Central Maine Power (CMP) CMP, a subsidiary of AVANGRID, serves more than 600,000 electricity customers in an 11,000 square-mile service area in central and southern Maine. Affiliated with Iberdrola SA, AVANGRID owns eight electricity, natural gas or combination utilities in Connecticut, Maine, Massachusetts, and New York. The utilities serve 2.2 million electricity customers, 930,000 natural gas customers, and are recognized for safe, reliable energy delivery, excellent customer service, and a commitment to the community and environment. For more information, visit avangrid.com.