Nigel Lythgoe

The decision on who will be sitting at the American Idol judges table next season will be announced within the next three weeks, reinstalled Idol executive producer Nigel Lythgoe says.

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"I guess the decision has got to be made within the next three weeks," Lythgoe told Ryan Seacrest on Seacrest's morning radio show Thursday. "I think decisions have been made, let's be honest about this. I think decisions have been made, and negotiations are taking place."

As for the lengthy negotiations, Lythgoe noted that dealing with possible big-name stars — perhaps like Steven Tyler, who has reportedly been in talks to join the show — takes time.

"When you are dealing with stars who have other lives to concentrate on, it's like, 'I want to take you off the planet and you'll join us on Planet American Idol for four months,' that's really tough," he said. "So you've got to let them work everything out and, of course, come up with the money that they will appreciate."

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Changes on the panel for the upcoming season spring from Simon Cowell leaving for X Factor, along with Ellen DeGeneres deciding to exit the series after one season and Kara DioGuardi's contract not being renewed.

Reps for the Fox reality series continued to refuse to comment Thursday.