March 23 (Reuters) - The average price for a gallon of gasoline in the United States rose nearly 5 cents over the past two weeks, driven mainly by a jump in the price of ethanol, according to a survey.
The price rose 4.74 cents to an average retail price of $3.5572 per gallon of regular grade gasoline, according to the Lundberg survey, which was released on Sunday and conducted on March 21.
Gas prices have been rising since Feb. 7, after falling late last year and the start of 2014, according to Trilby Lundberg, publisher of the survey.
"The increase has really lost steam," Lundberg said. "We may well see a few more pennies at the pump from here, but probably not much."
The essential cause for the latest increase is a sharp rise in the price of ethanol, which is blended into gasoline, Lundberg said. A secondary cause is that the refining industry is in the process of switching to a summer blend of gasoline,
which costs more to make, she said.
The price of gas is about 15 cents per gallon lower than a year ago.
Of the areas surveyed, Billings, Montana had the lowest price, at $3.18 per gallon. Los Angeles ranked highest at $4.00 per gallon. (Reporting by Lewis Krauskopf; Editing by Bernard Orr)