-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 PXS5GaqbJmEg7Anx5Fd6QWkRfeYKiJKup7N7kdsZrOj8Dky9B1RCs8nMXOcsghd8
 uVQh1uSERVmgckI6mCzlPg==

<SEC-DOCUMENT>0001140361-10-007935.txt : 20100223
<SEC-HEADER>0001140361-10-007935.hdr.sgml : 20100223
<ACCEPTANCE-DATETIME>20100223154322
ACCESSION NUMBER:		0001140361-10-007935
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090317
FILED AS OF DATE:		20100223
DATE AS OF CHANGE:		20100223

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SZTUKA SUSAN A
		CENTRAL INDEX KEY:			0001396350

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-16503
		FILM NUMBER:		10625843

	MAIL ADDRESS:	
		STREET 1:		TEN TRINITY SQUARE
		CITY:			LONDON
		STATE:			X0
		ZIP:			EC3P 3AX

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			WILLIS GROUP HOLDINGS PLC
		CENTRAL INDEX KEY:			0001140536
		STANDARD INDUSTRIAL CLASSIFICATION:	INSURANCE AGENTS BROKERS & SERVICES [6411]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			L2
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		C/O WILLIS GROUP LIMITED
		STREET 2:		51 LIME STREET
		CITY:			LONDON ENGLAND
		STATE:			X0
		ZIP:			EC3M 7DQ
		BUSINESS PHONE:		44-20-3124-6000

	MAIL ADDRESS:	
		STREET 1:		C/O WILLIS GROUP LIMITED
		STREET 2:		51 LIME STREET
		CITY:			LONDON ENGLAND
		STATE:			X0
		ZIP:			EC3M 7DQ

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	WILLIS GROUP HOLDINGS LTD
		DATE OF NAME CHANGE:	20010514
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4/A
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2009-03-17</periodOfReport>

    <dateOfOriginalSubmission>2009-03-17</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001140536</issuerCik>
        <issuerName>WILLIS GROUP HOLDINGS PLC</issuerName>
        <issuerTradingSymbol>WSH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001396350</rptOwnerCik>
            <rptOwnerName>SZTUKA SUSAN A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O WILLIS GROUP HOLDINGS PLC</rptOwnerStreet1>
            <rptOwnerStreet2>51 LIME STREET</rptOwnerStreet2>
            <rptOwnerCity>LONDON</rptOwnerCity>
            <rptOwnerState>X0</rptOwnerState>
            <rptOwnerZipCode>EC3M 7D</rptOwnerZipCode>
            <rptOwnerStateDescription>UNITED KINGDOM</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Group HR Director</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2009-03-17</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>578</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1490.8411</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2009-03-18</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>51</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>21.81</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1439.8411</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2009-03-19</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>160</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.4266</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1279.8411</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>121.6628</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401(k) Plan</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Includes 249.8411 Common Shares of the Issuer under the Issuer?s Employee Stock Purchase Plan.</footnote>
        <footnote id="F2">Represents the approximate share equivalent of 454.737458 units in the Issuer?s 401(k) Plan.</footnote>
        <footnote id="F3">This amendment on Form 4/A to the Form 4 filed on March 19, 2009 (the ?Original Form 4?) is made solely to: (a) correct the transaction code; (b) correct the number of securities beneficially owned following the reported transactions, so as also to include shares owned in the Issuer?s Employee Stock Purchase Plan and the equivalent shares owned in the Issuer?s 401(k) Plan.  Except for the foregoing, no new or revised transactions or holdings are being reported.  All other information in the Original Form 4 remains the same.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Susan Sztuka Gunn</signatureName>
        <signatureDate>2010-02-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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