TOKYO - Japan's Nippon Oil Corp plans to refine 1 percent less crude oil in December than a year ago, the same rate of annual decline as in November, as it maintains a pessimistic view of demand even with winter approaching.

Although Japan has emerged from its worst recession in decades, domestic demand for oil products has not returned to levels seen before the global financial crisis, forcing refiners to curb production.

Japan's biggest refiner plans to process 5.33 million kilolitres or 1.08 million barrels per day of crude oil in December, Masahito Nakamura, a Nippon Oil senior vice president, told reporters on Monday.

Nippon Oil's November crude refining volume was estimated at 4.82 million kl, down 1 percent from a year earlier, he said. That would be unchanged from its original plan.

Japan has seen a big drop in oil sales this year as the global recession accelerated already declining demand in a greying population where there is also a push towards greener energy, leading refiners to cut output.

Last week, Japan's No.3 refiner, Idemitsu Kosan Co, said it planned to refine 2 percent less crude oil in December than a year earlier due to sluggish demand for refined products.

Nippon Oil, which will merge with Nippon Mining Holdings Inc by April, has a crude refining capacity of 1.317 million barrels per day, more than a quarter of Japan's total crude refining capacity.

The two firms said late last month that their merged JX Group would bring forward a year plans to cut oil refining capacity by 400,000 barrels per day (bpd) in response to sliding domestic demand. (Reporting by Osamu Tsukimori and James Topham)