Judge Michael Luttig, one of the country’s most prominent conservative jurists and once considered a likely Supreme Court nominee, has resigned from the Fourth U.S. Circuit Court of Appeals in Richmond, Va., to become senior vice president and general counsel for Boeing in Chicago.

In a three-page letter to President Bush yesterday, Judge Luttig, a 1991 appointee of the first President Bush, wrote of his particular pride in helping define the law in the aftermath of the September 11, 2001, terrorist attacks. “In the prosecution of those who committed the atrocities against America on that morning, the court has been asked to address some of the most complex and far-reaching legal questions of our day,” Judge Luttig wrote.

Judge Luttig, 51 years old, was part of the Reagan administration generation that came to Washington in the 1980s ready to remake a federal judiciary it considered suffused with activist liberal judges. A graduate of the University of Virginia law school, Judge Luttig clerked for Antonin Scalia when he served on the federal appeals court in Washington, D.C., and later for Chief Justice Warren Burger. He held several positions in the Reagan and first Bush administrations, including the influential post of assistant attorney general for legal counsel, the prime interpreter of executive powers, during the first Persian Gulf War.