Oil price fell on concerns over the global oil glut as a deal on Iran's nuclear programmes could be reached soon. The deal could lead to a higher oil supply.
News that Saudi Arabia increase its crude oil production also weighed on oil prices. OPEC said on Monday that oil production in Saudi Arabia rose to 10.56 million barrels per day in June, up 231,000 barrels per day from May.
OPEC also said on Monday that it expects its own crude oil demand to climb by 860,000 barrels per day in 2016 to 30.07 million barrels per day. The forecast for this year was cut by 100,000 barrels per day to 29.21 million barrels per day.
OPEC's crude oil output rose by 283,000 barrels per day to 31.38 million barrels per day in June, led by Iraq, Saudi Arabia and Nigeria.
A deal between Greece and its lenders supported oil prices. "EuroSummit has unanimously reached agreement. All ready to go for ESM programme for Greece with serious reforms and financial support," European Council President Donald Tusk said on Monday.
The deal needs to be approved by national parliaments before talks about a bailout programme can start.
The Greek government should have to pass a series of reforms, including tax and pensions reforms, into law by Wednesday to restore trust.
WTI crude oil for August delivery decreased to $52.34 a barrel on the New York Mercantile Exchange.
Brent crude oil for August fell to $58.37 a barrel on ICE Futures Europe.