Gasoline prompt cracks in northwest Europe slipped on Monday but remained at eight-month-highs supported by strong demand from the United States, where inventories are low and refinery maintenance has curbed supply. Stocks on the U.S. East Coast, a major export destination for European gasoline, fell more than expected last week while demand in West Africa and the Mediterranean is strong. Maintenance at Canadian refineries that normally supply the U.S. East Coast also helped tighten the market as summer, the peak season for gasoline demand in the United States, looms. "The Irving refinery restart has been supposedly delayed, and the Montreal and Quebec refineries are both down for work so the East Coast is really tight," an industry source said.