The Securities and Exchange Commission today charged Dallas entrepreneur Mark Cuban with insider trading for selling 600,000 shares of the stock of an Internet search engine company on the basis of material, non-public information concerning an impending stock offering.

The Commission’s complaint, filed in the U.S. District Court for the Northern District of Texas, alleges that in June 2004, Mamma.com Inc. invited Cuban to participate in the stock offering after he agreed to keep the information confidential. The complaint further alleges that Cuban knew that the offering would be conducted at a discount to the prevailing market price and that it would be dilutive to existing shareholders.

Within hours of receiving this information, according to the complaint, Cuban called his broker and instructed him to sell Cuban’s entire position in the company. When the offering was publicly announced, Mamma.com’s stock price opened at $11.89, down $1.215 or 9.3 percent from the prior day’s closing price of $13.105. According to the complaint, Cuban avoided losses in excess of $750,000 by selling his stock prior to the public announcement of the offering.

“Insider trading cases are a high priority for the Commission. This case demonstrates yet again that the Commission will aggressively pursue illegal insider trading whenever it occurs,” said Linda Chatman Thomsen, Director of the SEC’s Division of Enforcement.

Scott W. Friestad, Deputy Director of the SEC’s Division of Enforcement, said, “As we allege in the complaint, Mamma.com entrusted Mr. Cuban with nonpublic information after he promised to keep the information confidential. Less than four hours later, Mr. Cuban betrayed that trust by placing an order to sell all of his shares. It is fundamentally unfair for someone to use access to nonpublic information to improperly gain an edge on the market.”

The complaint alleges that Cuban violated Section 17(a) of the Securities Act of 1933 and Section 10(b) of the Securities Exchange Act of 1934 and Rule 10b-5 thereunder. The Commission’s complaint seeks to permanently enjoin Cuban from future violations of the federal securities laws, disgorgement (with prejudgment interest), and a financial penalty.