People.com confirms that Simon Cowell picked Antonio L.A. Reid as a judge for The X Factor.

Reid is Island Def Jam chairman and will sit alongside Cowell as a judge.

While not noting anything specific, Reid sent out an e-mail Thursday morning announcing his departure from Def Jam.

I have decided to leave my position as chairman of the Island Def Jam Music Group. I have always thrived on growth and the next great challenge, and I look forward with much enthusiasm to what the future holds, he wrote in the e-mail.

Recently, when Cowell was asked about future judges, he said, We always wanted to work with [Reid], whether it was now or in the future. Because in terms of his credibility and what he's achieved, he's always somebody who we would love to work with ... He's had so much success. And he's also a good friend of mine.

Joining Cowell and Reid will be two more celebrity judges, though they have yet to be announced. There has been much speculation as to who will it be and Paula Abdul and Jessica Simpson are both frontrunners.

We met with Paula. What I've always loved about Paula is that she actually has got good taste in music, Cowell said.

As for Simpson, Cowell revealed that she's very into the mentoring side.

The X Factor is set to premiere on FOX in the fall. The music competition will hold auditions in Miami, New York, Seattle, Los Angeles, Dallas and Chicago. There is a $5 million recording contract waiting for the winner.