The head of the Washington office of newly-merged firm Dechert is joining the White House senior staff alongside president-elect George W Bush.
Complex commercial litigation partner Lewis Libby will hold three titles: assistant to the president, chief of staff to the vice-president and assistant to the vice-president for national security affairs.
Before joining Dechert, Libby served as deputy for the secretary of defence for policy in the Bush administration.
In a statement, vice-president-elect Dick Cheney says: "Libby's years of experience in the public and private sectors and his extensive knowledge of the federal government make him the ideal person to be my chief of staff."
Libby is also a partner in the firm's government affairs, government investigations and criminal and civil fraud practice groups.