Сrude oil fell after supplies rose at Cushing, Oklahoma, the contract's delivery point. Brent slipped to a one-month low amid signs Libyan oil exports will gain.

Cushing stockpiles rose by 447,000 barrels to 20.9 million last week, Energy Information Administration data showed. Total inventories dropped 2.37 million barrels to 382.6 million.

Libya plans to gradually boost exports to avoid disrupting the market, said Samir Kamal, the nation's governor to the Organization of Petroleum Exporting Countries.

WTI for August delivery dropped to $102.47 a barrel (-1.4%) on the New York Mercantile Exchange.

Brent for August settlement fell to $108.49 a barrel (-0.35%) on the London-based ICE Futures Europe exchange.

Gold rose as increasing tension in the Middle East boosted the appeal of the metal as a haven. Israel began a military offensive in the Gaza Strip this week by declaring its purpose was to halt Palestinian rocket attacks. The escalation in violence between Israel and Gaza-based militants is the worst since November 2012.

Gold futures for August delivery gained to $1323.90 an ounce (+0.61%).