American Idol judge Paula Abdul is quitting the TV singing contest after eight years.
Making the announcement on Twitter, the 47-year-old said: "With sadness in my heart, I've decided not to return."
She did not give any reasons for her decision which ends weeks of speculation about contract talks.
On Tuesday, it was announced songwriter Kara DioGuardi would be returning to the show to judge along with Simon Cowell and Randy Jackson.
"I'll miss nurturing all the new talent but, most of all, being a part of a show that I helped from day one become an international phenomenon," said Abdul.
"What I want to say most is how much I appreciate the undying support and enormous love that you have showered upon me," she added.
TV network Fox said it was "saddened" that Abdul would not be returning to the show, saying she had been "an important part of the American Idol family over the last eight seasons".
"While Paula will not be continuing with us, she's a tremendous talent and we wish her the best."
Abdul's future with American Idol had been unclear since the last series ended ended in May.
Speculation increased further as producers agreed new contracts with some of the other on-screen talent.
Last month, host Ryan Seacrest reportedly signed a $15m (£8.9m) deal to front American Idol for the next three years.
In an interview last month, Abdul said she had been invited to stay with the show as long as it aired and that she was optimistic about negotiating a new contract.
Despite a decline in ratings, American Idol remains the most popular show in the US with the last series drawing an average of 26.3 million viewers.
It has spawned stars including Kelly Clarkson, Carrie Underwood, Jordin Sparks and Chris Daughtry.