Oil refiner Idemitsu Kosan Co. said Monday it plans to process less crude oil from July to September because of weak domestic demand for fuel.

The company will process 6.2 million kiloliters of crude oil, 4 percent less than the same period a year earlier, it said.

Due to a drop in demand, Idemitsu also said it will shut the 160,000 barrel-a-day Aichi refinery for a month from late October and the 120,000 barrel-a-day Tokuyama refinery for a month from late September.

Japanese refiners cut operating rates by 4.6 percent in 2009 from a year earlier as oil-product sales volumes declined 6.9 percent.