Brent crude futures fell 46 cents, or 0.6%, to $76.23 a barrel by 2:15 p.m. EDT (1815 GMT), while the U.S. West Texas Intermediate crude futures slid by 57 cents, or 0.8%, to $70.33 a barrel.
Oil benchmarks were slightly higher before the news on hopes that a lower dollar and higher gasoline prices would spur more demand for the commodity.
A weaker greenback makes dollar-denominated oil more attractive to holders of foreign currencies, lifting demand.
Higher gasoline demand will encourage refiners to use more crude oil to turn it into the road transportation fuel, Mizuho analyst Robert Yawger said.
Also supportive, Goldman Sachs on Thursday said demand from China, the world's biggest oil importer, continued to surge across the commodity complex, with oil demand topping 16 million barrels per day.