July 31, 2012. BP Plc, Europe's second-biggest oil producer, reported a loss in the second quarter as the company wrote down the value of U.S. assets and output dropped. BP posted a net loss of $1.4 billion compared with a profit of $5.7 billion a year earlier, the company said. After one-time items and changes in inventories, profit missed analyst estimates. Production, excluding output from the Russian TNK-BP venture, slipped 7.4 percent to 2.3 million barrels of oil equivalent a day. The results, which included impairment charges totaling $4.8 billion, are a setback for Chief Executive Officer Bob Dudley's effort to rebuild the company after the 2010 Gulf of Mexico spill by focusing on higher-margin fields and selling off less-profitable assets. Output will remain limited by maintenance work in the third quarter, BP said.