the dismissals of nine United States attorneys late last year and whether he testified truthfully about the National Security Agency’s surveillance programs.

Earlier this month, at a news conference, Mr. Bush dismissed accusations that Mr. Gonzales had stonewalled or misled a congressional inquiry. “We’re watching a political exercise,” Mr. Bush said. “I mean, this is a man who has testified, he’s sent thousands of papers up there. There’s no proof of wrong.”

Mr. Gonzales’s resignation is the latest in a series of high-level departures that has reshaped the end of Mr. Bush’s second term. Karl Rove, another of Mr. Bush’s close circle of aides from Texas, stepped down two weeks ago.

The official who disclosed the resignation today said that the decision was Mr. Gonzales’s and that the president accepted it grudgingly. At the same time, the official acknowledged that the turmoil over Mr. Gonzales had made his continuing as attorney general difficult.

“The unfair treatment that he’s been on the receiving end of has been a distraction for the department,” the official said.

As recently as Sunday afternoon, Mr. Gonzales was denying through his press spokesman, Brian Roehrkasse, that he intended to leave.

Mr. Roehrkasse said Sunday afternoon that he had telephoned Mr. Gonzales about the reports circulating in Washington that a resignation was imminent, “and he said it wasn’t true, so I don’t know what more I can say.”

White House spokesmen also insisted on Sunday that they did not believe that Mr. Gonzales was planning to resign. Aides to senior members of the Senate Judiciary Committee said over the weekend that they had received no suggestion from the administration that Mr. Gonzales intended to resign.

Senator Charles Schumer, the New York Democrat who sits on the committee and has been calling for Mr. Gonzales’s resignation for months, said this morning: “It has been a long and difficult struggle, but at last the attorney general has done the right thing and stepped down. For the previous six months, the Justice Department has been virtually nonfunctional, and desperately needs new readership.”

Senator Schumer said that “Democrats will not obstruct or impede a nominee who we are confident will put the rule of law above political considerations.”