-----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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<SEC-DOCUMENT>0001480641-10-000002.txt : 20100219
<SEC-HEADER>0001480641-10-000002.hdr.sgml : 20100219
<ACCEPTANCE-DATETIME>20100219142331
ACCESSION NUMBER:		0001480641-10-000002
CONFORMED SUBMISSION TYPE:	D
PUBLIC DOCUMENT COUNT:		1
ITEM INFORMATION:		Rule 506
FILED AS OF DATE:		20100219
DATE AS OF CHANGE:		20100219
EFFECTIVENESS DATE:		20100219

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Unitil Energy Systems, Inc.
		CENTRAL INDEX KEY:			0001480641
		IRS NUMBER:				020121400
		STATE OF INCORPORATION:			NH

	FILING VALUES:
		FORM TYPE:		D
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	021-138875
		FILM NUMBER:		10619214

	BUSINESS ADDRESS:	
		STREET 1:		6 LIBERTY LANE WEST
		CITY:			HAMPTON
		STATE:			NH
		ZIP:			03842
		BUSINESS PHONE:		603 772 0775

	MAIL ADDRESS:	
		STREET 1:		6 LIBERTY LANE WEST
		CITY:			HAMPTON
		STATE:			NH
		ZIP:			03842
</SEC-HEADER>
<DOCUMENT>
<TYPE>D
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
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        <cik>0001480641</cik>
        <entityName>Unitil Energy Systems, Inc.</entityName>
        <issuerAddress>
            <street1>6 LIBERTY LANE WEST</street1>
            <city>HAMPTON</city>
            <stateOrCountry>NH</stateOrCountry>
            <zipCode>03842</zipCode>
        </issuerAddress>
        <issuerPhoneNumber>603 772 0775</issuerPhoneNumber>
        <jurisdictionOfInc>NEW HAMPSHIRE</jurisdictionOfInc>
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            <relatedPersonName>
                <firstName>Robert</firstName>
                <middleName>G</middleName>
                <lastName>Schoenberger</lastName>
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                <street1>6 Liberty Lane West</street1>
                <city>Hampton</city>
                <stateOrCountry>NH</stateOrCountry>
                <zipCode>03842</zipCode>
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            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
                <relationship>Director</relationship>
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            <relationshipClarification></relationshipClarification>
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            <relatedPersonName>
                <firstName>Mark</firstName>
                <middleName>H</middleName>
                <lastName>Collin</lastName>
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                <street1>6 Liberty Lane West</street1>
                <city>Hampton</city>
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                <zipCode>03842</zipCode>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Laurence</firstName>
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                <lastName>Brock</lastName>
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                <firstName>Thomas</firstName>
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                <firstName>Michael</firstName>
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            <relatedPersonRelationshipList>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Albert</firstName>
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                <lastName>Elfner</lastName>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>M. Brian</firstName>
                <lastName>O'Shaughnessy</lastName>
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                <city>Hampton</city>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>William</firstName>
                <middleName>D</middleName>
                <lastName>Adams</lastName>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Sarah</firstName>
                <middleName>P</middleName>
                <lastName>Voll</lastName>
            </relatedPersonName>
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                <street1>6 Liberty Lane West</street1>
                <city>Hampton</city>
                <stateOrCountry>NH</stateOrCountry>
                <zipCode>03842</zipCode>
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            <relatedPersonName>
                <firstName>Eben</firstName>
                <middleName>S</middleName>
                <lastName>Moulton</lastName>
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                <street1>6 Liberty Lane West</street1>
                <city>Hampton</city>
                <stateOrCountry>NH</stateOrCountry>
                <zipCode>03842</zipCode>
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                <relationship>Director</relationship>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>David</firstName>
                <middleName>P</middleName>
                <lastName>Brownell</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>6 Liberty Lane West</street1>
                <city>Hampton</city>
                <stateOrCountry>NH</stateOrCountry>
                <zipCode>03842</zipCode>
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            <relatedPersonRelationshipList>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Edward</firstName>
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                <lastName>Godfrey</lastName>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Michael</firstName>
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                <lastName>Green</lastName>
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            <relatedPersonName>
                <firstName>Robert</firstName>
                <middleName>V</middleName>
                <lastName>Antonucci</lastName>
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            <relatedPersonName>
                <firstName>Sandra</firstName>
                <middleName>L</middleName>
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            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
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            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
    </relatedPersonsList>

    <offeringData>
        <industryGroup>
            <industryGroupType>Electric Utilities</industryGroupType>
        </industryGroup>
        <issuerSize>
            <revenueRange>Decline to Disclose</revenueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
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            <dateOfFirstSale>
                <yetToOccur>true</yetToOccur>
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        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>false</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isDebtType>true</isDebtType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
            <clarificationOfResponse></clarificationOfResponse>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>5000000</minimumInvestmentAccepted>
        <salesCompensationList>
            <recipient>
                <recipientName>Banc of America Securities LLC</recipientName>
                <recipientCRDNumber>26091</recipientCRDNumber>
                <associatedBDName>None</associatedBDName>
                <associatedBDCRDNumber>None</associatedBDCRDNumber>
                <recipientAddress>
                    <street1>One Bryant Park</street1>
                    <city>New York</city>
                    <stateOrCountry>NY</stateOrCountry>
                    <zipCode>10036</zipCode>
                </recipientAddress>
                <statesOfSolicitationList>
                    <state>MN</state>
                    <state>NE</state>
                </statesOfSolicitationList>
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        </salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>15000000</totalOfferingAmount>
            <totalAmountSold>0</totalAmountSold>
            <totalRemaining>15000000</totalRemaining>
            <clarificationOfResponse></clarificationOfResponse>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>0</totalNumberAlreadyInvested>
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        <salesCommissionsFindersFees>
            <salesCommissions>
                <dollarAmount>135000</dollarAmount>
            </salesCommissions>
            <findersFees>
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            <clarificationOfResponse></clarificationOfResponse>
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        <useOfProceeds>
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                <isEstimate>true</isEstimate>
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        <signatureBlock>
            <authorizedRepresentative>false</authorizedRepresentative>
            <signature>
                <issuerName>Unitil Energy Systems, Inc.</issuerName>
                <signatureName>/s/ Sandra L. Whitney</signatureName>
                <nameOfSigner>Sandra L. Whitney</nameOfSigner>
                <signatureTitle>Secretary</signatureTitle>
                <signatureDate>2010-02-19</signatureDate>
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-----END PRIVACY-ENHANCED MESSAGE-----