-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0000205716-04-000014.txt : 20040203
<SEC-HEADER>0000205716-04-000014.hdr.sgml : 20040203
<ACCEPTANCE-DATETIME>20040203110259
ACCESSION NUMBER:		0000205716-04-000014
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040130
FILED AS OF DATE:		20040203

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SHIVERY CHARLES W
		CENTRAL INDEX KEY:			0001054818

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-05324
		FILM NUMBER:		04561372

	BUSINESS ADDRESS:	
		STREET 1:		BALTIMORE GAS & ELECTRIC CO
		STREET 2:		PO BOX 1475
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21203
		BUSINESS PHONE:		4102345575

	MAIL ADDRESS:	
		STREET 1:		BALTIMORE GAS & ELECTRIC CO
		STREET 2:		PO BOX 1475
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21203
</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>0001054818</rptOwnerCik>
            <rptOwnerName>SHIVERY CHARLES 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</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>610</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1119</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">Employer 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.  Mr. Shivery also beneficially owns 324 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; 29,024 stock options, previously reported on Form 4; and 17,560 shares owned directly, 501 of which were acquired on January 30, 2004 pursuant to the Northeast Utilities Employee Share Purchase Plan II, a Secton 423(b) plan, which are exempt from Form 4 reporting, and the balance of which were previously reported on Form 4.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Charles W. Shivery</signatureName>
        <signatureDate>2004-02-03</signatureDate>
    </ownerSignature>
</ownershipDocument>

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