John Paulson, one of the world's most closely watched hedge fund managers, told clients on Monday that he sees a 50 percent chance the euro zone will break up, according to an investor.
Paulson underscored his negative sentiment on Europe in a regularly scheduled call with investors.
The investor asked not to be named since Paulson & Co's funds are private.
A Paulson spokesman declined to comment.
Paulson earned billions of dollars betting against the overheated housing market in 2007, but he ranks as one of the year's worst performing hedge fund managers this year.
So far in 2012, his bets against Europe have hurt some of his portfolios. His Advantage Plus fund lost 18 percent during the first six months of the year after losing more than 50 percent last year, investors said.
Paulson is known for making big bets and sticking with them, and he has long suggested that European policymakers' efforts to solve the region's debt crisis will fall short.
