<SUBMISSION>
<ACCESSION-NUMBER>0001104659-13-033035
<TYPE>3
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20120820
<FILING-DATE>20130425
<DATE-OF-FILING-DATE-CHANGE>20130425
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>Ronan Terrence
<CIK>0001557506
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>3
<ACT>34
<FILE-NUMBER>001-34691
<FILM-NUMBER>13783519
</FILING-VALUES>
<MAIL-ADDRESS>
<STREET1>ONE FEDERAL STREET 30TH FLOOR
<CITY>BOSTON
<STATE>MA
<ZIP>02110
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>ATLANTIC POWER CORP
<CIK>0001419242
<ASSIGNED-SIC>4900
<IRS-NUMBER>550886410
<STATE-OF-INCORPORATION>A1
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>ONE FEDERAL STREET
<STREET2>FLOOR 30
<CITY>BOSTON
<STATE>MA
<ZIP>02110
<PHONE>617-977-2400
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>ONE FEDERAL STREET
<STREET2>FLOOR 30
<CITY>BOSTON
<STATE>MA
<ZIP>02110
</MAIL-ADDRESS>
</ISSUER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>a3.xml
<DESCRIPTION>3
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2012-08-20</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001419242</issuerCik>
        <issuerName>ATLANTIC POWER CORP</issuerName>
        <issuerTradingSymbol>AT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001557506</rptOwnerCik>
            <rptOwnerName>Ronan Terrence</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ATLANTIC POWER CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>ONE FEDERAL ST., 30TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02110</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive Vice President, CFO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person's original Form 3 incorrectly listed 6,000 common shares of the issuer held by the reporting person as of August 20, 2012. The reporting person held no common shares or other securities of the issuer as of August 20, 2012.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Barry E. Welch, attorney-in-fact</signatureName>
        <signatureDate>2013-04-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
