U.S. Treasury Secretary Timothy F. Geithner, the most senior Obama administration official remaining from the team that grappled with the worst financial crisis since the Great Depression, left office Friday as his likely successor seeks Senate approval.

Geithner, 51, hands a more stable economy to Jack Lew, President Barack Obama’s nominee, as the administration bounces from one confrontation to another with Republican lawmakers on issues including the budget and the debt ceiling. Geithner hasn’t said publicly what his next career move will be.