A reduction in OPEC crude output deepened as Libya’s biggest producing oilfield stopped pumping amid supply cuts from Saudi Arabia and potential disruptions to Nigerian exports. Libya halted the Sharara oilfield as a precaution after a rocket attack on the connected Zawiya refinery three days ago, closing down about 30 percent of national output. In Africa ’s largest oil producer, state-owned Nigerian National Petroleum Corp. was in talks yesterday to prevent a strike that threatened to disrupt exports. Saudi Arabia told the Organization of Petroleum Exporting Countries that in August it made the deepest production cut in 18 months. Brent crude futures declined 14 percent in the past three months, falling to a two-year low of $96.21 a barrel on Sept. 15. Global oil demand growth is the slowest since 2011, while the U.S. shale boom means oil production outside OPEC is rising by the most since the 1980s, […]