-----BEGIN PRIVACY-ENHANCED MESSAGE-----
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,
 ROp4OgL2yNjeLOKngUJQjf97TClDwjDvyOWmwVlAwwnttHP6tk+6/2khS2r5P7UY
 vWClMZkGJcSUYnnlMG030w==

<SEC-DOCUMENT>0001468729-09-000003.txt : 20090730
<SEC-HEADER>0001468729-09-000003.hdr.sgml : 20090730
<ACCEPTANCE-DATETIME>20090730202004
ACCESSION NUMBER:		0001468729-09-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090730
FILED AS OF DATE:		20090730
DATE AS OF CHANGE:		20090730

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			bogachev nikolay v
		CENTRAL INDEX KEY:			0001468730

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-05507
		FILM NUMBER:		09975141

	MAIL ADDRESS:	
		STREET 1:		9-3 SECHNEOVSKY PEREULOK
		CITY:			MOSCOW
		STATE:			1Z
		ZIP:			RUS-119034

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MAGELLAN PETROLEUM CORP /DE/
		CENTRAL INDEX KEY:			0000061398
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		IRS NUMBER:				060842255
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		10 COLUMBUS BLVD
		STREET 2:		10 FLOOR
		CITY:			HARTFORD
		STATE:			CT
		ZIP:			06106
		BUSINESS PHONE:		8602932006

	MAIL ADDRESS:	
		STREET 1:		10 COLUMBUS BLVD
		STREET 2:		10 FLOOR
		CITY:			HARTFORD
		STATE:			CT
		ZIP:			06106

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MAGELLAN PETROLEUM CORP PANAMA
		DATE OF NAME CHANGE:	19671130
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-07-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000061398</issuerCik>
        <issuerName>MAGELLAN PETROLEUM CORP /DE/</issuerName>
        <issuerTradingSymbol>MPET</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001468730</rptOwnerCik>
            <rptOwnerName>bogachev nikolay v</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>9-3 SECHNEOVSKY PEREULOK</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>RUS-119034 MOSCOW</rptOwnerCity>
            <rptOwnerState>1Z</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription>RUSSIAN FEDERATION</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-07-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>568985</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.15</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13612463</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Young Energy Prize S.A.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>Nikolay V Bogachev</signatureName>
        <signatureDate>2009-07-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----