WASHINGTON (Reuters) - President Barack Obama has asked Timothy Geithner to stay on as Treasury Secretary and a decision is expected soon, officials said on Thursday.

Geithner had indicated he might decide to leave once a decision to raise the U.S. debt limit was raised, which happened this week after a long and rancorous debate. He has headed Treasury since January 2009 and been involved in all the major economic decisions by the Obama administration.

Advisers said Geithner has not yet decided whether to leave his post but would likely come to a decision soon.

Both Obama and White House Chief of Staff Bill Daley have encouraged Geithner to stay, and one adviser said the officials have had numerous discussions.

Geithner has been considering departing to join his family in New York, where his son intends to finish high school.

There have been instances when Treasury secretaries served in Washington while their families remained elsewhere, as with former Treasury Secretary Robert Rubin, who served in the Clinton administration and commuted frequently to New York.

If Geithner did leave, the Obama administration would have to find a successor willing and able to withstand a confirmation process that would likely become another battle between Democrats and Republicans over the direction of the nation's economic policy.

(Reporting by Glenn Somerville and Tim Ahmann; Editing by James Dalgleish)