<SUBMISSION>
<ACCESSION-NUMBER>0001181431-07-075268
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20071211
<FILING-DATE>20071213
<DATE-OF-FILING-DATE-CHANGE>20071213
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>TA ADVENT VIII LP
<CIK>0001106837
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-33554
<FILM-NUMBER>071304250
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>125 HIGH ST
<CITY>BOSTON
<STATE>MA
<ZIP>02110
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>125 HIGH ST
<CITY>BOSTON
<STATE>MA
<ZIP>02110
</MAIL-ADDRESS>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>TA EXECUTIVES FUND LLC
<CIK>0001268755
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-33554
<FILM-NUMBER>071304246
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>125 HIGH STREET
<STREET2>SUITE 2500
<CITY>BOSTON
<STATE>MA
<ZIP>02110
<PHONE>6175746735
</BUSINESS-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>PROS Holdings, Inc.
<CIK>0001392972
<ASSIGNED-SIC>7371
<IRS-NUMBER>760168604
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>3100 MAIN STREET
<STREET2>SUITE 900
<CITY>HOUSTON
<STATE>TX
<ZIP>77002
<PHONE>713-335-5151
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>3100 MAIN STREET
<STREET2>SUITE 900
<CITY>HOUSTON
<STATE>TX
<ZIP>77002
</MAIL-ADDRESS>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>TA ASSOCIATES INC
<CIK>0001034569
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-33554
<FILM-NUMBER>071304251
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>125 HIGH STREET
<STREET2>SUITE 2500
<CITY>BOSTON
<STATE>MA
<ZIP>02110
<PHONE>6175746781
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>125 HIGH STREET
<STREET2>SUITE 2500
<CITY>BOSTON
<STATE>MA
<ZIP>02110
</MAIL-ADDRESS>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>ADVENT ATLANTIC & PACIFIC III LP
<CIK>0001235810
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-33554
<FILM-NUMBER>071304248
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>125 HIGH STREET
<STREET2>SUITE 2500
<CITY>BOSTON
<STATE>MA
<ZIP>02110
<PHONE>6175746781
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>125 HIGH STREET
<STREET2>SUITE 2500
<CITY>BOSTON
<STATE>MA
<ZIP>02110
</MAIL-ADDRESS>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>TA ASSOCIATES VIII LLC
<CIK>0001235812
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-33554
<FILM-NUMBER>071304249
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>125 HIGH STREET
<STREET2>SUITE 2500
<CITY>BOSTON
<STATE>MA
<ZIP>02110
<PHONE>6175746781
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>125 HIGH STREET
<STREET2>SUITE 2500
<CITY>BOSTON
<STATE>MA
<ZIP>02110
</MAIL-ADDRESS>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>TA ASSOCIATES AAP III PARTNERS
<CIK>0001235814
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-33554
<FILM-NUMBER>071304247
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>125 HIGH STREET
<STREET2>SUITE 2500
<CITY>BOSTON
<STATE>MA
<ZIP>02110
<PHONE>6175746781
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>125 HIGH STREET
<STREET2>SUITE 2500
<CITY>BOSTON
<STATE>MA
<ZIP>02110
</MAIL-ADDRESS>
</REPORTING-OWNER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>TA INVESTORS LLC
<CIK>0001235809
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-33554
<FILM-NUMBER>071304245
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>125 HIGH STREET
<STREET2>SUITE 2500
<CITY>BOSTON
<STATE>MA
<ZIP>02110
<PHONE>6175746781
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>125 HIGH STREET
<STREET2>SUITE 2500
<CITY>BOSTON
<STATE>MA
<ZIP>02110
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd181758.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-12-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001392972</issuerCik>
        <issuerName>PROS Holdings, Inc.</issuerName>
        <issuerTradingSymbol>PRO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001034569</rptOwnerCik>
            <rptOwnerName>TA ASSOCIATES INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>JOHN HANCOCK TOWER</rptOwnerStreet1>
            <rptOwnerStreet2>200 CLARENDON ST, 56TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See General Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001106837</rptOwnerCik>
            <rptOwnerName>TA ADVENT VIII LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>JOHN HANCOCK TOWER</rptOwnerStreet1>
            <rptOwnerStreet2>200 CLARENDON ST, 56TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See General Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001235812</rptOwnerCik>
            <rptOwnerName>TA ASSOCIATES VIII LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>JOHN HANCOCK TOWER</rptOwnerStreet1>
            <rptOwnerStreet2>200 CLARENDON ST, 56TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See General Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001235810</rptOwnerCik>
            <rptOwnerName>ADVENT ATLANTIC &amp; PACIFIC III LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>JOHN HANCOCK TOWER</rptOwnerStreet1>
            <rptOwnerStreet2>200 CLARENDON ST, 56TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See General Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001235814</rptOwnerCik>
            <rptOwnerName>TA ASSOCIATES AAP III PARTNERS</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>JOHN HANCOCK TOWER</rptOwnerStreet1>
            <rptOwnerStreet2>200 CLARENDON ST, 56TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See General Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001268755</rptOwnerCik>
            <rptOwnerName>TA EXECUTIVES FUND LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>JOHN HANCOCK TOWER</rptOwnerStreet1>
