Oil prices have plunged by more than $4 a barrel this afternoon as concerns that Hurricane Gustav would cause severe damage to the US oil sector eased. The storm weakened before hitting the Louisiana coast.
US crude fell $4.19 to $111.27, while London Brent crude fell $4.31 to $109.74.
At least 12.5% of total US refining capacity was shut down ahead of the storm and other plants cut rates. The Louisiana Offshore Oil Port, the only US port capable of offloading the biggest oil tankers, halted all operations.
Gustav is the biggest threat to the region - home to a quarter of US oil output and 15% of natural gas output - since Hurricanes Katrina and Rita wrecked more than 100 offshore oil platforms in 2005 and closed several large refineries for months.
Meanwhile, Iran's oil minister said on Sunday that $100 a barrel was the lowest acceptable price for crude. Iran, OPEC's second-largest producer, has said the oil market is oversupplied as prices have dropped from the record high over $147 a barrel struck in July.
OPEC meets in Vienna on September 9 to discuss output policy, but other member nations have backed Iran so far.
