With Geithner stepping down, who’s the next Treasury chief?

WASHINGTON (CNNMoney) — Even with the same president, the United States will have a new Treasury Secretary.

Tim Geithner, the last holdover from President Obama’s original economic team, has indicated he’s ready to leave after four tumultuous years. With Obama’s victory, Geithner is expected to resign soon, but Treasury officials are mum on the details.

The first big challenge for the next Treasury Secretary will be dealing with the so-called fiscal cliff, a series of massive tax hikes and spending cuts slated to kick in Jan. 2.

If Congress and the White House delay big decisions dealing with deficits until early next year, as many insiders expect, the next secretary will play a key role brokering a deal to avoid some $7 trillion worth of cuts and tax hikes that could take place.

Washington insiders’ top pick is White House Budget Director Jacob “Jack” Lew, who played a key role last year in debt ceiling and deficit reduction talks. While Lew doesn’t have as much international experience, he’d be a strong pick to navigate the budget drama ahead, veterans say.

Another top name mentioned is Larry Fink, CEO of BlackRock (BLK, Fortune 500), one of the world’s largest investment firms. He’s reportedly a friend of Geithner’s.

Other names floated include Gary Gensler, chair of the Commodity Futures Trading Commission and a Goldman Sachs (GS, Fortune 500) veteran, and Gene Sperling, director of the National Economic Council, who was also a top economic adviser to President Clinton.

An unlikely, but often talked-about candidate is Sheila Bair, a Republican with a populist bent. However, several Washington insiders say her book about the financial crisis and recent Fortune columns have made her too many enemies in Washington.

Two more finance-side possibilities include Pimco CEO Mohamed A. El-Erian and Kenneth Chenault, the CEO of American Express (AXP, Fortune 500).