UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934
(Amendment No.             )*

Huntsman Corporation
(Name of Issuer)

Common Stock, $0.01 par value per share
(Title of Class of Securities)

447011 10 7
(CUSIP Number)

Samuel D. Scruggs, 500 Huntsman Way, Salt Lake City, Utah 84108, (801) 584-5700
(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

February 16, 2005
(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. o

Note: The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

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Item 1. Security and Issuer

        This Statement relates to the Common Stock, $0.01 par value per share, of Huntsman Corporation, a Delaware corporation (the "Company"). The principal executive offices of the Company are located at 500 Huntsman Way, Salt Lake City, Utah 84108.

Item 2. Identity and Background.

        (a)   This Statement is filed jointly by (i) HMP Equity Trust, a Delaware statutory trust ("HMP Trust"), (ii) Huntsman Family Holdings Company LLC, a Utah limited liability company ("Huntsman Family Holdings"), (iii) Jon M. Huntsman ("J. Huntsman"), (iv) Peter R. Huntsman ("P. Huntsman"), (v) David J. Matlin ("Matlin"), (vi) Christopher R. Pechock ("Pechock"), (vii) MatlinPatterson Global Opportunities Partners L.P., a Delaware limited partnership ("Matlin Partners (Delaware)"), (viii) MatlinPatterson Global Opportunities Partners B, L.P., a Delaware limited partnership (the "Opt-Out Fund"), (ix) MatlinPatterson Global Opportunities Partners (Bermuda) L.P., an exempt limited partnership organized under the laws of Bermuda ("Matlin Partners (Bermuda)" and together with Matlin Partners Delaware and Opt-Out Fund, the "Matlin Partnerships"), (x) MatlinPatterson Global Advisers LLC, a Delaware limited liability company, by virtue of its investment authority over securities held by the Matlin Partnerships ("Matlin Advisers"), (xi) MatlinPatterson Global Partners LLC, a Delaware limited liability company, as general partner of the Matlin Partnerships ("Matlin Global Partners"), (xii) MatlinPatterson Asset Management LLC, a Delaware limited liability company, as the holder of all of the membership interests in Matlin Global Partners and Matlin Advisers ("Matlin Asset Management"), (xiv) MatlinPatterson LLC, a Delaware limited liability company, as the holder of all of the membership interests in Matlin Asset Management ("MatlinPatterson"), and (xv) Mark R. Patterson and Matlin, each as a holder of 50% of the membership interests in MatlinPatterson. Matlin, Pechock, the Matlin Partnerships, Matlin Advisers, Matlin Global Partners, Matlin Asset Management, MatlinPatterson and Mark R. Patterson are collectively referred to as the "Matlin Parties." The foregoing entities and persons are collectively referred to as the "Reporting Persons." The administrative trustees of HMP Trust consist of J. Huntsman, P. Huntsman, Matlin and Pechock. All of the outstanding beneficial interests in HMP Trust are owned by Huntsman Family Holdings and the Matlin Partnerships.

        HMP Trust is a new entity formed to hold shares of Common Stock of the Company ("Shares") received by Huntsman Family Holdings and the Matlin Partnerships pursuant to the Reorganization Transactions (defined below) among the Company, Huntsman Holdings, LLC ("Huntsman Holdings"), Huntsman Family Holdings, the Matlin Partnerships and other interest holders in Huntsman Holdings that were completed on February 16, 2005. The principal business of HMP Trust is to hold Shares.

        Huntsman Family Holdings was formed for the purpose of holding membership interests in Huntsman Holdings, an entity that owned all of the outstanding Shares prior to the Reorganization Transactions. The principal business of Huntsman Family Holdings is to hold interests in HMP Trust. The name, business address, present principal occupation or employment and citizenship of each manager and executive officer of Huntsman Family Holdings are set forth in Schedule A.

        Matlin Partners (Delaware) and the Opt-Out Fund are limited partnerships organized under the laws of Delaware. Matlin Partners (Delaware) generally invests in equity and subordinated debt securities of companies. The Opt-Out Fund holds investments of investors who originally invested in Matlin Partners (Delaware) but opted out of subsequent investments upon the spin off of MatlinPatterson entities from Credit Suisse First Boston in July 2002. The address of Matlin Partners (Delaware) is, and the Opt-Out Fund's principal business office, is c/o Matlin Global Partners 520 Madison Avenue, New York, New York 10022.

        Matlin Partners (Bermuda) is an exempt limited partnership organized under the laws of Bermuda. Matlin Partners (Bermuda) generally invests in equity and subordinated debt securities of companies.

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The address of Matlin Partners (Bermuda)'s principal business office is c/o Quorum International Limited, Reid House, 31 Church Street, Hamilton, Bermuda.

        Matlin Global Partners is a limited liability company organized under the laws of Delaware. Matlin Global Partners serves as General Partner of Matlin Partners (Delaware), Matlin Partners (Bermuda) and the Opt-Out Fund. The address of Matlin Global Partners' principal business office is 520 Madison Avenue, New York, New York 10022. The principal business of Matlin Global Partners is acting as the general partner to Matlin Partners (Delaware), Matlin Partners (Bermuda) and the Opt-Out Fund.

        Matlin Advisers is a limited liability company organized under the laws of Delaware. Matlin Advisers serves as investment advisor to Matlin Partners (Delaware), Matlin Partners (Bermuda) and the Opt-Out Fund. The address of Matlin Advisers' principal business office is 520 Madison Avenue, New York, New York 10022. Matlin Advisers performs certain investment advisory services on behalf of Matlin Partners (Delaware) and Matlin Partners (Bermuda), pursuant to a certain amended and restated Investment Advisory Agreement dated as of July 17, 2002 among Matlin Advisers, Matlin Partners (Delaware) and Matlin Partners (Bermuda).

        Matlin Asset Management is a limited liability company organized under the laws of Delaware. Matlin Asset Management is the holder of all of the membership interests in Matlin Global Partners and Matlin Advisers. The address of Matlin Asset Management's principal business office is 520 Madison Avenue, New York, New York 10022. Matlin Asset Management's principal business is owning Matlin Global Partners and Matlin Advisers.

        MatlinPatterson is a limited liability company organized under the laws of Delaware. MatlinPatterson is the holder of all of the membership interests in Matlin Asset Management. The address of MatlinPatterson's principal business office is 520 Madison Avenue, New York, New York 10022. MatlinPatterson's principal business is owning Matlin Asset Management.

        Mark R. Patterson and Matlin are each the holder of 50% of the membership interests in MatlinPatterson. The address of Mark R. Patterson and Matlin's principal business office is 520 Madison Avenue, New York, New York 10022. Mark R. Patterson's present principal occupation is acting as Chairman of Matlin Advisers and Matlin's present principal occupation is acting as Chief Executive Officer of Matlin Advisers. Matlin is a director of the Company. Mark R. Patterson and Matlin are citizens of the United States of America.

        Pechock's present principal occupation is acting as an employee of Matlin Advisers. The address of Pechock's principal business office is 520 Madison Avenue, New York, New York 10022. Pechock is a director of the Company. Pechock is a citizen of the United States of America.

        As a result of the Reorganization Transactions, the Matlin Partnerships received Shares which they contributed to HMP Trust.

