Tim Geithner Nominated for Treasury Secretary

Tim Geithner will be the new Treasury secretary under the Obama administration, sources have learned.

Geithner has played a key role in the government's response to the financial crisis, and he worked closely with Treasury Secretary Henry Paulson.

This month, when Geithner, who heads New York Federal Reserve, didn't go to Chicago for a meeting of Obama's powerhouse financial advisory team, a source familiar with the transition process strongly advised against reading too much into his absence.

"He couldn't go out there," the source told the New York Observer. "He has to be studiously neutral in all this stuff."

NBC news said Obama is expected to announce his economic team on Monday in an effort to calm markets. Geithner was considered a top prospect, along with former Treasury Secretary Lawrence Summers, for the Treasury post.