Oil prices fell slightly as attention switched to the OPEC oil producers' cartel which holds its latest output meeting this week.
Brent North Sea crude for delivery in November fell $0.38 to $83.65 a barrel in afternoon London trade.
US crude for November slipped $0.22 to $82.44 a barrel.
Oil prices have ranged $70-$80 for the past year - a level deemed reasonable by most OPEC members still faced with an uncertain demand outlook as countries struggle to recover from the global downturn.
The Organization of the Petroleum Exporting Countries (OPEC), which produces 40% of the world's oil, has had an official production level of 24.84m barrels a day since January 2009.
But member nations are failing to stick by the agreed cuts and OPEC in fact pumped out 26.83m barrels a day in August, according to data from the International Energy Agency, a body representing oil consumer nations.
