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                                                                    EXHIBIT 4.03



THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE INDENTURE
HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITORY (AS
DEFINED IN THE INDENTURE) OR A NOMINEE THEREOF. THIS GLOBAL SECURITY IS
EXCHANGEABLE FOR SECURITIES REGISTERED IN THE NAME OF A PERSON OTHER THAN THE
DEPOSITORY OR ITS NOMINEE ONLY IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE
INDENTURE AND, UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR
SECURITIES IN DEFINITIVE FORM, THIS GLOBAL SECURITY MAY NOT BE TRANSFERRED
EXCEPT AS A WHOLE BY THE DEPOSITORY TO A NOMINEE OF THE DEPOSITORY, OR BY A
NOMINEE OF THE DEPOSITORY TO THE DEPOSITORY OR ANOTHER NOMINEE OF THE
DEPOSITORY, OR BY THE DEPOSITORY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITORY
OR A NOMINEE OF SUCH SUCCESSOR DEPOSITORY.

UNLESS THIS SECURITY IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE
DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO THE COMPANY (AS
DEFINED BELOW) OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT,
AND ANY SECURITY ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH
OTHER NAME AS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT
IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED
REPRESENTATIVE OF DTC) ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR
OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER
HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
AMENDED (THE "SECURITIES ACT"), OR ANY STATE SECURITIES LAWS. NEITHER THIS
SECURITY NOR ANY INTEREST OR PARTICIPATION HEREIN MAY BE REOFFERED, SOLD,
ASSIGNED, TRANSFERRED, PLEDGED, ENCUMBERED OR OTHERWISE DISPOSED OF IN THE
ABSENCE OF SUCH REGISTRATION OR UNLESS SUCH TRANSACTION IS EXEMPT FROM, OR NOT
SUBJECT TO, REGISTRATION.

THE HOLDER OF THIS SECURITY BY ITS ACCEPTANCE HEREOF AGREES TO OFFER, SELL OR
OTHERWISE TRANSFER THIS SECURITY, PRIOR TO THE EARLIER OF (1) THE DATE WHEN
THIS SECURITY CAN BE SOLD PURSUANT TO RULE 144 UNDER THE SECURITIES ACT WITHOUT
ANY LIMITATIONS UNDER CLAUSES (c), (e), (f) AND (h) OF RULE 144 AND (2) THE
DATE WHICH IS THREE YEARS AFTER THE LATER OF THE ORIGINAL ISSUANCE DATE HEREOF
AND THE LAST DATE ON WHICH THE COMPANY OR ANY "AFFILIATE" OF THE COMPANY WAS
THE OWNER OF THIS SECURITY OR ANY PREDECESSOR OF THIS SECURITY (SUCH EARLIER
DATE, THE "RESALE RESTRICTION TERMINATION DATE") ONLY (A) TO THE COMPANY, (B)
PURSUANT TO A REGISTRATION STATEMENT WHICH HAS BEEN DECLARED EFFECTIVE UNDER
THE SECURITIES ACT, (C) SO LONG AS THIS SECURITY IS ELIGIBLE FOR RESALE
PURSUANT TO RULE 144A UNDER THE SECURITIES ACT ("RULE 144A"), TO A PERSON IT
REASONABLY BELIEVES IS A "QUALIFIED INSTITUTIONAL BUYER" AS DEFINED IN RULE
144A THAT PURCHASES FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED
INSTITUTIONAL BUYER TO WHOM NOTICE IS GIVEN THAT THE TRANSFER IS BEING MADE IN
RELIANCE ON RULE 144A, OR (D) PURSUANT TO ANY OTHER AVAILABLE EXEMPTION FROM
THE REGISTRATION REQUIREMENTS UNDER THE SECURITIES ACT, SUBJECT TO THE
COMPANY'S AND THE TRUSTEE'S RIGHT PRIOR TO ANY SUCH OFFER, SALE OR TRANSFER (i)


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PURSUANT TO CLAUSE (D) TO REQUIRE THE DELIVERY OF AN OPINION OF COUNSEL,
CERTIFICATIONS AND/OR OTHER INFORMATION SATISFACTORY TO EACH OF THEM, AND (ii)
IN EACH OF THE FOREGOING CASES, TO REQUIRE THAT A CERTIFICATE OF TRANSFER IN
THE FORM APPEARING ON THE OTHER SIDE OF THIS SECURITY IS COMPLETED AND
DELIVERED BY THE TRANSFEROR TO THE TRUSTEE.

