<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-09-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000101829</issuerCik>
        <issuerName>UNITED TECHNOLOGIES CORP /DE/</issuerName>
        <issuerTradingSymbol>UTX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001356702</rptOwnerCik>
            <rptOwnerName>MYERS RICHARD B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>UNITED TECHNOLOGIES CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>ONE FINANCIAL PLAZA</rptOwnerStreet2>
            <rptOwnerCity>HARTFORD</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06101</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock Unit</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-09-13</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2347.7853</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>63.8900</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2347.7853</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2347.7853</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-09-13</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1565.1902</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>63.8900</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1565.1902</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1565.1902</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Consists of Phantom Stock Units acquired at the election of the reporting person in lieu of his/her annual retainer for services as a non-employee director under a company program that permits him/her to defer receipt of the retainer.  Upon termination of services on the Board of Directors, all such Phantom Stock Units are payable in cash.</footnote>
        <footnote id="F2">Consists of a one-time grant of deferred Restricted Stock Units awarded on the date of election.  Vesting occurs over a five year period.  Upon termination of services on the Board of Directors, all such deferred Restricted Stock Units are payable in cash.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>By: /s/ Charles F. Hildebrand as Attorney-in-Fact</signatureName>
        <signatureDate>2006-09-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2006-09-13
0
0000101829
UNITED TECHNOLOGIES CORP /DE/
UTX
0001356702
MYERS RICHARD B
UNITED TECHNOLOGIES CORPORATION
ONE FINANCIAL PLAZA
HARTFORD
CT
06101
1
0
0
0
Phantom Stock Unit
2006-09-13
4
A
0
2347.7853
63.8900
A
Common Stock
2347.7853
2347.7853
D
Restricted Stock Units
2006-09-13
4
A
0
1565.1902
63.8900
A
Common Stock
1565.1902
1565.1902
D
Consists of Phantom Stock Units acquired at the election of the reporting person in lieu of his/her annual retainer for services as a non-employee director under a company program that permits him/her to defer receipt of the retainer.  Upon termination of services on the Board of Directors, all such Phantom Stock Units are payable in cash.
Consists of a one-time grant of deferred Restricted Stock Units awarded on the date of election.  Vesting occurs over a five year period.  Upon termination of services on the Board of Directors, all such deferred Restricted Stock Units are payable in cash.
By: /s/ Charles F. Hildebrand as Attorney-in-Fact
2006-09-14