Exhibit 10.4

EMPLOYEE STOCKHOLDERS AGREEMENT

BY AND AMONG

CELANESE CORPORATION

AND

THE OTHER PARTIES NAMED HEREIN

______________________________

Dated as of January 21, 2005

______________________________

TABLE OF CONTENTS

Annex I          Form of Consent of Spouse

-i-

Annex II         Form of Acknowledgment and Agreement

-ii-

EMPLOYEE STOCKHOLDERS AGREEMENT

This EMPLOYEE STOCKHOLDERS AGREEMENT (this “ Agreement ”) is dated as of January 21, 2005 by and among Celanese Corporation, a Delaware corporation (the “ Company ”), Blackstone Capital Partners (Cayman) Ltd. 1 (“ BCP 1 ”), Blackstone Capital Partners (Cayman) Ltd. 2 (“ BCP 2 ”), Blackstone Capital Partners (Cayman) Ltd. 3 (“ BCP 3 ” and, together with BCP 1 and BCP 2, the “ Sponsors ” and each a “ Sponsor ”) and the parties identified on the signature pages hereto or to the supplementary agreements referred to in Section 21 hereof as Employee Stockholders (the “ Employee Stockholders ” and, together with the Company and the Sponsors, the “ Parties ”).

R E C I T A L S :

WHEREAS, pursuant to the Company’s 2004 Stock Incentive Plan (as the same may be amended, supplemented or modified from time to time, the “ Plan ”), each Employee Stockholder has, either as of the date hereof or from time to time after the date hereof, entered into a Subscription Agreement (the “ Subscription Agreement ”) with the Company pursuant to which it has agreed to purchase from the Company, and the Company has agreed to sell to such Employee Stockholder, the number of shares of Common Stock set forth on Schedule A to the Subscription Agreement;

WHEREAS, pursuant to the Plan, the Company may from time to time grant other Awards (as defined in the Plan) to Employee Stockholders; and

WHEREAS, the Parties wish to enter into certain agreements with respect to the holdings by the Sponsors and the Employee Stockholders and their respective Permitted Transferees of Common Stock and securities exercisable or exchangeable for or convertible into Common Stock.

NOW, THEREFORE, in consideration of the mutual covenants and agreements contained in the this Agreement, the receipt and sufficiency of which are hereby acknowledged, the Parties further acknowledge and agree to the following:

1.             Definitions of Words and Phrases .   As used in this Agreement:

“ Affiliate ” means, with respect to any Person, any other Person directly or indirectly controlling, controlled by or under common control with such Person.

“ Board of Directors ” means the board of directors of the Company.

“ Business Day ” means a day other than a Saturday, Sunday, federal or New York State holiday or other day on which commercial banks in New York City are authorized or required by law to close.

“ Cause ” means, with respect to any Employee Stockholder, “Cause” as defined in the employment agreement or change in control agreement between the Company or any of its Subsidiaries and such Employee Stockholder (with respect to any such Employee Stockholder, as the same may be amended in accordance with the terms thereof, such Employee Stockholder’s

“ Employment Agreement ”) or, if not defined therein or if there is no such agreement, “Cause” means (A) such Employee Stockholder’s willful failure to perform his or her duties hereunder (other than as a result of total or partial incapacity due to physical or mental illness) for a period of 30 days following written notice by the Company to such Employee Stockholder of such failure, (B) commission of (x) a felony (other than traffic-related) under the laws of the United States or any state thereof or any similar criminal act in a jurisdiction outside the United States or (y) a crime involving moral turpitude, (C) such Employee Stockholder’s willful malfeasance or willful misconduct which is demonstrably injurious to the Company, (D) any act of fraud by such Employee Stockholder or (E) such Employee Stockholder’s breach of the provisions of Section 5 of this Agreement.

“ Change of Control ” means (i) the sale or disposition, in one or a series of related transactions, of all or substantially all of the assets of the Company to any Person or Group other than any of the Sponsors or any of their respective Permitted Transferees or (ii) if any Person or Group, other than any of the Sponsors or any of their respective Permitted Transferees, is or becomes the “beneficial owner” (as defined in Rules 13d-3 and 13d-5 under the Exchange Act), directly or indirectly, of more than 51% of the total voting power of the voting stock of the Company, including by way of merger, consolidation or otherwise.

