ALUMINUM CO OF AMERICA
S-3, 1998-07-17
PRIMARY PRODUCTION OF ALUMINUM
Previous: FRANKLIN HIGH INCOME TRUST, N-30D, 1998-07-17
Next: AMERICAN NATIONAL GROWTH FUND INC, 485APOS, 1998-07-17



<PAGE>
 
     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JULY 17, 1998
 
                                                       REGISTRATION NO. 333-
- -------------------------------------------------------------------------------
- -------------------------------------------------------------------------------
                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549
                                --------------
                                   FORM S-3
                            REGISTRATION STATEMENT
                                     UNDER
                          THE SECURITIES ACT OF 1933
                                --------------
                          ALUMINUM COMPANY OF AMERICA
              (EXACT NAME OF REGISTRANT AS SPECIFIED IN CHARTER)
             PENNSYLVANIA                            25-0317820
       (STATE OF INCORPORATION)         (I.R.S. EMPLOYER IDENTIFICATION NO.)
                                --------------
                                 ALCOA TRUST I
              (EXACT NAME OF REGISTRANT AS SPECIFIED IN CHARTER)
               DELAWARE                              APPLIED FOR
    (STATE OR OTHER JURISDICTION OF        (I.R.S. EMPLOYER IDENTIFICATION
    INCORPORATION OR ORGANIZATION)                     NUMBER)
                                --------------
                       425 SIXTH AVENUE, ALCOA BUILDING,
                      PITTSBURGH, PENNSYLVANIA 15219-1850
                                (412) 553-4545
         (ADDRESS AND TELEPHONE NUMBER OF PRINCIPAL EXECUTIVE OFFICES)
                                --------------
 LAWRENCE R. PURTELL, EXECUTIVE VICE PRESIDENT--ENVIRONMENT, HEALTH AND SAFETY
                              AND GENERAL COUNSEL
                       425 SIXTH AVENUE, ALCOA BUILDING,
                      PITTSBURGH, PENNSYLVANIA 15219-1850
                                (412) 553-3875
           (NAME, ADDRESS AND TELEPHONE NUMBER OF AGENT FOR SERVICE)
                                WITH COPIES TO:
        VINCENT J. PISANO, ESQ.                  JOHN W. WHITE, ESQ.
 SKADDEN, ARPS, SLATE, MEAGHER & FLOM          CRAVATH, SWAINE & MOORE
                  LLP                             825 EIGHTH AVENUE
           919 THIRD AVENUE                   NEW YORK, NEW YORK 10019
       NEW YORK, NEW YORK 10022                    (212) 474-1000
            (212) 735-3000
                                --------------
  APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC: From time
to time after the effective date of this Registration Statement, as determined
by market conditions and other factors.
  If the only securities being registered on this Form are being offered
pursuant to dividend or interest reinvestment plans, please check the
following box. [_]
  If any of the securities being registered on this Form are to be offered on
a delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or
interest reinvestment plans, check the following box. [X]
  If this Form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, please check the following
box and list the Securities Act registration statement number of the earlier
effective registration statement for the same offering. [_]
  If this Form is a post-effective amendment filed pursuant to Rule 462(c)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. [_]
  If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. [X]
                                --------------
                        CALCULATION OF REGISTRATION FEE
- -------------------------------------------------------------------------------
- -------------------------------------------------------------------------------
<TABLE>
<CAPTION>
                                                                          PROPOSED
                                                       PROPOSED           MAXIMUM
                                                        MAXIMUM          AGGREGATE       AMOUNT OF
     TITLE OF EACH CLASS           AMOUNT TO BE        OFFERING           OFFERING      REGISTRATION
OF SECURITIES TO BE REGISTERED      REGISTERED     PRICE PER UNIT(1)    PRICE(1)(2)        FEE(3)
- ----------------------------------------------------------------------------------------------------
<S>                             <C>                <C>               <C>                <C>
  Debt Securities of
   Aluminum Company of
   America (the
   "Company")(5)..........
- -------------------------------------------------------------
  Warrants to purchase
   Senior Debt Securities
   of the Company(6)......
- -------------------------------------------------------------
  Class B Serial Preferred
   Stock of the
   Company(7).............             (4)                (4)               (4)             (4)
- -------------------------------------------------------------
  Common Stock, $1.00 par
   value, of the
   Company(8).............
- -------------------------------------------------------------
  Trust Preferred
   Securities of Alcoa
   Trust I(9).............
- -------------------------------------------------------------
  Guarantee of Preferred
   Securities of Alcoa
   Trust I by the
   Company(10)............
- ----------------------------------------------------------------------------------------------------
  Total...................      $1,050,000,000(11)        100%       $1,050,000,000(11) $309,750(3)
</TABLE>
- -------------------------------------------------------------------------------
- -------------------------------------------------------------------------------
                                                       (footnotes on next page)
  PURSUANT TO RULE 429 UNDER THE SECURITIES ACT, THE PROSPECTUS INCLUDED IN
THIS REGISTRATION STATEMENT ALSO RELATES TO $150,000,000 OF SECURITIES
PREVIOUSLY REGISTERED UNDER THE COMPANY'S REGISTRATION STATEMENT ON FORM S-3
(NO. 33-60045), AND $300,000,000 OF SECURITIES PREVIOUSLY REGISTERED UNDER THE
COMPANY'S REGISTRATION STATEMENT ON FORM S-3 (NO. 33-64353). THIS REGISTRATION
STATEMENT CONSTITUTES POST-EFFECTIVE AMENDMENT NO. 1 TO THE COMPANY'S
REGISTRATION STATEMENT ON FORM S-3 (NO. 33-64353) AND POST-EFFECTIVE AMENDMENT
NO. 2 TO THE COMPANY'S REGISTRATION STATEMENT ON FORM S-3 (NO. 33-60045).
                                --------------
  THE REGISTRANTS HEREBY AMEND THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANTS
SHALL FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS
REGISTRATION STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH
SECTION 8(A) OF THE SECURITIES ACT, OR UNTIL THE REGISTRATION STATEMENT SHALL
BECOME EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID
SECTION 8(A), MAY DETERMINE.
 
