Growing demand for gasoline, coupled with tight supplies and expensive oil, is keeping pump prices climbing, according to a survey made public on Tuesday.

Pump prices would hit California the hardest, which had the most expensive gasoline among the states, said the survey.

The survey did not include Hawaii, where prices usually top those in most states.

California drivers paid an average of 3.5 cents more Monday for a gallon of self-serve regular gasoline compared with a week earlier, and the average U.S. price increased 3.9 cents a gallon.

That put the average cost of self-serve regular gasoline in California at 3.224 dollars a gallon, almost 70 cents above the year-earlier level, according to the government's weekly survey of about 800 U.S. filling stations.

Gasoline was cheapest in Gulf Coast states at 2.85 dollars a gallon, up 2.5 cents for the week.

The U.S. average reached 2.973 dollars a gallon, up nearly 65 cents from a year earlier. It was the highest U.S. average since Hurricane Katrina pushed gasoline to a record 3.069 dollars a gallon on Sept. 5.

Gasoline demand was robust during the week ending June 30 at more than 9.6 million barrels a day, the Energy Department said last week.

Gasoline inventories grew by 700,000 barrels to 213.1 million barrels, about a 22-day supply.

The record high demand of just over 9.7 million barrels a day may well be topped in July or August and oil price would hit 78- dollar a barrel before people saw anything below 70-dollar a barrel, analysts predicted.

Source: Xinhua