A Central Maine Power "smart meter" displays electricity usage at a business in Freeport in 2010. Credit: Robert F. Bukaty | AP

PORTLAND, Maine — Regulators are threatening sanctions including a $500,000 fine and profit reductions because of Central Maine Power’s billing and other problems.

A letter from the Public Utilities Commission takes CMP to task for failing to issue bills to thousands of new and existing customers and failing to address consumer complaints in a timely manner. CMP also failed to refer participants of the Arrearage Management Program to Efficiency Maine.

CMP spokeswoman Catharine Hartnett tells the Portland Press Herald that the complaints are being taken seriously and that the company intends to respond.

The letter noted the PUC may take certain actions when a utility violates a commission statute, order, or rule. Those include penalizing the utility up to $500,000, holding a utility in contempt and reducing profits.