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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>0000072741-10-000053.txt : 20100202
<SEC-HEADER>0000072741-10-000053.hdr.sgml : 20100202
<ACCEPTANCE-DATETIME>20100202153641
ACCESSION NUMBER:		0000072741-10-000053
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100129
FILED AS OF DATE:		20100202
DATE AS OF CHANGE:		20100202

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:		10566790

	MAIL ADDRESS:	
		STREET 1:		NORTHEAST UTILITIES SERVICE COMPANY
		STREET 2:		107 SELDEN STREET
		CITY:			BERLIN
		STATE:			CT
		ZIP:			06037

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NORTHEAST UTILITIES
		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:		ONE FEDERAL STREET
		STREET 2:		BUILDING 111-4
		CITY:			SPRINGFIELD
		STATE:			MA
		ZIP:			01105
		BUSINESS PHONE:		8606655000

	MAIL ADDRESS:	
		STREET 1:		107 SELDEN ST
		CITY:			BERLIN
		STATE:			CT
		ZIP:			06037-1616

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NORTHEAST UTILITIES SYSTEM
		DATE OF NAME CHANGE:	19961121
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>main4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-01-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001054818</rptOwnerCik>
            <rptOwnerName>SHIVERY CHARLES W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O NORTHEAST UTILITIES</rptOwnerStreet1>
            <rptOwnerStreet2>56 PROSPECT STREET</rptOwnerStreet2>
            <rptOwnerCity>HARTFORD</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06103</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chrmn of Bd, Pres &amp;CEO/Ttee</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares, $5.00 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>411330.0</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares, $5.00 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1754.0</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>401K Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Shares</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-01-29</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1036.0</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.88</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1036.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7548.0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Includes restricted share units and dividend equivalents thereon.  In addition, the reporting person holds 29,024 options to purchase Common Shares, previously reported on Form 4.  Included among shares directly held are 453 shares acquired on July 31, 2009 and 537 shares acquired on January 29, 2010, pursuant to the Northeast Employee Stock Purchase Plan II, a Section 423(b) plan under the Internal Revenue Code, which shares are exempt from Form 4 reporting.  Of the total shares owned, the reporting person holds 1,500 of these shares jointly with his spouse.</footnote>
        <footnote id="F2">Shares held in trust under the Northeast Utilities Service Company 401K Plan, a qualified plan as of January 29, 2010, according to information supplied by the Plan's recordkeeper.</footnote>
        <footnote id="F3">Matching contributions of reporting person's deferred compensation contributions in 2009 under the Northeast Utilities Deferred Compensation Plan for Executives, a non-qualified deferred compensation plan, that are nominally invested as Common Shares (hereby referred to as phantom shares).  While the average share price for the matching contributions was $22.88, the actual price was determined on the applicable payroll date on which the deferred compensation contribution was made.  Each phantom share represents the right to receive the cash value of one share of NU Common upon a distribution event, following vesting.  Additional phantom shares are issued upon the automatic reinvestment of dividend-equivalents exempt from the line item reporting under SEC Rule 16a-11.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Charles W. Shivery</signatureName>
        <signatureDate>2010-02-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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