Unless this certificate is presented by an authorized representative of The
Depository Trust Company, a New York corporation, to the Issuer or its agent
for registration of transfer, exchange, or payment, and any certificate issued
is registered in the name of Cede & Co. or in such other name as requested by
an authorized representative of The Depository Trust Company (and any payment
is made to Cede & Co. or such other entity as is requested by an authorized
representative of The Depository Trust Company), ANY TRANSFER, PLEDGE OR OTHER
USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL since the
registered owner hereof, Cede & Co., has an interest herein.
 
                           ATLANTIC RICHFIELD COMPANY
 
                                                               CUSIP
                                   [        ]
 
                % EXCHANGEABLE NOTES DUE     , 199  (THE "NOTES")
    (SUBJECT TO EXCHANGE AT MATURITY INTO SHARES OF COMMON STOCK, PAR VALUE
              $1.00 PER SHARE, OF LYONDELL PETROCHEMICAL COMPANY)
 
NO. 1                                                              $ 150,000,000
 
  ATLANTIC RICHFIELD COMPANY, a corporation duly organized and existing under
the laws of the State of Delaware (herein called "ARCO"), for value received,
hereby promises to pay to Cede & Co., or registered assigns, the principal sum
of $150,000,000 (or $      per Exchangeable Note) at the office or agency of
ARCO in the Borough of Manhattan, The City of New York, on     , 199  in such
coin or currency of the United States of America as at the time of payment
shall be legal tender for the payment of public and private debts (subject to
the mandatory exchange provisions at Maturity discussed below), and to pay
interest (computed on the basis of a 360-day year of twelve 30-day months)
thereon quarterly on       ,     ,     and       in each year (individually
referred to as an "Interest Payment Date" and collectively as the "Interest
Payment Dates"), commencing    , 1994, and at Maturity, at the rate per annum
specified in the title of this note from     , 1994, or from the most recent
Interest Payment Date to which interest has been paid or duly provided for,
until the principal hereof is paid or made available for payment. The interest
so payable, and punctually paid or duly provided for, on any Interest Payment
Date will, as provided in said Indenture, be paid to the Person in whose name
this Note (or one or more Predecessor Notes) is registered at the close of
business on the Regular Record Date for such interest, which shall be      ,
    ,    , or      , as the case may be, next preceding such Interest Payment
Date, provided that interest payable at Maturity shall be payable to the person
to whom the principal hereof is payable. In any case where such Interest
Payment Date shall not be a Business Day, then (notwithstanding any other
provision of said Indenture or the Notes) payment of such interest need not be
made on such date, but may be made on the next succeeding Business Day with the
same force and effect as if made on such date, and, if such payment is so made,
no interest shall accrue for the period from and after such date. Any such
interest not so punctually paid or duly provided for shall forthwith cease to
be payable to the registered Holder on such Regular Record Date, and may either
be paid to the Person in whose name this Note (or one or more Predecessor
Notes) is registered at the close of business on a Special Record Date for the
payment of such Defaulted Interest to be fixed by the Trustee for the Notes,
notice whereof shall be given to Holders of Notes not less than 10 days prior
to such Special Record Date, or 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 said Indenture.
 
 
                                       1

 
  At Maturity, the foregoing principal amount of this Note will be mandatorily
exchanged into a number of shares of Common Stock, par value $1.00 per share
("Lyondell Common Stock"), of Lyondell Petrochemical Company ("Lyondell") at
the Exchange Rate (as defined below) and, as a result, the Holder of this Note
will not necessarily receive an amount equal to the principal amount hereof.
The "Exchange Rate" is equal to, subject to adjustment as a result of certain
dilution events relating to the Lyondell Common Stock as provided for in the
Indenture, (a) if the Maturity Price (as defined below) per share of Lyondell
Common Stock is greater than or equal to $     per share of Lyondell Common
Stock (the "Threshold Appreciation Price"),        shares of Lyondell Common
Stock per Note, (b) if the Maturity Price is less than the Threshold
Appreciation Price but is greater than $     per share of Lyondell Common Stock
(the "Initial Price"), a fractional share of Lyondell Common Stock per Note so
that the value thereof (determined at the Maturity Price) is equal to the
Initial Price and (c) if the Maturity Price is less than or equal to the
Initial Price, one share of Lyondell Common Stock per Note. No fractional
shares of Lyondell Common Stock will be issued at Maturity as provided in the
Indenture. Notwithstanding the foregoing, ARCO may, at its option in lieu of
delivering shares of Lyondell Common Stock, deliver cash in an amount equal to
the value of such number of shares of Lyondell Common Stock at the Maturity
Price.
 
