Retail gasoline prices hit a record nationwide average of $2.61 a gallon last week as the effects of high crude oil prices trickled down to the pump, the U.S. government said on Monday.

The national average pump price for regular unleaded gasoline rose 6.2 cents, according to a weekly survey of more than 800 service stations by the Energy Information Administration (search).

That's on top of an 18.2-cent increase the previous week, which was the biggest weekly jump since the agency started reporting weekly retail prices in August 1990.

Still, when adjusted for inflation, the most expensive U.S. pump price was $3.12 a gallon in March 1981. Gasoline prices are about 73 cents per gallon higher than one year ago, according to EIA records.

Crude oil prices, responsible for half of the cost of a gallon of gasoline, hit an all-time high of $67.10 a barrel earlier this month. U.S. crude oil futures for September delivery came within less than $1 of that record in Monday trading, driven by global supply concerns.

Gasoline prices are sure to be a hot topic when Congress returns from its recess next month. The Senate Energy Committee (search) has set a Sept. 8 hearing on what's behind the prices, and Democrats have urged the Bush administration to investigate.

U.S. consumers use about 9 million barrels of gasoline a day, which translates to about 380 million gallons. Each penny increase in gasoline prices means that U.S. consumers pay about $1.39 billion extra at the pump each year, according to Senate Energy Committee data.

The government's weekly retail report showed prices in the five U.S. regions rose between 4.2 cents and 10.6 cents a gallon.

The average U.S. pump price was highest on the West Coast, where costs rose 4.2 cents to $2.711 per gallon. The Rocky Mountain region had the cheapest gasoline, increasing 10.6 cents to $2.546 a gallon during the last week, EIA said.

Among the 10 major urban areas highlighted by EIA, Houston pump prices were the cheapest at $2.565 per gallon, up 10.7 cents. San Francisco and Chicago tied for the most expensive prices at $2.786.

U.S. truckers saw retail diesel prices rise 21 cents to an average $2.588 per gallon last week, EIA said. The average cost for a gallon of diesel is 71.4 cents per gallon higher than it was one year ago.