UPDATE 1-Japan Energy to curb Q4 crude runs on weak demand

* Crude refining volume to fall 11 pct yr/yr in Oct-Dec

* Q3 crude runs down 9 pct, in line with initial plan (Adds details)

TOKYO, Sept 25 (Reuters) - Japan Energy Corp, the nation's sixth-biggest oil refiner, said on Friday it plans to cut its crude oil processing volumes for October-December by 11 percent from the same period a year earlier due to slow domestic demand.

Japan Energy, the refining unit of Nippon Mining Holdings Inc 5016.T, plans to refine 5.56 million kilolitres (380,000 barrels per day) of crude oil including condensate in the fourth quarter, a company spokesman said.

Excluding condensate, the company's crude refining will fall 13 percent from a year earlier to 4.86 million kl in October-December, the spokesman added.

"We anticipate sluggish demand will continue," the spokesman said.

For the July-September period, Japan Energy estimated its crude refining volume at 5.31 million kl, including condensate, down 9 percent from a year earlier and unchanged from its initial plan.

Excluding condensate, crude refining volumes for July-September are estimated to have fallen 10 percent from a year earlier to 4.71 million kl, unchanged from its initial plan, the spokesman said.

Japan Energy has the capacity to refine 475,200 barrels of crude oil and condensate per day.

The crude refining plan does not include volumes to be processed at a new 35,000 barrel-per-day condensate splitter at the company's 205,200 bpd Mizushima refinery in western Japan, which began trial operations in August.

The splitter is owned by Research Association of Refinery Integration for Group-Operation (RING), a consortium of refiners and chemical firms.

Products from the new splitter are being supplied to Japan Energy and its Mizushima industrial complex partners as part of the project to enhance competitiveness through cooperation. (Reporting by Osamu Tsukimori; Editing by Hugh Lawson)