World oil prices advanced for the fifth consecutive day, rising to unprecedented highs, above 66 usd a barrel, on strong global demand and continued refinery production problems in the US, dealers said New York's main contract, light sweet crude for delivery in September, climbed 14 cents to 65.94 usd per barrel in electronic trade LSW reached a record 66.11 usd overnight -- the highest level since it was first traded in 1983 The price of Brent North Sea crude oil for delivery in September gained 4 cents to 65.42 usd per barrel after earlier reaching 65.85 usd, also a fresh high In addition to strong energy demand, prices were also supported by massive speculative buying, refinery outages in the United States and raised tensions in the Middle East