THE HOLDER OF THIS SECURITY IS ENTITLED TO THE BENEFITS OF THE REGISTRATION
RIGHTS AGREEMENT REFERRED TO BELOW AND, BY ITS ACCEPTANCE HEREOF, AGREES TO BE
BOUND BY AND TO COMPLY WITH THE PROVISIONS OF SUCH REGISTRATION RIGHTS
AGREEMENT.

No. R-1                                                    $150,000,000
CUSIP No. 040422AA5


                         ARISTECH CHEMICAL CORPORATION

                             6 7/8% Notes due 2006

         Aristech Chemical Corporation, a Delaware corporation (hereinafter
called the "Company", which term includes any successor corporation under the
Indenture referred to below), for value received, hereby promises to pay to
Cede & Co. or registered assigns, the principal sum of One Hundred Fifty
Million Dollars ($150,000,000) on November 15, 2006, and to pay interest
thereon from November 25, 1996 or from the most recent date to which interest
has been paid or duly provided for, semiannually on May 15 and November 15 in
each year (each, an "Interest Payment Date"), commencing May 15, 1997, at the
rate of 6 7/8 percent per annum, until the principal hereof is paid or duly
made available for payment. Interest on this Note shall be calculated on the
basis of a 360-day year consisting of twelve 30-day months. The interest so
payable and punctually paid or duly provided for on any Interest Payment Date
will, as provided in such Indenture, be paid to the Person in whose name this
Note (or one or more Predecessor Securities) is registered at the close of
business on the Regular Record Date for such interest, which shall be the April
30 or October 31 (whether or not a Business Day), as the case may be, next
preceding such Interest Payment Date. Any such interest which is payable, but
is not punctually paid or duly provided for, on any Interest Payment Date shall
forthwith cease to be payable to the registered Holder hereof on the relevant
Regular Record Date by virtue of having been such Holder, and may be paid to
the Person in whose name this Note (or one or more Predecessor Securities) is
registered at the close of business on a Special Record Date for the payment of
such Defaulted Interest to be fixed by the Company, notice whereof shall be
given to the Holders of Notes of this series not less than 10 days prior to
such Special Record Date, or may be paid at any time in any other lawful manner
not inconsistent with the requirements of any securities exchange on which the
Notes may be listed, and upon such notice as may be required by such exchange,
all as more fully provided in such Indenture.

         The Holder of this Note is entitled to the benefits of the
Registration Rights Agreement dated as of November 25, 1996 among


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the Company and the Initial Purchasers named therein (as the same may be
amended from time to time, the "Registration Rights Agreement"). In the event
that either (a) the Exchange Offer Registration Statement (as such term is
defined in the Registration Rights Agreement) is not filed with the Securities
and Exchange Commission (the "Commission") on or prior to the 90th day
following November 25, 1996 (the "Original Issue Date"), (b) the Exchange Offer
Registration Statement has not been declared effective by the Commission or
prior to the 180th day following the Original Issue Date or (c) the Exchange
Offer (as such term is defined in the Registration Rights Agreement) is not
consummated or a Shelf Registration Statement (as such term is defined in the
Registration Rights Agreement) is not declared effective by the Commission on
or prior to the earlier of (x) the 30th day following the date on which the
Exchange Offer Registration Statement is declared effective and (y) the 210th
day following the Original Issue Date, the interest rate borne by this Note
shall be increased by 0.50 percent per annum following such 90th day in the
case of clause (a) above, such 180th day in the case of clause (b) above and
the earlier of such 30th day and such 210th day in the case of clause (c)
above; provided that the aggregate amount of any such increase in the per annum
interest rate on this Note pursuant to the foregoing provisions shall in no
event exceed 0.50 percent; and provided, further, that if the Exchange Offer
Registration Statement is not declared effective on or prior to the 180th day
following the Original Issue Date, and this Note is owned by a Person (as
defined in the Registration Rights Agreement) who does not comply in all
material respects with its obligations under the penultimate paragraph of
Section 3 of the Registration Rights Agreement, this Note will not be entitled
to any such increase in the interest rate for any day after the 210th day
following the Original Issue Date. Upon (x) the filing of the Exchange Offer
Registration Statement after the 90th day described in clause (a) above, (y)
the effectiveness of the Exchange Offer Registration Statement after the 180th
day described in clause (b) above or (z) the consummation of the Exchange Offer
or the effectiveness of a Shelf Registration Statement, as the case may be,
after the earlier of the 30th day and the 210th day described in clause (c)
above, the interest rate borne by this Note from the date of such filing,
effectiveness or consummation, as the case may be, will be reduced to 6 7/8
percent per annum. The Company shall promptly provide the Trustee with notice
of any change in the interest rate borne by this Note.

