Singer and rapper will appear alongside Mariah Carey, Randy Jackson and Keith Urban on panel of US reality TV series

Nicki Minaj has officially joined American Idol. As rumoured last month, the singer and rapper will appear as a judge on the US reality TV series, alongside Mariah Carey, long-time panellist Randy Jackson, and country singer Keith Urban.

The announcement on Sunday came at the last minute: the taping of American Idol’s 12th season was due to begin the same day in New York City. Contract negotiations “went down to the wire”, the LA Times reported; as of Saturday night, the network was unsure whether Minaj and Urban would be able to sit in on the first round of auditions. Jackson’s return was also a bit of a surprise: Enrique Iglesias had reported been in discussions to replace the industry veteran.

“American Idol’s star power has never been so great,” executive producer Simon Fuller said. Fox executive Mike Darnell said the network was “thrilled” about the panel. “Nicki’s an unbelievably captivating international phenomenon who has made an indelible mark on rap and pop … [And] I know that our fans and contestants will fall in love with [Keith].”

While the new series of American Idol is not set to air until 2013, the programme’s ratings will be compared to The X Factor and The Voice, both of which are running now. Both series have had a rocky start this year: although The X Factor enlisted Britney Spears and Demi Lovato as judges, ratings for its recent premiere were down about one third from last year.

Carey will receive almost $18m (£11m) for her appearance on American Idol, according to the Hollywood Reporter. Minaj’s contract is reportedly worth $12m (£7.4m), while Urban receives $6m (£3.6m). American Idol host Ryan Seacrest has committed to two more seasons for $15m (£9.2m) each.