"We are working with our partners to secure fuel for the Midwest region," the company said, adding that the Aug. 24 fire at the Whiting refinery was limited to a single electrical system but led to loss of utilities in other parts of the refinery.

The company is making progress in restoring the utilities needed to bring the plant back to normal operations, it added.

Whiting is the sixth-biggest by capacity in the United States and the company's largest in the nation, according to the U.S. Energy Information Administration.

(Reporting by Swati Verma in Bengaluru; editing by Barbara Lewis)