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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-04-07</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001306830</issuerCik>
        <issuerName>Celanese CORP</issuerName>
        <issuerTradingSymbol>CE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001314705</rptOwnerCik>
            <rptOwnerName>Blackstone LR Associates (Cayman) IV Ltd.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O THE BLACKSTONE GROUP</rptOwnerStreet1>
            <rptOwnerStreet2>345 PARK AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10154</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001314267</rptOwnerCik>
            <rptOwnerName>Blackstone Capital Partners (Cayman) Ltd 1</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O THE BLACKSTONE GROUP</rptOwnerStreet1>
            <rptOwnerStreet2>345 PARK AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10154</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001314268</rptOwnerCik>
            <rptOwnerName>Blackstone Capital Partners (Cayman) Ltd 2</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O THE BLACKSTONE GROUP</rptOwnerStreet1>
            <rptOwnerStreet2>345 PARK AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10154</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001314269</rptOwnerCik>
            <rptOwnerName>Blackstone Capital Partners (Cayman) Ltd 3</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O THE BLACKSTONE GROUP</rptOwnerStreet1>
            <rptOwnerStreet2>345 PARK AVENUE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10154</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001070843</rptOwnerCik>
            <rptOwnerName>PETERSON PETER G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O THE BLACKSTONE GROUP</rptOwnerStreet1>
            <rptOwnerStreet2>345 PARK AVE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10154</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001070844</rptOwnerCik>
            <rptOwnerName>SCHWARZMAN STEPHEN A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O THE BLACKSTONE GROUP</rptOwnerStreet1>
            <rptOwnerStreet2>345 PARK AVE</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10154</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Series A common stock, par value $0.0001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2005-04-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>57051899</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>61357578</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                    <footnoteId id="F7"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Series A common stock, par value $0.0001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2005-04-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3956713</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4255324</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                    <footnoteId id="F7"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Series A common stock, par value $0.0001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2005-04-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>31018837</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>33359813</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                    <footnoteId id="F7"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares of Series A common stock issued upon a mandatory conversion of all shared of Series B common stock pursuant
to the certificate of incorporation of Celanese Corporation which conversion is exempt under Rule 16b-6(b) under the
Securities Exchange Act of 1934, as amended (the &quot;Exchange Act&quot;).</footnote>
        <footnote id="F2">Blackstone Capital Partners (Cayman) Ltd. 1 (&quot;Cayman 1&quot;), Blackstone Capital Partners (Cayman) Ltd. 2 (&quot;Cayman 2&quot;) and
Blackstone Capital Partners (Cayman) Ltd. 3 (&quot;Cayman 3&quot; and, collectively with Cayman 1 and Cayman 2, the &quot;Cayman
Entities&quot;), respectively own 61,357,578, 4,255,324 and 33,359,813 shares of the Series A common stock reported as
beneficially owned in the above table. Blackstone Capital Partners (Cayman) IV L.P. (&quot;BCP IV&quot;) owns 100% of Cayman 1.
Blackstone Family Investment Partnership (Cayman) IV-A L.P. (&quot;BFIP&quot;) and Blackstone Capital Partners (Cayman) IV-A L.P.
(&quot;BCP IV-A&quot;) collectively own 100% of Cayman 2. Blackstone Chemical Coinvest Partners (Cayman) L.P. (&quot;BCCP&quot; and,
collectively with BCP IV, BFIP and BCP IV-A, the &quot;Blackstone Funds&quot;) owns 100% of Cayman 3.</footnote>
        <footnote id="F3">Each of the Blackstone Funds may be deemed to be the beneficial owner of the shares of Series A common stock held by the
Cayman Entities owned by such Blackstone Funds. Blackstone Management Associates (Cayman) IV L.P. (&quot;BMA&quot;) is the general
partner of each of the Blackstone Funds and, therefore, may be deemed to be the beneficial owner of the shares of Series A
common stock held by the Cayman Entities. Blackstone LR Associates (Cayman) IV Ltd. (&quot;BLRA&quot;) is the general partner of BMA
and may, therefore, be deemed to be the beneficial owner of the shares of Series A common stock held by the Cayman Entities.</footnote>
        <footnote id="F4">Messrs. Peter G. Peterson and Stephen A. Schwarzman are directors and controlling persons of BLRA and, as such, may be deemed
to share beneficial ownership of the shares of Series A common stock held by the Cayman Entities.</footnote>
        <footnote id="F5">Due to the electronic system's limitation of 10 Reporting Persons per joint filing, this statement is being filed in
duplicate.</footnote>
        <footnote id="F6">Information with respect to each of the Reporting Persons is given solely by such Reporting Persons, and no Reporting Person
has responsibility for the accuracy or completeness of information supplied by another Reporting Person.</footnote>
        <footnote id="F7">Pursuant to Rule 16a-1(a)(4) of the Exchange Act, each of the Reporting Persons, other than the Cayman Entities, herein
states that this filing shall not be deemed an admission that he or it is the beneficial owner of any of the shares of
Series A common stock covered by this Statement. Each of BLRA, BMA, Messrs. Peter G. Peterson and Stephen A. Schwarzman
disclaims beneficial ownership of the Series A common stock, except to the extent of its or his pecuniary interest in such
shares of Series A common stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>__________________________, Director</signatureName>
        <signatureDate>2005-04-08</signatureDate>
    </ownerSignature>
</ownershipDocument>
