Oil tumbled more than 5% today amid worries a global recession will crush fuel demand, limiting the impact of any supply cuts by OPEC.
US oil for November delivery tumbled $3.98 a barrel to $70.27, after hitting a session high of $75.69. London Brent crude traded $3.33 down to $68.70 a barrel.
The slide came as US stocks fell on concern that earnings could be driven down by slower consumer demand.
The oil market has slid 50% since hitting a record high above $147 in mid-July. The fall came as demand slumped in the US, the world's largest energy consumer, and other industrial countries hit by the credit crisis.
The Organisation of the Petroleum Exporting Countries is due to meet in Vienna on Friday. The producer group is expected to reduce output to defend prices and temper the effects of the financial crisis.
Iran has said a drop in demand could push OPEC to cut output by 2-2.5 million barrels per day, while other members have said a smaller cut may be needed.
OPEC could face an intense debate on how much oil members should take off global markets as they balance their price needs against risks to a fragile world economy.
The International Energy Agency, which advises industrialised countries, has said an OPEC output cut could prolong a global economic slowdown.
And US crude oil inventories probably rose 2.3 million barrels last week, a preliminary Reuters poll showed ahead of the US government energy data due tomorrow.
