Prince William is an R&B music fan

Cowell, who has signed up to US show American Idol for another three years, told the UK's Heat magazine: "Prince William would make a great pop idol."

"He's got the looks and class of a true star," he said.

The TV talent show judge said he could give the 21-year-old heir a massive hit - regardless of whether he has any singing talent.

"I don't know whether the prince can sing or not, but let's face it, that's not always a problem.

"I'd love to see him sing a ballad reflecting on the troubles in his life."

But the prince, who has spoken about his love of R&B music, is unlikely follow the example of Princess Stephanie of Monaco.

Cowell is producing Cupid, a reality dating show in the US

She launched a singing career in the 1980s and topped the charts in Europe.

US TV network Fox said on Monday that 43-year-old Cowell had signed a contract to judge American Idol for another three years.

Cowell agreed to return if Fox would help him to establish his own production company, Simcow Ltd, and consider a new reality TV series from him.

He said: "It's not a difficult show to do, American Idol, apart from the audition sequence.

"Once we're into the studio side it's only two days a week, so there's loads of other time to do the things I want to do."

Auditions for the third series of American Idol will begin this summer, with the show due to go out in January 2004.