            <rptOwnerStreet2>200 CLARENDON ST, 56TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See General Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001235809</rptOwnerCik>
            <rptOwnerName>TA INVESTORS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>JOHN HANCOCK TOWER</rptOwnerStreet1>
            <rptOwnerStreet2>200 CLARENDON ST, 56TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>BOSTON</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02116</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>See General Remarks</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-12-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1731179</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.8290</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3236424</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote 5</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-12-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>932360</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.8290</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote 6</value>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-12-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>31838</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.8290</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>59520</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote 7</value>
                    <footnoteId id="F7"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-12-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>34623</value>
                    <footnoteId id="F4"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.8290</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>64727</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote 8</value>
                    <footnoteId id="F8"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These securities were sold solely by TA/Advent VIII L.P.</footnote>
        <footnote id="F2">These securities were sold solely by Advent Atlantic and Pacific III L.P.</footnote>
        <footnote id="F3">These securities were sold solely by TA Executives Fund LLC.</footnote>
        <footnote id="F4">These securities were sold solely by TA Investors LLC.</footnote>
        <footnote id="F5">TA Associates, Inc. is the Manager of TA Associates VIII LLC, which is the General Partner of TA/Advent VIII L.P. Each of TA Associates, Inc. and TA Associates VIII LLC may be deemed to have a beneficial interest in shares held by TA/Advent VIII L.P. and each disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest in such shares which is subject to indeterminable future events.</footnote>
        <footnote id="F6">TA Associates, Inc. is the General Partner of TA Associates AAP III Partners, which is the General Partner of Advent Atlantic and Pacific  III L.P. Each of TA Associates, Inc. and TA Associates AAP III Partners may be deemed to have a beneficial interest in shares held by Advent Atlantic and Pacific III L.P. and each disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest in such shares which is subject to indeterminable future events.</footnote>
        <footnote id="F7">TA Associates, Inc. is the Manager of TA Executives Fund LLC. TA Associates, Inc. may be deemed to have a beneficial interest in shares held by TA Executives Fund LLC and disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest in such shares which is subject to indeterminable future events.</footnote>
        <footnote id="F8">TA Associates, Inc. is the Manager of TA Investors LLC. TA Associates, Inc. may be deemed to have a beneficial interest in shares held by TA Investors LLC and disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest in such shares which is subject to indeterminable future events.</footnote>
    </footnotes>

    <remarks>The Reporting Persons are members of a 13(d) group owning more than 10% of the Issuer's oustanding common stock. The Reporting Persons have a representative on the Issuer's board of directors. Kurt R. Jaggers currently serves as the Reporting Persons' representative on the board of directors and, as such, the Reporting Persons are deemed directors of the Issuer.</remarks>

    <ownerSignature>
        <signatureName>TA Associates, Inc., By Thomas P. Alber, Chief Financial Officer</signatureName>
        <signatureDate>2007-12-13</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>TA/Advent VIII, By TA Associates VIII LLC, Its General Partner, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer</signatureName>
        <signatureDate>2007-12-13</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>TA Associates VIII LLC, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer</signatureName>
        <signatureDate>2007-12-13</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Advent Atlantic and Pacific III L.P., By TA Associates AAP III Partners, Its General Partner, By TA Associates, Inc., Its General Partner, By Thomas P. Alber, Chief Financial Officer</signatureName>
        <signatureDate>2007-12-13</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>TA Associates AAP III Partners, By TA Associates, Inc., Its General Partner, By Thomas P. Alber, Chief Financial Officer</signatureName>
        <signatureDate>2007-12-13</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>TA Executives Fund LLC, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer</signatureName>
        <signatureDate>2007-12-13</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>TA Investors LLC, By TA Associates, Inc., Its Manager, By Thomas P. Alber, Chief Financial Officer</signatureName>
        <signatureDate>2007-12-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
