CALGARY, Alberta/WINNIPEG, Manitoba (Reuters) – Enbridge Inc’s plan to overhaul contracts on its Mainline pipeline system has outraged many Canadian shippers but is cheered by investors who see monetizing existing infrastructure as a safer bet than trying to build new pipelines. The Mainline is North America’s largest pipeline network, transporting nearly 3 million barrels per day, or 70%, of crude from western Canada to the U.S. Midwest. Many shippers opposed say Enbridge is abusing its market power and the changes will hurt Canadian producers by imposing unfair terms and tolls.