May 28 (Bloomberg) -- Mark Cuban, the billionaire owner of the Dallas Mavericks basketball team, sued the U.S. Securities and Exchange Commission claiming the agency is unlawfully withholding documents about an insider-trading probe of him.

Cuban’s complaint, filed today in federal court in Washington, seeks an order to force the SEC to give him documents he requested in December, including records of any investigations of Copernic Inc., formerly known as Mamma.com, HDNet, his National Basketball Association team and other entities he owns or controls. It also seeks records of any internal probes of SEC Trial Counsel Jeffrey Norris related to his interactions with Cuban.

“The SEC improperly refused to produce any records,” citing an exemption to the Freedom of Information Act related to law enforcement activities, according to the complaint.

The suit is the latest salvo in the legal battle between Cuban and the SEC. Yesterday, a lawyer for Cuban asked a federal judge in Dallas to dismiss the agency’s insider-trading suit, saying it failed to show that Cuban was barred from selling shares of Mamma.com Inc. in 2004.

SEC spokesman John Heine declined to comment.

The SEC’s Nov. 17 lawsuit focuses on a conversation Cuban had with Mamma.com’s chief executive officer about the company’s plans to sell stock. Cuban had planned to keep information about the transaction confidential before learning that Mama.com planned to sell shares below their current trading price through a private investment in public equity offering, known as a PIPE, the SEC wrote in its complaint.

‘Upset, Angry’

Cuban became “very upset and angry” during the conversation with the CEO, stating that he did not like PIPEs because they were dilutive to existing shareholders, according to the SEC. Cuban ultimately sold his stock, avoiding more than $750,000 in losses, the SEC said in the complaint.

Cuban, 50, in a blog written the day the SEC filed its suit, said the agency’s claims are “false and they will proven to be so.”

The cases are SEC v. Cuban, 08-cv-2050, U.S. District Court, Northern District of Texas (Dallas) and Cuban v. Securities and Exchange Commission, 09-cv-996, U.S. District Court, District of Columbia (Washington).

To contact the reporter on this story: Cary O’Reilly in Washington at caryoreilly@bloomberg.net

Last Updated: May 28, 2009 18:38 EDT