- -------------------------------------------------------------------------------
- -------------------------------------------------------------------------------
<PAGE>
 
(footnotes from previous page)
- --------
 (1) The proposed maximum offering price per unit will be determined from time
     to time by the Registrants in connection with the issuance by the
     Registrants of the securities registered hereunder.
 (2) The proposed maximum aggregate offering price has been estimated solely
     for the purpose of calculating the registration fee pursuant to Rule 457
     under the Securities Act.
 (3) The amount of securities eligible to be sold under prior registration
     statements to be carried forward to this Registration Statement is
     $450,000,000. The amount of the filing fee associated with such
     securities that was previously paid with the prior registration
     statements was $155,172.42.
 (4) Not applicable pursuant to General Instruction II.D. of Form S-3.
 (5) Subject to note (11) below, there is being registered hereunder an
     indeterminate principal amount of Debt Securities of the Company as may
     be sold from time to time. If any Debt Securities are issued at an
     original issue discount, then the offering price shall be in such greater
     principal amount as shall result in an aggregate initial offering price
     not to exceed $1,500,000,000.
 (6) Subject to note (11) below, there is being registered hereunder an
     indeterminate number of Warrants to be issued from time to time.
 (7) Subject to note (11) below, there is being registered hereunder an
     indeterminate number of shares of Class B Serial Preferred Stock of the
     Company as may be sold, from time to time.
 (8) Subject to note (11) below, there is being registered hereunder an
     indeterminate number of shares of Common Stock of the Company as shall be
     issuable upon conversion of Debt Securities or Class B Serial Preferred
     Stock of the Company or Trust Preferred Securities of Alcoa Trust I being
     registered hereunder, to the extent any of such securities are by their
     terms convertible into or exchangeable for Common Stock, plus such
     additional shares as may be issued pursuant to anti-dilution adjustments.
 (9) Subject to note (11) below, there is being registered hereunder an
     indeterminate amount and number of Trust Preferred Securities of Alcoa
     Trust I (the "Trust Preferred Securities") as may be sold from time to
     time.
(10) No separate consideration will be received for the Guarantee of the Trust
     Preferred Securities (the "Guarantee"). The Guarantee includes the rights
     of holders of Trust Preferred Securities under the Guarantee and certain
     back-up undertakings, as described in the Registration Statement.
(11) In no event will the aggregate offering price of all securities issued
     from time to time pursuant to this Registration Statement exceed
     $1,500,000,000 or the equivalent thereof in one or more foreign
     currencies, foreign currency units or composite currencies. The aggregate
     amount of Common Stock of the Company registered hereunder is further
     limited to that which is permissible under Rule 415(a)(4) under the
     Securities Act. The securities registered hereunder may be sold
     separately or as units with other securities registered hereunder.
<PAGE>
 
