ByJohn S. McClenahen Higher prices for imported petroleum were the major factor in January's 1.5% rise in the Labor Department's Import Price Index. The increase followed a 0.6% rise in December and was the largest increase since a 1.6% advance in the index last April. Prices for imported petroleum rose 12.4% in January and now are at their highest level since November 2000, says the Labor Department. January's 0.2% price index rise for nonpetroleum imports was led by a 1.4% increase in nonpetroleum industrial supplies and materials, an increase that stems mainly from rising natural gas prices. In contrast, led by computers, computer peripherals, and semiconductors, prices for capital goods imports fell 0.1% in January, its fifth consecutive decline. On the other side of the ledger, the Export Price Index increased 0.4% in January, its largest increase since April 2002. Price increases for both agricultural and nonagricultural exports figured in the overall increase. Prices for agricultural exports rose 0.3% Simultaneously, price increases for nonagricultural industrial supplies and materials led a 0.4% rise in nonagricultural export prices last month. Primarily responsible were higher prices for petroleum and petroleum-based products, but also contributing was a 0.3% rise in prices for U.S. capital goods exports, the first increase since April 2002.