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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2005-03-21</periodOfReport>

    <dateOfOriginalSubmission>2005-03-22</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000101271</issuerCik>
        <issuerName>UNITED INDUSTRIAL CORP /DE/</issuerName>
        <issuerTradingSymbol>UIC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001251057</rptOwnerCik>
            <rptOwnerName>STRADER FREDERICK M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>124 INDUSTRY LANE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>HUNT VALLEY</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21030</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>32.79</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-03-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>30000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2009-03-10</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>30000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30000</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The option will vest in three equal installments on March 10, 2006, March 10, 2007, and March 10, 2008.</footnote>
        <footnote id="F2">Not applicable.</footnote>
        <footnote id="F3">The sole purpose of this amendment is to correct an error in the number reported in column 9 of the Form 4 as originally filed on March 22, 2005.  Following the reported transaction, Mr. Strader beneficially owned 30,000 units of the class of derivative securities that were the subject of the original Form 4 filing (i.e., the right to buy 30,000 shares of the common stock of the Company at an exercise price of $32.79).  The 225,000 units originally reported in column 9 represented the number of underlying shares of common stock of the Company beneficially owned by Mr. Strader on the date of filing.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Lara L. Hjortsberg, as power of attorney for Frederick M. Strader</signatureName>
        <signatureDate>2005-06-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
