PASADENA, Calif. – NBC said Sunday it decided to pull the plug on the Jay Leno experiment when some affiliate stations considered dropping the nightly prime-time show, and the network is waiting to hear if Leno and "Tonight" host Conan O'Brien accept its new late-night TV plans.

"The Jay Leno Show," which airs at 10 p.m. EST, will end with the Feb. 12 beginning of the Winter Olympics, said NBC Universal Television Entertainment Chairman Jeff Gaspin. Leno would return to his former 11:35 p.m. slot after the Olympics ended under the network's new plan, which also calls for O'Brien to retain his job with "Tonight" but at the later hour of 12:05 a.m. EST.

Jimmy Fallon and his "Late Night" would be pushed a half-hour later as well, to 1:05 a.m. EST.

"My goal is to keep Jay, Conan and Jimmy as our late-night lineup," Gaspin said, adding later that they "have the weekend to think about it" and discussions with them will resume Monday.

NBC had moved Leno to prime-time last year in order to keep him from leaving the company and keep a promise it had made to give O'Brien the "Tonight" show. The change was one of the most dramatic in prime-time television in a generation. It was also a roll of the dice at a time NBC was suffering in prime-time. It didn't even last six months.

Gaspin said the new proposal gives Leno what's important to him — telling jokes at a later hour — and O'Brien his top priority, retaining "Tonight."

"I hope and expect that before the Olympics begin, we'll have everything set. I can't imagine we won't have everything in place before then," Gaspin told a meeting of the Television Critics Association.

Gaspin said that despite lower ratings for NBC at 10 p.m. compared to last year, the network was making money off the show.

But affiliates were upset that it was leading fewer viewers into their late news programs, costing them significant advertising revenue. Some affiliates told NBC in December they would go public soon about their complaints if a change wasn't made, or even take Leno's show off the air.

Gaspin said about one-third of the affiliates were really hurt by the Leno show, although he wasn't clear on how many said they might pre-empt his show.

"I asked them (the affiliates) 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," he said.

Michael Fiorile, chairman of the NBC Affiliate Board, said it was a great move for NBC stations, the networks and viewers.

"We admire their willingness to innovate, and their willingness to change course when it didn't work for us," Fiorile said.

Gaspin said he pondered combinations of possible schedule changes before the holidays and then called his boss, NBC Universal Chairman Jeff Zucker, for approval to act.

"I don't want to wait anymore. Now is the time," Gaspin recounted telling Zucker.

Both Leno and O'Brien made comedic hay out of the issue last week. Leno joked in his monologue that NBC was working on a solution in which all parties would be treated unfairly, while O'Brien wisecracked that he and Leno would be thrown by the network into a pit to fight and "the one that crawls out gets to leave NBC."

Gaspin said he's "perfectly fine" with their on-air remarks "if that's how they blow off steam and that's how they're comfortable."

NBC's "Saturday Night Live" and its "Weekend Update" with Seth Meyers also got into the act.

"It was reported Thursday that in the wake of poor ratings for `The Jay Leno Show,' NBC will move his show back to the 11:35 time slot, and then start Conan O'Brien's `Tonight Show' at midnight — though it's a little weird to start the `Tonight Show' at a time when it's no longer tonight," Meyers said Saturday.

Asked if O'Brien and Fallon expressed anger at his proposal, Gaspin said both men were professional and understanding when they talked. "Beyond that, it was a private conversation," Gaspin said.

O'Brien reportedly has a contract that guarantees him a multimillion-dollar payment if "Tonight" is moved later than 12:05 a.m. EST.

But Gaspin, asked if a contractual penalty weighed into the decision to bump O'Brien's show a half-hour rather than a full hour, replied, "No, not at all."

As for reports that Fox may be considering courting O'Brien for a late-night program, Gaspin repeated his desire to keep him, Leno and Fallon at NBC.

The decision to shift Leno will leave a gaping hole in NBC's prime-time schedule, at a time the network is already struggling. A mix of reality programming, "Dateline NBC" and at least two hours of scripted shows will be added to fill in the five hours taken up by Leno's prime-time show each week.

Looking ahead to the 2010-11 season, NBC announced seven drama pilots under development, including an updated version of "The Rockford Files" from "House" executive producer David Shore; "Undercovers," a husband-wife spy drama from producer J.J. Abrams ("Lost") and "Prime Suspect," based on the BBC series about a female detective.

The network's heavy development slate is a reversal of its most recent approach of attempting to make series without pilots.