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    <periodOfReport>2007-08-01</periodOfReport>

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    <issuer>
        <issuerCik>0001362705</issuerCik>
        <issuerName>Constellation Energy Partners LLC</issuerName>
        <issuerTradingSymbol>CEP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000806085</rptOwnerCik>
            <rptOwnerName>LEHMAN BROTHERS HOLDINGS INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>745 SEVENTH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

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                <value>Common Stock</value>
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            <transactionTimeliness>
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            <transactionAmounts>
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                </transactionShares>
                <transactionPricePerShare>
                    <value>49.30</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
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                    <value>49.19</value>
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                    <value>See Footnote</value>
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                    <value>See Footnote</value>
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                    <value>17839</value>
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                    <value>47.45</value>
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                    <value>D</value>
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                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F5"/>
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        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
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            <transactionDate>
                <value>2007-08-03</value>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness>
                <value></value>
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                <transactionShares>
                    <value>1500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>47.18</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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                <sharesOwnedFollowingTransaction>
                    <value>1706786</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F6"/>
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        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">By indirect, wholly-owned subsidiaries of the Reporting Person: 596,060 shares held by Lehman Brothers Inc. and 1,164,736 shares held by Lehman Brothers MLP Opportunity Fund LP.</footnote>
        <footnote id="F2">By indirect, wholly-owned subsidiaries of the Reporting Person: 593,750 shares held by Lehman Brothers Inc. and 1,164,736 shares held by Lehman Brothers MLP Opportunity Fund LP.</footnote>
        <footnote id="F3">By indirect, wholly-owned subsidiaries of the Reporting Person: 593,550 shares held by Lehman Brothers Inc. and 1,164,736 shares held by Lehman Brothers MLP Opportunity Fund LP.</footnote>
        <footnote id="F4">By indirect, wholly-owned subsidiaries of the Reporting Person: 580,539 shares held by Lehman Brothers Inc. and 1,164,736 shares held by Lehman Brothers MLP Opportunity Fund LP.</footnote>
        <footnote id="F5">By indirect, wholly-owned subsidiaries of the Reporting Person: 562,700 shares held by Lehman Brothers Inc. and 1,164,736 shares held by Lehman Brothers MLP Opportunity Fund LP.</footnote>
        <footnote id="F6">By indirect, wholly-owned subsidiaries of the Reporting Person: 561,200 shares held by Lehman Brothers Inc. and 1,164,736 shares held by Lehman Brothers MLP Opportunity Fund LP.</footnote>
    </footnotes>

    <remarks>Joint Filer Information
Title of Derivative Securities: Common Stock
Issuer &amp;  Ticker Symbol: Constellation Energy Partners LLC
Designated Filer:
Lehman Brothers Holdings Inc.
745 Seventh Avenue
New York, NY 10019

Other Joint Filer Information (all filers share the Reporting Person's address):

Lehman Brothers Inc., a Delaware corporation, a direct wholly-owned subsidiary of the Reporting Person.

Lehman Brothers MLP Opportunity Associates LLC, a Delaware limited liability company, a direct wholly-owned subsidiary of the Reporting Person.

Lehman Brothers MLP Opportunity Associates LP, a Delaware limited partnership, a direct wholly-owned subsidiary of Lehman Brothers MLP Opportunity Associates LLC and general partner of LB MLP Opp. Fund LP

Lehman Brothers MLP Opportunity Fund LP, a Delaware limited partnership.</remarks>

    <ownerSignature>
        <signatureName>/s/ James J. Killerlane III</signatureName>
        <signatureDate>2007-08-06</signatureDate>
    </ownerSignature>
</ownershipDocument>
