Oil prices decline after the release of U.S. crude oil inventories data. The U.S. Energy Information Administration (EIA) released its crude oil inventories data on Wednesday. U.S. crude inventories increased by 2.4 million barrels to 465.4 million in the week to June 26.

Gasoline inventories declined by 1.8 million barrels to 216.7 million barrels last week, according to the EIA.

Crude stocks at the Cushing, Oklahoma, increased by 123,000 barrels to 56.4 million barrels.

U.S. crude oil imports rose by 748,000 barrels per day.

Refineries in the U.S. were running at 95.0% of capacity, up from 94.0% the previous week.

The Greek debt crisis also weighed on oil prices. The International Monetary Fund (IMF) confirmed that Greece has not repaid €1.538 billion IMF loans. A Greek default would be the first by an advanced economy in the IMF's seven-decade history, putting the country on a par with countries such as Afghanistan, Haiti and Zimbabwe, which also not paid IMF loans on time.

News that OPEC increased oil production in June also weighed on oil prices. According to a Reuters survey, OPEC supply rose in June to 31.60 million barrels per day from a revised 31.30 million barrels per day in May.

Traders expect the results of talks on the Iranian nuclear program. Talks will continue until July 07.

WTI crude oil for August delivery decreased to $57.98 a barrel on the New York Mercantile Exchange.

Brent crude oil for August declined to $62.61 a barrel on ICE Futures Europe.