Clooney "robbed" a casino in Ocean's Eleven

Clooney, who played a casino robbing character in the film Ocean's Eleven, will put an undisclosed sum into the planned $3 billion Las Ramblas resort.

"I could end up just losing my shirt on this whole thing, but these guys are pretty good at what they do," Clooney said. "It's going to be an adventure."

The project is expected to take five years to complete.

Clooney declined to say how much money he is investing in the project but added he wanted to have a serious stake.

The actor is partners with real estate developers Related Las Vegas and Centra Properties, along with influential nightclub owner Rande Gerber, husband of model Cindy Crawford.

I wanted it to be like old Vegas and old Hollywood George Clooney

"We want to be real investors, to have some percentage of it," he said.

'Sophisticated'

"You got to put your money where your mouth is. How much did I put in? A lot. A lot more than I expected."

Clooney said the hotel would be smart and sophisticated.

"I wanted it to be like old Vegas and old Hollywood. It's going to be a classy joint,� Clooney said from his home on Lake Como in Italy.

Clooney said Ocean's Eleven co-star Brad Pitt and his other Hollywood friends had not committed to buying into the development.

"You bet, I'd love them all to be there. We've talked with Brad."