NBC

Pressed by affiliates and shrinking ratings, NBC has a plan in the works to radically alter its late-night television lineup, restoring Jay Leno to his old spot at 11:35 each weeknight, while pushing the man who replaced him, Conan O’Brien, to a starting time of 12:05 a.m.

NBC executives held extensive discussions with Mr. Leno and Mr. O’Brien on Thursday about the future of the network’s late-night lineup.

And while NBC officially said no final decision on the plan had been made, two senior NBC executives who had talked to the top management about the moves said that under the plan being discussed, Mr. Leno would definitely shift back to 11:35 but in a half-hour format, while Mr. O’Brien would slide back his start time by a half hour and then produce an hourlong show.

“We remain committed to keeping Conan O’Brien on NBC,” the network said in a statement Thursday evening. “He is a valued part of our late-night lineup, as he has been for more than 16 years, and is one of the most respected entertainers on television.”

The third NBC late-night star, Jimmy Fallon, would then begin his show at 1:05 a.m., the executives said. The revised lineup would go into effect after NBC concludes its coverage of the Winter Olympics on Feb. 28. NBC will pre-empt its prime-time and late-night lineup for more than two weeks to cover the Olympics, creating a natural break in which to put the late-night changes into effect.