Eversource Energy is the parent company of the Northeast Utilities system. The NU system furnishes franchised retail electric service to customers in 419 cities and towns in Connecticut, New Hampshire and western Massachusetts through three of NU's wholly-owned subsidiaries: The Connecticut Light and Power Company, Public Service Company of New Hampshire and Western Massachusetts Electric Company. The NU system also furnishes franchised retail natural gas service in a large part of Connecticut through Yankee Gas Services Company, a subsidiary of Yankee Energy System, Inc., the natural gas distribution company in Connecticut. Yankee Gas serves approximately 199,000 residential, commercial and industrial customers in 71 cities and towns in Connecticut, including large portions of the central and southwest parts of the state. NU, through its wholly-owned subsidiary, NU Enterprises, Inc., owns a number of competitive energy and related businesses, including Northeast Generation Company, Northeast Generation Services Company, Select Energy, Inc., Select Energy Services, Inc. and Mode 1 Communications, Inc. Holyoke Water Power Company, a subsidiary of NU, is a resource of NUEI through an output contract with Select Energy. Northeast Utilities Service Company provides centralized accounting, administrative, information technology, engineering, financial, legal, operational, planning, purchasing and other services to the NU system companies and, on a limited basis, to certain other New England utilities. Three other subsidiaries construct, acquire or lease some of the property and facilities used by the NU system companies. The NU system is regulated in virtually all aspects of its business by various federal and state agencies, including the Securities and Exchange Commission, the Federal Energy Regulatory Commission, the Nuclear Regulatory Commission and various state and/or local regulatory authorities with jurisdiction over the industry and the service areas in which each company operates, including the Connecticut Department of Public Utility Control, the New Hampshire Public Utilities Commission and the Massachusetts Department of Telecommunications and Energy.