Sterling takes witness stand

• NEW: Donald Sterling says he is negotiating with Fox for Clippers games


• NEW: He cites how the Lakers struck a $3 billion deal with Time Warner Cable


• NEW: He denies he is opposing his wife over 'dignity'


• NEW: 'My wife can't run anything,' Donald Sterling testifies

Los Angeles (CNN) -- Billionaire Donald Sterling opposes his wife's effort to sell the couple's ownership of the Los Angeles Clippers for a record $2 billion because he was negotiating a big broadcast deal with Fox that would be worth more, he testified Tuesday.

Sterling was asked by his wife's attorney whether he was fighting her proposed deal because he wanted to restore his dignity.

"The reason you are handling the case is because you want to charge millions in fees, right?" Donald Sterling said in a probate court trial. "The reason is not because of my dignity."

Sterling cited how another NBA franchise in Los Angeles -- the Lakers -- struck a deal with Time Warner Cable to broadcast its games for 20 years for a reported $3 billion in 2011.

"The reason is that the Lakers signed a deal with Warners for $3 billion. The reason is, I am negotiating with Fox," Sterling said.

Fox representatives couldn't be immediately reached for comment Tuesday.

Donald Sterling became tearful describing his wife as a wonderful person, but one who cannot run all the couple's corporations.

"My wife can't run anything. She is beautiful, she is intelligent. But she can't run these things. You think it's my ego?" Donald Sterling said on the stand.

Donald Sterling testified for the first time in a trial examining how his wife had him declared mentally incapacitated and then took over the couple's trust that owns the Clippers.

Shelly Sterling is trying to sell the basketball team to former Microsoft CEO Steve Ballmer, but Donald Sterling is opposing the proposed sale. The NBA ordered the couple to sell the team after Donald Sterling made racial slurs against African-Americans in an audio recording.

Donald Sterling, an attorney, was combative on the stand at times, but he also had the entire courtroom laughing at least three times. The judge warned him he was a witness, and not a lawyer trying to control the courtroom.

The trial, which began Monday, was continued until Wednesday. Donald Sterling will return to the witness stand at 1:30 p.m. PT.

Shelly Sterling also was in the courtroom Tuesday. During an afternoon recess, Shelly Sterling approached her husband, and he gave her a kiss. She cried and then left the courtroom. She later returned.

Earlier in the trial's second day, the attorneys for Donald Sterling cross-examined a physician who had certified Sterling as mentally incapacitated. The questioning of the doctor stopped when she needed to retrieve more of her notes.

Dr. James Edward Spar, a second physician who examined Sterling and also certified him as similarly incapacitated, also took the stand Tuesday. He was asked to send more documents to Donald Sterling's legal team.

A state judge in Los Angeles is hearing evidence on whether Shelly Sterling acted properly when she removed her husband from the couple's trust, in which they equally own the NBA franchise.

Tuesday's proceeding began with testimony from Dr. Meril S. Platzer, a neurologist who was one of two physicians who examined Donald Sterling and certified him as being mentally incapacitated and unable to continue as trustee. A third physician reviewed those findings and endorsed their conclusions.

Shelly Sterling took over the couple's trust after doctors made the determination about his mental state.

Donald Sterling's lawyers say he was tricked into the medical examinations. They also dispute the assessment that their client is mentally deficient. Late last month, another doctor found Donald Sterling to be mentally fit, a source with knowledge of the situation told CNN.

In court Monday, Platzer said she examined Donald Sterling on May 19 and found he is suffering from early stages of Alzheimer's and may have had it for three to five years.

Platzer said in a May 29 certification that Donald Sterling has "an impairment of his level of attention, information processing, short-term memory impairment and ability to modulate mood, emotional liability, and is at risk of making potentially serious errors of judgment," court papers said.

Spar, a specialist in geriatric psychiatry who examined Donald Sterling on May 22, said Sterling suffers "mild global cognitive impairment" and "the overall picture is consistent with early Alzheimer's disease, but could reflect other forms of brain disease," court papers said.

Under the trust agreement, if Donald Sterling became mentally incapacitated, he would be removed as a trustee, Shelly Sterling's attorney said.

But the judge said he is not deciding on Donald Sterling's mental capacity. Rather, the judge is going to rule only on issues of the trust and whether its procedures were followed correctly.

Donald Sterling's mental capacity not issue for trial

CNN's Paul Vercammen contributed to this report.