-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 RGTYzlUmEc/mKTeZpJ47oE4QLG40jIKTZMCr4OnQgp0Q31faL/0+qAeebs+qcBhr
 5ec4S2OFcIcDnnNHq6RUsw==

<SEC-DOCUMENT>0001209191-06-048485.txt : 20060901
<SEC-HEADER>0001209191-06-048485.hdr.sgml : 20060901
<ACCEPTANCE-DATETIME>20060901121355
ACCESSION NUMBER:		0001209191-06-048485
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060830
FILED AS OF DATE:		20060901
DATE AS OF CHANGE:		20060901

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:			BAK MARCUS P
		CENTRAL INDEX KEY:			0001259457

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-12515
		FILM NUMBER:		061070642

	MAIL ADDRESS:	
		STREET 1:		C/O OM GROUP INC TOWER CITY
		STREET 2:		3500 TERMINAL TOWER 50 PUBLIC SQUARE
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44113-2204
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>bcl22184_bcl1mpb.xml
<DESCRIPTION>MAIN DOCUMENT DESCRIPTION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-08-30</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001259457</rptOwnerCik>
            <rptOwnerName>BAK MARCUS 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>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP and General Manager, Nickel</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-08-30</value>
            </transactionDate>
            <deemedExecutionDate>
                <footnoteId id="F1"/>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2940</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>26.67</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13050</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-08-30</value>
            </transactionDate>
            <deemedExecutionDate>
                <footnoteId id="F1"/>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2223</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>40.90</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10827</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1670</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Profit-Sharing Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>26.67</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-08-30</value>
            </transactionDate>
            <deemedExecutionDate>
                <footnoteId id="F1"/>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2940</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>1997-12-31</value>
            </exerciseDate>
            <expirationDate>
                <value>2006-11-05</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2940</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This field is not applicable.</footnote>
        <footnote id="F2">Of these shares, 2,100 are subject to vesting on May 1, 2009 and 7,650 are subject to vesting based upon performance criteria of OM Group, Inc. for the three year period ending December 31, 2008.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Marcus P. Bak, by Cipriano S. Beredo as attorney-in-fact</signatureName>
        <signatureDate>2006-09-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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