Gasoline prices may rise above $4 a gallon next summer as refineries along the U.S. East Coast close, reducing fuel supply, Edward Morse, head of commodities research at Citigroup Global Markets Inc., New York, told Bloomberg. Sunoco Inc. and ConocoPhillips have idled two plants and plan to shut a third that together can process more than 700,000 barrels a day of oil, or about 46% of the region's refining capacity.