West Texas Intermediate futures for August delivery started this session with a decline, but later on it managed to advance slightly to $59.74 (+0.07%). Meanwhile Brent crude for August advanced to $63.46 (+0.41%) a barrel. Market participants are waiting for results of Greece's negotiations with its partners and talks between Iran and six world powers. Both issues have a deadline on June 30.

Meanwhile U.S. crude was supported by a 0.9% surge in consumer spending in May (the best result in six years) and weighed by recent data, which showed a build-up in U.S. gasoline stockpiles.