WASHINGTON (AFP) - President Barack Obama plans to nominate his chief of staff Jack Lew as his next Treasury secretary, replacing Timothy Geithner, United States (US) media reported on Wednesday.

Mr Lew, 57, is a veteran Washington insider who previously served as Director of the Office of Management and Budget. His nomination - which must be confirmed by the Senate - is likely to be announced this week, CNN reported.

The White House would neither confirm or deny the reports. One official said a final decision had not yet been made.

Mr Geithner, a key player in Mr Obama's effort to revive the US economy since the worst recession in decades, has made it known that he does not want to serve a second term at Treasury. He is expected to leave by month's end.

The 51-year-old Geithner has long been keen to return to New York, where he was president of the local Federal Reserve Bank.

The Treasury secretary had previously delayed his departure to help Mr Obama maintain the economic recovery and to play a major role in the successful effort to avert the fiscal cliff budgetary crisis last week.