WASHINGTON -- Associate Attorney General Webster Hubbell, a longtime confidant of Bill and Hillary Clinton, has resigned due to a billing dispute with his old law firm.


Both Hubbell and the White House stressed that the resignation has no connection to the Whitewater affair and that the former Justice Department official acted on his own when he quit.


But the timing could not have been worse for the Clinton administration, which has been struggling to shift the national focus back to policy and away from Whitewater.


"This is, to me, more of a personal deal for Webb Hubbell," President Clinton told reporters Monday when asked whether Hubbell's decision was a setback for his administration as it sought to dig itself out from Whitewater.


"I'm just hoping that it works out for him and I think he made the right decision," Clinton said, stating that he had not been involved in Hubbell's decision.


Hubbell said he had to resign to deal with an ugly billing dispute with his former law partners at the Rose Law Firm in Little Rock, Arkansas.


In his resignation letter, he said he could no longer be effective as the Justice Department's third-ranking official because of the time he had to spend dealing with questions about his billing and expenses at the Arkansas firm.


Hubbell had been a partner of first lady Hillary Rodham Clinton at the law firm, and he has been a longtime friend and golfing companion of the president.


His resignation marked the third recent departure of a senior administration official. The others were:


?White House counsel Bernard Nussbaum -- also a close friend of the first lady -- who was forced to resign earlier this month after admitting he met with Treasury Department officials concerning a federal probe into Whitewater.


?Deputy Attorney General Philip Heymann, who quit due to a clash with Attorney General Janet Reno.