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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,
 EXr3v39nbLAjgdzun5qHcQPHEZ31TKXwDC0mcBxkRwk7z9CApQ0pjfA7KSBj0Vc+
 FIMDhvxHLjbMf8MMXSrmdg==

<SEC-DOCUMENT>0001209191-05-007651.txt : 20050208
<SEC-HEADER>0001209191-05-007651.hdr.sgml : 20050208
<ACCEPTANCE-DATETIME>20050208172224
ACCESSION NUMBER:		0001209191-05-007651
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050125
FILED AS OF DATE:		20050208
DATE AS OF CHANGE:		20050208

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			OM GROUP INC
		CENTRAL INDEX KEY:			0000899723
		STANDARD INDUSTRIAL CLASSIFICATION:	SECONDARY SMELTING & REFINING OF NONFERROUS METALS [3341]
		IRS NUMBER:				521736882
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1500 KEY TOWER
		STREET 2:		127 PUBLIC SQUARE
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44114
		BUSINESS PHONE:		2167810083

	MAIL ADDRESS:	
		STREET 1:		1500 KEY TOWER
		STREET 2:		127 PUBLIC SQUARE
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44114

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MOONEY JAMES P
		CENTRAL INDEX KEY:			0001129867

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12515
		FILM NUMBER:		05585031

	MAIL ADDRESS:	
		STREET 1:		3800 TERMINAL TOWER
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44113
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>bcl11950_bcl1jpm.xml
<DESCRIPTION>MAIN DOCUMENT DESCRIPTION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2005-01-25</periodOfReport>

    <dateOfOriginalSubmission>2005-01-26</dateOfOriginalSubmission>

    <issuer>
        <issuerCik>0000899723</issuerCik>
        <issuerName>OM GROUP INC</issuerName>
        <issuerTradingSymbol>OMG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001129867</rptOwnerCik>
            <rptOwnerName>MOONEY JAMES P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1500 KEY TOWER</rptOwnerStreet1>
            <rptOwnerStreet2>127 PUBLIC SQUARE</rptOwnerStreet2>
            <rptOwnerCity>CLEVELAND</rptOwnerCity>
            <rptOwnerState>OH</rptOwnerState>
            <rptOwnerZipCode>44114</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-01-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3350</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>31.05</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12730</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1723</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trustee</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents the disposition of shares pursuant to tax withholding obligation in connection with the automatic vesting of restricted shares of common stock.</footnote>
        <footnote id="F2">This number was previously reported incorrectly due to an internal clerical error.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ James P. Mooney</signatureName>
        <signatureDate>2005-02-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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