WASHINGTON -- The Securities and Exchange Commission has accused Dallas Mavericks owner Mark Cuban of insider trading. Regulators accused him of using confidential information on a stock sale to avoid more than $750,000 in losses.

Cuban, 50, disputed the allegations and said he would contest the SEC's civil lawsuit, filed in Dallas federal court.

The SEC said that in June 2004, Cuban was invited to get in on a stock offering by Mamma.com after he agreed to keep the information private.

The SEC said Cuban knew the shares would be sold below the market price then. It said a few hours after getting the information, Cuban told his broker to sell his entire stake of 600,000 shares before the public announcement of the offering.

Cuban purchased a majority stake in the NBA's Dallas Mavericks in 2000 for $285 million from H. Ross Perot Jr.

He also owns Landmark Theaters, a large national chain dedicated to independent films, and the HDNet cable television channel.

Cuban is one of the richest people in the world, according to Forbes magazine, which pegged his net worth at $2.3 billion as of March 2007.

Additional Resource:

• Link: Mark Cuban's Blog