Cox Broadcasting wants to buy two more TV stations so it can create a regional group of NBC affiliates, sources say. Cox is talking to Sunrise Television about buying WJAC-TV Johnstown, Pa., and WTOV-TV Steubenville, Ohio. Both are NBC affiliates close to Pittsburgh, where Cox already owns WPXI(TV). Wpxi is the only NBC affiliate owned by Cox, which has 11 other TVs. "We have had conversations with Sunrise," confirms Executive VP, TV, Andy Fisher. But "it would be premature [to comment further]."