-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 uuvvLbc7FLcE0W0d/vrcbQ==

<SEC-DOCUMENT>0001181431-05-036133.txt : 20050622
<SEC-HEADER>0001181431-05-036133.hdr.sgml : 20050622
<ACCEPTANCE-DATETIME>20050622160933
ACCESSION NUMBER:		0001181431-05-036133
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050617
FILED AS OF DATE:		20050622
DATE AS OF CHANGE:		20050622

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Brock Laurence M
		CENTRAL INDEX KEY:			0001330516

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08858
		FILM NUMBER:		05910308

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		603-773-6510

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

ISSUER:		

	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

	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
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>rrd83396.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2005-06-17</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000755001</issuerCik>
        <issuerName>UNITIL CORP</issuerName>
        <issuerTradingSymbol>UTL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001330516</rptOwnerCik>
            <rptOwnerName>Brock Laurence M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6 LIBERTY LANE WEST</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HAMPTON</rptOwnerCity>
            <rptOwnerState>NH</rptOwnerState>
            <rptOwnerZipCode>03842</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Controller &amp; C.A.O.</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, no par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>924.469</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, no par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>727.000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>held in trust</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, no par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2000.000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>held in trust</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Common Stock, no par value</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>23.375</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2002-03-05</value>
            </exerciseDate>
            <expirationDate>
                <value>2009-03-05</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>03/05/2005</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1500</value>
                    <footnoteId id="F3"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Common Stock, no par value</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>32.125</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2003-01-17</value>
            </exerciseDate>
            <expirationDate>
                <value>2010-01-17</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>01/17/2003</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1500</value>
                    <footnoteId id="F4"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Common Stock, no par value</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>25.875</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2004-01-16</value>
            </exerciseDate>
            <expirationDate>
                <value>2011-01-16</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>01/16/2004</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1500</value>
                    <footnoteId id="F5"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Shares are held in trust under the terms of the Unitil Corporation Tax Deffered Savings and Investment Plan.</footnote>
        <footnote id="F2">Shares are held in the Brock Family Trust</footnote>
        <footnote id="F3">Options were granted March 5, 1999 under the terms and conditions of the Company's 1998 Stock Option Plan.</footnote>
        <footnote id="F4">Options were granted January 17, 2000 under the terms and conditions of the Company's 1998 Stock Option Plan</footnote>
        <footnote id="F5">Options were granted January 16, 2001 under the terms and conditions of the Company's 1998 Stock Option Plan</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Laurence M. Brock</signatureName>
        <signatureDate>2005-06-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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