New York’s main contract, light sweet crude for August delivery, shed 53 cents to $92.13 a barrel and Brent North Sea crude for delivery in September slid 38 cents to $107.42.
Crude prices were winding down after soaring for most of the week, said Justin Harper, market strategist for IG Markets Singapore.
“They’ve come down a little bit because of the inevitable profit taking,” he told Agence France-Presse.
“They have seen some solid gains in the last few days… so there will be a little bit of profit taking at the end of this week,” Harper added.
Crude had rallied for most of the week, first on assurances by the US Federal Reserve that they would intervene should the economy falter, and then on increasing tensions in Syria and Iran.
In overnight trade, crude had surged more than $2.50 as fighting raged in Damascus and China and Russia vetoed UN resolutions on the conflict.
Meanwhile, Israel accused Iran and Lebanese group Hezbollah of carrying out a suicide bomb attack that killed six Israeli tourists in Bulgaria.