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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Uw/BohEXbCK3QVskdHEmT/uHjtTa2p0tHxG7W1314g7r1i8wqesgiSFmb8RYzZsE
 ssjOAEjZYWlO1NF24G7ANg==

<SEC-DOCUMENT>0000205716-04-000015.txt : 20040203
<SEC-HEADER>0000205716-04-000015.hdr.sgml : 20040203
<ACCEPTANCE-DATETIME>20040203114955
ACCESSION NUMBER:		0000205716-04-000015
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040130
FILED AS OF DATE:		20040203

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GRISE CHERYL W
		CENTRAL INDEX KEY:			0001192342

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-05324
		FILM NUMBER:		04561561

	MAIL ADDRESS:	
		STREET 1:		NORTHEAST UTILTIES
		STREET 2:		107 SELDEN STREET
		CITY:			BERLIN
		STATE:			CT
		ZIP:			06037

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NORTHEAST UTILITIES SYSTEM
		CENTRAL INDEX KEY:			0000072741
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC SERVICES [4911]
		IRS NUMBER:				042147929
		STATE OF INCORPORATION:			MA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		174 BRUSH HILL AVE
		CITY:			WEST SPRINGFIELD
		STATE:			MA
		ZIP:			01090-0010
		BUSINESS PHONE:		4137855871

	MAIL ADDRESS:	
		STREET 1:		107 SELDEN ST
		CITY:			BERLIN
		STATE:			CT
		ZIP:			06037-1616
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-01-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000072741</issuerCik>
        <issuerName>NORTHEAST UTILITIES SYSTEM</issuerName>
        <issuerTradingSymbol>NU</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001192342</rptOwnerCik>
            <rptOwnerName>GRISE CHERYL W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O NORTHEAST UTILITIES</rptOwnerStreet1>
            <rptOwnerStreet2>107 SELDEN STREET</rptOwnerStreet2>
            <rptOwnerCity>BERLIN</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06037</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President - Utility Group</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares, $5 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2004-01-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>417</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1539</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Deferred Comp Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Employee matching contributions under the Northeast Utilities Deferred Compensation Plan for Executives, receipt of which has been deferred.</footnote>
        <footnote id="F2">Shares (including reinvested dividends) receipt of which has been deferred pursuant to the Northeast Utilities Deferred Compensation Plan for Executives, as of January 30, 2004, according to information supplied by the plan's recordkeeper.  Mrs. Grise also beneficially owns 3,456 shares indirectly, which are held by the trustee of the Northeast Utilities Service Company 401k Plan, according to information supplied by the plan's recordkeeper; 40,807 shares directly, previously reported on Form 4; 285 shares indirectly, which are owned by her husband as custodian for their children and were previously reported on Form 4; and 171,228 stock options previously reported on Form 4.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Cheryl W. Grise</signatureName>
        <signatureDate>2004-02-03</signatureDate>
    </ownerSignature>
</ownershipDocument>

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