        The principal occupation of J. Huntsman is serving as Chairman of the Board of the Company. The principal occupation of P. Huntsman is serving as President, Chief Executive Officer and Director of the Company. Each of J. Huntsman and P. Huntsman are citizens of the United States of America. J. Huntsman is the father of P. Huntsman. The business address of each of HMP Equity Trust, Huntsman Family Holdings, and J. Huntsman is 500 Huntsman Way, Salt Lake City, Utah 84108. The business address of P. Huntsman is 10003 Woodloch Forest Dr., The Woodlands, Texas 77380.

        None of the Reporting Persons nor, to the knowledge of the Reporting Persons, any of the other persons listed on Schedule A attached hereto has been convicted in a criminal proceeding in the past five years (excluding traffic violations or similar misdemeanors).

        During the past five years, none of the Reporting Persons nor, to the knowledge of the Reporting Persons, any of the other persons listed on Schedule A attached hereto was a party to a civil proceeding of a judicial or administrative body of competent jurisdiction as a result of which such

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person was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

Item 3. Sources and Amount of Funds or Other Consideration.

        On February 10, 2005, the Company, Huntsman Holdings, Huntsman Holdings Preferred Member, LLC ("HHPM"), and two wholly owned subsidiaries of the Company entered into merger agreements pursuant to which the Company agreed to acquire Huntsman Holdings and HHPM (the "Reorganization Transactions"). Pursuant to the Reorganization Transactions, on February 16, 2005, subsidiaries of the Company merged into HHPM and Huntsman Holdings and, in connection therewith, the Company issued Shares in exchange for the limited liability company interests in Huntsman Holdings and HHPM, including those owned by Huntsman Family Holdings, P. Huntsman and the Matlin Partnerships. As part of the Reorganization Transactions, Huntsman Family Holdings and the Matlin Partnerships caused to be delivered to HMP Trust the Shares they were to receive in the mergers. No other consideration was paid or given by Huntsman Family Holdings or the Matlin Partnerships in connection with the Reorganization Transactions.

Item 4. Purpose of Transaction.

        Before the Reorganization Transactions were effectuated in order to reorganize the structure of the Company and its affiliates in a manner that would facilitate the initial public offering of Shares in connection with the Reorganization Transactions, on February 10, 2005, Huntsman Family Holdings and the Matlin Partnerships, as holders of beneficial interests in HMP Trust, and J. Huntsman, P. Huntsman, Matlin and Pechock, as administrative trustees (the "Administrative Trustees"), and Deutsche Bank Trust Company Delaware, as Delaware trustee, entered into the HMP Equity Trust Amended and Restated Trust Agreement (the "Trust Agreement"). Pursuant to the terms of the Trust Agreement, each of Huntsman Family Holdings and the Matlin Partnerships caused to be delivered to HMP Trust all of the Shares that they were entitled to receive pursuant to the Reorganization Transactions.

        The Trust Agreement provides that the two trustees of HMP Trust designated by Huntsman Family Holdings (the "HFH Designees") shall have the power to exercise all of the voting rights related to the Shares held directly or indirectly by HMP Trust in accordance with their sole discretion except that, unless the Administrative Trustees (at least one of whom must be a HFH Designee and one of whom must be one of the two trustees of HMP Trust designated by the Matlin Partnerships (the "MP Designees")) shall approve otherwise, all of such Shares shall be voted as follows:

        (i)    so as to cause:

        (A)  the certificate of incorporation or bylaws of the Company to provide for its Board of Directors (the "Corporate Board") to be divided into three classes of approximately equal size, with staggered, three-year terms: the first class consisting of directors ("Class I") whose terms will expire at the first annual meeting of the stockholders of the Company following the effectiveness of the Amended and Restated Certificate of Incorporation of the Company adopted in connection with the Company's initial public offering ("IPO"), the second class consisting of directors ("Class II") whose terms will expire at the second annual meeting of stockholders of the Company following such effectiveness and the third class consisting of directors ("Class III") whose terms will expire at the third annual meeting of stockholders of the Company following such effectiveness;

        (B)  the certificate of incorporation or bylaws of the Company to provide that upon the expiration of the term of a class of directors, directors in that class will be elected for three-year

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terms at the annual meeting of stockholders of the Company in the year in which their term expires;

        (C)  the Corporate Board to consist, immediately after the consummation of the IPO, of five members, with Class I consisting of two directors, Class II consisting of two directors and Class III consisting of one director; and

        (D)  the certificate of incorporation or bylaws of the Company to provide that any additional directorships resulting from an increase in the number of directors, and any reduction in the number of directors resulting from a decrease in the size of the Corporate Board (other than temporary vacancies) will be distributed among the three classes so that, as nearly as possible, each class will consist of one-third of the members of the Corporate Board;

        (ii)   in any such stockholders meeting at which, or with respect to any such consent pursuant to which, directors are to be elected or appointed:

        (A)  until the second anniversary of the consummation of the IPO, so as to have the Board of Directors consist of, and only of, the following persons, subject to their consent to so serve: Alvin V. Shoemaker, Nolan D. Archibald, Marsha J. Evans, H. William Lichtenberger, Wayne A. Reaud and Richard Michaelson (the "Initial Directors"), the Adviser Directors (as defined below), the Huntsman Directors (as defined below) and/or other persons approved for nomination by the Company's nominating or governance committee or by an affirmative vote of at least two of the Administrative Trustees (as defined below), at least one of whom must be an HFH Designee and one of whom must be an MP Designee;

        (B)  so as to nominate and elect two persons designated by the MP Designees (the "Adviser Directors"), one of which shall be a director in Class I and one of which shall be a director in Class II, and, in the event any of such persons does not serve, or ceases to serve, as a director of the Company, such other persons designated by the MP Designees in place of such person;

        (iii)  With respect to the removal of directors of the Company, the Administrative Trustees shall vote or consent with respect to (or cause to be voted or consented with respect to) the Shares held directly or indirectly by HMP Trust as directed by the MP Designees with respect to any proposed removal of any Adviser Director, and as directed by the HFH Designees with respect to any proposed removal of any other director. Notwithstanding the previous sentence, however, until the second anniversary of the consummation of the IPO, the Administrative Trustees shall not vote or consent with respect to (or cause to be voted or consented with respect to) the Shares held directly or indirectly by HMP Trust to remove any of the Initial Directors unless such removal shall have received the approval of at least one of the Adviser Directors or is approved by an affirmative vote by at least two of the Administrative Trustees (at least one of whom must be an HFH Designee and one of whom must be an MP Designee);

        (iv)  Unless such action shall have received the approval of at least one of the Adviser Directors, in no event shall the Administrative Trustees vote or consent with respect to (or cause to be voted or consented with respect to) the Shares held directly or indirectly by HMP Trust to any of the following ("Special Actions"); provided that nothing in this provision shall be construed to require any vote of the stockholders of the Company or prohibit any director of the Company from voting as a director of the Company on any such matter in any manner he or she deems appropriate:

        (1)   entering into any transaction, agreements or arrangements between the Company or any of its subsidiaries, on the one hand, and any holder of beneficial interests in HMP Trust or any affiliate of any such holder (other than a subsidiary of the Company), on the other hand, and other than transactions in the ordinary course of business with respect to officers and directors (e.g., employee expense reimbursement, indemnification agreement, employee benefits, director or employee compensation, housing relocations, and similar transactions),

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        (2)   amending or supplementing the Company's certificate of incorporation, repealing, adopting or modifying bylaws or modifying the size of the Corporate Board,

        (3)   filing by the Company of any petition for bankruptcy or consent to the entry of an order for relief in an involuntary bankruptcy case or make any assignment for the benefit of creditors,

        (4)   selling all or substantially all assets or stock of the Company, or merging, consolidating or combining the Company with any other entity (other than a subsidiary) or approving the sale of all or substantially all assets or stock of the Company, or the merger, consolidation or combination of the Company with any other entity (other than a subsidiary),

        (5)   issuing any new equity securities of the Company (or securities convertible into equity securities of the Company) other than with respect to director and employee compensation, or

        (6)   adopting a shareholder rights plan or any agreement or plan of the type commonly called a "poison pill" or any similar plan or agreement; and

        (v)   With respect to all matters other than those described in clauses (i) through (iv) above, the HFH Designees may vote (or cause to be voted or consented) the Shares held directly or indirectly by HMP Trust as they shall direct in their sole discretion.

