SAN FRANCISCO (MarketWatch) -- The Securities and Exchange Commission on Monday charged Dallas Mavericks owner and Internet entrepreneur Mark Cuban with insider trading. The SEC alleges Cuban in June 2004 sold 600,000 shares of Internet search engine company Mamma.com Inc. on inside information that the company would initiate a stock offering. The charges allege Cuban knew that the offering would be at a discount and it would be dilutive to existing shareholders.