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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 EaSfKEoVWyooJRtRs75jPDfW4jvPsK0q0KUEHopNYGFIVEORzHURgnjkNfId1Zzn
 x4Rfe3utKnbtJcZHmtfvGA==

<SEC-DOCUMENT>0001181431-09-011413.txt : 20090225
<SEC-HEADER>0001181431-09-011413.hdr.sgml : 20090225
<ACCEPTANCE-DATETIME>20090225172358
ACCESSION NUMBER:		0001181431-09-011413
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090223
FILED AS OF DATE:		20090225
DATE AS OF CHANGE:		20090225

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Thayer Jonathan W
		CENTRAL INDEX KEY:			0001448765

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12869
		FILM NUMBER:		09634802

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		(410)470-2821

	MAIL ADDRESS:	
		STREET 1:		CONSTELLATION ENERGY GROUP, INC.
		STREET 2:		100 CONSTELLATION WAY, SUITE 1800P
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21202

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CONSTELLATION ENERGY GROUP INC
		CENTRAL INDEX KEY:			0001004440
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC SERVICES [4911]
		IRS NUMBER:				521964611
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		100 CONSTELLATION WAY
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21202
		BUSINESS PHONE:		4107832800

	MAIL ADDRESS:	
		STREET 1:		100 CONSTELLATION WAY
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21202

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CONSTELLATION ENERGY CORP
		DATE OF NAME CHANGE:	19951220

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RH ACQUISITION CORP
		DATE OF NAME CHANGE:	19951205
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd234552.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-02-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001004440</issuerCik>
        <issuerName>CONSTELLATION ENERGY GROUP INC</issuerName>
        <issuerTradingSymbol>CEG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001448765</rptOwnerCik>
            <rptOwnerName>Thayer Jonathan W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>100 CONSTELLATION WAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BALTIMORE</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21202</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Sr.VP&amp;Chief Financial Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-02-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>20.75</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>762.9072</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401(k) Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This amount includes 117.5486 shares acquired since the Form 3 filed on 10/31/08.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Jonathan W. Thayer</signatureName>
        <signatureDate>2009-02-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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