ByJohn S. McClenahen In a reversal of their pattern in recent months, prices for both U.S. imports and exports decreased in April. U.S. Labor Department data show the Import Price Index declined 2.7% last month, its first fall since November 2002, and the Export Price Index edged down 0.1% after three consecutive monthly increases. The 2.7% decline in import prices in April was the largest one-month drop on record and was led by a 16.2% decline in prices for petroleum imports, which posted their largest monthly decrease since 1991. Meanwhile, the Labor Department says, falling prices for nonagricultural exports offset an increase in prices of agricultural exports. A 0.4% decline in prices of industrial supplies and materials, led by decreasing prices for export petroleum products and nonmonetary gold, helped drive down overall nonagricultural prices. Prices for consumer goods exports were down in April as well, falling 0.3%. In contrast, prices for U.S. capital goods exports rose 0.1% in April, their third increase in four months.