Oil price rose as the Chinese stock index Shanghai Composite rebounded due to measures taken by the Chinese government.

Stalled talks on the Iranian nuclear program also supported oil prices. Talks will continue until July 10. A deal could lead to a higher oil supply.

The Greek debt crisis remains in focus. Greek Prime Minister Alexis Tsipras promised on Wednesday that Athens will provide credible reform proposals on Thursday.

An emergency summit of all 28 European Union members is scheduled to take place on Sunday.

WTI crude oil for August delivery increased to $53.54 a barrel on the New York Mercantile Exchange.

Brent crude oil for August rose to $57.56 a barrel on ICE Futures Europe.