By John S. McClenahen Following three consecutive months of declines, the U.S. Import Price Index increased 0.3% in May as prices for petroleum imports rose. The U.S. Export Price Index, also compiled by the U.S. Labor Dept.'s Bureau of Labor Statistics, fell 0.3% in May, its fourth consecutive decline. On the import side, a 5.5% increase in petroleum prices came after a 1.7% decline in April and 6.5% decline in March. Meanwhile, the major non-petroleum import price indexes fell or were unchanged for the second consecutive month. For example, driven by falling prices for unfinished metals and chemicals, the price index for industrial supplies and materials -- excluding petroleum -- fell 0.7% in May, its fourth consecutive decline. On the export side, prices for non-agricultural goods were down 0.3% in May, the third consecutive month they've declined. All of the major non-agricultural export price indexes either declined or posted no change in May. Export prices for non-agricultural industrial supplies and materials, for example, fell 0.8%, their fourth consecutive monthly decline. And export prices for consumer goods fell 0.1%, their fourth consecutive monthly fall also.