LOS ANGELES, July 30 (UPI) -- Jennifer Lopez and Steven Tyler are to replace Kara DioGuardi and Ellen DeGeneres as judges on "American Idol," TMZ said.

DioGuardi was fired from the post and DeGeneres announced Thursday she had quit, the Web site said.

The casting changes mean the show is going back to a three-judge format and Randy Jackson will be the only holdover from the cast when the singing competition series returns for a 10th season.

Simon Cowell was the fourth judge, but left at the end of Season 9 to executive-produce and eventually star in another talent show, "The X Factor."