By early afternoon in Europe, benchmark oil for July delivery was up 41 cents to $91.07 a barrel in electronic trading on the New York Mercantile Exchange. The contract rose 76 cents to settle at $90.66 in New York on Thursday.
In London, Brent crude for July delivery was up 46 cents at $107.01 per barrel on the ICE Futures exchange.
Crude has sunk about 15 percent from $106 three weeks ago amid dimming global growth prospects and signs of an impending agreement between Iran and the six world powers.
On Thursday, however, Iran and six world powers ended talks without making any progress toward a deal, agreeing to continue meetings next month in Moscow. Crude rose to above $110 earlier this year the US and Israeli war rhetoric against Iran made traders feel worried about disruption in global crude supplies.
"Ahead of the talks there had been hopes of a breakthrough," said analysts at Commerzbank in Frankfurt. "Now that these hopes have not been fulfilled, part of the risk premium may return, which would argue against any further fall in the price of oil."
In other energy trading, heating oil was up 1.03 cents at $2.8360 per gallon and gasoline futures added 0.92 cent at $2.8285 per gallon. Natural gas fell 3.2 cents at $2.615 per 1,000 cubic feet.