<SEC-DOCUMENT>0001193125-18-034179-index.html : 20180207
<SEC-HEADER>0001193125-18-034179.hdr.sgml : 20180207
<ACCEPTANCE-DATETIME>20180207105703
ACCESSION NUMBER:		0001193125-18-034179
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20180207
DATE AS OF CHANGE:		20180207

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			UNITIL CORP
		CENTRAL INDEX KEY:			0000755001
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC & OTHER SERVICES COMBINED [4931]
		IRS NUMBER:				020381573
		STATE OF INCORPORATION:			NH
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-40265
		FILM NUMBER:		18579743

	BUSINESS ADDRESS:	
		STREET 1:		6 LIBERTY LANE WEST
		CITY:			HAMPTON
		STATE:			NH
		ZIP:			03842
		BUSINESS PHONE:		6037736504

	MAIL ADDRESS:	
		STREET 1:		6 LIBERTY LANE WEST
		CITY:			HAMPTON
		STATE:			NH
		ZIP:			03842

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FRONTIER CAPITAL MANAGEMENT CO LLC
		CENTRAL INDEX KEY:			0001216488
		IRS NUMBER:				043492668
		STATE OF INCORPORATION:			DE

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		99 SUMMER STREET
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02110
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>d529996dsc13ga.htm
<DESCRIPTION>SC 13G/A
<TEXT>
Document 1 - file: d529996dsc13ga.htm

</DOCUMENT>
</SEC-DOCUMENT>