WASHINGTON, April 23 (Reuters) - U.S. gasoline prices dropped for a third straight week and marked the first year-on-year decline since October 2009, the Energy Department said on Mo nday.
The national average price for U.S. regular gasoline fell to $3.87 a gallon in the week ended Monday, down more than 5 cents from the previous week, the Energy Information Administration said in its weekly survey of service stations.
Surging fuel prices have become a hot button on the campaign trail this election year, as Republicans sought to place blame on the White House.
But a drop in the cost of oil has stymied gasoline's climb toward $4 a gallon ahead of the summer driving season.
Gasoline fell nearly a penny from a year earlier. Prices have gone up and down on weekly terms since 2009, but the past week saw the first year-on-year decline over that period.
Sunoco said on Monday it would delay shuttering the largest refinery on the U.S. East Coast, easing fears of a fuel shortage in that region this summer. Sunoco is in talks with private equity firm Carlyle Group LP on a potential joint venture to run the plant.
The East Coast has been threatened with the loss of three refineries due to poor margins, raising concerns about a potential shortfall and helping to drive up prices.
Additional relief could come from a potential deal for Delta Air Lines to buy ConocoPhillips' refinery in Trainer, Pennsylvania.