Heavy Canadian crude prices widened to the biggest discount against New York futures this year as pipeline-operator Enbridge Inc. reported that rationing on its heavy oil lines would increase next month. Western Canadian Select, an oil sands benchmark, traded at $15 a barrel below West Texas Intermediate futures Tuesday, $1.50 wider than on Friday and the biggest discount this year, according to data compiled by Bloomberg. The discount widened as Enbridge said that crude shipments through the heavy oil pipelines of its Mainline, which is the largest Canadian oil export pipeline system, would be apportioned 41 percent in March, up from 39 percent in February. The system carries oil from Alberta to Superior, Wisconsin, where it connects to other lines linked to refineries in the U.S. Gulf Coast. Pipeline rationing on the system has barely budged since […]