The average price for a gallon of regular gasoline in the United States fell nearly a dime over the past three weeks, following a drop in crude oil prices and as refineries increased output, according to a widely followed survey released on Sunday.

Gasoline prices averaged $3.3766 per gallon on Dec. 7, down 9.62 cents from Nov. 16, according to Trilby Lundberg, editor of the Lundberg Survey.

This marks the ninth week of straight declines, totaling 46.06 cents per gallon since prices hit $3.84 on Oct. 5.

"Softer crude oil prices were the essential enabler," Lundberg said. "Refinery glitches were reduced and resolved one after the other, enhancing supply," she said, adding that seasonally weak demand also contributed.

Hurricane Sandy also had an effect on demand, she said.