Former Los Angeles Clippers owner Donald Sterling on Wednesday filed for divorce from his wife Shelly Sterling. They have been married nearly 60 years.

Donald reportedly filed the papers with the Los Angeles Superior Court and cited "irreconcilable differences" as a reason for his decision, attorney Bobby Samini said, according to the Associated Press. The papers reportedly claim that Shelly refused to give Donald his share of the money from the sale of the basketball team to former Microsoft CEO Steve Ballmer for $2 billion. The documents also reportedly list the date of separation as Aug. 1, 2012. The couple is three weeks away from their sixtieth wedding anniversary.

"For the last 20 years, I've been seeing attorneys for a divorce," Shelly said last May, in an interview with ABC News, adding: "In fact, I have here-- I just filed-- I was going to file the petition. I signed the petition for a divorce. And it came to almost being filed. And then, my financial advisor and my attorney said to me, 'Not now.'"

However, Donald's filing was dismissed by the court because it was incomplete, a spokeswoman said, according to the Los Angeles Times, which added that the petition is expected to be filed again.

Donald, who was removed from the family trust that owned the Clippers after two doctors declared him to be mentally incompetent last year, is suing his wife and the NBA in federal court over the team's sale.

He also filed a petition in probate court Wednesday for an accounting and distribution of assets related to the sale, and claimed that he has the right to half of the community property, AP reported. Shelly’s attorney said that she did not yet have a comment.

Last July, Donald also reportedly called his wife a “pig” during a probate hearing in L.A. Superior Court, which was examining the circumstances of the Clippers sale, the LA Times reported. Shelly's name was added to the lawsuit against the NBA and Commissioner Adam Silver in U.S. District Court in Los Angeles in March.

Donald claimed in the case that Shelly "fraudulently induced" and "fraudulently arranged" for her doctors to testify last year. The lawsuit added that this led to "extreme mental distress .. including worry, anxiety, anger, embarrassment, sleeplessness and fatigue," the LA Times reported.

Four months back, a judge ordered V. Stiviano, alleged by Shelly to be Donald’s mistress, to turn over the keys to a $1.8 million house that Donald bought her and pay back $800,000 he spent on her. She was also told to return a Ferrari and other luxury vehicles.

Donald has contested the findings of the doctors who ruled him mentally incompetent after he was heard making racially charged comments against African-Americans in an audio recording, leaked in 2014. NBA's Silver banned Sterling for life after the incident and pressured the Clippers' previous owners to sell the team.