“ Closing Date ” means, with respect to any Employee Stockholder, the date on which such Employee Stockholder initially acquired Shares pursuant to such Employee Stockholder’s Subscription Agreement.

“ Commission ” means the U.S. Securities and Exchange Commission.

“ Common Stock ” means the Series A Common Stock, par value $0.0001 per share, of the Company and the Series B Common Stock, par value $0.0001 per share, of the Company.

“ Common Stock Equivalent ” means any stock, warrants, rights, calls, options or other securities exchangeable or exercisable for or convertible into Common Stock.

“ Company ” has the meaning set forth in the Preamble.

“ Confidential Information ” has the meaning set forth in Section 5.

“ Employee Stockholder ” has the meaning set forth in the Preamble.

“ Employee Stockholder Group ” means, with respect to any Employee Stockholder, collectively such Employee Stockholder and any Employee Stockholder’s Trust and Employee Stockholder’s Estate of such Employee Stockholder.

“ Employee Stockholder’s Estate ” means, with respect to any Employee Stockholder, the conservators, guardians, executors, administrators, testamentary trustees, legatees, spouse (or ex-spouse) or lineal descendants (including adopted children) of such Employee Stockholder.

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“ Employee Stockholder’s Trust ” means, with respect to any Employee Stockholder, a limited partnership, limited liability company, trust or custodianship, the beneficiaries of which may include only such Employee Stockholder, his or her spouse (or ex-spouse) or his or her lineal descendants (including adopted) or, if at any time after any transfer of Shares to such Employee Stockholder’s Trust there shall be no then living spouse or lineal descendants, such beneficiaries may include the estate of a deceased beneficiary.

“ Exchange Act ” means the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder, or any successor statute thereto.

“ Good Reason ” means, with respect to any Employee Stockholder, “Good Reason” as defined in such Employee Stockholder’s Employment Agreement or, if not defined therein or if there is no such agreement, “Good Reason” means (i) a substantial diminution in such Employee Stockholder’s position or duties, adverse change in reporting lines, or assignment of duties materially inconsistent with his position (other than due to increased responsibility or a promotion), (ii) any reduction in such Employee Stockholder’s base salary or annual bonus opportunity or (iii) failure of the Company (or a Subsidiary of the Company, if such Subsidiary is the Employee Stockholder’s employer) to pay compensation or benefits when due, in each case which is not cured within 30 days following the Company’s (or Subsidiary’s) receipt of written notice from such Employee Stockholder describing the event constituting Good Reason.

“ Good Termination ” means the termination of an Employee Stockholder’s employment with the Company or a Subsidiary of the Company, as the case may be (i) by the Company (or Subsidiary) without Cause, (ii) by the Employee Stockholder for Good Reason or (iii) due to death or Disability.

“ Group ” means any syndicate or group that would be considered a “person” for purposes of Sections 13(d) of the Exchange Act.

“ Initial Public Offering ” means the closing of the first sale of common equity or equivalent securities of the Company to the public pursuant to an effective registration statement (other than a registration statement on Form S-4 or S-8 or any similar or successor form) filed under the Securities Act.

“ IPO Effectiveness Date ” means the date upon which the Company closes its Initial Public Offering.

“ Lock-Up Period ” has the meaning set forth in Section 2(a).

“ Parties ” has the meaning set forth in the Preamble.

“ Permitted Transferee ” means any Employee Stockholder’s Estate or Employee Stockholder’s Trust of such Employee Stockholder that becomes a party to, and is bound to the same extent as its transferor by the terms of, this Agreement.

“ Person ” means any individual, corporation, limited liability company, partnership, trust, joint stock company, business trust, unincorporated association, joint venture, governmental authority or other legal entity of any nature whatsoever.

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“ Plan ” has the meaning set forth in the Preamble.

“ Public Offering ” means a sale of Shares to the public in a firm commitment underwritten public offering pursuant to an effective registration statement (other than a registration statement on Form S-4, S-8 or any successor to such forms) filed under the Securities Act.

“ Register ”, “ registered ” and “ registration ” refer to a registration effected by preparing and filing a registration statement or similar document in compliance with the Securities Act, and the automatic effectiveness or the declaration or ordering of effectiveness of such registration statement or document.

