Retired federal judge Michael Mukasey, who has presided over high-profile terrorism cases, was chosen by President Bush today to replace attorney general Alberto Gonzales. CHARLES DHARAPAK | Associated Press

As chief judge of the busy U.S. District Court for the Southern District of New York, Mukasey had presided over high-profile terrorism cases.

"He knows what it takes to fight this war effectively and he knows how to do it in a manner consistent with our laws and our Constitution," Bush said, standing next Mukasey in the Rose Garden.

The president urged the Senate to quickly confirm Mukasey, who would be Bush's third attorney general.

If approved by the Senate, Mukasey would take charge of a Justice Department where morale is low following months of investigations into the firings of nine U.S. attorneys and Gonzales' sworn testimony on the Bush administration's terrorist surveillance program.

Mukasey said he was honored to be Bush's nominee to take the helm of the department.

"My finest hope and prayer at this time is that if confirmed I can give them the support and the leadership they deserve," he said.

There had been rampant speculation that Bush might turn to former Solicitor General Ted Olson for the job, but key Democrats on Capitol Hill said they believed Olson too partisan a figure and indicated they would fight his nomination. The White House acknowledged that Bush had interviewed others for the job besides Mukasey.

The White House said that ease of confirmation was a factor, but not the decisive one, in Bush's selection. Bush critics contended that Mukasey's nomination was evidence of the president's weakened political clout as he heads into the final 15 months of his term.

Senate Democrats declared no outright opposition to Mukasey. But they made clear that there would be no confirmation hearings until the administration answers outstanding questions about the White House's role in the firings of federal prosecutors over the winter.

"Our focus now will be on securing the relevant information we need so we can proceed to schedule fair and thorough hearings," said Sen. Patrick Leahy, D-Vt., the chairman of the Senate Judiciary Committee. "Cooperation from the White House will be essential in determining that schedule."

Sen. Arlen Specter, R-Pa., said the answers Leahy seeks are important, but not enough to delay the installation of someone to stabilize a leaderless Justice Department hobbled by scandal.

Senate Majority Leader Harry Reid said he believes the president listened to Congress and decided against a more partisan replacement for Gonzales. He said Mukasey had "strong professional credentials and a reputation for independence."

"A man who spent 18 years on the federal bench surely understands the importance of checks and balances and knows how to say no to the president when he oversteps the Constitution," said Reid, D-Nev. "But there should be no rush to judgment. The Senate Judiciary Committee must carefully examine Judge Mukasey's views on the complex legal challenges facing the nation."

Some legal conservatives and Republican activists have expressed reservations about Mukasey's legal record. Even before he was nominated, Mukasey met on Sunday with six conservative leaders to answer their questions.

Mukasey currently serves as a judicial adviser to GOP presidential hopeful Rudy Giuliani; the White House said he would sever ties with the campaign.

Mukasey, chosen in large part for his experience in national security matters, noted the threat of terrorism in his brief remarks. "Thirty five years ago, our foreign adversaries saw widespread devastation as a deterrent," he said. "Today, our fanatical enemies see it as a divine fulfillment."

Friday was the last day of Gonzales' 2-1/2 years at Justice. He resigned amid a continuing controversy over the firings of several federal prosecutors and questions about the administration's warrantless eavesdropping program.

Until a new attorney general is confirmed by the Senate, Bush said, Assistant Attorney General Peter D. Keisler will serve as acting attorney general. Keisler oversaw the Bush administration's lengthy legal fight over the rights of terrorism war-era prisoners at Guantanamo Bay.

Keisler had announced his resignation from the department in early September. He had been nominated by Bush earlier in the year for a seat on the U.S. Court of Appeals for the District of Columbia Circuit. The Senate has not acted on Keisler's nomination.

Bush said that Keisler had agreed to stay on at the Justice Department, which will allow Solicitor General Paul Clement to focus on his duties as the government's chief advocate as the Supreme Court nears the opening of its new fall term.

During his 18 years as a judge, Mukasey presided over thousands of cases, including the trial of Sheik Omar Abdel-Rahman, who was accused of plotting to destroy New York City landmarks. In the 1996 sentencing of co-conspirators in the case, Mukasey accused the sheik of trying to spread death "in a scale unseen in this country since the Civil War." He then sentenced the blind sheik to life in prison.

Campaign finance records show Mukasey has made few political donations at the federal level, and that not all of the money he gave went to Republicans.