Oil prices rose slightly on Monday, to hold above $65 a barrel after rising late last week on fears of potential supply disruptions in the Middle East, Reuters reported. U.S. crude CLc1 ended Monday up 10 cents at $65.45 a barrel, after having jumped more than $2 a barrel on Friday. London Brent crude LCOc1 ended the trading day up 14 cents to $64.50. U.S. crude reached as high as $66.25 before following gasoline futures prices in a late-day swoon. Only a week remains in the U.S. summer driving season. Global production and refining constraints combined with political tensions in oil-producing countries have kept U.S. oil at an average $53.79 this year versus an average $41.47 in 2004. The rally has yet to slow economic growth dramatically. "Unless one or more of the factors underpinning oil prices eases, we can expect oil to trade above $50/bbl again in 2006," said the Centre for Global Energy Studies (CGES) in its monthly report. A series of production outages -- and the threat of more to come -- has overshadowed relatively comfortable crude stock levels in the United States, the world's biggest consumer. --more 2257 Local Time 1957 GMT