Oil prices slid Friday on concerns about global oversupply as traders looked ahead to next week's OPEC meeting, skeptical the oil producers cartel will lower high output levels.
US benchmark West Texas Intermediate for delivery in January slid $1.27 to $41.71 a barrel in a shortened post-Thanksgiving holiday trading session on the New York Mercantile Exchange.
Brent North Sea crude for January, the international benchmark for oil, was down 58 cents at $44.88 a barrel in late trade in London.
Energy economist James Williams, of WTRG Economics, said the market was paring down some of the surge in prices resulting from Turkey's shoot down Tuesday of a Russian warplane on the Syrian border.
"Prices reacted up for a day or two, and we've just reversed this reaction, as there's fundamentally no oil involved," Williams said.
With global crude supplies outpacing demand, traders were focused on next Friday's OPEC meeting.
Price falls that began in mid-2014 accelerated after the Organization of the Petroleum Exporting Countries decided in November 2014 to maintain output levels despite the weaker prices.
"The market is certainly looking ahead to next week's OPEC meeting and sensing not only there's going to be no change in OPEC oil production but also Iran will be rejoining to the market in January with substantial quantities of oil," said Andy Lipow of Lipow Oil Associates.
The 12-nation OPEC, which counts the world's biggest oil producer Saudi Arabia among its members as well as Nigeria, Venezuela and Iran, has scheduled a regular meeting in Vienna on December 4.