It appears that after he played in "Ocean's Eleven" and "Ocean's Twelve", actor George Clooney started to enjoy the idea of having a casino.

Clooney, 44, decided to invest an undisclosed amount in a proposed $US3 billion development called Las Ramblas, which will be built east of the Las Vegas Strip.

The project contains a casino and more than 4,400 flats and hotel units in 11 high-rise towers.

''We have this romantic notion of a place where you put on a jacket or a dress to go to dinner,'' Clooney said today.

''We will have some sort of dress code so that it will feel like you are walking into a more formal Las Vegas of a different age or a classic Monte Carlo casino.''

Clooney is partner with major real estate developers Related Las Vegas and Centra Properties, along with influential nightclub owner Rande Gerber and his company, After Midnight.

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