Oil prices gained on Thursday, supported by a weakening U.S. dollar, continuing Middle East geopolitical tensions and hopes of progress in talks between Greece and its international creditors. U.S. July crude CLc1 gained 1 cent to $59.93 a barrel as of 0749 GMT(3.49a.m. ET) after falling 5 cents in the previous session. Brent August crude LCOc1 gained 35 cents to $64.22 a barrel after it settled 17 cents higher on Wednesday at $63.87.