Paula Abdul announced Tuesday she is quitting "American Idol," a show that she said became an international phenomenon with her help.

"With sadness in my heart, I've decided not to return" to the hit Fox TV singing contest, Abdul said in a posting on her Twitter account.

In a statement, Fox and the show's producers said Abdul was "an important part of the 'American Idol' family over the last eight seasons, and we are saddened that she has decided not to return to the show."

They said she was a "tremendous talent" and wished her the best.

On Monday, Fox announced that Kara DioGuardi would return for a second season on the "American Idol" judging panel that includes Simon Cowell and Randy Jackson. The addition of Grammy-nominated songwriter DioGuardi last year raised questions about Abdul's future.

In July, Abdul told The Associated Press that she had been invited to stay with "Idol" as long as the show lasted and that she was optimistic that she would be able to negotiate a new contract.

But the 47-year-old singer-dancer said the invitation to come back was subject to agreement on the details of a new deal.

Abdul began working with a new manager, David Sonenberg, in recent weeks.

"I'll miss nurturing all the new talent, but most of all being a part of a show that I helped from day 1 become an international phenomenon," Abdul said on Twitter.

Copyright 2009 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.