        "Huntsman Directors" means J. Huntsman and P. Huntsman, and in the event that any of such persons does not serve, or ceases to serve, as a director of the Company, such other persons designated by the HFH Designees in place of such person.

        The Trust Agreement also provides that, if at any time HMP Trust is not the holder of more than 50% of the outstanding voting securities of the Company (or, in the event of a modification to, or replacement of, the definition of "operating company" under United States Department of Labor Regulation § 2510.3-101 that would require HMP Trust to own a higher percentage of the outstanding voting securities of the Company in order for HMP Trust to meet the definition of "operating company", then such higher percentage), then, upon the request of any holder of beneficial interests of HMP Trust, the Administrative Trustees shall cause Shares held by HMP Trust for the benefit of the various owners of beneficial interests in HMP Trust to be distributed to such owners, provided that such distributees have entered into the Voting Agreement included as Exhibit C to the Trust Agreement. Such Voting Agreement contains substantially similar voting provisions as specified in clauses (ii) through (iv) of the second paragraph of this Item 4.

        As a result of the provisions of the Trust Agreement and the ownership by HMP Trust of Shares representing appropriately 58.9% of the outstanding Shares as of the date of this Statement, the Reporting Persons will have the ability to:

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elect a majority of the members of the board of directors of the Company;



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subject to applicable law and the rights of holders of the Company's mandatory convertible preferred stock, determine, without the consent of the Company's other stockholders, the outcome of certain matters submitted to the Company's stockholders for approval, including amendments to the Company's certificate of incorporation, mergers, consolidations and the sale of all or substantially all of the Company's assets; and



•

subject to applicable law, prevent or cause a change in control of the Company.

        Except as described in this Item 4, none of the Reporting Persons nor, to the best knowledge of such persons, any other person named in Schedule A to this Statement has formulated any plans or proposals which relate to or would result in any matter required to be disclosed in response to paragraphs (a) through (j) of Item 4 of Schedule 13D.

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Item 5. Interest in Securities of the Issuer.

        (a)   HMP Trust is the direct owner of 129,776,387 Shares, or approximately 58.9% of the 220,454,546 Shares outstanding as of February 16, 2005. By virtue of the relationships described in Item 2 and Item 4 of this Statement, each of the other Reporting Persons may be deemed to share indirect beneficial ownership of all of the Shares owned by HMP Trust, and HMP Trust may be deemed to control the Company. The Trust Agreement provides that HMP Trust holds all 129,776,387 Shares for the benefit of the Matlin Partnerships (subject to participation agreements among the partnerships as described in Section 6 below), as the holder of all of the outstanding Class A Trust Interests of HMP Trust, and Huntsman Family Holdings, as the holder of all of the outstanding Class B Trust Interests of HMP Trust. The allocation of Shares held by HMP Trust for the benefit of each of the Matlin Partnerships and Huntsman Family Holdings will be determined in the future based on formulas set forth in the Trust Agreement. Huntsman Family Holdings disclaims beneficial ownership of all of the Shares that are held by HMP Trust for the benefit of the Matlin Partnerships as determined pursuant to the terms of the Trust Agreement. Each of the Matlin Parties disclaims beneficial ownership of all of the Shares held by HMP Trust for the benefit of Huntsman Family Holdings as determined pursuant to the terms of the Trust Agreement. The filing of this Statement shall not be construed as an admission by any of the Reporting Persons that it is, for purposes of Section 13(d) of the Exchange Act, the beneficial owner of Shares owned by, or held for the benefit of, other parties. P. Huntsman is also the beneficial owner of an additional 362,843 Shares.

        Matlin Global Partners serves as General Partner of each of the Matlin Partnerships. By reason of such relationships, Matlin Global Partners may be deemed to beneficially own the shares owned by Matlin Partners (Delaware). Matlin Advisers serves as investment advisor to the Matlin Partnerships. By reason of such relationships, Matlin Advisers may be deemed to beneficially own the shares owned by Matlin Partners (Delaware). Matlin Asset Management is the holder of all of the membership interests in Matlin Global Partners and Matlin Advisers. By reason of such relationships, Matlin Asset Management may be deemed to beneficially own the shares owned by Matlin Partners (Delaware). MatlinPatterson is the holder of all of the membership interests in Matlin Asset Management. By reason of such relationship, MatlinPatterson may be deemed to beneficially own the shares owned by Matlin Partners (Delaware). Mark R. Patterson and Matlin are the holders of all of the membership interests in MatlinPatterson. By reason of such relationships, each of Mark R. Patterson and Matlin may be deemed to share voting and dispositive power over the shares owned by Matlin Partnerships.

        (b)   HMP Trust, J. Huntsman, P. Huntsman, Matlin and Pechock share voting power with respect to all of the 129,776,387 Shares owned by HMP Trust, which Shares represent 58.9% of the outstanding Shares as of the date of this Statement. Due to the relationships described in Item 6, all of the Reporting Persons may share dispositive power with respect to all of the Shares owned by HMP Trust until such time as the Shares owned by HMP Trust are allocated among the Class A Trust Interests and the Class B Trust Interests of HMP Trust pursuant to the terms of the Trust Agreement, following which allocation (i) the Matlin Partnerships, as the holders of the Class A Trust Interests, will share dispositive power with HMP Trust with respect to all Shares allocated to the holders of the Class A Trust Interests pursuant to the terms of the Trust Agreement and (ii) Huntsman Family Holdings, as the holders of the Class B Trust Interests of HMP Trust, will share dispositive power with HMP Trust and J. Huntsman with respect to all Shares allocated to the holders of the Class B Trust Interests pursuant to the terms of the Trust Agreement. In addition to the shared voting power and shared dispositive power that P. Huntsman may hold with respect to the 129,776,387 Shares owned by HMP Trust, P. Huntsman has (i) sole voting power and sole dispositive power with respect to an additional 212,709 Shares (0.1% of the outstanding Shares) and (ii) sole voting power with respect to an additional 150,134 Shares (0.1% of the outstanding Shares).

