-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 NgXypQ5ALdEBpGFcfMdq/60eodTVLGEdyzCiZuGzwxx258izOvyB0IxYyTC1Zp4V
 cDEZspb+6GrFnINEqShgIw==

<SEC-DOCUMENT>0001179110-03-008027.txt : 20030929
<SEC-HEADER>0001179110-03-008027.hdr.sgml : 20030929
<ACCEPTANCE-DATETIME>20030929124206
ACCESSION NUMBER:		0001179110-03-008027
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030925
FILED AS OF DATE:		20030929

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DENNEY ARTHUR J
		CENTRAL INDEX KEY:			0001235071

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14841
		FILM NUMBER:		03914230

	BUSINESS ADDRESS:	
		STREET 1:		155 INVERNESS DRIVE
		CITY:			ENGLEWOOD
		STATE:			CO
		ZIP:			80112-5004

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MARKWEST HYDROCARBON INC
		CENTRAL INDEX KEY:			0001019756
		STANDARD INDUSTRIAL CLASSIFICATION:	NATURAL GAS DISTRIBUTION [4924]
		IRS NUMBER:				841352233
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		155 INVERNESS DRIVE WEST
		STREET 2:		SUITE 200
		CITY:			ENGLEWOOD
		STATE:			CO
		ZIP:			80112-5004
		BUSINESS PHONE:		3032908700

	MAIL ADDRESS:	
		STREET 1:		155 INVERNESS DRIVE WEST
		STREET 2:		SUITE 200
		CITY:			ENGLEWOOD
		STATE:			CO
		ZIP:			80112-5004
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2003-09-25</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0001019756</issuerCik>
        <issuerName>MARKWEST HYDROCARBON INC</issuerName>
        <issuerTradingSymbol>MWP</issuerTradingSymbol>
</issuer>
<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001235071</rptOwnerCik>
            <rptOwnerName>DENNEY ARTHUR J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MARKWEST HYDROCARBON, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>155 INVERNESS DRIVE WEST, STE 200</rptOwnerStreet2>
            <rptOwnerCity>ENGLEWOOD</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80112</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector>
<isOfficer>1</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle>Executive Vice President</officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value>
</securityTitle>
<transactionDate><value>2003-09-25</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>S</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>746</value>
</transactionShares>
<transactionPricePerShare><value>7.09</value>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>D</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>10481</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
</nonDerivativeTable>
<derivativeTable></derivativeTable>
<footnotes></footnotes>
<ownerSignature><signatureName>Lucy Woods POA for Arthur J Denney</signatureName>
<signatureDate>2003-09-29</signatureDate>
</ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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