  The "Maturity Price" of the Lyondell Common Stock is defined as the average
Closing Price per share of Lyondell Common Stock on the 20 Trading Days
immediately prior to, but not including, Maturity. The "Closing Price" of any
security on any date of determination means the closing sale price (or, if no
closing price is reported, the last reported sale price) of such security on
the New York Stock Exchange (the "NYSE") on such date or, if such security is
not listed for trading on the NYSE on any such date, as reported in the
composite transactions for the principal United States securities exchange on
which such security is so listed, or if such security is not so listed on a
United States national or regional securities exchange, as reported by the
National Association of Securities Dealers, Inc. Automated Quotation System,
or, if such security is not so reported, the last quoted bid price for such
security in the over-the-counter market as reported by the National Quotation
Bureau or similar organization, or, if such bid price is not available, the
market value of such security on such date as determined by a nationally
recognized independent investment banking firm retained for this purpose by
ARCO. A "Trading Day" is defined as a day on which the security the Closing
Price of which is being determined (A) is not suspended from trading on any
national or regional securities exchange or association or over-the-counter
market at the close of business and (B) has traded at least once on the
national or regional securities exchange or association or over-the-counter
market that is the primary market for the trading of such security. "Business
Day" means any day, other than a Saturday or Sunday, on which banking
institutions in the City of New York are open for business.
 
  Interest on this Note will be payable, and delivery of Lyondell Common Stock
(or, at ARCO's option, cash in an amount equal to the value of such Lyondell
Common Stock) in exchange for the principal amount of this Note at Maturity
will be made upon surrender of this Note, at the office or agency of ARCO
maintained for that purpose in the City of New York, New York, and payment of
interest on (and, if ARCO elects not to deliver Lyondell Common Stock upon
exchange at Maturity, the cash equivalent thereof payable upon exchange for the
principal amount of) this Note will be made 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 ARCO
payment of interest may be made by check mailed to the address of the Person
entitled thereto as such address shall appear on the Note Register at the close
of business on the Regular Record Date.
 
  This Note shall not be valid or become obligatory for any purpose until the
certificate of authentication hereon shall have been signed by the Trustee
under the Indenture.
 
  This Note is one of a duly authorized issue of debentures, notes, bonds or
other evidences of indebtedness of ARCO (herein called the "Securities"), of
the series hereinafter specified, all issued or to be issued under and pursuant
to the Indenture, to which Indenture and all indentures supplemental thereto
reference is hereby made for a description of the rights, limitation of rights,
obligations, duties and immunities thereunder of the Trustee, ARCO and the
Holders of the Securities.
 
                                       2

 
  The Securities may be issued in one or more series, which different series
may be issued in various aggregate principal amounts, may mature at different
times, may bear interest (if any) at different rates, may be subject to
different redemption provisions (if any), may be subject to different sinking,
purchase or analogous funds (if any), may be subject to different covenants
and Events of Default and may otherwise vary as provided in the Indenture.
This Note is one of a duly authorized issue of notes of the series above
(hereinafter called the "Notes") of ARCO, which series is limited to
[39,921,400] Exchangeable Notes; all such Notes issued and to be issued under
an indenture dated as of January 1, 1992 between ARCO and The Bank of New
York, as Trustee, (as supplemented by a First Supplemental Indenture, dated as
of May 1, 1994) (herein collectively the "Indenture"), to which Indenture and
all other indentures supplemental thereto reference is hereby made for a
statement of the rights and limitation of rights thereunder of the Holders of
the Notes and of the rights, obligation, duties and immunities of the Trustee
for each series of Notes and of ARCO, and the terms upon which the Notes are
and are to be authenticated and delivered. This Note is one of a series of the
Notes designated   % Exchangeable Notes due     , 199 .
 
  The Notes may not be redeemed prior to Maturity.
 
  If an Event of Default with respect to the Notes, as defined in the
Indenture, shall occur and be continuing, the principal of all the Notes may
be declared due and payable in the manner and with the effect provided in the
Indenture.
 