        (c)   HMP Trust sold an aggregate of 13,579,546 Shares at a per share price of $23.00 on February 16, 2005 in connection with the completion of the Company's initial public offering of Shares

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and the exercise of the underwriters' over-allotment option in connection therewith. Of these Shares, 6,521,739 Shares were sold by HMP Trust for the benefit of Huntsman Family Holdings, as the holder of the Class B Trust Interests of HMP Trust, and 7,057,807 Shares were sold by HMP Trust for the benefit of the Matlin Partnerships, (5,143,054 for the benefit of Matlin Partners (Delaware), 1,792,164 for the benefit of Matlin Partners (Bermuda) and 122,589 for the benefit of the Opt-Out Fund pursuant to the participation agreements described in Item 6) as the holders of the Class A Trust Interests of HMP Trust. Of the 6,521,739 Shares that were sold by HMP Trust for the benefit of Huntsman Family Holdings, none of such Shares were sold for the benefit of P. Huntsman. In addition, HMP Trust transferred 513,864 Shares to Consolidated Press (Finance) Limited that were attributed to Class B Trust Interests of Huntsman Family Holdings. The Reporting Persons did not engage in any other transactions with respect to Shares within the last 60 days except for the Reorganization Transactions.

        (d)   Not applicable

        (e)   Not applicable

Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer.

        See Response to Item 4.

        The Trust Agreement provides that HMP Trust holds all of the shares owned by HMP Trust for the benefit of Huntsman Family Holdings and the Matlin Partnerships as the holders of the Class B Trust Interests and the Class A Trust Interests, respectively, of HMP Trust. The Trust Agreement also provides that, upon the allocation of shares to Huntsman Family Holdings and the Matlin Partnerships as the holders of the Class B Trust Interests and the Class A Trust Interests, respectively, pursuant to the terms of the Trust Agreement, each of Huntsman Family Holdings and the Matlin Partnerships will have the right to withdraw all or any portion of the shares held by HMP Trust for the benefit of such Reporting Person in connection with certain sales or other transfers of Shares by such Reporting Person.

        The Company, Huntsman Family Holdings, the Matlin Partnerships and other stockholders of the Company entered into a Registration Rights Agreement on February 10, 2005 pursuant to which the Company granted to Huntsman Family Holdings and the Matlin Partnerships demand and piggyback registration rights (including, without limitation, rights to demand shelf registration statements) for the Shares beneficially owned by them. Demand rights may not be exercised, however, to require registration during the period of time covered by any applicable lock-up agreement. Despite a registration demand, the Company may delay filing of the registration statement for a reasonable time not to exceed 60 days if, in the judgment of the Company's board of directors, filing the registration statement would require the disclosure of pending or contemplated matters or information which would have a material adverse effect on the business, operations or prospects of the Company or the disclosure otherwise relates to a material business transaction which has not yet been publicly disclosed. The agreement also provides that the Company will pay the costs and expenses, other than underwriting discounts and commissions, related to the registration and sale of Shares that are registered pursuant to the registration rights agreement. The agreement contains customary registration procedures and indemnification and contribution provisions requiring indemnification or contribution by the Company for the benefit of the stockholders whose shares are registered and sold pursuant to the agreement. Each of the stockholders whose shares are registered and sold pursuant to the agreement has agreed to indemnify the Company solely with respect to information provided by such person for use in the prospectus related to the offering of Shares by such person, with such indemnification being limited to the proceeds of the offering received by such person.

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        Each of the Reporting Persons have entered into an agreement with the underwriters of the IPO pursuant to which they have agreed that, for a period of 180 days from February 10, 2005, they will not, subject to limited exceptions, without the prior written consent of Citigroup Global Markets Inc., offer, sell, contract to sell, pledge or otherwise dispose of, directly or indirectly, including the filing (or participation in the filing) of a registration statement under the Securities Act relating to, any Shares, including, without limitation, any Shares acquired by such persons through the Company's directed share program, or any securities convertible into or exchangeable for Shares, including shares of the Company's mandatory convertible preferred stock and Shares issued upon conversion thereof. In the event that either (x) during the last 17 days of the 180-day period referred to above, the Company issues an earnings release or a press release announcing a significant event or (y) prior to the expiration of such 180 days, the Company announces that it will release earnings or issue a press release announcing a significant event during the 17-day period beginning on the last day of such 180-day period, the restrictions described above shall continue to apply until the expiration of the 17-day period beginning on the date of the earnings or the significant even press release.

        Matlin Partners (Delaware) and Matlin Partners (Bermuda) have entered into a Participation Agreement (the "Bermuda Participation Agreement") dated as of May 15, 2001. Pursuant to such agreement, Matlin Partners (Bermuda) holds a participation interest in its pro rata share of the right, title and interest in the Shares held by HMP Trust for the benefit of Matlin Partners (Delaware). Matlin Partners (Bermuda)'s pro rata share is 25.2% in relation to the Shares held by HMP Trust for the benefit of Matlin Partners (Delaware). Matlin Partners (Delaware) and the Opt-Out Fund have entered into a Participation Agreement (the "Opt-Out Fund Participation Agreement") dated as of July 16, 2002. Pursuant to such agreement, the Opt-Out Fund holds a participation interest in 2.41% of the right, title and interest in the Shares held by HMP Trust for the benefit of Matlin Partners (Delaware).

Item 7. Material to be Filed as Exhibits

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Signatures

        After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this Statement is true, complete and correct.

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SCHEDULE A

EXECUTIVE OFFICERS AND MANAGERS
OF
HUNTSMAN FAMILY HOLDINGS COMPANY LLC

        The name and titles of the executive officers and managers of Huntsman Family Holdings Company LLC and their principal occupations are set forth below. Under otherwise indicated, each such person is a United States citizen.

A-1

QuickLinks

Item 1. Security and Issuer
Item 2. Identity and Background.
Item 3. Sources and Amount of Funds or Other Consideration.
Item 4. Purpose of Transaction.
Item 5. Interest in Securities of the Issuer.
Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer.
Item 7. Material to be Filed as Exhibits

SCHEDULE A

EXHIBIT 1

JOINT FILING AGREEMENT

        In accordance with Rule 13d-1(f) under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree to the joint filing with all other Reporting Persons (as such term is defined in the Schedule 13D referred to below) on behalf of each of them of a Statement on Schedule 13D (including amendments thereto) with respect to the Common Stock, par value $0.01 per share, of Huntsman Corporation and that this Agreement be included as an exhibit to such joint filing. This Agreement may be executed in any number of counterparts, all of which taken together shall constitute one and the same instrument.

        IN WITNESS WHEREOF, the undersigned hereby execute this Agreement as of February 22, 2005.

I-1

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EXHIBIT 1

EXHIBIT 2

EXECUTION COPY

HMP EQUITY TRUST
AMENDED AND RESTATED
TRUST AGREEMENT

Dated as of February 10, 2005

TABLE OF CONTENTS

i

ii

AMENDED AND RESTATED
TRUST AGREEMENT
OF
HMP EQUITY TRUST

        AMENDED AND RESTATED TRUST AGREEMENT (this "Trust Agreement") dated and effective as of February 10, 2005, by the Trustees (as defined herein) and by the depositor of the Trust and the holders named on the signature pages hereto of beneficial interests in the Trust (as defined below) to be issued pursuant to this Trust Agreement;

        WHEREAS, the Delaware Trustee, the Administrative Trustees and Family Holdings, as depositor, entered into a Trust Agreement dated as of February 9, 2005 establishing the HMP Equity Trust (the "Trust"), a trust created under the Statutory Trust Act;

        WHEREAS, the parties hereto desire to amend and restate the Trust Agreement;

        NOW, THEREFORE, it being the intention of the parties hereto that this Trust Agreement constitute the governing instrument of the Trust, the Trustees declare that all assets contributed to the Trust will be held in trust for the benefit of the holders, from time to time, of the Trust Interests (as defined herein) issued hereunder, subject to the provisions of this Trust Agreement:

ARTICLE I
DEFINITIONS AND INTERPRETATION

SECTION 1.1 Definitions.

