World oil prices firmed on Thursday, after recent sharp falls, as traders absorbed positive economic data and the weak dollar, and shrugged off Federal Reserve chief Ben Bernanke's gloomy outlook.
New York's main contract, light sweet crude for delivery in September, gained 44 cents to $77 per barrel.
Brent North Sea crude for September added 31 cents to $75.68 in early afternoon deals.
"Crude oil prices rebounded and traded around $77 area, supported by a weakening U.S. dollar and a quick recovery in the equity markets after better-than-expected economic data from the eurozone and UK," said Sucden Analyst Myrto Sokou.
On Thursday, a leading indicator of economic activity, the purchasing managers' index for the 16-nation eurozone, accelerated for the first time in three months in July.
The latest purchasing managers' index (PMI) compiled by data and research group Markit rose to 56.7 points, from 56.0 in June. Any score above the 50-point line indicates economic growth.
Traders will focus later on major company results, weekly jobless claims data and existing homes sales in the United States.
"It is a busy and quite interesting day for economic figures and corporate earnings results, with focus on Microsoft and American Express earnings," added Sokou.
"It seems that investors' sentiment has slightly improved after stronger-than-expected eurozone economic data, while the current weakening U.S. dollar provides further support to the market.
"However, investors might remain cautious and wait for clarification from the eurozone's banks stress tests tomorrow that could give some direction to the energy market."
The weak U.S. unit makes dollar-priced oil cheaper for buyers using