LOS ANGELES — Richard Parsons, the interim CEO of the Los Angeles Clippers, is due to step into the battle of billionaires going on in probate court over the proposed sale of the Los Angeles Clippers.

Parsons, once known as the “Mr. Fixit” of the business world during his tenure as CEO of Time Warner and Citigroup, will be called as a witness Tuesday to support Shelly Sterling’s bid to sell the team for $2 billion to former Microsoft CEO Steve Ballmer. Donald Sterling, who owns the team along with estranged wife Shelly, is resisting the sale.

Parsons took over leadership of the Clippers in May during the media blitz surrounding the banishment of Sterling from the NBA for making racist comments. Sterling was ordered to sell his team, a plan he seemed to accept until he rescinded his agreement for his wife to sell the team. By then, she had a $2 billion offer from Ballmer.

Shelly Sterling also is on the witness list Tuesday along with Dean Bonham, an expert on sponsorship and marketing issues who is also the president of an NBA franchise. He is a leading negotiator of business and sports sponsorship contracts.

The high-stakes financial fight centers on whether Shelly Sterling was authorized to make a deal with Ballmer for the team’s ownership on behalf of the Sterling Family Trust.

While she was negotiating, Donald Sterling revoked the trust, a move designed to rescind his signed agreement for the sale of the Clippers, a team he bought for $12 million.

He announced from the witness stand earlier in the trial that he would never sell the team and would be suing the NBA for the rest of his life.

Shelley Sterling says her estranged husband has the onset of Alzheimer’s.