LOS ANGELES - Simon Cowell confirmed he will quit talent show "American Idol" later this year to concentrate on launching a US version of his British hit "The X Factor."

The acid-tongued star of Fox's reality series -- the highest rated show on US television -- told reporters he had negotiated a contract which would see "The X Factor" make its long-awaited debut, also on Fox, in early 2011.

Cowell's previous contract with Fox had barred him from launching a US edition of "The X Factor" talent contest while he continued as a judge "Idol," which begins its 10th season on Tuesday.

Fox Broadcasting Entertainment Chairman Peter Rice told reporters at a press event in Pasadena that "The X Factor" and "American Idol" would air at different times of the year.

"The X Factor" made its debut in Britain in 2004 and has since been exported to 16 other nations.

It differs from "American Idol" in that it allows contestants as young as 14 -- "Idol" limits contestants to the ages fo 16-28; does not have an upper age limit; allows groups; has different categories; and has the judges serving as mentors, Cowell said.

"I'm thrilled that we have put a date on the launch of the US version of 'The X Factor,' and delighted to be continuing to work with Fox," said Cowell, who has become famous for his merciless put-downs of "Idol" contestants.

Asked who Fox should seek as his replacement, Cowell replied: "Just get somebody who knows what they're talking about."