mariah_arey_web.jpgBEVERLY HILLS, Calif. — Mariah Carey will join American Idol as a judge next season, Fox announced Monday, bringing her star power to the show that remains a ratings leader but has seen its viewership and pop culture status diminish.

“I am so excited to be joining Idol,” said Carey, addressing the Television Critics Association via Fox entertainment chief Kevin Reilly's cell phone, which he put on speaker for the hotel ballroom meeting.

She couldn't be on hand with the group because “this kind of all just happened really quickly,” Carey said.

The show, which saw judges Steven Tyler and Jennifer Lopez exit at the end of last season, will be back on the air for season 12 in January.

Reilly called Carey “the biggest recording artist that any of these (talent) shows has ever had,” adding that she was the “artist that many of these contestants have tried to emulate, have tried some of the songs, have tried to hit the notes.”

Playing the drama up, Reilly dialed Carey's number and put her on speaker.

“Hi Mariah. How are you? It's Kevin,” he said. “We do have the deal, don't we?”

“Yes” Carey replied.

The exit of Tyler and Lopez left original judge Randy Jackson and started a guessing game about potential replacements, with Carey at the top of the list.

As one of music's best-selling singers, she could provide the clout Idol needs to compete in an increasingly crowded talent show field. Besides Fox sibling The X Factor, which recently added Britney Spears and Demi Lovato as judges, there's NBC’s The Voice, which boasts Christina Aguilera among its big names.

The search is on for a third judge, and Reilly said promised another impressive pick.

“For the next couple of weeks it will be a matter of picking the right one, with the right chemistry,” he said.

Carey’s signing enhanced the value of Jackson, her co-manager, although Fox has yet to say whether he'll judge next season. Ryan Seacrest will be back as host.

Photo: Mariah Carey