LONDON - OIL prices slumped further on Thursday, with Brent crude sliding below US$68(S$100) a barrel to the lowest level for more than 15 months, as slowing energy demand took its toll, traders said.

Crude oil futures were down more than 50 per cent from record highs of above US$147 reached in July, when prices rocketed on fears of supply disruptions.

In early London trade, Brent North Sea crude for delivery in November slumped to US$67.17 a barrel - the lowest point since mid-2007.

It later recovered to US$68.17 by about 0830 GMT (4.30pm Singapore time), down US$2.63 from Wednesday's close.

The contract had ended down US$3.73 on Wednesday as mounting fears of a global recession raised expectations of a prolonged slowdown to global energy demand.

In Thursday trade, New York's main futures contract, light sweet crude for November delivery, was down US$2.06 at US$72.48 a barrel after sinking as low as US$71.21.

The Organisation of the Petroleum Exporting Countries (Opec) on Wednesday cut its estimate for growth in demand for oil this year and in 2009 largely because of an 'excessive' easing of demand in the United States.

For 2008, the cartel cut its estimate for growth in demand to 550,000 barrels per day, giving average total demand of about 86.5 million bpd.

The cartel was to hold a special meeting on November 18 to discuss the global financial crisis and its impact on the oil market.

Several Opec members have called for the meeting to cut crude output to shore up oil prices. -- AFP