Clooney ups his bet with Pfeiffer that he will stay single forever

George Clooney may be the world's most eligible bachelor – or the most visible bachelor, anyway – but not all of his Hollywood friends think he will stay that way.

Michelle Pfeiffer, his co-star in one of his first hit movies, One Fine Day, revealed yesterday that she has upped a long-standing bet that he will, one day, find a nice girl and settle down.

The bet started out years ago at $100 (£50). But Clooney, ever more adamant about staying unattached, has steadily increased the stakes. "I bet him he would get married and he keeps inflating the bet, from $100 to $100,000," Pfeiffer told Jonathan Ross in an interview set for broadcast last night. "I still think he will, he's a handsome devil."

A hundred grand for Pfeiffer and Clooney is not, of course, the daunting sum it might be for the rest of us. Aside from her own stellar career, Pfeiffer is married to one of television's most successful producers, David E. Kelley. She is in Britain to promote the new musical version of the old John Waters movie Hairspray – a huge hit on the other side of the Atlantic and a hot early favourite for multiple Oscars.

Clooney, meanwhile, is still basking in last year's banner year in which he won an Oscar for his supporting role in Syriana, and received universal acclaim for writing and directing Good Night, and Good Luck. He has a slew of producing and acting projects, including a legal thriller called Michael Clayton which just came out in the United States.

At 46, Clooney is of course a celebrated charmer, frequently listed in the gossip rags as one of the sexiest men alive. He hardly lives like a monk – he rarely goes anywhere without a beautiful woman on his arm, and his list of reported girlfriends has included Kelly Preston (now married to John Travolta), Renee Zellweger and Mariella Frostrup.

But he also keeps his focus squarely on his work, on his core of longstanding friends, on his homes in Los Angeles and Lake Como, and on his growing passion for international politics. Clooney has campaigned harder than anyone to try to stop the genocide in Darfur, addressing the UN and lobbying politicians on both sides of the American political aisle.

He's often touted as a possible future political candidate, along the lines of Ronald Reagan, a charmer from another era, or Arnold Schwarzenegger. That, though seems unlikely, though. "Run for office?" he once said. "No. I've slept with too many women, I've done too many drugs, and I've been to too many parties."

That's about as specific as Clooney gets about his personal life. As he puts it: "It wouldn't be personal if I shared it."

But he does know a thing or two about marriage, because he tied the knot once in the late 1980s. His union with Talia Balsam, predating his break-out role on television in ER, lasted just three years.

As for his record on winning bets, he looks like he's sitting pretty. Pfeiffer, along with Nicole Kidman, once bet him $20,000 he would have a child by the time he turned 40. When he turned that corner six years ago, he graciously returned the cheques the two women wrote with a note saying: "Double or nothing for another 10 years."