U.S. automaker giant General Motors Corporation (GM) said Thursday that its first-quarter profit declined by 85.5 percent year on year, due to a massive recall of vehicles with potentially defective ignition switches that have been linked to 13 deaths. In a statement on its website, the Detroit-based company reported a net revenue of 37.4 billion U.S. dollars in the first quarter of 2014, slightly up from 36.9 billion dollars of the same period last year. However, net income came in at 125 million dollars, or 6 cents a share, down from 865 million dollars, or 58 cents a share, in the year-earlier period. The figure still topped Wall Street estimates of 4 cents per share. The automaker has been embroiled in a series of investigations and lawsuits since February. Recalls involving up to 7 million vehicles worldwide this year have incurred a 1.3-billion-dollar charge, which market analysts said has sunk GM's earnings in the first quarter. But GM CEO Mary Barra said the recalls did not impact sales. " The performance of our core operations was very strong this quarter, reflecting the positive response of customers to the new vehicles we are bringing to market," she said. GM and its partners produce vehicles in 30 countries, enjoying leadership positions in the world's largest and fastest-growing automotive markets.