The nation's oil distributors are now working to increase domestic oil stocks in light of global uncertainty following the recent terrorist attacks in the United States, industry sources said Monday.

While they are not worried about instability in supplies of crude, the oil market may be adversely affected amid uncertainties over when the U.S. will start retaliatory military attacks and how large they will be, the sources said.

Idemitsu Kosan Co. has decided to hold more oil stocks at the end of each month than previously planned. The stocks will be some 3 percent, or a two-day sales amount, larger than under the initial plan, they said.

It will have stocks for as many as 74 days of sales at the end of this month and 78 days of sales at the end of October and November, mainly by moving forward acceptance dates of crude oil.

Idemitsu has decided to change its policy of reducing stocks to cut operating costs.

Nippon Mitsubishi Oil Corp., the largest distributor in Japan, will restrict exports of oil products, such as gasoline and kerosene, the sources said.

Nippon Mitsubishi will export products this month that are already under contract, but will not conclude new export contracts for the time being so it can increase its stocks, they said.

Idemitsu will follow Nippon Mitsubishi's move.

Japan Energy Corp., meanwhile, will not move to increase its stocks, but its president has ordered staff to submit reports on daily oil price movements at home and abroad since the terrorist attacks Sept. 11.

The Japanese oil industry presently sees little possibility that supplies from the Middle East will be suspended, as it believes that the U.S. will attack only Afghanistan in retaliation, the sources said.