Oil prices gained Friday on speculation that OPEC plans to cut output, recovering somewhat from sharp losses earlier in the week over worries about weakening Chinese economic growth.
In New York, the main contract, WTI crude for delivery in May, added 28 cents from Thursday to end at $88.01 a barrel.
In London, Brent North Sea crude for delivery in June gained 52 cents to $99.65 a barrel, unable to hold onto a rebound above the $100 line earlier in the day.
"There are rumors that OPEC may call for an emergency meeting to discuss output if Brent prices stay below $100 a barrel," Ker Chung Yang, senior investment analyst at Phillip Futures in Singapore, told AFP.
"This is boosting oil prices in the near term."
According to news reports, Venezuela's top oil official said Thursday that OPEC officials were weighing holding a special meeting on the market if prices continue to fall.
Brent prices had hit multi-month lows this week after China said its economy grew just 7.7 percent in the January-March quarter, slower than expected and worse than during the previous three months.
Poor figures from the United States added to selling pressure for crude.
The Organization of Petroleum Exporting Countries (OPEC) earlier this month kept its global demand forecasts for 2012 and 2013 virtually unchanged, with China expected to contribute the most to growth while industrialized countries appeared to be headed for a decline.
Sanctions-hit Iran, OPEC's fourth largest producer, said on Wednesday that it considers the "logical" price of crude to be around $100-$120 a barrel.
Analysts said the $100 price for Brent is considered ideal by Saudi Arabia, the world's top oil exporter, and falling below it could prompt OPEC to cut back on output.