By Liam Moloney Of DOW JONES NEWSWIRES ROME -(Dow Jones)- Italian oil major Eni SpA (E) Friday said it expects 2012 to be challenging due to the continuing economic slowdown in the euro zone as first-quarter net profit was lifted by higher prices and as output recovers in Libya. International oil prices will be supported by "robust" demand growth from China and other emerging economies as well as ongoing geopolitical risks, it said. Net profit for the three months to March 31 increased to EUR3.62 billion from EUR2.55 billion a year earlier on a 16% increase in net sales from operations to EUR33.48 billion. Adjusted net profit--closely watched by analysts because it excludes the value of oil inventories--rose 13% to EUR2.48 billion from EUR2.20 billion a year earlier, ahead of an average forecast of EUR2.26 billion. Eni's hydrocarbon output for the period averaged an expected 1.674 million barrels of oil equivalent a day, compared with the 1.684 million in the first quarter 2011 with the 0.6% slip due to lower production entitlements reflecting higher oil prices. As fields of "easy oil" around the world start to dry up, Western oil majors are turning to untapped markets that have been off limits. Wednesday, Eni --apeing Exxon Mobil Corp. (XOM) only a few days beforte--signed a major offshore exploration deal in the Russian waters of the Barents and Black Seas with state oil company OAO Rosneft (ROSN.RS). Eni shares closed Thursday at EUR16.56, giving it a market value of EUR66.33 billion--making it Italy's biggest company. -By Liam Moloney, Dow Jones Newswires; +39 06 6976 6924; liam.moloney@dowjones.com