        Unless the context otherwise requires:

        (a)   capitalized terms used in this Trust Agreement but not defined in the preamble above have the respective meanings assigned to them in this Section 1.1;

        (b)   a term defined anywhere in this Trust Agreement has the same meaning throughout;

        (c)   all references to "the Trust Agreement" or "this Trust Agreement" are to this Trust Agreement as modified, supplemented or amended from time to time;

        (d)   all references in this Trust Agreement to "Articles" and "Sections" and "Exhibits" are to Articles and Sections of and Exhibits to this Trust Agreement unless otherwise specified; and

        (e)   a reference to the singular includes the plural and vice versa.

        "Administrative Trustee" has the meaning set forth in Section 4.1.

        "Affiliate" has the same meaning as given to that term in Rule 405 under the Securities Act or any successor rule thereunder.

        "Authorized Officer" of a Person means any other Person that is authorized to legally bind such former Person.

        "Average Market Price" means, with respect to the Corporation Common Stock after an IPO, the quotient obtained by dividing (A) the sum of the volume-weighted average price per share of the Corporation Common Stock for each of the ten (10) days on which trading in such securities which occurred immediately prior to the date of such determination, as reported by Bloomberg Professional Service (or, if such service is unavailable, through another service acceptable to the HFH Designees and the MP Designees) for the period during each trading day beginning at 9:30 a.m., New York City time and ending at 4:00 p.m., New York City time, by (B) ten.

        "Business Day" means any day other than a Saturday or a Sunday or a day on which banking institutions in New York, New York are authorized or required by law or executive order to close.

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        "Certificates" means the certificates evidencing the Trust Interests and shall be substantially in the form of Exhibit A to this Trust Agreement.

        "Class A Assets" means all assets of the Trust allocated to, or held for the benefit of, the Class A Trust Interests or the Holders of the Class A Trust Interests pursuant to the terms of this Agreement, and all distributions thereon and all income and proceeds with respect thereto.

        "Class B Assets" means all assets of the Trust allocated to, or held for the benefit of, the Class B Trust Interests or the Holders of the Class B Trust Interests pursuant to the terms of this Agreement, and all distributions thereon and all income and proceeds with respect thereto.

        "Class A Preferred Position Corporation Interest" means the number of IPO Shares equal to $400,000,000 divided by the Average Market Price as determined on the Business Day immediately following the Fourteenth Trading Day rounded to the nearest whole share.

        "Class A Trust Interests" means all of the beneficial interests in the Class A Assets of the Trust and having the rights provided for in this Trust Agreement.

        "Class B Trust Interests" means all of the beneficial interests in the Class B Assets of the Trust and having the rights provided for in this Trust Agreement.

        "Code" means the Internal Revenue Code of 1986, as amended from time to time, or any successor legislation.

        "Commission" means the United States Securities and Exchange Commission as from time to time constituted, or if any time after the execution of this Trust Agreement such Commission is not existing and performing the duties now assigned to it under applicable federal securities laws, then the body performing such duties at such time.

        "Company Indemnified Person" means (a) any Administrative Trustee; (b) any Affiliate of any Administrative Trustee; (c) any officers, directors, shareholders, members, partners, employees, representatives or agents of any Administrative Trustee; or (d) any officer, employee or agent of the Trust or its Affiliates.

        "Corporation" means Huntsman Corporation, a Delaware corporation.

        "Corporation Common Stock" means the common stock, $0.01 par value per share of the Corporation.

        "Corporation Preferred Stock" means the 5% mandatory convertible preferred stock, $0.01 par value per share, of the Corporation.

        "Covered Person" means (a) any officer, director, shareholder, partner, member, representative, employee or agent of (i) the Trust or (ii) the Trust's Affiliates, and (b) any Holder of Trust Interests.

        "CPF" means Consolidated Press (Finance) Limited (CAN 001 557 035), a public company incorporated in New South Wales, or its designated Affiliate.

        "Definitive Agreement" means, collectively, all of the binding agreements setting forth any of the terms of a Trade Sale or Merger Transaction and which together set forth all of the terms of such transaction in sufficient detail to cause the parties thereto (which must include, at a minimum, the proposed acquirer in the transaction and the Corporation) to be bound to consummate such transaction, subject to such conditions as may be agreed upon by the parties to such agreement.

        "Delaware Trustee" has the meaning set forth in Section 4.2.

        "Distribution" means a distribution payable to Holders in accordance with Sections 5.2 or 5.3.

        "Escrowed Corporation Interest" means the Post-Preferred Corporation Interest multiplied by .05.

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        "Exchange Act" means the Securities Exchange Act of 1934, as amended from time to time, or any successor legislation.

        "Family Holdings" means Huntsman Family Holdings Company LLC, a Utah limited liability company.

        "Fiduciary Indemnified Person" has the meaning set forth in Section 9.4(b).

        "Fiscal Year" has the meaning set forth in Section 10.1.

        "Fourteenth Trading Day" means the fourteenth day of trading after the IPO on the principal stock exchange or trading market on which the IPO Shares are traded (it being acknowledged for the avoidance of doubt that the first day of trading after the IPO shall be the first trading day following the "pricing" of the IPO even though the IPO has not yet been consummated).

        "HFH Designees" has the meaning set forth in Section 4.1.

        "Holder" means a Person in whose name a Trust Interest is registered, such Person being a beneficial owner within the meaning of the Statutory Trust Act.

        "Holdings" means Huntsman Holdings, LLC, a Delaware limited liability company.

        "Holdings Merger" means the acquisition by the Corporation of all of the outstanding limited liability company interests in Holdings (other than the Preferred Interest) pursuant to the merger of a wholly owned subsidiary of the Corporation with and into Holdings and the issuance of Corporation Common Stock to the members of Holdings (other than Preferred Member) in exchange for such limited liability company interests.

        "Huntsman Directors" means Jon M. Huntsman and Peter R. Huntsman, and in the event that any of such persons does not serve, or ceases to serve, as a Corporation director, such other persons designated by the HFH Designees in place of such person.

        "Indemnified Person" means a Company Indemnified Person or a Fiduciary Indemnified Person.

        "Interest" means the entire ownership interest of a Holder in the Trust at any particular time, including the right of such Holder to any and all benefits to which a Holder may be entitled as provided in this Trust Agreement or the Statutory Trust Act, together with the obligations of such Holder to comply with all the terms and provisions of this Trust Agreement.

        "Investment Company" means an investment company as defined in the Investment Company Act.

        "Investment Company Act" means the Investment Company Act of 1940, as amended from time to time, or any successor legislation.

        "IPO" means the first occurrence of a firm-commitment underwritten offering of IPO Shares to the public in a transaction registered under the Securities Act provided that in connection with such offering the Corporation becomes the direct or indirect owner of substantially all of the assets of Holdings.

