Paula Abdul has decided to quit the top-rated US television show ``American Idol,'' ending weeks of speculation about her future as a judge on the popular singing contest.

Making her announcement on her Twitter feed Tuesday, Abdul said ``with sadness in my heart,'' she had decided not to return to ``Idol'' which is due to start auditions for its ninth season within days. She did not give any reason.

Abdul, 47, a singer/dancer turned TV personality, has been a mainstay of the show since it was launched in 2002 and quickly became an audience juggernaut for News Corp's Fox network, growing into an estimated $1 billion-plus brand.

``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,'' said Abdul, who was known for finding something positive in almost every performance.

``What I want to say most, is how much I appreciate the undying support and enormous love that you have showered upon me.''    

Fox and the show's producers FremantleMedia North America and 19 Entertainment said they were ``saddened'' that Abdul would not be returning to the show as 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,'' they said in a joint statement, also giving no reason for her departure.

Abdul's future with the show had been unclear since the eighth season ended in May with speculation rising as producers locked in new contracts with some of the other key players. - Reuters