sentences:  ExxonMobil acquired XTO Energy in a deal valued at $36 billion, involving the issuance of 416 million shares of stock and assuming the company's $11 billion in debt.The deal increased ExxonMobil's U.S. natural gas production to 3.68 billion cubic feet per day, making it the largest producer in the U.S.The purchase by ExxonMobil was the largest by the company since the deal that created ExxonMobil in 1999.