Russia's Dec western port oil loadings may slip by 100,000 bpd, sources say

MOSCOW, Nov 22 (Reuters) - Oil loadings from Russia's western ports in December are expected to slip by some 100,000 barrels per day (bpd) to 1.8 million bpd amid rising refinery runs, according to three market sources and Reuters calculations.

Crude output is expected to stay flat after OPEC+ countries decided to extend oil cuts.

"Oil loadings from western ports in December may fall by some 500,000 (metric) tons from November," a source with a trader said.

Urals, Siberian Light and KEBCO crude oil loadings from the ports of Primorsk, Ust-Luga and Novorossiisk may fall by some 5% on a daily basis, Reuters calculations showed.

"Provisional lifting plans will likely emerge early next week, while our estimates show the schedule for December will be slightly shorter than in November. Novorossiisk oil loadings may stay in line with November, while loadings from Baltic ports will fall," another source said.

December is one day longer than November.

Members of the group of OPEC+ oil-producing nations were due to raise output in December as part of a plan to gradually unwind their most recent layer of output curbs, but agreed to delay the move amid weak demand notably from China and rising supply from outside the group.

Russia plans to take 680,000 tons of refining capacity offline in November, down from 2.42 million tons in a revised plan for November, reducing the amount of crude oil available for export, according to Reuters calculations based on data from industry sources.

An expected rise in output at the Ilsky oil plant and the end of maintenance work at Rosneft's refineries will add to higher domestic crude intake in December, but lower idle refining capacity will not result in a proportional drop in export volumes, treader say.

"I don't see a linear correlation. Oil refining in December will go up, but not as high as the refining capacity that returns online. Margins at some complex refineries are not very good, so the plants are not working at full capacity," one of the sources noted.

(Reporting by Reuters; editing by Jason Neely)