The Supreme Court dismissed a challenge Friday by suspected Al Qaeda sleeper agent Ali Al-Marri to the president's authority to detain people without charges, granting an Obama administration request to end the high court case.

The Supreme Court also threw out, as moot, the federal appeals court ruling al-Marri was challenging that affirmed the president's power to detain people in the United States without trial.

Al-Marri and civil liberties groups had asked the court not to leave the appeals court ruling in place in the event it dismissed al-Marri's appeal.

Last week, President Barack Obama ordered al-Marri transferred from military to civilian custody to face federal charges of conspiracy and providing support to terrorists.

But Obama has not renounced the use of preventive detention, which was pursued and defended aggressively by the Bush administration after the terror attacks of Sept. 11, 2001.

The administration's silence on this issue was the main reason al-Marri's lawyers pushed the court to hear the case even after their client got what he was seeking — if not his release, a trial at which he could answer criminal charges.

The new administration also made clear, however, that it had no desire to take a position on the Bush policies in what would have been a major Supreme Court battle.

The court had scheduled arguments for April 27 and would have issued a decision by July.

Jonathan Hafetz, the American Civil Liberties Union lawyer who represents al-Marri, said he would have preferred a Supreme Court ruling that finally settled the issue.

But he was pleased the court did not let stand the ruling by the 4th U.S. Circuit Court of Appeals in support of the president's authority to detain people picked up inside the United States as enemy combatants.

"We trust that the Obama administration will not repeat the abuses of the Bush administration having now chosen to prosecute Mr. al-Marri in federal court rather than defend the Bush administration's actions in this case," Hafetz said.

Al-Marri is under indictment in Peoria, Ill. The court's order allows the government to move him from the Navy brig in Charleston, S.C., where he has been held for 5 1/2 years, to a civilian jail cell. Al-Marri, a native of Qatar, was a legal U.S. resident who was studying at Bradley University in Peoria when he was arrested in late 2001 as part of the investigation of the Sept. 11 attacks.

He was indicted on fraud charges, but that indictment was dropped in 2003 when President George W. Bush declared him an enemy combatant.

The government has said al-Marri met with Usama bin Laden and volunteered for a suicide mission or whatever help Al Qaeda wanted. He arrived in the U.S. the day before terrorists struck the World Trade Center and the Pentagon.

A computer specialist, al-Marri was ordered to wreak havoc on the U.S. banking system and serve as a liaison for other Al Qaeda operatives entering this country, according to a court document filed by Jeffrey Rapp, a senior member of the Defense Intelligence Agency.

Al-Marri was helped in his mission by Khalid Sheikh Mohammed, the alleged mastermind of the Sept. 11 attacks, and Mustafa Ahmad al-Hawsawi, who allegedly helped the Sept. 11 hijackers with money and Western-style clothing, according to Rapp's memo. Mohammed and al-Hawsawi are being held at the Guantanamo Bay, Cuba, naval base.

The Bush administration also avoided Supreme Court review of the detention of U.S. citizen Jose Padilla, alleged to be part of a plot to set off a radiological "dirty bomb" in the United States.

Padilla was arrested in 2002 at Chicago's O'Hare International Airport and held in the same brig as al-Marri. With his case headed for the high court, Padilla was indicted and eventually convicted on criminal charges in Miami that were not related to the "dirty bomb" plot.

Padilla's lawyers argued that the justices should hear his case anyway, but the court turned them down.

Even so, three justices — Stephen Breyer, Ruth Bader Ginsburg and David Souter — said Padilla's case should have been heard because it raised "a question of profound importance to the nation."

There were no similar statements from the court Friday.