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    <submissionType>D/A</submissionType>

    <testOrLive>LIVE</testOrLive>

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        <entityName>MASTEC INC</entityName>
        <issuerAddress>
            <street1>800 S. DOUGLAS ROAD</street1>
            <street2>12TH FLOOR</street2>
            <city>CORAL GABLES</city>
            <stateOrCountry>FL</stateOrCountry>
            <stateOrCountryDescription>FLORIDA</stateOrCountryDescription>
            <zipCode>33134</zipCode>
        </issuerAddress>
        <issuerPhoneNumber>305-599-1800</issuerPhoneNumber>
        <jurisdictionOfInc>FLORIDA</jurisdictionOfInc>
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            <previousName>BURNUP &amp; SIMS INC</previousName>
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        <entityType>Corporation</entityType>
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                <firstName>Jorge</firstName>
                <lastName>Mas</lastName>
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                <street1>800 S. Douglas Road</street1>
                <street2>12th Floor</street2>
                <city>Coral Gables</city>
                <stateOrCountry>FL</stateOrCountry>
                <stateOrCountryDescription>FLORIDA</stateOrCountryDescription>
                <zipCode>33134</zipCode>
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                <relationship>Director</relationship>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Jose</firstName>
                <lastName>Mas</lastName>
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                <street1>800 S. Douglas Road</street1>
                <street2>12th Floor</street2>
                <city>Coral Gables</city>
                <stateOrCountry>FL</stateOrCountry>
                <stateOrCountryDescription>FLORIDA</stateOrCountryDescription>
                <zipCode>33134</zipCode>
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            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
                <relationship>Director</relationship>
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            <relationshipClarification></relationshipClarification>
        </relatedPersonInfo>
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            <relatedPersonName>
                <firstName>Robert</firstName>
                <lastName>Apple</lastName>
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                <street1>800 S. Douglas Road</street1>
                <street2>12th Floor</street2>
                <city>Coral Gables</city>
                <stateOrCountry>FL</stateOrCountry>
                <stateOrCountryDescription>FLORIDA</stateOrCountryDescription>
                <zipCode>33134</zipCode>
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                <relationship>Executive Officer</relationship>
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            <relatedPersonName>
                <firstName>Paul</firstName>
                <lastName>DiMarco</lastName>
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                <street2>12th Floor</street2>
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                <stateOrCountryDescription>FLORIDA</stateOrCountryDescription>
                <zipCode>33134</zipCode>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Alberto</firstName>
                <lastName>de Cardenas</lastName>
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                <street1>800 S. Douglas Road</street1>
                <street2>12th Floor</street2>
                <city>Coral Gables</city>
                <stateOrCountry>FL</stateOrCountry>
                <stateOrCountryDescription>FLORIDA</stateOrCountryDescription>
                <zipCode>33134</zipCode>
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                <relationship>Executive Officer</relationship>
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        </relatedPersonInfo>
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            <relatedPersonName>
                <firstName>Robert</firstName>
                <lastName>Campbell</lastName>
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                <street2>12th Floor</street2>
                <city>Coral Gables</city>
                <stateOrCountry>FL</stateOrCountry>
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                <zipCode>33134</zipCode>
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                <relationship>Director</relationship>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Ernst</firstName>
                <lastName>Csiszar</lastName>
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                <street1>800 S. Douglas Road</street1>
                <street2>12th Floor</street2>
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                <stateOrCountryDescription>FLORIDA</stateOrCountryDescription>
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        <relatedPersonInfo>
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                <firstName>Robert</firstName>
                <lastName>Dwyer</lastName>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Julia</firstName>
                <lastName>Johnson</lastName>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Javier</firstName>
                <lastName>Palomarez</lastName>
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        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Ava</firstName>
                <lastName>Parker</lastName>
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                <stateOrCountry>FL</stateOrCountry>
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                <zipCode>33134</zipCode>
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            <relatedPersonRelationshipList>
                <relationship>Director</relationship>
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    <offeringData>
        <industryGroup>
            <industryGroupType>Other</industryGroupType>
        </industryGroup>
        <issuerSize>
            <revenueRange>Over $100,000,000</revenueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06b</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>true</isAmendment>
                <previousAccessionNumber>0001200876-22-000008</previousAccessionNumber>
            </newOrAmendment>
            <dateOfFirstSale>
                <value>2021-12-30</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>false</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isEquityType>true</isEquityType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>true</isBusinessCombinationTransaction>
            <clarificationOfResponse></clarificationOfResponse>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>0</minimumInvestmentAccepted>
        <salesCompensationList></salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>Indefinite</totalOfferingAmount>
            <totalAmountSold>194397549</totalAmountSold>
            <totalRemaining>Indefinite</totalRemaining>
            <clarificationOfResponse></clarificationOfResponse>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>false</hasNonAccreditedInvestors>
            <totalNumberAlreadyInvested>102</totalNumberAlreadyInvested>
        </investors>
        <salesCommissionsFindersFees>
            <salesCommissions>
                <dollarAmount>0</dollarAmount>
            </salesCommissions>
            <findersFees>
                <dollarAmount>0</dollarAmount>
            </findersFees>
            <clarificationOfResponse></clarificationOfResponse>
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        <useOfProceeds>
            <grossProceedsUsed>
                <dollarAmount>0</dollarAmount>
            </grossProceedsUsed>
            <clarificationOfResponse></clarificationOfResponse>
        </useOfProceeds>
        <signatureBlock>
            <authorizedRepresentative>false</authorizedRepresentative>
            <signature>
                <issuerName>MASTEC INC</issuerName>
                <signatureName>/s/Alberto de Cardenas</signatureName>
                <nameOfSigner>Alberto de Cardenas</nameOfSigner>
                <signatureTitle>Executive Vice President, General Counsel and Secretary</signatureTitle>
                <signatureDate>2024-11-12</signatureDate>
            </signature>
        </signatureBlock>
    </offeringData>
</edgarSubmission>