Aborting after four months what it had originally promised would be a one-year incubation of The Jay Leno Show at 10 00 p.m., NBC said Sunday that it will return to conventional programming in that time period after the Winter Olympics ends in late February. Leno would return to his former slot at 11 35 p.m., it said. NBC Universal Television Entertainment Chairman Jeff Gaspin told TV critics meeting for their winter "tour" in Pasadena that the show would be trimmed to 30 minutes and be followed by The Tonight Show with Conan O'Brien at 12 05 a.m. and Late Night with Jimmy Fallon at 1 05 a.m. While it was regarded as a virtual certainty that Leno and Fallon would agree to the changes, O'Brien's consent was regarded as iffy. "As much as I'd like to tell you we have a done deal, the talks are still going on," said Gaspin on Saturday. On Friday's Tonight Show , O'Brien listed some of the "rumors" being circulated about the show, the last of which was "NBC is going to throw me and Jay in a pit with sharpened sticks. The one who crawls out alive gets to leave NBC. Trust me," he added, "that's an appealing proposition." (Leno also addressed the issue, showing what he said was a new postage stamp that was being issued displaying his face. "It gets canceled after four months," he quipped.) Gaspin acknowledged that the decision to cancel the Leno show at 10 00 p.m. was prompted by a rising revolt among affiliates, who have seen ratings for their 11 00 p.m. newscasts plummet since the Leno show debuted, with some threatening to pull the show and move their own programming into the time period. Last month, "they started talking about preemption," Gaspin said. "I asked them how many are they talking about, because I could have lived with one or two, but I got the sense that it was more than one or two." Chris Wayland, general manager of Boston affiliate WHDH, was regarded as one of the leaders of the affiliate revolt. He told today's (Monday) Boston Herald "This is obviously a step in the right direction." Boston University broadcast journalism professor Susan Walker added "They had to get rid of Leno. It was just a death march for local NBC affiliates."