Shares in Italian aerospace and defence giant Finmeccanica plummeted nearly 14 percent on the Milan stock exchange on Thursday, a day after the company issued a warning on its earnings. Finmeccanica on Wednesday revised down its forecast for turnover this year to 17.5-18 billion euros ($25-26 billion) from a previous forecast of 18.3 billion to 19 billion euros and said it would make no prediction on revenues. The warning comes after a difficult first half for the industrial giant. Net profit went up 135 percent to 456 million euros compared to the same period last year, mainly thanks to the sale of 45 percent of Ansaldo Energia. But the company\'s turnover was down 3.0 percent to 8.432 billion euros and its gross revenues fell 25 percent to 440 million euros. Without the value of the Ansaldo sale, net profit would have plunged 93 percent to 13 million euros compared to 194 million a year earlier. The economic stall in Europe and the instability in North Africa where Finmeccanica has many contracts have hit the firm. Finmeccanica also pointed to problems linked to technological advances in the aerospace and transport sectors.