The U.S. Securities and Exchange Commission has already picked out a possible illegal insider trading case in this week’s banking mega merger between Bank of America and FleetBoston Financial Corporation.

The SEC has obtained a temporary restraining order and asset freeze against a former FleetBoston employee and his relatives in connection with insider trading in FleetBoston.

According to the commission’s complaint, the defendants bought FleetBoston securities late on October 24, just prior to October 27 announcement of Fleet’s acquisition by Bank of America. The SEC alleges that the purchasers engaged in illegal insider trading and, without the freeze, would have realized profits of at least US$500,000, and potentially more than US$1 million.

According to the SEC’s court pleadings, Guillermo Simon, a former FleetBank employee at the bank’s Buenos Aires office, together with his wife and his brother, purchased 1,100 Fleet call options during the last hours of trading on October 24. The options entitled them to buy Fleet stock for US$35 per share. The acquisition price of US$45 per share was announced before the market opened on October 27.

The complaint alleges that the defendants traded while in possession of material, nonpublic information about the merger. The commission seeks permanent injunctive relief, the disgorgement of all illegal profits, and the imposition of civil monetary penalties.