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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 CuVa18qsKuw3xOsEBZ78WHodD4AC2gBvbj2V8bPx/DZ06bH1KRZEIl+Iifev2fST
 mGM8GxqY54hrtfMbxxdLug==

<SEC-DOCUMENT>0000890926-05-000113.txt : 20050914
<SEC-HEADER>0000890926-05-000113.hdr.sgml : 20050914
<ACCEPTANCE-DATETIME>20050914130654
ACCESSION NUMBER:		0000890926-05-000113
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050912
FILED AS OF DATE:		20050914
DATE AS OF CHANGE:		20050914

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PRIMUS GUARANTY LTD
		CENTRAL INDEX KEY:			0001170593
		STANDARD INDUSTRIAL CLASSIFICATION:	FINANCE SERVICES [6199]
		IRS NUMBER:				000000000

	BUSINESS ADDRESS:	
		STREET 1:		C/O PRIMUS ASSET MANAGEMENT INC
		STREET 2:		360 MADISON AVE 23RD FL
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10017
		BUSINESS PHONE:		2126972227

	MAIL ADDRESS:	
		STREET 1:		C/O PRIMUS ASSET MANAGEMENT INC
		STREET 2:		360 MADISON AVE 23RD FL
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10017

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			RADIAN GROUP INC
		CENTRAL INDEX KEY:			0000890926
		STANDARD INDUSTRIAL CLASSIFICATION:	SURETY INSURANCE [6351]
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32307
		FILM NUMBER:		051083937

	BUSINESS ADDRESS:	
		STREET 1:		1601 MARKET STREET
		STREET 2:		12TH FLOOR
		CITY:			PHILADELPHIA
		STATE:			PA
		ZIP:			19103
		BUSINESS PHONE:		2155646600

	MAIL ADDRESS:	
		STREET 1:		1601 MARKET ST
		STREET 2:		12TH FLOOR
		CITY:			PHILADELPHIA
		STATE:			PA
		ZIP:			19103

	FORMER NAME:	
		FORMER CONFORMED NAME:	CMAC INVESTMENT CORP
		DATE OF NAME CHANGE:	19960126
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-09-12</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000890926</rptOwnerCik>
            <rptOwnerName>RADIAN GROUP INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1601 MARKET ST</rptOwnerStreet1>
            <rptOwnerStreet2>11TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>PHILADELPHIA</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>19103</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Former 10% Owner</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares, par value $.08 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2005-09-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>660000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>10.56</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4084506</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>/s/ Howard S. Yaruss, Secretary of Radian Group Inc.</signatureName>
        <signatureDate>2005-09-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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