Paula Abdul to join 'X Factor' judges

She's ba-aaa-ack.

Minutes before the singing competition "The X Factor" began taping its first judges' round of auditions in Los Angeles Sunday, series creator Simon Cowell formally announced what industry observers have been predicting: He's appointed his old "American Idol" colleague Paula Abdul -- with whom he sometimes playfully, sometimes snipingly, sparred as a fellow judge -- to join his new show.

"I am excited beyond words to be a part of 'The X Factor,' " singer-choreographer Abdul, 48, said in a statement. "I'm also delighted and grateful to be sitting next to Simon again . . . but you might want to check back with me in a week or two!"

Almost immediately afterward she tweeted to her 1.95 million followers, "I wanted so much to give you a confirmation sooner . . . Well here it is right now!"

This American version of Cowell's British show -- a hit in England and in over two dozen other countries and regions since premiering in 2004 -- debuts on Fox this September.

Of reuniting with his on-screen frenemy, Cowell, 51, said in a statement, "This show would never have been the same without Paula and I can't believe I am saying this: I have missed her a lot, and I am thrilled she's on the show."

Abdul was staying mum about the last-minute negotiations. "You know what? I'm here," she told reporters at Sunday's auditions. "And only Simon and I understand what went on. That's all I can say. It's fun though. I'm here."

Abdul is the best-known personality on the new show. Cowell and Fox Sunday announced that the co-hosts would be choreographer and former Pussycat Dolls lead singer Nicole Scherzinger, who won season 10 of "Dancing With the Stars" last year, and Steve Jones, a TV host in Britain who is little known in America.

The previously announced fellow judges are music producer Antonio "L.A." Reid and singer and British "X Factor" judge Cheryl Cole.