White House Chief of Staff William Daley, 63, has tendered his resignation to U.S. President Barack Obama, according to senior administration officials. The news was reported earlier Monday by the Los Angeles Times.
Daley, the son and brother of Chicago mayors, is to be replaced by Budget Director Jacob "Jack" Lew, 56, officials said.
The change reportedly won't be effective until the end of the month because Lew is still engaged in completing his work on the administration's budget proposal to Congress, due for presentation in the first week of February.
The president is set to make a formal announcement about the change later in the day, said officials, requesting anonymity because they were unauthorized to comment publicly on the matter.
Lew will be Obama's third chief of staff in four years and like Obama's first chief of staff, Rahm Emanuel, has close ties to the Jewish community.
No reason was given for Daley's resignation, although he has been gradually scaling back his day-to-day White House activities for the past several months, according to Bloomberg News.