Analysts say an Enbridge Inc. plan to use an idled leg of its Mainline pipeline system to store surplus Western Canadian oil will help offset lower volumes on the system as U.S. refineries buy less oil to match lower demand.

A senior executive with Enbridge Inc. says the company won't change course on its plan to convert most of its Mainline pipeline system to long-term contracts despite growing opposition from major Canadian oil producers.

 A Native American tribe in Wisconsin is suing Enbridge Inc in a bid to shut down an aging oil pipeline that runs across its tribal land, the latest in a string of challenges against the Canadian company's pipelines in the U.S. Midwest.

Enbridge insists the Line 5 dual pipes, which have been in place since 1953, are in sound condition and could operate indefinitely.