Top White House economic adviser Allan Hubbard plans to leave the Bush administration by the end of this year, a US official said.
The official, who spoke on condition of anonymity, said the resignation -- the latest in a string of departures by senior White House officials -- would be announced later today. A successor will also be announced, the official said.
Hubbard, 60, joined the White House as director of the National Economic Council after Bush's re-election in 2004.
His departure would come as the Bush administration is facing a crisis in the mortgage industry that has caused rising housing foreclosures and sparked recession fears.
Hubbard said yesterday US recession risks have increased but said "real America" is still doing well.
"Obviously the chances of a recession are higher now than they were a year ago, but we still think it's less than 50-50," Hubbard told CNBC television in an interview.
"We obviously have problems in the housing sector and we have problems in the financial sector, but ... real America is doing just fine," he said.
Other top officials who have left the White House this year include political adviser Karl Rove, communications director Dan Bartlett and budget director Rob Portman.