AUGUSTA, Maine — Utility regulators are investigating whether a natural gas company’s failure to correctly bill several big commercial customers will impact other customers.

The Maine Public Utilities Commission recently decided to review Maine Natural Gas Corp.’s under-billing of several large commercial customers.

The investigation will consider whether the company correctly responded to the issue, and whether the company is entitled to recover any of the previously unbilled revenue.

Utility regulators were tipped off in June following a customer complaint. Regulators learned that the company discovered in late 2016 that a large customer had been under-billed.

The company found that it not billed 11 accounts for their full actual usage. It issued make-up bills for the period from November through 2017.