        "IPO Price" means $23.00, which is the initial public offering per IPO Share in the IPO as shown on the cover of the final prospectus relating to the IPO.

        "IPO Shares" means the shares of Corporation Common Stock.

        "Legal Action" has the meaning set forth in Section 2.7(a)(v).

        "MatlinPatterson" means, collectively, MatlinPatterson Global Opportunities Partners, L.P., a Delaware limited partnership, MatlinPatterson Global Opportunities Partners B, L.P., a Delaware limited partnership, and MatlinPatterson Global Opportunities Partners (Bermuda), L.P., a Bermuda limited partnership.

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        "Majority" means, as the context may require, the Holders of outstanding Class A Trust Interests or the Holders of outstanding Class B Trust Interests, in either case voting separately as a class, who are the record owners of more than 50% of the outstanding Trust Interests of the relevant class.

        "MOU" means a memorandum of understanding or similar expression relating to a proposed Trade Sale or Merger Transaction that sets forth the material terms of such transaction and is executed by the Corporation and by the proposed acquirer.

        "MP Designees" has the meaning set forth in Section 4.1.

        "Payment Amount" has the meaning set forth in Section 5.2(b).

        "Person" means a legal person, including any individual, corporation, estate, partnership, joint venture, association, joint stock company, limited liability company, trust, unincorporated association, or government or any agency or political subdivision thereof, or any other entity of whatever nature.

        "Post-IPO Escrow Allocation Date" means the first Business Day after the Price Measurement Period, except that, if a Definitive Agreement relating to a Trade Sale or Merger Transaction shall be entered into after consummation of the IPO and prior to the end of the Price Measurement Period, it shall mean (i) if such transaction is consummated, the Business Day immediately following the closing of such transaction or (ii) if such transaction is terminated, the later of (A) the first Business Day after the Price Measurement Period and (B) the first Business Day after any extension of the measurement period as provided in the penultimate sentence of the definition of "Share Performance" required as a result of any such termination.

        "Post-Preferred Corporation Interest" means the number of shares of Corporation Common Stock that is equal to the excess of (x) the number of shares of Corporation Common Stock to be contributed to the Trust as provided in Section 3.2 (including IPO Shares sold for the account of MatlinPatterson and Family Holdings in the IPO as contemplated by Section 5.1(d)) over (y) the Class A Preferred Position Corporation Interest.

        "Preferred Interest" means the limited liability company interests in Holdings held by Preferred Member.

        "Preferred Member" means Huntsman Holdings Preferred Member, LLC, a Delaware limited liability company.

        "Preferred Member Merger" means the acquisition by the Corporation of all of the outstanding limited liability company interests in Preferred Member pursuant to the merger of a wholly owned subsidiary of the Corporation with and into Preferred Member and the issuance of Corporation Common Stock to the members of Preferred Member in exchange for such limited liability company interests.

        "Price Measurement Period" means the 365 day period ending the later of (a) the first anniversary of the date of expiration or termination of the underwriters' IPO-related lock-up agreements applicable to Family Holdings and MatlinPatterson and (b) the date that is 545 days after the first trading day of the IPO Shares on the principal exchange or trading market for such shares.

        "Registration Rights Agreement" means that certain registration rights agreement entered into by and among the Corporation and certain of its shareholders in connection with the IPO, as amended, restated, supplemented or replaced.

        "Securities Act" means the Securities Act of 1933, as amended from time to time, or any successor legislation.

        "Share Performance" means an amount equal to (x) the quotient, expressed as a percentage (positive or negative), of the average of the closing prices, as reported on the principal exchange or

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trading market on which the IPO Shares are traded, on each of the trading days in the Price Measurement Period divided by the IPO Price, minus (y) 100%, provided, however, that, in the event that at any time or from time to time after the consummation of the IPO and prior to the end of the Price Measurement Period (1) there shall be paid, without consideration (or declared and the record date for such dividend shall have occurred), any dividend on the IPO Shares which dividend is paid in such shares or in any right to acquire such shares for no consideration, or there shall be effected a subdivision of such outstanding shares into a greater number of shares (by stock split, reclassification or otherwise than by payment of a dividend in such shares or in any right to acquire such shares), or in the event such outstanding shares shall be combined or consolidated, by reclassification or otherwise, into a lesser number of shares, then the closing prices for all trading days thereafter (i.e., in the case of a dividend, from and after the relevant "ex-dividend date" and, in the case of such subdivision, combination or consolidation, from and after the effective date thereof) shall be proportionately increased or decreased, as appropriate, to reflect such event or (2) there shall be paid (or declared and the record date for such dividend shall have occurred) any dividend or distribution on the IPO Shares in cash or other property (other than as provided in clause (1) above), then the closing prices for all trading days thereafter (i.e., from and after the relevant "ex-dividend" date) shall be increased by the fair market value per share of such dividend or distribution. Notwithstanding the foregoing, in the event that a Definitive Agreement with respect to a Trade Sale or Merger Transaction shall be entered into after the consummation of the IPO and prior to the end of the Price Measurement Period, then (a) in the event the Trade Sale or Merger Transaction is consummated the consideration to be received in such transaction with respect to each IPO Share (based upon the value at the time of closing such transaction) shall be substituted for the "average of the closing prices" in the calculation of the quotient in clause (x) of this definition and (b) in the event the Definitive Agreement with respect to the Trade Sale or Merger Transaction is terminated without consummation of the transaction, the Share Performance shall be calculated in accordance with the first sentence of this definition except that the Price Measurement Period shall exclude any Transaction Affected Trading Days. Notwithstanding the foregoing, if such exclusion would result in the Price Measurement Period being based upon the closing price for less than 180 trading days then there shall also be included in the Price Measurement Period up to 90 additional trading days (each an "Additional Trading Day") taken from the period beginning on the later of (A) the third day of trading after announcement of the termination and (B) the first day of trading after the date the Price Measurement Period would have expired had there been no Transaction Affected Trading Days (in either case, using first the closing price on the Additional Trading Day closest to the termination date or expiration date, as the case may be, and then using the closing price on such Additional Trading Days in chronological order), provided that no Additional Trading Day shall be included that would cause the total number of trading days that the calculation is based on to exceed 180. By means of illustration of the foregoing, hypothetical examples of the operation of this paragraph are given in Exhibit B, which is hereby incorporated by reference into this paragraph.

        (1)   In the event that in any Trade Sale or Merger Transaction the consideration to be received in such transaction with respect to the IPO Shares shall be proposed to include consideration other than cash in United States Dollars or U.S. government securities (which shall be valued at the product of the average of the bid price and the asked price for the security as reported in the Wall Street Journal in the last issue published prior to the date of the determination, or, if such information is not available, according to a method mutually agreeable to Family Holdings and MatlinPatterson) or other marketable securities (which shall be valued at their Average Market Price), Family Holdings and MatlinPatterson shall use their reasonable efforts to agree prior to execution of a Definitive Agreement upon a method to be used to ascertain the fair market value of such consideration at the time of the determination; provided, however, that if Family Holdings and MatlinPatterson do not agree on the fair market value of such consideration, then either Family Holdings or MatlinPatterson shall be entitled to a valuation determination from a nationally recognized investment banking firm independent of Family

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Holdings, MatlinPatterson and their respective Affiliates with significant experience in the chemical industry (the "Expert") as follows:

          (i)  the identity of Expert shall be agreed between Family Holdings and MatlinPatterson within five Business Days of the date on which either party gives notice to the other of its election to have the determination of the fair market value of the non-cash consideration referred to the Expert;

         (ii)  if Family Holdings and MatlinPatterson fail to agree within such five Business Day period, then each of Family Holdings and MatlinPatterson shall choose a nationally recognized investment banking firm independent of Family Holdings, MatlinPatterson and their respective Affiliates with significant experience in the chemical industry and the two firms so chosen shall select the Expert (which shall be a nationally recognized investment banking firm independent of Family Holdings and shall not be either of the two choosing firms); and

        (iii)  the Expert shall be requested to make its determination within a period of 15 days after the deadline for submissions to be made by Family Holdings and MatlinPatterson pursuant to clause (2) below, or as soon as practicable thereafter.

