Federal regulators on Monday charged Dallas Mavericks owner Mark Cuban with insider trading for allegedly using confidential information on a stock sale to avoid more than $750,000 in losses.

Cuban disputed the Securities and Exchange Commission’s allegations and said he would contest them.

In a civil lawsuit filed in federal court in Dallas, the SEC alleged that in June 2004, Cuban was invited to get in on the coming stock offering by Mamma.com Inc. after he agreed to keep the information private.

Cuban owned 6.3 percent of Mamma.com’s stock at that time and was the largest known shareholder in the search engine company, according to the SEC. The agency said Cuban knew the shares would be sold below the current market price, and a few hours after receiving the information, he told his broker to sell all 600,000 shares before the public announcement of the offering.

By selling when he did, Cuban avoided losses exceeding $750,000, the SEC said in its lawsuit.

Cuban, 50 and a multibillionaire, 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.