Franken said that on Sept. 26 Comcast had named its chief operating officer, Steve Burke, as the prospective chief executive of NBC Universal. Last week, Comcast named several executives who would hold top jobs at NBC Universal."As a result, Comcast's actions may constitute 'gun-jumping' in violation of the letter and spirit of federal antitrust law," Franken wrote in the letter to Christine Varney, head of the Justice Department's antitrust division.