A growing overhang of gasoline and diesel fueled a sharp sell-off in oil futures on Monday that reversed a recent rally over the wildfires in the heart of Canada’s oil sands region, traders and analysts said. The sell-off came amid warnings that supplies could outpace global demand even during the peak summer driving season that traditionally kicks in at the end of May. While crude oil supplies have significantly tightened in recent weeks due to outages linked to unrest in Libya, militant attacks in Nigeria, the fire in Canada and gradually slowing U.S. shale production, refineries have continued to run at full throttle in anticipation of rising demand. But refining profit margins, known as cracks, are coming under heavy pressure as storage tanks brim and […]