Mariah Carey is taking over as a judge on American Idol after the departure of Aerosmith's Steven Tyler and pop diva Jennifer Lopez.

"As a singer, songwriter and producer, it's going to be fun and rewarding to help find new talent and give back to American Idol," Carey said.

"I'm currently in the studio working on my new album and its first single, Triumphant, which will be out early next month. I can't wait to channel my creative energy as a part of this show which is a massive global phenomenon."

Producer Simon Fuller told Fox: "We are proud to have one of the world's greatest-ever female singers join our show.

"Mariah defines the word 'Idol' and will inspire every singer that has the honour of performing in front of her."

A show insider told Us Magazine that Carey will be the "highest paid judge on any music competition show", when she joins Idol, claiming that the star will get paid $18-million with a one-year option to do Idol.

Fellow pop diva Christina Aguilera is reportedly earning $10-million to appear on the third season of The Voice, while Britney Spears will earn approximately $16-million for her stint on the US X Factor.

Lopez and Tyler announced earlier this month their departure from Idol, which is struggling to maintain ratings against rival singing competition The Voice on NBC.

The show has aired for 11 seasons, but was thrown into disarray by the departure of judges Simon Cowell, Ellen DeGeneres and Kara DioGuardi two years ago.