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+INFORMATION CONTAINED HEREIN IS SUBJECT TO COMPLETION OR AMENDMENT. A         +
+REGISTRATION STATEMENT RELATING TO THESE SECURITIES HAS BEEN FILED WITH THE   +
+SECURITIES AND EXCHANGE COMMISSION. THESE SECURITIES MAY NOT BE SOLD NOR MAY  +
+OFFERS TO BUY BE ACCEPTED PRIOR TO THE TIME THE REGISTRATION STATEMENT        +
+BECOMES EFFECTIVE. THIS PRELIMINARY PROSPECTUS SHALL NOT CONSTITUTE AN OFFER  +
+TO SELL OR THE SOLICITATION OF AN OFFER TO BUY NOR SHALL THERE BE ANY SALE OF +
+THESE SECURITIES IN ANY STATE IN WHICH SUCH OFFER, SOLICITATION OR SALE WOULD +
+BE UNLAWFUL PRIOR TO REGISTRATION OR QUALIFICATION UNDER THE SECURITIES LAWS  +
+OF ANY SUCH STATE.                                                            +
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
                   SUBJECT TO COMPLETION DATED JULY 17, 1998
 
                        $1,500,000,000
              ALUMINUM COMPANY OF AMERICA
LOGO                    DEBT SECURITIES,
            WARRANTS TO PURCHASE SENIOR DEBT SECURITIES,
                PREFERRED STOCK AND COMMON STOCK
                        ALCOA TRUST I
         TRUST PREFERRED SECURITIES FULLY AND UNCONDITIONALLY
           GUARANTEED BY ALUMINUM COMPANY OF AMERICA
 
                                  ----------
 
  Aluminum Company of America, a Pennsylvania corporation (the "Company" or
"Alcoa"), may issue from time to time, together or separately up to an
aggregate initial offering price of $1,500,000,000 of its (i) unsecured senior
debt securities (the "Senior Debt Securities"), (ii) unsecured subordinated
debt securities (the "Subordinated Debt Securities" and, together with the
Senior Debt Securities, the "Debt Securities"), (iii) warrants to purchase
Senior Debt Securities (the "Warrants"), (iv) Class B Serial Preferred Stock
(the "Preferred Stock" or "Class B Stock") in one or more series, and (v)
shares of common stock, $1.00 par value, of the Company (the "Common Stock")
issuable only upon conversion of securities which are, pursuant to the terms
thereof, convertible into shares of Common Stock. The Debt Securities,
Preferred Stock and Warrants may be offered independently or together in any
combination for sale directly to purchasers or through dealers, underwriters or
agents designated and in amounts, at prices and on terms to be determined by
market conditions at the time of the offering. The Debt Securities, Warrants,
Preferred Stock and Common Stock are referred to herein collectively as the
"Company Securities."
 
  Alcoa Trust I (the "Alcoa Trust"), a statutory business trust formed under
Delaware law, may offer, from time to time, preferred securities (the "Trust
Preferred Securities") with the payment of dividends and payments on
liquidation or redemption of the Trust Preferred Securities issued by the Alcoa
Trust guaranteed on a subordinated basis by the Company (the "Trust Guarantee")
to the extent described herein and in an accompanying prospectus supplement
(the "Prospectus Supplement"). The Company will be the owner of the trust
interests represented by common securities (the "Trust Common Securities") to
be issued by the Alcoa Trust. Unless indicated otherwise in a Prospectus
Supplement, the Alcoa Trust exists for the sole purpose of issuing its trust
interests and investing the proceeds thereof in Subordinated Debt Securities.
The Company Securities and the Trust Preferred Securities are referred to
herein collectively as the "Offered Securities."
 