         Payment of the principal of and the interest on this Note will be made
at the office or agency of the Company maintained for that purpose in The
Borough of Manhattan, The City of New York, in such coin or currency of the
United States of America as at the time of payment is legal tender for payment
of public and private debts; provided, however, that, at the option of the
Company, interest may be paid by check mailed to the address of the Person
entitled thereto as such address shall appear in the Security Register;
provided, further, that payment to DTC or any successor depository

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may be made by wire transfer to the account designated by DTC or such successor
depository in writing.

         This Note is one of a duly authorized issue of securities of the
Company (herein called the "Notes") issued and to be issued in one or more
series under an Indenture dated as of November 1, 1996 (herein called, together
with all indentures supplemental thereto, the "Indenture") between the Company
and The Chase Manhattan Bank, as Trustee (herein called the "Trustee", which
term includes any successor trustee under the Indenture), to which Indenture
and all indentures supplemental thereto reference is hereby made for a
statement of the respective rights, limitations of rights, duties and
immunities thereunder of the Company, the Trustee and the Holders of the Notes,
and of the terms upon which the Notes are, and are to be, authenticated and
delivered. This Note is one of the series designated on the face hereof,
limited (subject to exceptions provided in the Indenture) to the aggregate
principal amount specified in the Officers' Certificate dated November 25, 1996
establishing the terms of the Notes pursuant to the Indenture.

         The Notes are not redeemable prior to maturity and are not subject to
any sinking fund.

         If an Event of Default with respect to the Notes shall occur and be
continuing, the principal of the Notes may be declared due and payable in the
manner and with the effect provided in the Indenture.

         The Indenture permits, with certain exceptions as therein provided,
the amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Securities of each series issued
under the Indenture at any time by the Company and the Trustee with the consent
of the Holders of not less than a majority in aggregate principal amount of the
Securities at the time Outstanding of each series affected thereby. The
Indenture also contains provisions permitting the Holders of specified
percentages in aggregate principal amount of the Securities of any series at
the time Outstanding, on behalf of the Holders of all Securities of such
series, to waive compliance by the Company with certain provisions of the
Indenture and certain past defaults under the Indenture and their consequences.
Any such consent or waiver by the Holder of this Note shall be conclusive and
binding upon such Holder and upon all future Holders of this Note and of any
Notes issued upon the registration of transfer hereof or in exchange herefor or
in lieu hereof, whether or not notation of such consent or waiver is made upon
this Note.

         No reference herein to the Indenture and no provision of this Note or
of the Indenture shall alter or impair the obligation of the Company, which is
absolute and unconditional, to pay the principal of and interest on this Note,
at the times, place and rate, and in the coin or currency, herein and in the
Indenture prescribed.

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         As provided in the Indenture and subject to certain limitations set
forth therein and in this Note, the transfer of this Note may be registered on
the Security Register upon surrender of this Note for registration of transfer
at the office or agency of the Company maintained for the purpose in any place
where the principal of and interest on this Note are payable, duly endorsed by,
or accompanied by a written instrument of transfer in form satisfactory to the
Company and the Security Registrar duly executed by, the Holder hereof or by
his attorney duly authorized in writing, and thereupon one or more new Notes of
this series and of like tenor, of authorized denominations and for the same
aggregate principal amount, will be issued to the designated transferee or
transferees.

         The Notes are issuable only in registered form without coupons in the
denominations specified in the Officers' Certificate dated November 25, 1996
establishing the terms of the Notes, all as more fully provided in the
Indenture and such Officers' Certificate. As provided in the Indenture and in
such Officers' Certificate, and subject to certain limitations set forth in the
Indenture, such Officers' Certificate and in this Note, the Notes are
exchangeable for a like aggregate principal amount of Notes of this series in
different authorized denominations, as requested by the Holders surrendering
the same.

         No service charge shall be made for any such registration of transfer
or exchange, but the Company may require payment of a sum sufficient to cover
any tax or other governmental charge payable in connection therewith, other
than in certain cases provided in the Indenture.

         Prior to due presentment of this Note for registration of transfer,
the Company, the Trustee and any agent of the Company or the Trustee may treat
the Person in whose name this Note is registered as the owner hereof for all
purposes, whether or not this Note be overdue, and neither the Company, the
Trustee nor any such agent shall be affected by notice to the contrary.

         The Indenture contains provisions whereby (i) the Company may be
discharged from its obligations with respect to the Notes (subject to certain
exceptions) or (ii) the Company may be released from its obligation under
specified covenants and agreements in the Indenture, in each case if the
Company irrevocably deposits with the Trustee money or U.S. Government
Obligations sufficient to pay and discharge the entire indebtedness on all
Notes of this series, and satisfies certain other conditions, all as more fully
provided in the Indenture.

