-----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,
 A9khgoD4Wrvj6n+cxA+O64M1kZpGaIyYMgQH39nABbAqZ6bxjt9cxQEsaBAxjRf8
 xNtxzwVibIzaCJo8foo09A==

<SEC-DOCUMENT>0001179110-03-008408.txt : 20031003
<SEC-HEADER>0001179110-03-008408.hdr.sgml : 20031003
<ACCEPTANCE-DATETIME>20031003132955
ACCESSION NUMBER:		0001179110-03-008408
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031001
FILED AS OF DATE:		20031003

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			APPEL PETER A
		CENTRAL INDEX KEY:			0001227104

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-16209
		FILM NUMBER:		03927245

	MAIL ADDRESS:	
		STREET 1:		C/O ARCH CAPITAL HOLDINGS LTD
		STREET 2:		20 HORSENECK LANE
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ARCH CAPITAL GROUP LTD
		CENTRAL INDEX KEY:			0000947484
		STANDARD INDUSTRIAL CLASSIFICATION:	FIRE, MARINE & CASUALTY INSURANCE [6331]
		IRS NUMBER:				061424716
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		20 HORSENECK LANE
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830
		BUSINESS PHONE:		2038624300

	MAIL ADDRESS:	
		STREET 1:		20 HORSENECK LANE
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RISK CAPITAL HOLDINGS INC
		DATE OF NAME CHANGE:	19950816

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	RISK CAPITAL RE INC
		DATE OF NAME CHANGE:	19950703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
<periodOfReport>2003-10-01</periodOfReport>
<notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000947484</issuerCik>
        <issuerName>ARCH CAPITAL GROUP LTD</issuerName>
        <issuerTradingSymbol>ACGL</issuerTradingSymbol>
</issuer>
<reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001227104</rptOwnerCik>
            <rptOwnerName>APPEL PETER A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ARCH CAPITAL GROUP LTD.</rptOwnerStreet1>
            <rptOwnerStreet2>45 REID STREET, 3RD FLOOR</rptOwnerStreet2>
            <rptOwnerCity>HAMILTON</rptOwnerCity>
            <rptOwnerState>D0</rptOwnerState>
            <rptOwnerZipCode>HM 12</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector>
<isOfficer>0</isOfficer>
<isTenPercentOwner>0</isTenPercentOwner>
<isOther>0</isOther>
<officerTitle></officerTitle>
<otherText></otherText>
</reportingOwnerRelationship>
</reportingOwner>
<nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Shares, par value $0.01 per share</value>
</securityTitle>
<transactionDate><value>2003-10-01</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>A</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>1092</value>
<footnoteId id="F1"></footnoteId>
</transactionShares>
<transactionPricePerShare><footnoteId id="F1"></footnoteId>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>147279</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
<nonDerivativeTransaction><securityTitle><value>Common Shares, par value $0.01 per share</value>
</securityTitle>
<transactionDate><value>2003-10-01</value>
</transactionDate>
<transactionCoding><transactionFormType>4</transactionFormType>
<transactionCode>A</transactionCode>
<equitySwapInvolved>0</equitySwapInvolved>
</transactionCoding>
<transactionAmounts><transactionShares><value>607</value>
<footnoteId id="F2"></footnoteId>
</transactionShares>
<transactionPricePerShare><footnoteId id="F2"></footnoteId>
</transactionPricePerShare>
<transactionAcquiredDisposedCode><value>A</value>
</transactionAcquiredDisposedCode>
</transactionAmounts>
<postTransactionAmounts><sharesOwnedFollowingTransaction><value>147886</value>
</sharesOwnedFollowingTransaction>
</postTransactionAmounts>
<ownershipNature><directOrIndirectOwnership><value>D</value>
</directOrIndirectOwnership>
</ownershipNature>
</nonDerivativeTransaction>
</nonDerivativeTable>
<derivativeTable></derivativeTable>
<footnotes><footnote id="F1">Represents shares granted as a part of director-elected annual retainer for serving as a director of Arch Capital Group Ltd.</footnote>
<footnote id="F2">Subject to the terms of the restricted share agreement, this represents restricted shares that will vest on August 31, 2004.</footnote>
</footnotes>
<ownerSignature><signatureName>/s/ Peter A. Appel</signatureName>
<signatureDate>2003-10-01</signatureDate>
</ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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