Nicki Minaj and country star Keith Urban have been confirmed as judges on the next series of American Idol.

Fox television made the official announcement hours before the first round of auditions were due to take place in New York.

The duo replace Jennifer Lopez and Aerosmith singer Steve Tyler, both of whom quit earlier this year.

Mariah Carey and Randy Jackson complete the line-up on the programme, which has been suffering falling ratings.

Nicki Minaj and country star Keith Urban have been confirmed as judges on the next series of American Idol

Audience’s for this year’s series – the eleventh – were down about 30% on 2011. The season finale drew 21.5 million viewers, a record low, to see Phillip Phillips win.

Therefore, the appointment of Nicki Minaj, 25, is likely to be of key importance to Fox, who will hope to draw in a younger, hipper audience.

Nicki Minaj sold three million copies of her recent single Starships in the US alone; while her cartoonish blend of pop, rave and hip-hop has seen her top the charts in the UK, US and Canada.

Keith Urban, meanwhile, is one of the biggest names in country music. He boasts 14 US number ones, and has won the Grammy for best male country vocal performance four times in the last six years.

The singer is also married to actress Nicole Kidman.

Mariah Carey, who first found fame with the number one single Vision Of Love in 1990, will reportedly receive $18 million for her one-year contract on Idol. The salaries of the other judges have not been revealed.

The appointment of three newcomers means Randy Jackson is the sole returning judge.

He has been with the show since it first began in 2002, when his fellow judges were Simon Cowell and Paula Abdul.

Over the years, American Idol has produced stars such as Kelly Clarkson, Carrie Underwood, Chris Daughtry and Jennifer Hudson.

It now faces competition from the likes of The Voice and X Factor US, which boast Cee-Lo Green, Britney Spears, Adam Levine and Simon Cowell on their judging panel.

American Idol returns for its 12th series in January.