Oil producers' US bonds pile

Oil producing countries are poised to become the biggest creditors to the US as the nation's fuel bill soars.

Petrol exporters from Saudi Arabia to Russia now hold $510.8 billion (£258.2 billion) in US Treasury bonds, just short of the $592.2 billion held by Japan, America's largest creditor.

While the inflows of petrodollars are helping keep a lid on interest rates, they have also reignited concerns among Americans of growing foreign ownership of assets.

"We should be very happy that they're buying US Treasuries because they're keeping interest rates low, and that's a positive for bond investors," Gary Pollack, head of fixed-income trading at Deutsche Bank's Private Wealth Management unit in New York, told Bloomberg. "Whether there's geopolitical risk is something else."

Assets held by oil exporters rose to $4.6 trillion at the end of 2007, according to management consultant McKinsey.