Kara DioGuardi becomes 3rd judge to quit "American Idol"

Judge Kara DioGuardi poses backstage during the 9th season finale of 'American Idol' in Los Angeles May 26, 2010.

LOS ANGELES (Reuters Life!) - Songwriter Kara DioGuardi has quit "American Idol," the third of four judges to leave the top-rated U.S. television singing contest this year following Simon Cowell and Ellen DeGeneres.

Fox network announced on Friday that DioGuardi is departing the show after weeks of media speculation, leaving just one of the original judges, Randy Jackson, still on the panel.

DioGuardi thanked everyone who supported her during her two seasons on the show and wished the best to everyone taking part in the upcoming Season 10 that will be broadcast from January.

"I felt like I won the lottery when I joined "American Idol" two years ago, but I feel like now is the best time to leave 'Idol," DioGuardi said in a statement.

"It has truly been an amazing experience ... I look forward to my next challenge," she said without elaborating on the reasons for her departure.

While DioGuardi's statement suggested the move was her choice, her exit comes amid speculation that she was axed as the network and producers shake up the judging panel in the wake of Cowell's departure and to arrest a ratings decline.

The American Idol franchise has had some of the highest ratings on U.S. television since it began in 2001 and remained the most-watched show on U.S. television last season, generating big advertising revenues for Fox.

But ratings have been sliding for four years which has also affected sales of the up-and-artists who find fame on the show.

National auditions for the show's new season are already underway but the new lineup of judges is yet to be unveiled.

Media reports have suggested that Fox has secured singer Jennifer Lopez and Areosmith rocker Steven Tyler to sit as judges alongside veteran judge Jackson.

It is uncertain whether Fox will stick with a four judge panel or revert to its original panel of three.

Fox released a flurry of statements praising DioGuardi and saying she would be missed on the show.

"Idol" creator and executive producer Simon Fuller, who modeled the show after his popular British series "Pop Idol," described DioGuardi as one of the world's best songwriters.

"She has been passionate and committed to "Idol" over the last two seasons. I will miss having her on the show, but I look forward to working with her in music for many years to come," he said.

Cowell, the abrasive British judge, was the first to quit the show, leaving in May to launch another talent show "The X Factor."

DeGeneres, who joined "Idol" to replace Paula Abdul, decided to leave in July after just one season, with the popular U.S. talk show host and comedian saying it was not the right fit for her.

"American Idol" is produced by Fuller's 19 Entertainment, a unit of CKX Inc and by London-based Fremantle Media, a unit of Bertelsmann AG-controlled braodcaster RTL Corp. Fox is a unit of News Corp.

(Editing by Belinda Goldsmith)