<?xml version="1.0"?><?xml-stylesheet type="text/xsl" href="../4_X02.xsl"?><ownershipDocument>    <schemaVersion>X0303</schemaVersion>    <documentType>4</documentType>    <periodOfReport>2010-03-05</periodOfReport>    <notSubjectToSection16>0</notSubjectToSection16>    <issuer>        <issuerCik>0001361658</issuerCik>        <issuerName>WYNDHAM WORLDWIDE CORP</issuerName>        <issuerTradingSymbol>WYN</issuerTradingSymbol>    </issuer>    <reportingOwner>        <reportingOwnerId>            <rptOwnerCik>0001366776</rptOwnerCik>            <rptOwnerName>Rossi Nicola</rptOwnerName>        </reportingOwnerId>        <reportingOwnerAddress>            <rptOwnerStreet1>WYNDHAM WORLDWIDE CORPORATION</rptOwnerStreet1>            <rptOwnerStreet2>22 SYLVAN WAY</rptOwnerStreet2>            <rptOwnerCity>PARSIPPANY</rptOwnerCity>            <rptOwnerState>NJ</rptOwnerState>            <rptOwnerZipCode>07054</rptOwnerZipCode>            <rptOwnerStateDescription></rptOwnerStateDescription>        </reportingOwnerAddress>        <reportingOwnerRelationship>            <isDirector>0</isDirector>            <isOfficer>1</isOfficer>            <isTenPercentOwner>0</isTenPercentOwner>            <isOther>0</isOther>            <officerTitle>Sr. VP and Chief Account. Ofc.</officerTitle>        </reportingOwnerRelationship>    </reportingOwner>    <nonDerivativeTable>        <nonDerivativeTransaction>            <securityTitle>                <value>Common Stock</value>            </securityTitle>            <transactionDate>                <value>2010-03-05</value>            </transactionDate>            <transactionCoding>                <transactionFormType>4</transactionFormType>                <transactionCode>S</transactionCode>                <equitySwapInvolved>0</equitySwapInvolved>            </transactionCoding>            <transactionAmounts>                <transactionShares>                    <value>5000</value>                </transactionShares>                <transactionPricePerShare>                    <value>24.0064</value>                    <footnoteId id="F1"/>                </transactionPricePerShare>                <transactionAcquiredDisposedCode>                    <value>D</value>                </transactionAcquiredDisposedCode>            </transactionAmounts>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>6045</value>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>D</value>                </directOrIndirectOwnership>            </ownershipNature>        </nonDerivativeTransaction>        <nonDerivativeHolding>            <securityTitle>                <value>Common Stock</value>            </securityTitle>            <postTransactionAmounts>                <sharesOwnedFollowingTransaction>                    <value>45659</value>                    <footnoteId id="F2"/>                </sharesOwnedFollowingTransaction>            </postTransactionAmounts>            <ownershipNature>                <directOrIndirectOwnership>                    <value>D</value>                </directOrIndirectOwnership>            </ownershipNature>        </nonDerivativeHolding>    </nonDerivativeTable>    <footnotes>        <footnote id="F1">The average price for the sale of 5,000 shares in the aggregate was $24.0064 per share. Actual prices of shares sold was as follows: 2,700 shares at $24.00; 1,400 shares at $24.01; and 900 shares at $24.02.</footnote>        <footnote id="F2">Includes restricted stock units granted under the Wyndham Worldwide Corporation 2006 Equity and Incentive Plan as previously reported.</footnote>    </footnotes>    <ownerSignature>        <signatureName>/s/ Scott G. McLester as Attorney-in-Fact for Nicola Rossi</signatureName>        <signatureDate>2010-03-09</signatureDate>    </ownerSignature></ownershipDocument>