Four U.S. senators say they intend to block the confirmation of President Bush's choice for U.S. ambassador to Libya.

The nomination of Gene Cretz is a step in restoring normal diplomatic relations after decades of tensions over Libya's alleged involvement in terrorism. The Bush administration has sought to reward Libyan leader Moammar Gadhafi since he surprised the world by agreeing to dismantle his country's weapons of mass destruction programs.

But the four Democrats — Frank Lautenberg and Robert Menendez of New Jersey and Charles Schumer andHillary Rodham Clinton of New York — say they will invoke a Senate procedure to delay the nomination until Libya pays compensation for terrorist attacks in the 1980s.

Libya was held responsible for the bombing of Pan Am flight 103 over Lockerbie, Scotland, in 1988, which claimed 270 lives, most of them American. Gadhafi later agreed to pay $2.7 billion in reparations to the victims' families.

The lawmakers also want the administration to settle with the families of the victims of a 1986 Berlin disco bombing that killed two U.S. troops.

They contend that rewarding Libya will ease the pressure on Aadhafi.

The Bush administration said in May 2006 that it was resuming regular diplomatic relations with Libya for the first time in more than a quarter-century after removing Gadhafi's regime from a list of state sponsors of terrorism.