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

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2004-09-29</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001170593</issuerCik>
        <issuerName>PRIMUS GUARANTY LTD</issuerName>
        <issuerTradingSymbol>PRS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001164098</rptOwnerCik>
            <rptOwnerName>TRANSAMERICA LIFE INSURANCE CO</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O AEGON USA INVESTMENT MANAGEMENT LLC</rptOwnerStreet1>
            <rptOwnerStreet2>4333 EDGEWOOD ROAD N.E.</rptOwnerStreet2>
            <rptOwnerCity>CEDAR RAPIDS</rptOwnerCity>
            <rptOwnerState>IA</rptOwnerState>
            <rptOwnerZipCode>52499-5335</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Series A Conv. Voting Pref. Shares, par value $.01 per share</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F5"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2004-09-29</value>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Shares, par value $.01 per share</value>
                    <footnoteId id="F1"/>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>46289152</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Par value shall become $.08 per share upon completion of the initial public offering by Primus Guaranty, Ltd., reflecting a one for eight reverse share split to be effected immediately prior to such offering.</footnote>
        <footnote id="F2">Includes 1,200,000 shares of Series A Convertible Voting Preferred Shares, par value $.01 per share, that are convertible into 46,289,152 common shares, par value $.01 per share.</footnote>
        <footnote id="F3">Upon completion of the initial public offering of Primus Guaranty, Ltd., Series A Convertible Voting Preferred Shares will convert into common shares, par value $.08 per share.</footnote>
        <footnote id="F4">Not Applicable.</footnote>
        <footnote id="F5">Each Series A Convertible Voting Preferred Share, par value $.01 per share, is converted by dividing $25.00 by $0.6481.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ TRANSAMERICA LIFE INSURANCE COMPANY</signatureName>
        <signatureDate>2004-09-29</signatureDate>
    </ownerSignature>
</ownershipDocument>

