By Daniel Huang 

Oil futures slipped Thursday despite government storage data indicating shrinking supplies and geopolitical crises in Eastern Europe and the Middle East.

Light, sweet crude for September delivery edged down 52 cents, or 0.5%, at $102.60 a barrel on the New York Mercantile Exchange. Brent crude on the ICE Futures Europe exchange fell 67 cents, or 0.6%, to $107.36 a barrel.

U.S. crude-oil stockpiles dropped by almost 4 million barrels last week, the U.S. Energy Information Administration said Wednesday. The slide included a 1.5 million decline in supplies at Cushing, Okla., the delivery point for Nymex crude futures.

Refinery demand has peaked for the summer and the market is already starting to look ahead to the fall, when demand for crude oil is going to drop significantly, said Stephen Schork, editor of the Schork Report in Pennsylvania.

On the global front, European Union leaders met Thursday to consider stricter sanctions against Russia as investigations continue into whether pro-Russia separatists in eastern Ukraine were responsible for last week's Malaysia Airlines plane crash that killed nearly 300 people. But traders appear to be waiting for new developments before placing their bets, analysts said.

"The oil market clearly does not expect the [European Union] to impose sanctions against the Russian energy sector, meaning that the market's response would be all the more dramatic if this turned out to be the case after all," said analysts at Commerzbank in a note to clients.

In the Middle East, Israeli tanks and warplanes bombarded the Gaza Strip. Fighting between Israel and Hamas showed no letup amid U.S. efforts to broker a cease-fire.

"The markets are getting smarter and asking, 'Is this going to actually affect the oil supply or not?'" said Sal Gilbertie, founder of Teucrium Trading in Vermont.

"Everything comes back to supply and demand," Mr. Gilbertie said. "When you don't get a fresh headline, prices will drift back a little bit."

Front-month August reformulated gasoline blendstock, or RBOB, fell 2.4 cents, or 0.8%, to $2.8361 a gallon.

August diesel fell 0.52 cent, or 0.2%, to $2.8702 a gallon.

Cassie Werber contributed to this article.

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