“ Registrable Shares ” means the Shares, provided that such Shares shall cease to be Registrable Shares if and when (i) a registration statement with respect to the disposition of such Shares shall have become effective under the Securities Act and such Shares shall have been disposed of pursuant to such effective registration statement, (ii) such Shares shall have been sold under circumstances in which all of the applicable conditions of Rule 144 (or any similar provisions then in force) under the Securities Act are met, (iii) such Shares shall have been otherwise transferred, new certificates not bearing restrictive legends shall have been delivered by the Company in lieu thereof and further disposition thereof shall not require registration or qualification of them under the Securities Act or any state securities or Blue Sky laws, (iv) such Shares may be sold pursuant to Rule 144(k) under the Securities Act or (v) such Shares shall have ceased to be outstanding.

“ Registration Rights Agreement ” means the amended and restated registration rights agreement, dated as of January 26, 2005, by and among the Company, the Sponsors and BA Capital Investors Sidecar Fund, L.P., as it may be amended, modified, supplemented or restated from time to time.

“ Securities Act ” means the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder, or any successor statute thereto.

“ Senior Manager ” means any of Mr. David N. Weidman, Mr. Lyndon B. Cole, Mr. Corliss J. Nelson and Dr. Andreas Pohlmann.

“ Shares ” means, with respect to each Stockholder, all shares, whether now owned or hereafter acquired, of Common Stock, and any other Common Stock Equivalents owned thereby.

“ Sponsors ” has the meaning set forth in the Preamble.

“ Stockholder ” means each of the Sponsors, the Employee Stockholders and their respective Permitted Transferees.

“ Subsidiary ” means, with respect to any Person, any corporation, partnership, association or other business entity of which 50% or more of the total voting power of shares of capital stock entitled (without regard to the occurrence of any contingency) to vote in the election of directors, managers or trustees thereof, or 50% or more of the equity interests therein,

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is at the time owned or controlled, directly or indirectly, by any Person or one or more of the other Subsidiaries of such Person or a combination thereof.

“ Subscription Agreement ” has the meaning set forth in the Preamble.

“ Transfer ” or “ transfer ” means a transfer, sale, assignment, pledge, hypothecation or other disposition, whether directly or indirectly pursuant to the creation of a derivative security, the grant of an option or other right, the imposition of a restriction on disposition or voting or transfer by operation of law.  When used as a verb, “ transfer ” shall have the correlative meaning.  In addition, “ transferred ” and “ transferee ” shall have the correlative meanings.

“ Triggering Event ” has the meaning set forth in Section 3(a).

2.             Limitations on Transfer . 

(a)           Until the earlier of (i) the date that is two years and one day after the expiration of any Company or underwriter “lock-up” period applicable to an Employee Stockholder following an Initial Public Offering or (ii) the date on which a Change of Control occurs (the period ending on the earlier of (i) or (ii), the “ Lock-Up Period ”), except as required by law, no Employee Stockholder shall transfer any Shares (other than a transfer pursuant to Section 2(b), Section 2(c) or any other transfer to the Company) without the prior written consent of the Sponsors; provided , that this clause (a) shall not apply to a transfer of Shares issued to such Employee Stockholder pursuant to the Company’s Deferred Compensation Plan following the applicable Closing Date.

(i)            After the Lock-Up Period, any Employee Stockholder may transfer all or a portion of its Shares in accordance with and subject to the provisions of this Agreement (including, without limitation, Sections 2(d)).

(ii)           Any attempt to transfer any Shares or any rights thereunder in violation of this Section 2 shall be null and void ab initio .  The Company shall not record on its stock transfer books or otherwise any transfer of Shares in violation of the terms and conditions set forth herein.

(b)   Permitted Transfers .  Notwithstanding anything to the contrary contained in this Agreement, but subject to Section 2(d), at any time, each of the Employee Stockholders may transfer all or a portion of his or her Shares to any of its Permitted Transferees.  A Permitted Transferee of Shares pursuant to this Section 2(b) may transfer its Shares pursuant to this Section 2(b) only to the transferor Employee Stockholder or to a Person that is a Permitted Transferee of such transferor Employee Stockholder.