  The Offered Securities may be issued in one or more series or issuances and
will be limited to $1,500,000,000 in aggregate public offering price (or its
equivalent, based on the applicable exchange rate, to the extent Debt
Securities are issued for one or more foreign currencies or currency units).
The Offered Securities may be sold for U.S. dollars, or any foreign currency or
currencies or currency units, and the principal of, any premium on, and any
interest on, the Debt Securities may be payable in U.S. dollars, or any foreign
currency or currencies or currency units.
 
  The Offered Securities may be offered separately or as units with other
Offered Securities, in separate series in amounts, at prices and on terms to be
determined at or prior to the time of sale.
 
  The specific terms of the Offered Securities in respect of which this
Prospectus is being delivered are set forth in the accompanying Prospectus
Supplement, including, where applicable, (i) in the case of Debt Securities,
the specific designation, aggregate principal amount, authorized denomination,
initial offering price, maturity (which may be fixed or extendible), premium
(if any), interest rate (which may be fixed or floating), time of and method of
calculating the payment of interest, if any, the currency in which principal,
premium, if any, and interest, if any, are payable, any redemption, conversion
or sinking fund terms and other specific terms; (ii) in the case of the
Warrants, a description of the Debt Securities for which each Warrant is
exercisable and the offering price, if any, the exercise price, duration and
any other specific terms not set forth herein of the Warrants; (iii) in the
case of the Preferred Stock, the specific title, number of shares, rate (or
method of calculation) and time of payments of dividend, liquidation amounts,
any conversion or exchange provisions and any other specific terms of the
Preferred Stock; (iv) in the case of Trust Preferred Securities, the
designation, number of shares, liquidation amount per share, initial public
offering price, dividend rate (or method of calculation thereof), dates on
which dividends shall be payable and dates from which dividends shall accrue,
any redemption or sinking fund provisions and any conversion or exchange
provisions; and (v) in the case of all Offered Securities, whether such Offered
Securities will be offered separately or as a unit with other Offered
Securities. The Prospectus Supplement will also contain information, where
applicable, about certain United States Federal income tax considerations
relating to, and any listing on a securities exchange of, the Offered
Securities covered by the Prospectus Supplement.
 
                                  ----------
 
 THESE SECURITIES HAVE NOT BEEN APPROVED  OR DISAPPROVED BY THE SECURITIES AND
   EXCHANGE COMMISSION  OR  ANY  STATE  SECURITIES  COMMISSION  NOR  HAS  THE
    SECURITIES AND  EXCHANGE COMMISSION OR ANY  STATE SECURITIES COMMISSION
      PASSED UPON  THE  ACCURACY  OR  ADEQUACY  OF  THIS  PROSPECTUS.  ANY
       REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.
 
  The Offered Securities will be sold directly, through agents, dealers or
underwriters as designated from time to time, or through a combination of such
methods. If any agents of the Company or the Alcoa Trust or any dealers or
underwriters are involved in the sale of the Offered Securities in respect of
which this Prospectus is being delivered, the names of such agents, dealers or
underwriters and any applicable agent's commission, dealer's purchase price or
underwriter's discount will be set forth in or may be calculated from the
Prospectus Supplement. The net proceeds to the Company or the Alcoa Trust from
such sale will be the purchase price less such commission in the case of an
agent, the purchase price in the case of a dealer, or the public offering price
less such discount in the case of an underwriter and less, in each case, other
attributable expenses. See "Plan of Distribution."
 
  This Prospectus may not be used to consummate sales of Offered Securities
unless accompanied by a Prospectus Supplement.
 
                   THE DATE OF THIS PROSPECTUS IS       ,   .
<PAGE>
 
                             AVAILABLE INFORMATION
 
  The Company and the Alcoa Trust have filed with the Securities and Exchange
Commission (the "Commission") a joint registration statement on Form S-3
(herein, together with all amendments and exhibits, referred to as the
"Registration Statement") under the Securities Act of 1933, as amended (the
"Securities Act") with respect to the securities offered hereby. This
Prospectus, which forms a part of the Registration Statement, does not contain
all of the information set forth in the Registration Statement, certain parts
of which are omitted in accordance with the rules and regulations of the
Commission. For further information with respect to the Company, the Alcoa
Trust and the securities offered hereby, reference is made to the Registration
Statement and to the exhibits thereto. Any statements made in this Prospectus
concerning the provisions of certain documents are not necessarily complete
and, in each instance, reference is made to the copy of such document filed as
an exhibit to the Registration Statement or otherwise filed with the
Commission.
 
