US oil giant Exxon Mobil reported Thursday that its third-quarter profit fell 10 per cent as stagnating petrol prices bit into profit margins, according to dpa. The Houston, Texas-based company said it earned 9.4 billion dollars in the third quarter, a drop of 10 per cent from the same 2006 period. The drop came despite a rise in sales revenues, to 102.3 billion dollars, compared with 99.6 billion dollars in the year-earlier period. Exxon Mobil said that prices at the petrol pumps had shown no further rises despite rising oil costs, in turn cutting into profit margins.