Christopher also led a task force that helped then-Arkansas Gov. Bill Clinton select Gore as his 1992 vice presidential running mate. He later helped Clinton pick his first Cabinet, which included Christopher at State.

The Gore aides, speaking on condition of anonymity, said the California lawyer agreed to take the job in recent conversations with the campaign. Gore's staff planned to announce the move today, kicking off a lengthy process to pick the vice presidential candidate in time for the Democratic National Convention in August.

Advisers to Texas Gov. George W. Bush, the presumptive Republican nominee, say he will soon put his search committee in place.

The fact that neither candidate has begun his formal search hasn't stopped advisers and supporters from speculating who might be in the running.

Among the Democrats mentioned: California Gov. Gray Davis, North Carolina Gov. James B. Hunt Jr., Indiana Sen. Evan Bayh, Sen. Bob Graham of Florida, Energy Secretary Bill Richardson, former Treasury Secretary Robert Rubin and Secretary of Defense William Cohen.

Potential Republican candidates include retired Gen. Colin Powell; former presidential candidate Elizabeth Dole; Sens. John McCain of Arizona, Fred Thompson of Tennessee and George Voinovich of Ohio and Govs. Tom Ridge of Pennsylvania, Frank Keating of Oklahoma, Tommy Thompson of Wisconsin and George Pataki of New York.