Brent crude oil futures declined 25 cents, to fell below 86 dollars at 85.88 dollars a barrel, on Monday, after Goldman Sachs slashed its price forecasts, citing abundant supply and lacklustre demand despite a pick-up in global economic growth. But the US crude oil future was up 2 cents, at 81.03 dollars a barrel.The US investment bank said in a research note that it had cut its forecast for Brent to 85 dollars a barrel from 100 dollars for the first quarter of 2015 and reduced its projection for US crude to 75 dollars from 90 dollars a barrel. The bank said Brent could fall to 80 dollars a barrel in the second quarter of 2015, and US crude dipping to 70 dollarsThe 12-member Organization of the Petroleum Exporting Countries meets on November 27 to consider adjusting its output target of 30 million barrels per day for the first half of 2015. So far only a minority of members have called for an output cut.Saudi Arabia has previously sent signals it is comfortable with lower oil prices and willing to maintain high supply levels to compete for market share.Global oil supply remains high despite disruption in producers such as Iraq and Libya.