Oil headed for the biggest annual decline since the 2008 global financial crisis as U.S. producers and the Organization of Petroleum Exporting Countries ceded no ground in their battle for market share amid a supply glut. Futures slid as much as 1.8 percent in New York , bringing losses for 2014 to 46 percent. U.S. guidelines allowing overseas sales of ultralight oil without government approval may boost the country’s export capacity and “throw a monkey wrench” into Saudi Arabia ’s plan to curb American output, according to Citigroup Inc. U.S. crude inventories are forecast to rise to the highest level for this time of the year in three decades. Oil’s slump has roiled markets from the Russian ruble to the Nigerian naira and squeezed government budgets in producing nations including Venezuela and Ecuador . It’s also boosted China ’s emergency crude reserves and helped shrink fuel subsidies in India […]