Oil prices dropped on Monday as US refineries cut crude production in anticipation of a plunge in energy demand owing to Hurricane Sandy bearing down on the eastern United States, analysts said.
New York's main contract, light sweet crude for delivery in December shed 58 cents to $85.70 a barrel.
Brent North Sea crude for December fell 33 cents to $109.22 a barrel in London morning deals.
A projected fall in energy demand in the United States, the world's biggest consumer of oil as the megastorm approached, led refineries to slash production and traders to flee the market.
"Oil has fallen and the market is reacting to Hurricane Sandy," said Purvin and Gertz energy consultant Victor Shum.
"Quite a few refineries on the east coast have reduced throughput in preparation for the hurricane to hit the US east coast and that means crude oil consumption is going to come down," the Singapore-based analyst told AFP.
Tamas Varga, analyst at PVM brokers, added: "When life stands still the effect should be bearish for oil prices as consumers consume less oil when they are forced to stay indoors."
After claiming 66 lives in the Caribbean, Hurricane Sandy forced a lockdown on the US coast as 10 states declared emergencies.
Airports, businesses, schools and even the Statue of Liberty brought down their shutters as nervous Americans stripped supermarket shelves of water, bread and batteries before the hurricane hit.
US President Barack Obama on Sunday urged Americans to take the storm "very seriously."
Forecasters warn that Hurricane Sandy might bring "life-threatening" storm surges of six to 11 feet (1.8 to 3.3 metres) in waters around New York City and northern New Jersey.