LOS ANGELES (AFP) - A federal judge dismissed former Los Angeles Clippers owner Donald Sterling's US$600 million (S$822.7 million) antitrust lawsuit against the National Basketball Association, court papers obtained on Wednesday showed.

Sterling sued the league for more than US$1 billion in damages immediately after his wife Shelly agreed in May 2014 to sell the team to former Microsoft chief executive Steve Ballmer for US$2 billion.

The NBA countersued, claiming that Sterling harmed the league with widely publicised racist comments that sparked a firestorm of controversy.

Lawyers for the 81-year-old last year amended the suit to include as defendants the last two NBA commissioners, Adam Silver and David Stern, Shelly Sterling and two doctors who found him mentally incapable of continuing as the team's owner.

In a 13-page order dated Tuesday, US District Judge Fernando M. Olguin wrote that the court was "sceptical Sterling suffered any injury at all, let alone an antitrust injury" and described other portions of the lawsuit as "clearly implausible".

The ruling comes less than two weeks after it was reported by the Los Angeles Times that Donald and Shelly Sterling had decided not to divorce.

Donald Sterling cited "irreconcilable differences" in seeking a divorce last August, but this month his lawyer Bobby Samini told the Times that the couple had resolved their differences.