  Alcoa is subject to the informational requirements of the Securities
Exchange Act of 1934, as amended (the "Exchange Act"), and in accordance
therewith files reports and other information with the Securities and Exchange
Commission. The Registration Statement, the exhibits forming a part thereof
and the reports and other information filed by the Company with the Commission
may be inspected and copies may be obtained at the principal office of the
Commission at 450 Fifth Street, N.W., Washington D.C. 20549, and at the
following regional offices of the Commission: 500 West Madison Street, Suite
1400, Chicago, Illinois 60661, and 7 World Trade Center, 13th Floor, New York,
New York 10048. Copies of such materials can be obtained from the Public
Reference Section of the Commission, 450 Fifth Street, N.W., Washington, D.C.
20549, at prescribed rates. Such information may also be accessed
electronically by means of the Commission's home page on the Internet at
(http://www.sec.gov.). Reports and other information concerning Alcoa can also
be inspected at the offices of the New York Stock Exchange, Inc., 20 Broad
Street, New York, New York 10005.
 
  No separate financial statements of the Alcoa Trust have been included or
incorporated by reference herein. Neither the Alcoa Trust nor the Company
considers such financial statements material to holders of Trust Preferred
Securities because (i) all of the voting securities of the Alcoa Trust will be
owned, directly or indirectly, by the Company, a reporting company under the
Exchange Act, (ii) the Alcoa Trust has no independent operations but rather
exists for the purpose of issuing securities representing undivided beneficial
interests in the assets of the Alcoa Trust and investing the proceeds thereof
in Subordinated Debt Securities, and (iii) the obligations of the Alcoa Trust
under the Trust Preferred Securities are fully and unconditionally guaranteed
on a subordinated basis by the Company to the extent set forth herein. See
"The Alcoa Trust" and "Description of Trust Preferred Securities and Trust
Guarantee--Trust Guarantee."
 
                INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE
 
  Alcoa has filed with the Commission, pursuant to the Exchange Act, an Annual
Report on Form 10-K for the fiscal year ended December 31, 1997, filed on
March 11, 1998, as amended by Amendment No. 1 on Form 10-K/A, filed on June
26, 1998 (the "Alcoa 1997 Form 10-K"), a Quarterly Report on Form 10-Q for the
quarter ended March 31, 1998, and a Current Report on Form 8-K, dated June 10,
1998, each of which is hereby incorporated in and made a part of this
Prospectus. Statements contained in any such documents as to the contents of
any contract or other document referred to therein are not necessarily
complete and, in each instance, reference is made to the copy of such contract
or other document filed with the Commission, each such statement being
qualified in all respects by such reference.
 
  All documents filed by the Company pursuant to Sections 13(a), 13(c), 14 or
15(d) of the Exchange Act subsequent to the date of this Prospectus and prior
to the termination of the offering of
 
                                       2
<PAGE>
 
the Offered Securities shall be deemed to be incorporated by reference in this
Prospectus and to be a part hereof from the date of filing of such documents.
Any statement contained in a document incorporated, or deemed to be
incorporated, by reference herein or contained in this Prospectus shall be
deemed to be modified or superseded for purposes of this Prospectus to the
extent any statement contained herein or in any subsequently filed document
which also is, or is deemed to be, incorporated by reference herein modifies
or supersedes such statement. Any such statement so modified or superseded
shall not be deemed to constitute a part hereof except as so modified or
superseded. This Prospectus does not contain all the information set forth in
the Registration Statement of which this Prospectus forms a part which the
Company has filed with the Commission and to which reference is hereby made.
 
  THE COMPANY WILL PROVIDE WITHOUT CHARGE TO EACH PERSON TO WHOM A COPY OF
THIS PROSPECTUS HAS BEEN DELIVERED, UPON THE WRITTEN OR ORAL REQUEST OF SUCH
PERSON, A COPY OF ANY OR ALL OF THE DOCUMENTS WHICH ARE INCORPORATED HEREIN BY
REFERENCE, OTHER THAN EXHIBITS TO SUCH DOCUMENTS (UNLESS SUCH EXHIBITS ARE
SPECIFICALLY INCORPORATED BY REFERENCE INTO SUCH DOCUMENTS). REQUESTS FOR SUCH
COPIES SHOULD BE DIRECTED TO ALUMINUM COMPANY OF AMERICA, 425 SIXTH AVENUE,
PITTSBURGH, PENNSYLVANIA 15219-1850, ATTENTION: TREASURER (TELEPHONE:
(412) 553-4545). (EFFECTIVE AUGUST 14, 1998, THE PRINCIPAL EXECUTIVE OFFICES
OF THE COMPANY WILL BE LOCATED AT 201 ISABELLA STREET, PITTSBURGH,
PENNSYLVANIA 15212-5858.)
 