        (2)   Within five Business Days of the appointment of the Expert, each of Family Holdings and MatlinPatterson shall submit to the Expert (i) its proposed determination of the fair market value of the non-cash consideration as of the date of the determination, (ii) a list of factors which it believes to be relevant in the determination of the fair market value of the non-cash consideration, and (iii) the reasons for that proposed value. In addition, each such party shall at the same time deliver to the other a copy of any submission or information supplied by Family Holdings or MatlinPatterson to the Expert.

        (3)   The Expert shall then make its own determination (having requested such further information from the Corporation, Family Holdings and/or MatlinPatterson as it shall require) of the fair market value as of the date of the determination of any non-cash or other than U.S. Government Securities consideration taking into account any appropriate discount (including, without limitation, minority discounts) if such securities are not publicly traded.

        (4)   The Expert shall certify to each of Family Holdings and MatlinPatterson (i) that, having considered the respective submissions of Family Holdings and MatlinPatterson, it has made its own determination and (ii) the proposed value of which of Family Holdings and MatlinPatterson it determines to be closer to the fair market value of the non-cash consideration. The value proposed by Family Holdings or MatlinPatterson so certified by the Expert shall thereupon be deemed to be the fair market value of the non-cash consideration.

        (5)   Family Holdings and MatlinPatterson shall equally bear and pay the costs of the Expert's determination. The Expert shall act as an expert and not as an arbitrator and its determination shall be final and binding upon Family Holdings and MatlinPatterson in the absence of manifest terror. To the extent permitted by law, the Expert shall have no liability to any of Family Holdings or MatlinPatterson in respect of its determination.

        "Statutory Trust Act" means Chapter 38 of Title 12 of the Delaware Code, 12 Del. Code § 3801 et seq., as it may be amended from time to time, or any successor legislation.

        "Successor Administrative Trustee" has the meaning set forth in Section 4.6(d).

        "Successor Delaware Trustee" has the meaning set forth in Section 4.6(b).

        "Trade Sale or Merger Transaction" means, in a single transaction or series of related transactions (1) any sale or transfer in any manner, directly or indirectly, of all or substantially all of the business or assets of the Corporation (including the capital stock of or other ownership interest in the subsidiaries

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of the Corporation) or (2) any merger, business combination, reorganization, recapitalization, liquidation or dissolution of the Corporation, in each case other than in connection with the IPO.

        "Transaction Affected Trading Day" means each trading day in the period beginning three trading days prior to the public announcement of the existence of negotiations regarding, or the execution of an MOU or a Definitive Agreement with respect to, a Trade Sale or Merger Transaction and ending on the second trading day after the public announcement of termination of such agreement.

        "Treasury Regulations" means the income tax regulations, including temporary and proposed regulations, promulgated under the Code by the United States Treasury, as such regulations may be amended from time to time (including corresponding provisions of succeeding regulations).

        "Trust Interests" has the meaning set forth in Section 6.1(a).

        "Trustee" or "Trustees" means each Person who has signed this Trust Agreement as a trustee, so long as such Person shall continue as a trustee in accordance with the terms hereof, and all other Persons who may from time to time be duly appointed, qualified and serving as trustees in accordance with the provisions hereof, and references herein to a Trustee or the Trustees shall refer to such Person or Persons solely in their capacity as trustees hereunder.

ARTICLE II
ORGANIZATION

SECTION 2.1 Name.

        The Trust is named "HMP Equity Trust" as such name may be modified from time to time by the Administrative Trustees following written notice to the Delaware Trustee and the Holders. The Trust's activities may be conducted under the name of the Trust or any other name deemed advisable by the Administrative Trustees.

SECTION 2.2 Office.

        The address of the principal office of the Trust is 500 Huntsman Way, Salt Lake City, UT 84108. On three Business Days written notice to the Delaware Trustee and the Holders of Trust Interests, the Administrative Trustees may designate another principal office.

SECTION 2.3 Purpose.

        The exclusive purposes and functions of the Trust are (a) to issue Trust Interests pursuant to this Trust Agreement, (b) to acquire, hold, vote, transfer, manage, distribute and sell the assets and property of the Trust in accordance with the terms of this Trust Agreement, and (c) except as otherwise limited herein, to engage in only those other activities necessary, advisable or incidental thereto.

SECTION 2.4 Beneficial Owners.

        The beneficial owners of the Trust shall be the Holders of the Trust Interests.

SECTION 2.5 Authority.

        Subject to the limitations provided in this Trust Agreement, the Administrative Trustees shall have exclusive and complete authority to carry out the purposes of, and manage the property and affairs of, the Trust. An action taken by the Administrative Trustees in accordance with their powers shall constitute the act of and serve to bind the Trust. In dealing with the Trustees acting on behalf of the Trust, no Person shall be required to inquire into the authority of the Trustees to bind the Trust. Persons dealing with the Trust are entitled to rely conclusively on the power and authority of the Trustees as set forth in this Trust Agreement.

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SECTION 2.6 Title to and Beneficial Interest in Property of the Trust.

        Except as otherwise provided in this Trust Agreement, legal title to all assets of the Trust shall be vested at all times in the Trust as a separate legal entity. The Holders shall not have legal title to any part of the assets of the Trust, but the Holders of Class A Trust Interests shall have all of the beneficial interests in all Class A Assets and the Holders of Class B Trust Interests shall have all of the beneficial interests in all Class B Assets.

SECTION 2.7 Powers and Duties of the Administrative Trustees.

