<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-07-01</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000949968</issuerCik>
        <issuerName>FREEMARKETS INC</issuerName>
        <issuerTradingSymbol>FMKT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001218039</rptOwnerCik>
            <rptOwnerName>NEWKIRK KARL E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>FREEMARKETS CENTER</rptOwnerStreet1>
            <rptOwnerStreet2>210 SIXTH AVENUE</rptOwnerStreet2>
            <rptOwnerCity>PITTSBURGH</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>15222</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.52</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-07-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>100000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.52</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-08-11</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>100000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Upon consummation of the merger, (the &quot;Merger&quot;) contemplated by that certain Agreement and Plan of Merger and Reorganization dated January 23, 2004 (the &quot;Merger Agreement&quot;) by and among Ariba, Inc. (&quot;Ariba&quot;), Fleet Merger Corporation, and the Corporation, each outstanding option to purchase Issuer Common Stock was converted to an option to purchase shares of Ariba Common Stock on substantially the same terms, except that the number of shares was adjusted by multiplying the number of options to purchase Issuer Common Stock by 3.271 and the option exercise price was adjusted by dividing the exercise price of each option to purchase shares of Issuer Common Stock by 3.271.</footnote>
        <footnote id="F2">Options to purchase 25,000 shares are currently vested. Options to purchase 75,000 shares vest in eight quarterly installments beginning August 11, 2004 .</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Karl E. Newkirk</signatureName>
        <signatureDate>2004-07-09</signatureDate>
    </ownerSignature>
</ownershipDocument>

