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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 JDp2DKJk6YYysubVMGJ5C14paCpgv+I3brQUstTyDSwPoJaeUgyO090WmLjvklyG
 mIALeB/r7zbodnDMI+xV0w==

<SEC-DOCUMENT>0001179110-09-011334.txt : 20090730
<SEC-HEADER>0001179110-09-011334.hdr.sgml : 20090730
<ACCEPTANCE-DATETIME>20090730183143
ACCESSION NUMBER:		0001179110-09-011334
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090729
FILED AS OF DATE:		20090730
DATE AS OF CHANGE:		20090730

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BENNETT ROBERT R
		CENTRAL INDEX KEY:			0001119603

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33982
		FILM NUMBER:		09975015

	MAIL ADDRESS:	
		STREET 1:		C/O LIBERTY MEDIA CORP
		STREET 2:		12300 LIBERTY BLVD
		CITY:			ENGLEWOOD
		STATE:			CO
		ZIP:			80112

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LIBERTY MEDIA CORP
		CENTRAL INDEX KEY:			0001355096
		STANDARD INDUSTRIAL CLASSIFICATION:	CABLE & OTHER PAY TELEVISION SERVICES [4841]
		IRS NUMBER:				841288730
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		12300 LIBERTY BOULEVARD
		CITY:			ENGLEWOOD
		STATE:			CO
		ZIP:			80112
		BUSINESS PHONE:		7208755400

	MAIL ADDRESS:	
		STREET 1:		12300 LIBERTY BOULEVARD
		CITY:			ENGLEWOOD
		STATE:			CO
		ZIP:			80112

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Liberty Media Holding CORP
		DATE OF NAME CHANGE:	20060303
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-07-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001355096</issuerCik>
        <issuerName>LIBERTY MEDIA CORP</issuerName>
        <issuerTradingSymbol>LMDIA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001119603</rptOwnerCik>
            <rptOwnerName>BENNETT ROBERT R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>12300 LIBERTY BLVD.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ENGLEWOOD</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80112</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Series A Liberty Entertainment Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-07-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>7134</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>27.987</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30726</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Series A Liberty Entertainment Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-07-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F4"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>11466</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>27.987</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Hilltop Investments, LLC</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Series A Liberty Entertainment Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8819</value>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401(k) Savings Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The sales reported in this Form 4 were effected pursuant to a 10b5-1 plan adopted by the Reporting Person on June 18, 2009.</footnote>
        <footnote id="F2">Price reflects a weighted average of sales made at prices ranging from $27.97 to $28.00.</footnote>
        <footnote id="F3">The Reporting Person undertakes to provide upon request by the staff of the Securities and Exchange Commission, the Issuer, or a security holder of the Issuer, information regarding the number of shares sold at each separate price.</footnote>
        <footnote id="F4">The sales reported in this Form 4 were effected pursuant to a 10b5-1 plan adopted by Hilltop Investments, LLC on June 18, 2009.</footnote>
        <footnote id="F5">The number of shares represents equivalent shares based on the fair market value of the shares of Series A Liberty Entertainment Common Stock held by the unitized stock fund under the Issuer's 401(k) Savings Plan based on a report from the Plan Administrator dated as of June 30, 2009.  The Reporting Person has an interest in the unitized fund, which holds shares of Series A Liberty Entertainment Common Stock, Series A Liberty Capital Common Stock, Series A Liberty Interactive Common Stock and short-term investments.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Robert R. Bennett</signatureName>
        <signatureDate>2009-07-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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