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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 O2QNj9UqUu3bgfOc7J7RxcyvIxa6fU/8TDMtC1u2l9LVRdMvKZGfqLqzUPgbDPNA
 VPNOp3REWiHuWWQCAjtuVw==

<SEC-DOCUMENT>0000072741-10-000102.txt : 20100305
<SEC-HEADER>0000072741-10-000102.hdr.sgml : 20100305
<ACCEPTANCE-DATETIME>20100305160929
ACCESSION NUMBER:		0000072741-10-000102
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100303
FILED AS OF DATE:		20100305
DATE AS OF CHANGE:		20100305

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			WRAASE DENNIS R
		CENTRAL INDEX KEY:			0001180178

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-05324
		FILM NUMBER:		10660826

	MAIL ADDRESS:	
		STREET 1:		56 PROSPECT STREET
		CITY:			HARTFORD
		STATE:			CT
		ZIP:			06103
</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>2010-03-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001180178</rptOwnerCik>
            <rptOwnerName>WRAASE DENNIS R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O NORTHEAST UTILITIES,</rptOwnerStreet1>
            <rptOwnerStreet2>ONE FEDERAL STREET, BUILDING 111-4</rptOwnerStreet2>
            <rptOwnerCity>SPRINGFIELD</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01105</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Trustee</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares, $5.00 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2010-03-03</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4000.0</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>26.16</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4000.0</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price.  These shares were purchased in multiple transactions at prices ranging from $26.16 to $26.17, inclusive.  The reporting person undertakes to provide Northeast Utilities, any security holder, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth above.</footnote>
        <footnote id="F2">The reporting person holds these 4,000 shares jointly with his spouse.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Dennis R. Wraase By:  O. Kay Comendul/POA</signatureName>
        <signatureDate>2010-03-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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