"I have decided that I must fight to protect my rights," Sterling said Monday in a letter circulated widely among those involved in the sale and obtained by ESPN.com. "While my position may not be popular, I believe that my rights to privacy and the preservation of my rights to due process should not be trampled."
Sterling's attorney Max Blecher earlier told ESPN.com in an email, "The deal is off."
Blecher also suggested Donald Sterling would be challenging wife Shelly Sterling's actions and negotiation of the sale in probate court.
Sources told ESPN.com on Tuesday that Shelly Sterling and her lawyers intend to seek an emergency order from a California probate court Wednesday morning for an expedited hearing to resolve the situation with her estranged husband.
Last week, both Donald Sterling and Blecher indicated publicly that they would accept the record $2 billion sale to former Microsoft CEO Steve Ballmer. In an interview with NBC4 during a charity function, Sterling said he was ready to "move on."
However, Sterling has since changed course. Whether he will be successful in this new challenge remains to be seen.
"From the onset, I did not want to sell the Los Angeles Clippers," he said in the letter. "I believe that Adam Silver acted in haste by illegally ordering the forced sale of the Clippers, banning me for life from the NBA and imposing the fine. Adam Silver's conduct in doing so without conducting any real investigation was wrong.
"The action taken by Adam Silver and the NBA constitutes a violation of my rights and fly in the face of the freedoms that are afforded to all Americans."
Blecher and another Sterling attorney, Bobby Samini, declined Monday to comment on whether the NBA's refusal to drop Sterling's lifetime ban and $2.5 million fine is the impetus for his change of heart.
"There was never a discussion involving the NBA in which we would modify Mr. Sterling's penalty in any way whatsoever," NBA spokesman Mike Bass said. "Any suggestion otherwise is complete fabrication."
The lawsuit alleges the league violated Sterling's constitutional rights by relying on information from an "illegal" recording that publicized racist remarks he made to a girlfriend. It also said the league committed a breach of contract by fining Sterling and that it violated antitrust laws by trying to force a sale.
Meanwhile, Shelly Sterling, Ballmer and the league remain confident the sale will proceed.
"Nobody doubts this thing will go through in the end. I guess it's just a matter of what mood Donald wakes up in tomorrow," one source close to the situation said.
In an interview taped Sunday and released Monday, Silver told CNN that the league will be able to "take a deep breath" when the sale is complete.
"He's unsold his club several times over the years," Silver said. "There's well-noted incidents in the league when he was right there at a closing and at the last minute decided not to sell. And until he signs that document, we still have a pending litigation with him."
Shelly Sterling indemnified the NBA from damages in future lawsuits from her estranged husband as part of the sale agreement with the league. She negotiated the sale as the sole trustee of the Sterling family trust, which owns LA Clippers LLC, after two neurologists had declared Donald Sterling unable to conduct his own business and legal affairs.
The provisions of the family trust did not require a court order. To challenge her authority to conduct the sale, Donald Sterling would have to challenge her in California probate court, according to sources with knowledge of the situation.
Information from The Associated Press was used in this report.
Sterling Decides To Sue NBA After All
ESPNLosAngeles.com's Ramona Shelburne breaks down Donald Sterling decision to pursue a $1 billion lawsuit against the NBA and commissioner Adam Silver, withdrawing his support for the sale of the Clippers.