The price of gasoline in the Washington area has jumped about 10 cents a gallon in the past two weeks as the effects of nearly $40-a-barrel crude oil have begun hitting the marketplace.

The average local cash price of self-service unleaded gasoline rose nearly a dime a gallon, to $1.347, in the two weeks ended Oct. 5, according to the Lundberg Letter, a Los Angeles-based industry newsletter. Nationally, the price of self-service unleaded -- the cheapest, most popular type of gasoline -- has risen a little more than 6 cents a gallon, to $1.336, in the same period.

Experts say there are likely to be more increases here and around the country as oil companies accelerate their efforts to raise prices to catch up with higher crude costs.

Still, it is not entirely clear why the local increase is outpacing the national price rise, especially since gas prices in Washington have tended to trail the national average -- sometimes considerably so -- since Iraq invaded Kuwait Aug. 2, throwing the world oil market into turmoil.

The latest increase in the price of gas at the pump came after crude prices soared two weeks ago on fears that war was imminent between the United States and Iraq. The crude price briefly touched $40 a barrel before falling back early last week. Prices have since recovered, however; the price of a benchmark barrel of high-quality crude rose 96 cents yesterday to $38.95 on the New York Mercantile Exchange.

Analysts say rising crude prices are the driving force behind the increase in gasoline, and they note that while the price of crude is up about $20 a barrel, or 50 cents per gallon since Aug. 1, the retail price of gasoline has risen by about 25 cents a gallon in the same period. If fully passed through, each $1 rise in the price of a barrel of crude oil is worth about a 2.5 cent rise per gallon of gas. There are 42 gallons per barrel of petroleum.

Rising oil prices aren't the only thing that could push gasoline prices higher. The budget package being negotiated in Congress is likely to include higher gasoline taxes as well. The original budget compromise reached last week called for a 12-cent-a-gallon increase in federal taxes on gasoline by next July, but the most recent version of the package calls for an unspecified gas tax rise.

The rate of increase seems to have accelerated last week. In another survey, the American Automobile Association's Potomac branch said its survey showed the average cash price for a gallon of self-service unleaded in the Washington area rising 5.8 cents, to $1.337, in the week ended last Thursday. Nationally, AAA said, the price rose 3.6 cents last week, to $1.346 a gallon.

Last week's 5.8-cent increase in the local price was the largest one-week jump recorded by the American Automobile Association's Potomac branch since the early part of August, when prices shot up immediately after the Iraqi invasion. At some local stations, the credit-card price of full-service premium gasoline, the most expensive grade, is nearly $2 a gallon.

Despite the recent surge, oil companies say they have been slow to fully implement price increases because of market volatility and President Bush's call for price restraint, but experts say the gap is slowly narrowing.

Ted Eck, chief economist at Amoco Corp., the Chicago-based oil company, said many oil companies appear to have been holding prices down on the assumption that the price of crude will settle around the $30-a-barrel level, which would equal about a 25-cent-a-gallon increase since early August. But with crude prices staying high, that strategy is being rethought.

"Prices have been going up faster in October than they were in September, and I think the reason for that is that people are beginning to think that, hey, maybe prices are going to be closer to $40," Eck said. "If crude oil sticks in the $35 to $40 range, there's no question that gasoline prices have to go up, and will."

"What it looks like to me is that the gasoline price will keep aiming to reach ... the crude price, but of course the crude price is a moving target," said Tom Burns, an economist for Chevron Corp. in San Francisco. "Gasoline prices are still lagging tremendously the fundamental increase in crude prices that's occurred."

Trilby Lundberg, publisher of the Lundberg Letter, said some of the price increase is attributable to efforts by gasoline dealers to make up profit margins they gave up in trying to stay competitive when gasoline prices started to skyrocket in August. Contrary to allegations at the time of price-gouging, many service stations sold gasoline to their customers virtually at cost, and only recently have they restored their margins to about 11 cents a gallon -- still a few cents below pre-crisis levels.

Efforts to increase gas station margins may be a partial reason for the faster price increases in the Washington area, according to Rob Krebs, a spokesman for AAA-Potomac. As bargain-hunting motorists shift from high-priced premium grades -- on which dealers and oil companies make higher profit margins -- to cheaper grades, gas station owners are losing profits that they may be trying to make up by increasing unleaded regular prices, Krebs said. "They had a loss leader {in regular unleaded} and they had a premium gas that was a high-priced product for them, and people switched," Krebs said.

There has been some speculation that oil companies have deliberately limited price increases in the Washington area to avoid antagonizing Congress into putting controls or taxes on the industry. Krebs said it did not appear that gasoline sellers were taking advantage of local apathy or a shift in attention to the federal budget negotiations to raise prices to national levels, and Lundberg said it was probable that the lower local prices were a market fluke that was being made up.

"If you were trailing before, there's catch-up going on at all times," Lundberg said. "This is not a regulated market. ... The response behavior of markets is not predictable."