Oil prices have been in retreat from levels above $100 a barrel

Oil prices finished a bit lower Monday ahead of an OPEC meeting expected to maintain policies that have kept prices down.

US benchmark West Texas Intermediate for January delivery ended down six cents at $41.65 a barrel on the New York Mercantile Exchange.

Brent North Sea crude for January delivery shed 25 cents to $44.61 a barrel.

Friday's meeting of the Organization of the Petroleum Exporting Countries, though eagerly anticipated, is generally expected to maintain the cartel's policy of keeping production elevated in order to press high-cost producers out of the market.

Daniel Holder, analyst at Schneider Electric, described OPEC's "overproduction stance" as "firm" heading into the gathering.

"An OPEC production cut might be welcome or even needed, but it's also unlikely," said Tim Evans, analyst at Citi Future.

"A split decision, with Saudi Arabia and its closest allies still insisting on battling for market share, remains the base case scenario, with an ongoing surplus as the result."

Oil prices have been in retreat from levels above $100 a barrel since July 2014, with the decline accelerating after OPEC's November 2014 meeting signaled the group would keep output high.

While analysts do not expect OPEC to alter course, some said there is an outside chance of a surprise that could lift prices.