Opec is widely expected to cut production when it meets on Friday
Oil prices have recovered from 16-month lows on growing expectations that oil producers' cartel Opec will cut output.
US light crude added $1.63 to reach $68.38 a barrel, after falling as low as $66.73 a barrel - its lowest point since June 2007.
Members of Opec are meeting in Vienna ahead of emergency talks, which are set to start on Friday.
Oil prices have fallen sharply recently on expectations that a global economic slowdown will cut demand.
On Wednesday, official US data showed that US crude stocks had risen by 3.2 million barrels in the week to 17 October, which was higher than expected and indicated that consumers were reducing their consumption of energy.
Despite Opec's expected reduction in production, oil analysts said crude prices could fall as low as $60 a barrel, as signs that the world is heading for a recession continue to grow.
The oil cartel is reluctant to let the price drop below $70 a barrel.
Opec delegates have said that output needs to be reduced by at least a million barrels per day.
Opec president Chakib Khelil said: "The decision should not leave the producer countries in the situation where they will be joining the group of countries which are already suffering from the financial crisis."
Opec's meeting has been brought forward by three weeks, reflecting the 12-nation group's concern at falling prices.
Oil hit an all-time high of $147 a barrel back in July, but has since fallen back steadily.
Opec members include Saudi Arabia, Iran, Iraq and Venezuela.