Ballmer's lawyer quickly denounced the move as part of Sterling's ''egotistical crusade to destroy the Clippers.''
Lawyers for Sterling asked the Second District Court of Appeals to stay a probate judge's ruling that cleared the way for the sale. They said the judge prematurely finalized his ruling so the sale can be completed without a chance to appeal.
Sterling's appellate lawyers said in their request for a writ of mandate that if the sale goes through, ''Donald will have lost a unique and irretrievable asset: a `trophy asset' coveted by high net worth individuals around the world - one of thirty NBA franchises in the country, and one that under Donald's thirty-year ownership has recently become one of the most successful.''
The main complaint of the appellants is the judge's decision to allow the sale to go forward with no time for an appeal. He used a section of law that bars a stay of his decision.
Given that provision, it was unclear if the appeal would have any effect. The sale could conceivably go forward while the appeal makes its way through the courts.
Adam Streisand, the attorney for Ballmer, said in a statement: ''We won this trial because Donald Sterling is on an egotistical crusade to destroy the Clippers if he can't keep the team, and he can't. We will win the appeal for the very same reason.''
A spokesman for the attorneys representing Sterling's estranged wife, Shelly Sterling, issued a statement similarly attacking Donald Sterling's motives.
''Donald's petition for writ of mandate is another desperate act by a desperate man,'' the statement said. ''The decision by Judge Michael Levanas - after three weeks of trial - is a correct decision on the law and the undisputed evidence. Donald will do anything to kill the record-shattering $2B sale of the Clippers. His petition is frivolous.''
The appellate lawyers who filed the writ petition late Friday afternoon acknowledged that Donald Sterling has a public image problem.
''Admittedly, in light of recent events, Donald Sterling does not cut a sympathetic figure,'' his appellate lawyers wrote. ''But the issues raised by the trial court's decision here impact more than just him, and involve core issues of probate law and the right to appellate review.''
Shelly Sterling negotiated the record sale after the NBA banned the 80-year-old billionaire for making offensive remarks about blacks.
The writ filed by the Donald Sterling legal team demanded an immediate stay of the judge's ruling. It said that in the absence of a stay, the sale could go forward immediately. It noted that the NBA plans to meet on Aug. 15 to approve the sale.
Addressing the ruling by Superior Court Judge Michael Levanas, the document said his action ''was unreasonable, arbitrary, a prejudicial abuse of discretion, and manifestly against the law.''
The 39-page filing challenged the opinions of two doctors who examined Donald Sterling and who said he had the beginnings of Alzheimer's disease, rendering him incompetent to handle his own business affairs.
The filing said the examinations were ''insufficient to support a determination of incapacity'' and said Shelly Sterling improperly removed her estranged husband as a trustee of the Sterling family trust.