Simon Cowell has set his sights on Katy Perry to be his next superstar judge on America's The X Factor.

The I Kissed A Girl hitmaker, who reached a divorce settlement with Russell Brand earlier this week, has previously stepped in as a guest panellist on the British version two years ago.

And Cowell was so impressed he's keen to sign her up as a permanent fixture on the US show after both Nicole Scherzinger and Paula Abdul were given the boot after just one series.

He told his ex-girlfriend Terri Seymour on US TV show Extra: "I worked with Katy once. I think she would be fun because she is hard - in a good way - and she's feisty.

"She would be great, in terms of experience, success... brilliant."

But the music mogul has ruled out signing up rumoured stars Mariah Carey and Sir Elton John.

He adds: "I don't think Mariah would make that commitment. She's just had kids," adding about Elton: "Absolutely not. He wouldn't do it and he'd be really difficult to work with."

If Perry agrees to join the show she will sit alongside Cowell and LA Reid, who has kept his place following his debut as judge last year.