Oil prices declined on concerns over the possible Greek exit from the Eurozone. The Eurogroup's meeting ended without results today. According to multiple sources, Athens did not present new proposals. Reuters reported that Greece will present new proposals maybe tomorrow.

The summit of the Eurozone leaders is scheduled to be later in the day.

Market participants are awaiting the release of U.S. crude oil inventories data. The American Petroleum Institute (API) is scheduled to release its U.S. oil inventories data later in the day, and U.S. oil inventories data from the U.S. Energy Information Administration is expected on Wednesday.

Traders expect the results of talks on the Iranian nuclear program. Talks will continue until July 10. A deal could lead to a higher oil supply.

WTI crude oil for August delivery decreased to $50.58 a barrel on the New York Mercantile Exchange.

Brent crude oil for August fell to $56.35 a barrel on ICE Futures Europe.