The subprime mortgage meltdown has begun to spread beyond the U.S., as a British hedge fund said it would wind up operations after suffering heavy losses on high-risk home loans to Americans.

Caliber Global Investment, a $908 million fund listed in London, said it would sell its assets and return capital to investors after posting an $8.8 million loss on its subprime investments and concluding that the market would not turn around anytime soon.

The decision by Caliber, which is managed by Cambridge Place Investment Management, came less than a week after another British fund, Queen's Walk Investment, said it lost $91 million because of defaults in the U.S. subprime mortgage market and early repayments of British home loans.

Queen's Walk, which is run by Cheyne Capital Management, one of Europe's biggest hedge fund firms, said it sold three of its four holdings in the U.S. subprime mortgage market.

As of March, about 11 percent of subprime mortgages included in bonds were delinquent by at least 90 days, in foreclosure, or already turned into seized property, Bloomberg News reports.

That is the highest rate in a decade. Two years ago, less than 5.4 percent of subprime mortgages were considered "nonperforming," Bloomberg said, citing a report from Friedman Billings Ramsey Group in Arlington, Virginia.

Risky mortgages have already caused plenty of problems in the U.S. Two hedge funds managed by Bear Stearns Asset Management nearly collapsed earlier this month because of their losses on subprime loans.

Its parent company,Bear Stearns, eventually agreed to lend one fund $1.6 billion to shore it up. It has so far declined to bail out the other fund.