US oil giant ExxonMobil Thursday reported a 57 percent drop in earnings due to exceptional items and lower refinery margins, missing analyst expectations by a wide margin. Exxon, the largest US oil company, said second-quarter earnings came in at $6.9 billion on revenues of $106.5 billion, compared with year-ago profits of $15.9 billion on revenues of $127.4 billion. The results translated into $1.55 per share, compared with expectations of $1.90. The year-ago results were inflated by a number of one-time items, including a $5.3 billion gain associated with the restructuring of its downstream and chemical operations in Japan. Exxon continued to struggle with maintaining oil and gas output, seeing a 1.9 percent drop in oil-equivalent production from the prior year. Refinery margins were also weaker, reducing earnings by $510 million. Exxon has ramped up capital spending in recent years to replace and grow output. Capital spending rose 10 percent in the quarter to $10.2 billion. \"ExxonMobil\'s second quarter results reflect continued strong operational performance and investments to meet growing demand for oil, natural gas and chemical products in the years ahead,\" said Exxon chief executive Rex Tillerson. Exxon shares were down 1.7 percent in pre-market trading.