         This Note shall be governed by and construed in accordance with the
laws of the State of New York.

         All terms used in this Note which are defined in the Indenture shall
have the meanings assigned to them in the Indenture.

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         Unless the certificate of authentication hereon has been executed by
or on behalf of the Trustee under the Indenture by the manual signature of one
of its authorized signatories, this Note shall not be entitled to any benefits
under the Indenture or be valid or obligatory for any purpose.

         IN WITNESS WHEREOF, the Company has caused this instrument to be duly
executed under its corporate seal.

Dated:  November 25, 1996

[Seal]                                ARISTECH CHEMICAL CORPORATION

Attest:                             By:

        ----------------------         ----------------------
        Name:                          Name:
        Title:                         Title:



                    TRUSTEE'S CERTIFICATE OF AUTHENTICATION

    This is one of the Securities of the series designated therein referred to
in the within-mentioned Indenture.

                                    THE CHASE MANHATTAN BANK,
                                    as Trustee

                                    By:
                                       ------------------------
                                         Authorized Signatory

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                                 ABBREVIATIONS

    The following abbreviations, when used in the inscription on the face of
this instrument, shall be construed as though they were written out in full
according to applicable laws or regulations:

TEN COM--  as tenants in     UNIF GIFT MIN ACT--      Custodian
           common                                ----           ----
TEN ENT -- as tenants by the entireties        (Cust)         (Minor)
JT TEN  -- as joint tenants with                Under Uniform Gifts
           right of survivorship                to Minors
           and not as tenants in common         Act

                                                ------------------
                                                     (State)

Additional abbreviations may also be used though not in the
above list.

          ---------------------------------------

FOR VALUE RECEIVED, the undersigned registered holder hereby
sell(s), assign(s) and transfer(s) unto

PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF
ASSIGNEE

- ---------------------------------------------------------------
    PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS OF ASSIGNEE

- ----------------------------------------------------------------
the within Note and all rights thereunder, hereby irrevocably
constituting and appointing

- ----------------------------------------------------------------
to transfer said Note on the books of the Company with full
power of substitution in the premises.

Dated:
      ----------------------------------------------------------

       Notice: The signature to this assignment must correspond
           with the name as it appears upon the face of the
                within Note in every particular, without
            alteration or enlargement or any change whatever.

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                            CERTIFICATE OF TRANSFER

             In connection with any transfer of this Note occurring prior to
the earlier of (1) the date when this Note can be sold pursuant to Rule 144
under the Securities Act of 1933, as amended, without any limitations under
clauses (c), (e), (f) and (h) of Rule 144 and (2) the date that is three years
after the later of November 25, 1996 and the last date on which this Note (or
any Predecessor Security) was owned by the Company or any affiliate of the
Company, the undersigned confirms that this Note is being transferred:

                              CHECK ONE BOX BELOW

/ /          (a) as long as this              / /         (b) to the Company.
             Note is eligible for
             resale pursuant to Rule
             144A under the Securities
             Act of 1933, as amended, 
             to a person the undersigned
             reasonably believes is
             a "qualified institutional 
             buyer" (a "QIB") as defined 
             in such Rule 144A that
             purchases for its own
             account or for the
             account of a QIB to
             whom notice is given
             that the transfer is
             being made in reliance
             on such Rule 144A; or


      Unless the certificate of authentication hereon has been executed by or
on behalf of the Trustee under the Indenture by the manual signature of one of
its authorized signatories, this Note shall not be entitled to any benefits
under the Indenture or be valid or obligatory for any purpose.

Dated:
      -------------------------         -----------------------
                                                SIGNATURE

Signature Guaranteed:

- -------------------------------         -----------------------
                                               SIGNATURE

TO BE COMPLETED BY PURCHASER IF (a) ABOVE IS CHECKED.

      The undersigned represents and warrants that it is acquiring this Note
for its own account or an account with respect to which it exercises sole
investment discretion and that it or any such account, as the case may be, is a
"qualified institutional buyer" within the meaning of Rule 144A under the
Securities Act of 1933, as amended, and is aware that the sale to it is being
made in reliance on Rule 144A and acknowledges that it has received such
information regarding the Company as the undersigned has requested pursuant to
Rule 144A or has determined not to request such

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information and that it is aware that the transferor is relying upon the
undersigned's foregoing representations in order to claim the exemption from
registration provided by Rule 144A.

Dated:
       --------------------------       ---------------------------
                                          NOTICE: To be executed
                                          by an executive officer

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