U.S. crude oil stocks are at their lowest level since October 1975, but government and industry officials say that if war in Iraq should disrupt the supply, the United States and other industrial countries are ready to draw on government reserves.

While inventories are low, "it doesn't necessarily mean there will be shortages. . . . Refineries are still running," said Ron Planting, an economist for the American Petroleum Institute, the trade group of the major oil companies.

Stocks of heating oil and gasoline are low, the government said. Demand for both has been higher than expected.

The Energy Department said yesterday that crude stocks fell by 4.5 million barrels last week to 269.8 million barrels, just below the minimum to assure efficient refinery operation. That is the lowest level since October 1975, when refiners used about 20 percent less oil than today. Gasoline inventories rose by an equivalent of 3 million barrels.

President Bush has resisted calls to draw on some of the 600 million barrels of oil in the government's emergency Strategic Petroleum Reserve.

Energy Secretary Spencer Abraham said his department maintains that the reserves should be used, he said, only if there are "severe supply issues and disruptions" related to national security.

War worries have caused crude prices to soar and the low inventories have added to the tight oil markets. The price of light, sweet crude rose to $35.95 a barrel on the New York Mercantile Exchange yesterday before settling at $35.77.

Some analysts said the supply crunch may ease soon.

World oil output increased by nearly 1.2 million barrels a day in January, according to the International Energy Agency. Saudi Arabia and other members of the Organization of Petroleum Exporting Countries agreed to increase production to help make up for the lack of Venezuelan oil even as Venezuela's output began to rebound.

"There's some crude oil from the Middle East arriving soon that could help build up stocks," said John Lichtblau, chairman of the New York-based Petroleum Industry Research Foundation. It takes about 40 days for Middle East oil to reach the United States.

While Venezuela's production, stymied by months of political strife, increased in late January, its exports remained sporadic and well below levels before the country's recent troubles.