WASHINGTON: Attorney General Alberto Gonzales announced his resignation on Monday, ending a stormy tenure at the Justice Department that included repeated battles with Congress over whether he had allowed his intense personal loyalty to President Bush to overwhelm his responsibilities to the law.

Gonzales, the nation's first Hispanic attorney general, offered no clear explanation for his departure or its timing. The announcement caught his top aides at the Justice Department by surprise, leading to speculation among lawmakers and department officials that Gonzales might have been pressured from within the administration to step down.

In a statement to reporters Monday on the airport tarmac in Waco, Texas, as he prepared to board Air Force One, Bush said he had ''reluctantly'' accepted the resignation. He portrayed Gonzales as a ''man of integrity, decency and principle'' who had been hounded from office for political reasons.

''It's sad that we live in a time when a talented and honorable person like Alberto Gonzales is impeded from doing important work because his good name was dragged through the mud,'' Bush said.

For months, Gonzales, with what appeared to be Bush's full backing, had rebuffed bipartisan calls for his ouster and suggested that he intended to remain indefinitely at the Justice Department, Please see Gonzales, A6

possibly through the end of the Bush presidency.

The most persistent calls for his resignation came from Democrats who questioned whether Gonzales had lied under oath about his involvement in the dismissal of several U.S. attorneys. He was also accused of misleading Congress about his role, in his earlier job as White House counsel, in promoting a government eavesdropping program.

Bush said Monday that Solicitor General Paul D. Clement, the Justice Department's chief lawyer before the Supreme Court, would be acting attorney general until a permanent successor is chosen for Gonzales, who is to step down Sept. 17.

White House officials said the president expects to find a successor quickly, though associates of some prospective candidates said the White House would struggle to find someone who was well qualified and could be easily confirmed.

Among the candidates, they said, were Michael Chertoff, the secretary of homeland security and a former federal appeals court judge and top Justice Department official; Christopher Cox, the chairman of the Securities and Exchange Commission; George J. Terwilliger III, a deputy attorney general under the first President Bush; Laurence H. Silberman, a court of appeals judge in Washington; and Larry D. Thompson, a former deputy attorney general who is now senior vice president and general counsel of PepsiCo.

White House officials said Thompson would have special appeal as a nominee, as he would be the first black attorney general.

No explanations

In the brief statement he read to reporters at the Justice Department to announce his departure, Gonzales did not explain why he was resigning or refer to the turmoil over his actions as attorney general. Instead, he focused his remarks on his gratitude to Bush, who appointed Gonzales to every government job he has held since law school, beginning in Texas, and to his colleagues at the Justice Department.

''Even my worst days as attorney general have been better than my father's best days,'' Gonzales said. ''I have lived the American dream.'' Gonzales' father was a Mexican-American construction worker who raised eight children in a two-room home near Houston.

Gonzales refused to answer questions reporters shouted to him as he left the briefing room.

Gonzales has been a controversial figure in Washington since shortly after the terrorist attacks on Sept. 11, 2001, when, as White House counsel, he supported legal policies that broadly expanded the powers of the executive branch and allowed for the imprisonment and interrogation of terrorism suspects in conditions that human-rights groups said amounted to torture. He became attorney general in February 2005, succeeding John Ashcroft.

The president's passionate defense of Gonzales in his comments Monday reflected the almost familial bonds of loyalty between the two men. They met when Bush was governor of Texas in the 1990s and Gonzales was a young Houston lawyer with an impressive, up-by-the-bootstraps life story.

There were expressions of relief on Capitol Hill on Monday at news of his resignation, including from Republicans who said Gonzales' presence at the Justice Department was making it impossible for Bush to pursue his law enforcement agenda in Congress.

''Our country needs a credible, effective attorney general who can work with Congress on critical issues ranging from immigration to investigating terrorism at home and abroad,'' said Sen. John E. Sununu, R-N.H. ''Alberto Gonzales' resignation will finally allow a new attorney general to take on this task.''