NBA commissioner Adam Silver said on Sunday a single obstacle blocked completion of the $2-billion sale of the Los Angeles Clippers - a lawsuit brought by embattled owner Donald Sterling against the league.

Sterling, 80, sued the NBA and Silver on May 30 seeking at least $1 billion in damages just as the league tentatively approved a deal by his estranged wife and co-owner of the franchise, Shelly, to sell the club to former Microsoft Corp chief executive Steve Ballmer.

Days later, Sterling's lawyer, Max Blecher, said his client had agreed to the sale and would withdraw the lawsuit. But Silver said the case is still pending and is holding up a final disposition of the deal.

"We're almost there. There is this last piece, and that is the lawsuit that Donald brought against the League and me personally," Silver told reporters before Game 2 of the NBA Finals in San Antonio.

In an email, Blecher told Reuters that no decision had been made on the lawsuit and all options were under consideration.

At a news conference before Game 2 of the NBA Finals, Silver said there was "absolutely no possibility" of rescinding the lifetime ban or the $2.5-million fine he handed down to Sterling following his racist remarks.

Sterling was banned for life from the NBA in April after a tape recording of disparaging remarks he made about blacks was leaked to TMZ.com, igniting an uproar among fans, players and commercial sponsors of his team.

Silver also fined Sterling $2.5 million, the league's maximum monetary penalty, and urged its 29 other team owners to take the unprecedented step of forcing Sterling to sell the Clippers, which he bought in 1981 for $12.5 million.

After first threatening not to relinquish the team without a fight, Sterling ceded a controlling interest in the team to his wife who was already a 50-percent co-owner through a family trust, for the purpose of negotiating a sale.

After she struck a deal to sell the Clippers to Ballmer for a league record $2 billion, Sterling sued the NBA, seeking, among other things, to recoup the capital gains taxes he would have to pay, though Blecher later said the lawsuit would be dropped.

"I have absolute confidence it will be resolved because as part of the sale agreement with Shelly Sterling, she agreed to indemnify the league against a lawsuit by her husband. So in essence, Donald is suing himself and he knows that. While I understand he is frustrated, I think it's over," Silver said.