West Texas Intermediate retreated from the biggest gain since September amid speculation a drop in Saudi Arabian oil supplies isn’t a signal that OPEC’s largest producer has decided to cut production. Brent slid in London . Futures fell as much as 1 percent in New York and are poised for a fourth weekly decline. Saudi Arabia’s crude supplies to the market declined last month even as production increased, a person familiar with the kingdom’s oil policy said yesterday. A New York City doctor tested positive for Ebola after returning from aid work in West Africa, spurring demand for haven assets including U.S. Treasuries. The market’s reaction to the fall in Saudi supply underscores the focus on the Organization of Petroleum Exporting Countries before the group’s meeting next month. The highest U.S. crude output in almost 30 years helped drive oil futures into a bear market […]