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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0001181431-11-008962.txt : 20110210
<SEC-HEADER>0001181431-11-008962.hdr.sgml : 20110210
<ACCEPTANCE-DATETIME>20110210141109
ACCESSION NUMBER:		0001181431-11-008962
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101231
FILED AS OF DATE:		20110210
DATE AS OF CHANGE:		20110210

REPORTING-OWNER:	

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

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08858
		FILM NUMBER:		11591446

	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>5
<SEQUENCE>1
<FILENAME>rrd300877.xml
<TEXT>
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<ownershipDocument>

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    <periodOfReport>2010-12-31</periodOfReport>

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    <form4TransactionsReported>0</form4TransactionsReported>

    <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>
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        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
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            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Controller &amp; C.A.O.</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
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            <transactionDate>
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            <transactionAmounts>
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                <transactionPricePerShare>
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        <nonDerivativeTransaction>
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            <transactionDate>
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            <securityTitle>
                <value>Common stock, no par value</value>
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            <transactionDate>
                <value>2010-11-15</value>
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        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, no par value</value>
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            <transactionDate>
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                <transactionFormType>5</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>73</value>
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                <transactionPricePerShare>
                    <value>22.31</value>
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                <transactionAcquiredDisposedCode>
                    <value>A</value>
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                    <value>D</value>
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        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, no par value</value>
            </securityTitle>
            <transactionDate>
                <value>2011-02-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F6"/>
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            <transactionAmounts>
                <transactionShares>
                    <value>97</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.31</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
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                <sharesOwnedFollowingTransaction>
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        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, no par value</value>
            </securityTitle>
            <transactionDate>
                <value>2011-02-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F7"/>
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            <transactionAmounts>
                <transactionShares>
                    <value>57</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.78</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
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                <sharesOwnedFollowingTransaction>
                    <value>0</value>
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        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common stock, no par value</value>
            </securityTitle>
            <transactionDate>
                <value>2011-02-09</value>
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            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>840.000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F8"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2361.014</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Acquisition pursuant to reinvestment of dividends.</footnote>
        <footnote id="F2">Acquisition pursuant to reinvestment of dividends.</footnote>
        <footnote id="F3">Acquisition pursuant to reinvestment of dividends.</footnote>
        <footnote id="F4">Acquisition pursuant to reinvestment of dividends.</footnote>
        <footnote id="F5">Shares granted pursuant to the Unitil Corporation Restricted Stock Plan on February 5, 2010.  Shares represent 25% of total grant and vested on February 7, 2011.  The terms of the Unitil Corporation Restricted Stock Plan specify valuation at time of vesting.  Vested shares are unrestricted and fully transferable by owner.</footnote>
        <footnote id="F6">Shares granted pursuant to the Unitil Corporation Restricted Stock Plan on February 6, 2008.  Shares represent 25% of total grant and vested on February 7, 2011.  The terms of the Unitil Corporation Restricted Stock Plan specify valuation at time of vesting.  Vested shares are unrestricted and fully transferable by owner.</footnote>
        <footnote id="F7">Shares were granted pursuant to the Unitil Corporation Restricted Stock Plan on February 9, 2007.  Shares represent 25% of total grant and vested on February 9, 2011.  The terms of the Unitil Corporation Restricted Stock Plan specify valuation at the time of vesting.  Vested shares are unrestricted and fully transferable by owner.</footnote>
        <footnote id="F8">Shares were granted pursuant to the Unitil Corporation Restricted Stock Plan.  Shares will vest 25% per year over four years from date of grant.  Shares will be valued at current market price on date of vesting.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Laurence M. Brock</signatureName>
        <signatureDate>2011-02-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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