Unitil Corporation is a public utility holding company. The Company's principal business is the local distribution of electricity in the southeastern seacoast and state capital regions of New Hampshire and the greater Fitchburg area of north central Massachusetts and the local distribution of natural gas in southeastern New Hampshire, portions of southern Maine to the Lewiston-Auburn area and in the greater Fitchburg area of north central Massachusetts. Its segments include utility gas operations, utility electric operations and non-regulated. Its operations include natural gas operations; natural gas distribution utility operations; gas transmission pipeline operations; electric distribution utility operations, and non-regulated and other non-utility operations. As of December 31, 2016, it was engaged in the distribution of electricity and natural gas to approximately 184,200 customers throughout its service territories in the states of New Hampshire, Massachusetts and Maine.