(c)   Good Termination of Employee Stockholders . Notwithstanding anything to the contrary contained in this Agreement, but subject to Section 2(d), at any time, each Employee Stockholder (other than a Senior Manager) whose employment with the Company is terminated due to a Good Termination may transfer all or a portion of his or her Shares beginning on the date that is three (3) months and one day following the date of such Good Termination (the “ Determination Date ”); provided , that, in no event shall any Employee Stockholder transfer a

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number of Shares in excess of (i) with respect to the three month period beginning on the Determination Date, 33% of the number of Shares owned by such Employee Stockholder on the applicable Closing Date, (ii) for the three months following the period described in clause (i), the sum of (x) 33% of the number of Shares owned by such Employee Stockholder on the applicable Closing Date and (y) any Shares which were eligible for sale during the period described in clause (i) above, but were not sold and (iii) for the three months following the period described in clause (ii), the sum of (x) 34% of the number of Shares owned by such Employee Stockholder on the applicable Closing Date and (y) any Shares which were eligible for sale during the periods described in clauses (i) and (ii) above, but were not sold.

(d)   Transfers in Compliance with Law; Substitution of Transferee .  No transfer by any Employee Stockholder may be made pursuant to this Agreement unless (i) the transferee has agreed in writing to be bound by the terms and conditions of this Agreement pursuant to an instrument substantially in the form attached hereto as Annex II (other than if (x) the transfer is conducted pursuant to and in accordance with Section 3 hereof or (y) the transfer is conducted following the IPO Effectiveness Date pursuant to and in accordance with Rule 144 under the Securities Act), (ii) the transfer complies in all respects with the applicable provisions of this Agreement, (iii) the transfer complies in all respects with applicable federal and state securities laws, including, without limitation, the Securities Act and (iv) the transfer complies with all applicable Company policies and restrictions (including any trading “window periods” or other policies regulating insider trading).  No transfer by any Employee Stockholder may be made pursuant to this Agreement (except pursuant to an effective registration statement under the Securities Act) unless and until such Employee Stockholder has first delivered to the Company an opinion of counsel (reasonably acceptable in form and substance to the Company) that neither registration nor qualification under the Securities Act and applicable state securities laws is required in connection with such transfer.

3.             “Piggyback” Registration Rights .

(a)    Incidental Registration .  (i)  At any time after the expiration of the Lock-Up Period that the Company determines to proceed with the preparation and filing of a registration statement under the Securities Act in connection with a proposed Public Offering, the Company will give written notice of such determination to the Employee Stockholders.  Upon written request of any Employee Stockholder given within fifteen (15) Business Days after receipt of any such notice from the Company, the Company will, except as herein provided, cause all Registrable Shares held by such Employee Stockholder which have been requested to be included in the registration to be included in such registration statement; provided , however , that nothing herein shall prevent the Company from, at any time, abandoning or delaying any registration.

(ii)           If any Public Offering pursuant to this Section 3(a) shall be underwritten on a firm commitment basis, in whole or in part, the Company may require that the Common Stock requested for inclusion pursuant to this Section 3(a) be included in such Public Offering on the same terms and conditions as the securities otherwise being sold through the underwriters.  If, upon the written advice of the managing underwriter of such Public Offering, the number of securities requested to be included in such registration (including securities of the Company which are not Registrable Shares)

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exceeds the maximum number of securities which can be sold in such offering without having an adverse effect on the offering of securities (including the price at which such securities could be offered), the Company will include in such registration such maximum number of shares of Common Stock as follows:  (A) if such registration has been initiated by one or more of the Company’s stockholders holding demand registration rights with the Company pursuant to the Registration Rights Agreement or any similar agreements, then (i) first, the number of shares of Common Stock requested to be registered by such initiating stockholder(s) and any other holder(s) of the Company’s securities which are entitled to sell pro rata with such initiating stockholder(s), pro rata in accordance with the number of shares owned by such stockholders; (ii) second, the number of Registrable Shares requested to be registered by Employee Stockholders and the number of shares of Common Stock requested to be registered by any other holders of Common Stock having equivalent rights under similar agreements, pro rata in accordance with the number of shares owned by such stockholders; and (iii) third, the number of shares of Common Stock proposed to be sold by the Company for