NBC executives acknowledged Tuesday that a principal reason for turning over the 10 00 p.m. M-F time period to Jay Leno was to preclude the possibility of his jumping to ABC with a competing late-night variety show. "There's no question that had Jay gone against [Conan O'Brien at 11 30 p.m.], it would have split the audience," NBC CEO Jeff Zucker told today's (Wednesday) New York Times. Earlier, at a news conference, Leno himself indicated that he had considered jumping networks. ""There were reports that I was going to ABC but that was started by a disgruntled employee -- me," he quipped. However, an unidentified executive at a rival network told the Times that O'Brien could still be hurt by the move. ""He won't be getting a good lead-in and viewers will already have seen a late-night style show," the exec said. (O'Brien said on his own show Tuesday night/Wednesday morning that he was "absolutely thrilled that Jay is staying at NBC. ... He is a fantastic lead-in. He is a huge part of my success.") The newspaper observed, however, that Leno's show could be successful even if it attracts low ratings, "because Mr. Leno's cost would be only about $350,000 a show, about a tenth as much as a typical drama."