(Reuters) -- Enbridge Inc said on Sunday it has no indication yet when it can restart a major U.S. Midwest oil pipeline after a deadly vehicle accident in Illinois the day before caused an oil leak and fire, forcing the company to shut down the line.

Enbridge, whose pipelines carry the bulk of Canadian crude exports to the United States, said it does not yet know how much oil spilled at the incident site near New Lenox, about 40 miles southwest of Chicago.

The pipeline, called Line 14/64, normally carries up to 318,000 barrels of oil a day to Griffith, Ind., from Superior, Wis.

Line 14/64 remains shut down as the investigation into the incident continues, enabling Enbridge to assess the damage and determine how long it will take to complete the necessary repairs caused by the vehicle collision early Saturday morning, Enbridge spokeswoman Lorraine Little said in an email.

Because of the reduced capacity for Enbridge pipelines running from Superior, the company has also slowed the flow on pipelines that feed oil into that hub from Alberta, Canada, she said.

Market sources said it is likely that discounts for Canadian crude, which have been unusually deep in recent weeks due partly to tight pipeline capacity, could deepen more on Monday.

(Reporting by Jeffrey Jones in Calgary; Editing by Maureen Bavdek)