        (a)   Without limiting the generality of Section 2.5, but subject to this Section 2.7 and to the express limitations set forth elsewhere in this Trust Agreement, the Administrative Trustees shall have full, exclusive authority, power and sole discretion and all necessary powers to (x) take any actions they deem necessary or advisable for the administration of the Trust's affairs, (y) carry out the purposes, and manage the property and affairs, of the Trust, and (z) exercise, on behalf and in the name of the Trust, all of the powers described in the Statutory Trust Act and to cause the Trust to engage in the following activities:

          (i)  to execute, deliver and issue the Trust Interests in accordance with this Trust Agreement;

         (ii)  to acquire IPO Shares;

        (iii)  to establish a record date with respect to all actions to be taken hereunder that require a record date be established, including and with respect to, Distributions, voting rights, redemptions and exchanges, and to issue relevant notices to the Holders of Trust Interests as to such actions and applicable record dates;

        (iv)  to take all actions and perform such duties as may be required of the Administrative Trustees pursuant to this Trust Agreement;

         (v)  to bring or defend, pay, collect, compromise, arbitrate, resort to legal action, or otherwise adjust claims or demands of or against the Trust ("Legal Action");

        (vi)  to employ or otherwise engage agents and advisors, and consultants and pay reasonable compensation for such services;

       (vii)  to incur expenses that are necessary or incidental to carry out any of the purposes of the Trust;

      (viii)  to act as Registrar for the Trust Interests;

        (ix)  to take all action that may be necessary or appropriate for the preservation and the continuation of the Trust's valid existence, rights, franchises and privileges as a statutory trust under the laws of the State of Delaware and of each other jurisdiction in which such existence is necessary to protect the limited liability of the Holders or to enable the Trust to effect the purposes for which the Trust was created;

         (x)  to take any action, not inconsistent with this Trust Agreement or with applicable law, that the Administrative Trustees determine in their sole discretion to be necessary or desirable in carrying out the activities of the Trust as set out in this Section 2.7, including, but not limited to:

        (A)  causing the Trust not to be deemed to be an Investment Company required to be registered under the Investment Company Act;

        (B)  causing the Trust not to be classified for United States federal income tax purposes as an association taxable as a corporation or as a partnership; and

        (C)  causing the Trust to be classified as a grantor trust for United States federal income tax purposes;

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        (xi)  to take all action necessary to cause all applicable tax returns and tax information reports that are required to be filed with respect to the Trust and all reports, statements, notices and other information that are required to be filed with respect to the Trust pursuant to applicable federal and state securities laws to be duly prepared and filed by the Administrative Trustees, on behalf of the Trust;

       (xii)  to execute and perform its obligations under an underwriting agreement in connection with the sale of IPO Shares by the Trust in the IPO for the benefit of one or more of the Holders and any lock-up agreement entered pursuant thereto; and

      (xiii)  to execute all documents or instruments, perform all duties and powers, and do all things for and on behalf of the Trust in all matters necessary or incidental to the foregoing.

        (b)   Notwithstanding anything in this Trust Agreement to the contrary, in connection with any annual or special meeting or adjournment thereof, or any action or approval by written consent, of the stockholders of the Corporation, the HFH Designees on behalf of the Trust shall have the power to exercise all of the rights, powers and privileges of a holder of Corporation Common Stock and full power to vote, or cause to be voted, all of the Corporation Common Stock held directly or indirectly by the Trust (and any other voting securities of the Corporation held, directly or indirectly, by the Trust) in accordance with their sole discretion, except that unless the Administrative Trustees (at least one of whom must be an HFH Designee and one of whom must be an MP Designee) shall have approved otherwise, all such shares shall be voted as follows:

          (i)  so as to cause:

        (A)  the certificate of incorporation or bylaws of the Corporation to provide for its Board of Directors (the "Corporate Board") to be divided into three classes of approximately equal size, with staggered, three-year terms: the first class consisting of directors ("Class I"), whose terms will expire at the first annual meeting of stockholders following the effectiveness of the Amended and Restated Certificate of Incorporation of the Corporation adopted in connection with the IPO, the second class consisting of directors ("Class II") whose terms will expire at the second annual meeting of stockholders following such effectiveness and the third class consisting of directors ("Class III") whose terms will expire at the third annual meeting of stockholders following such effectiveness;

        (B)  the certificate of incorporation or bylaws of the Corporation to provide that upon the expiration of the term of a class of directors, directors in that class will be elected for three-year terms at the annual meeting of stockholders in the year in which their term expires;

        (C)  the Corporate Board to consist, immediately after the consummation of the IPO, of five members, with Class I consisting of two directors, Class II consisting of two directors and Class III consisting of one director; and

        (D)  the certificate of incorporation or bylaws of the Corporation to provide that any additional directorships resulting from an increase in the number of directors, and any reduction in the number of directors resulting from a decrease in the size of the Corporate Board (other than temporary vacancies) will be distributed among the three classes so that, as nearly as possible, each class will consist of one-third of the members of the Corporate Board;

         (ii)  in any such stockholders meeting at which, or with respect to any such consent pursuant to which, directors are to be elected or appointed:

        (A)  until the second anniversary of the consummation of the IPO, so as to have the Board of Directors consist of, and only of, the following persons, subject to their consent to so serve: Alvin V. Shoemaker, Nolan D. Archibald, Marsha J. Evans, H. William Lichtenberger, Wayne A. Reaud and Richard Michaelson (the "Initial Directors"), the Adviser Directors, the

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Huntsman Directors and/or other persons approved for nomination by the Corporation's nominating or governance committee or by an affirmative vote of at least two of the Administrative Trustees (at least one of whom must be an HFH Designee and one of whom must be an MP Designee);

        (B)  so as to nominate and elect two persons designated by the MP Designees (the "Adviser Directors") one of which shall be a director in Class I and one of which shall be a director in Class II, and, in the event any of such persons does not serve, or ceases to serve, as a Corporation director, such other persons designated by the MP Designees in place of such person.

        (iii)  With respect to the removal of directors of the Corporation, the Administrative Trustees shall vote or consent with respect to (or cause to be voted or consented with respect to) the Corporation Common Stock held directly or indirectly by the Trust as directed by the MP Designees with respect to any proposed removal of any Adviser Director, and as directed by the HFH Designees with respect to any proposed removal of any other director. Notwithstanding the previous sentence, however, until the second anniversary of the consummation of the IPO, the Administrative Trustees shall not vote or consent with respect to (or cause to be voted or consented with respect to) the Corporation Common Stock held directly or indirectly by the Trust to remove any of the Initial Directors unless such removal shall have received the approval of at least one of the Adviser Directors or is approved by an affirmative vote by at least two of the Administrative Trustees (at least one of whom must be an HFH Designee and one of whom must be an MP Designee);

        (iv)  Unless such action shall have received the approval of at least one of the Adviser Directors, in no event shall the Administrative Trustees vote or consent with respect to (or cause to be voted or consented with respect to) the Corporation Common Stock held directly or indirectly by the Trust to any of the following ("Special Actions"); provided that nothing in this provision shall be construed to require any vote of the stockholders of the Corporation or prohibit any director of the Corporation from voting as a director of the Corporation on any such matter in any manner he or she deems appropriate:

        (1)   entering into any transaction, agreements or arrangements between the Corporation or any of its subsidiaries, on the one hand, and any Holder or any Affiliate of any Holder (other than a subsidiary of the Corporation), on the other hand, and other than transactions in the ordinary course of business with respect to officers and directors (e.g., employee expense reimbursement, indemnification agreement, employee benefits, director or employee compensation, housing relocations, and similar transactions),

        (2)   amending or supplementing the Corporation's Certificate of Incorporation, repealing, adopting or modifying bylaws or modifying the size of the Corporate Board,

        (3)   filing by the Corporation of any petition for bankruptcy or consent to the entry of an order for relief in an involuntary bankruptcy case or make any assignment for the benefit of creditors,

        (4)   selling all or substantially all assets or stock of the Corporation, or merging, consolidating or combining the Corporation with any other entity (other than a subsidiary) or approving the sale of all or substantially all assets or stock of the Corporation, or the merger, consolidation or combination of the Corporation with any other entity (other than a subsidiary),

        (5)   issuing any new equity securities of the Corporation (or securities convertible into equity securities of the Corporation) other than with respect to director and employee compensation, or