Dallas Mavericks owner Mark Cuban was charged Monday with insider trading for selling 600,000 shares of Mamma.com, reported The Securities and Exchange Commission.

Regarding SEC, in 2004 Cuban was invited to join the stock offering by Mamma.com Inc. after he agreed to keep the information confidential. Cuban became the largest shareholder owning 6.3% of Mamma.com, knowing that the shares would be sold below the current market price, and after receiving the information, he told his broker to sell all 600,000 shares before the public announcement of the offering. By this action, he was charged insider trading for allegedly using confidential information on a stock sale to avoid more than $750,000 in losses.

Cuban disputed the SEC’s judgment and said he would contest them.

Cuban, 50 and a multi billionaire, is a tech entrepreneur who sold his Broadcast.com to Yahoo Inc. in 1999 at the height of the dot-com boom. He bought the Mavericks in 2000 and spent heavily to improve the roster.

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.