New York's main contract, light sweet crude for November, slid 4.56 dollars to close at 93.97 dollars a barrel.
In London, Brent North Sea crude for delivery in November dropped 4.77 dollars to settle at 90.56 dollars a barrel.
"It's the same story that started earlier this week: fears of a very slow global economy," said Adam Sieminski at Deutsche Bank.
Traders worried that the financial crisis roiling markets and weighing on the US and European economies will erode demand for crude oil.
The US Senate's passage late Wednesday of a 700-billion-dollar bailout of financial firms did little to reassure the markets.
On Wall Street, the Dow Jones Industrial Average of 30 blue-chip stocks plunged over three percent.
Approval of the bailout bill by the House of Representatives in a vote expected Friday was uncertain after the House rejected a similar measure Monday.
"If the economy slows down, and people don't have money to buy, and they don't buy oil, consumption will fall,"