  The Indenture contains provisions permitting ARCO and the Trustee, with the
consent of the Holders of not less than 50% in aggregate principal amount at
Stated Maturity of the Securities at the time outstanding of each series
affected by such supplemental indenture or indentures, evidenced as provided
in the Indenture, to execute supplemental indentures adding any of the
provisions to or changing in any manner or eliminating any of the provisions
of the Indenture or of any supplemental indenture as such provisions apply to
such Securities or modifying in any manner the rights of the Holders of the
Securities of each such series; provided, however, that no such supplemental
indenture shall without the consent of the Holder of each outstanding Security
affected thereby (i) extend the fixed maturity of any Security or reduce the
rate or extend the time of payment of interest thereon or reduce the principal
thereof or the time during which premium is payable thereon or make the
principal thereof or any premium or interest thereon payable in any coin or
currency other than that provided in the Securities, or (ii) reduce the
percentage in principal amount at Stated Maturity of the outstanding
Securities, the consent of whose Holders is required for any such supplemental
indenture, or the consent of whose Holders is required for any waiver of
compliance with certain provisions of the Indenture or of certain defaults
under and their consequences provided for in the Indenture, or (iii) change
the terms under which the Exchangeable Notes are exchangeable as set forth in
Section 16 of the Indenture without the consent of the Holders of each
Exchangeable Note so affected. Any such consent or waiver by the Holder of
this Note (unless revoked as provided in the Indenture) shall be conclusive
and binding upon such Holder and upon all future Holders and owners of this
Note and any Note which may be issued in exchange or substitution herefor,
irrespective of whether or not any notation thereof is made upon this Note or
such other Note.
 
  No reference herein to the Indenture and no provision of this Note or of the
Indenture shall alter or impair the obligation of ARCO, which is absolute and
unconditional, to pay the principal of and interest on this Note at the place,
at the respective times, at the rate and in the manner herein prescribed.
 
  As provided in the Indenture and subject to certain limitations therein set
forth, this Note is transferable on the Note Register of ARCO, upon surrender
of this Note for registration of transfer at the office or agency of ARCO to
be maintained for that purpose in the City of New York, or at any other office
or agency of ARCO maintained for that purpose, duly endorsed by, or
accompanied by a written instrument of transfer in form satisfactory to ARCO
and the Note Registrar duly executed by the Holder hereof or his attorney duly
authorized in writing, and thereupon one or more new Notes, of authorized
denominations and for the same aggregate principal amount, will be issued to
the designated transferee or transferees.
 
                                       3

 
  No service charge shall be made for any such transfer or exchange, but ARCO
may require payment of a sum sufficient to cover any tax or other governmental
charge payable in connection with the registration of such transfer or
exchange, other than certain exchanges not involving any transfer.
 
  Certain terms used in this Note which are defined in the Indenture have the
meanings set forth therein.
 
  This Note shall be governed by, and construed in accordance with, the laws of
the State of New York.
 
  Prior to due presentment for registration of transfer of this Note, ARCO, the
Trustee any paying agent and any Note registrar may deem and treat the
registered Holder hereof as the absolute owner of this Note (whether or not
this Note shall be overdue and notwithstanding any notation of ownership or
other writing hereon by anyone other than ARCO, any Note registrar or the
Trustee), for the purpose of receiving payment hereof or on account hereof, and
for all other purposes (subject to the provisions of the first paragraph
hereof), and neither ARCO nor the Trustee nor any paying agent nor any Note
registrar shall be affected by any notice to the contrary.
 
  No recourse for the payment of the principal of or premium, if any, or
interest on this Note, or for any claim based hereon or otherwise in respect
hereof, and no recourse under or upon any obligation, covenant or agreement of
ARCO in the Indenture or any indenture supplemental thereto or in any Note, or
because of the creation of any indebtedness represented thereby, shall be had
against any incorporator, stockholder, officer or director, as such, past,
present or future, of ARCO or of any successor corporation, either directly or
through ARCO or any successor corporation, whether by virtue of any
constitution, statute or rule of law or by the enforcement of any assessment or
penalty or otherwise, all such liability being, by the acceptance hereof and as
a condition of and as part of the consideration for the issue hereof, expressly
waived and released.
 
  Terms used herein which are defined in the Indenture shall have the meanings
assigned to them in the Indenture.
 
                                       4

 
  IN WITNESS WHEREOF, Atlantic Richfield Company has caused this instrument to
be signed, manually or by facsimile, by its Chairman of the Board, its
President or one of its Vice Presidents and by its Treasurer or one of its
Assistant Treasurers, and its corporate seal to be printed, engraved or
otherwise reproduced hereon, by facsimile or otherwise.
 
                           ATLANTIC RICHFIELD COMPANY
 
 
 
 
By___________________________________     By___________________________________
     Vice President and Treasurer                  Chairman of the Board
 
 
Dated:               , 1994
 
  This is one of the securities issued under the within-mentioned Indenture.
 
                                                      , as Trustee
 
 
 
Dated:               , 1994               By___________________________________
                                                    Authorized Officer
 
                                       5