Judge tosses insider trading charge against Mark Cuban

DALLAS -- A federal judge has dismissed an civil insider trading lawsuit against Dallas Mavericks owner Mark Cuban.

U.S. District Judge Sidney Fitzwater granted Cuban's motion Friday. Fitzwater gave the Securities and Exchange Commission 30 days to file an amended complaint.

The SEC alleged Cuban was involved in insider trading when he sold shares in an Internet search engine company, Mamma.com, after receiving confidential information about a private offering in 2004.

The SEC said Cuban avoided a loss of $750,000 by selling his 600,000 shares, which represented a 6.3% stake in the company.

On Cuban's Twitter account, he wrote: "Its been a great day so far, and its only going to get better! Back to Dallas to see the [family]."

In his 35-page ruling, Fitzwater wrote that the SEC didn't accuse Cuban of promising not to trade based on the confidential information he received. Thus, the commission could not hold him liable for illegal insider trading, the judge wrote.

Fitzwater said the SEC could file a new complaint if it can allege that Cuban promised not to trade on the information.

The judge rejected some of Cuban's claims about his fiduciary relationship with the company, however.

Cuban's lawyers argued that the NBA team owner wasn't legally an "insider."

An SEC spokesman didn't immediately return e-mail and phone messages seeking comment.