                                       3
<PAGE>
 
                                  THE COMPANY
 
  The Company is the world's leading producer of aluminum and alumina and a
major participant in all segments of the industry: mining, refining, smelting,
fabricating and recycling. The Company serves customers worldwide in the
packaging, automotive, aerospace, construction and other markets with a great
variety of fabricated and finished products. Its operations consist of the
three segments described below.
 
  The alumina and chemicals segment includes the production and sale of
bauxite, alumina chemicals and related transportation services. The aluminum
processing segment comprises the production and sale of molten metal, ingot
and aluminum products that are flat-rolled, engineered or finished. Also
included are power, transportation and other services. The non-aluminum
products segment includes the production and sale of electrical, plastic and
composite materials products, manufacturing equipment, gold, magnesium
products and steel and titanium forgings.
 
  Alcoa is organized into 21 independently-managed business units and has over
180 operating locations in 28 countries, serving a broad range of markets in
developing and industrialized economies. The principal executive offices of
the Company are located at 425 Sixth Avenue, Alcoa Building, Pittsburgh,
Pennsylvania 15219-1850 (Telephone: (412) 553-4545). (Effective August 14,
1998, the principal executive offices of the Company will be located at 201
Isabella Street, Pittsburgh, Pennsylvania 15212-5858.)
 
RATIOS OF EARNINGS TO FIXED CHARGES
 
  The ratios of the Company's earnings to fixed charges for the years ended
December 31, 1993 through 1997 are 2.22, 6.47, 10.45, 7.25 and 9.44. The ratio
of the Company's earnings to fixed charges for the three month period ended
March 31, 1998 is 9.10. The ratios include all earnings, before extraordinary
items and the cumulative effects of accounting changes, and fixed charges of
the Company and its majority owned subsidiaries plus the Company's
proportionate share of earnings of 50% owned entities. Earnings have been
calculated by adding to net income the provision for taxes on income,
amortization of capitalized interest, interest expense and an amount
representative of the interest factor in rentals, and have been decreased by
the undistributed earnings of entities less than 50% owned, preferred stock
dividend requirements of majority owned subsidiaries and the minority interest
share in the losses of majority owned subsidiaries without fixed charges of
the Company. Fixed charges consist of total interest expense, amortization of
debt expense, an amount representative of the interest factor in rentals,
capitalized interest and preferred stock dividend requirements of majority
owned subsidiaries.
 
                                       4
<PAGE>
 
                                 ALCOA TRUST I
 
  Alcoa Trust I (the "Alcoa Trust") is a statutory business trust formed under
Delaware law pursuant to (i) a Declaration of Trust (a "Declaration") executed
by the Company, as sponsor for the Alcoa Trust, and the Trustees (as defined
herein) of the Alcoa Trust and (ii) the filing of a certificate of trust with
the Delaware Secretary of State. Unless an accompanying Prospectus Supplement
provides otherwise, the Alcoa Trust exists for the sole purposes of (i)
issuing the Trust Preferred Securities and investing the proceeds thereof in a
specific series of Subordinated Debt Securities, (ii) issuing and selling
Common Securities to the Company in exchange for cash and investing the
proceeds thereof in additional Subordinated Debt Securities, and (iii)
engaging in such other activities as are necessary, convenient or incidental
thereto. The Alcoa Trust shall not borrow money, issue debt or reinvest
proceeds derived from investments, pledge any of its assets, or otherwise
undertake (or permit to be undertaken) any activity that would cause the Alcoa
Trust not to be classified for United States federal income tax purposes as a
grantor trust. All of the Trust Common Securities will be owned by the
Company. The Trust Common Securities will rank pari passu, and payments will
be made thereon pro rata, with the Trust Preferred Securities, except that
upon the occurrence and continuance of an event of default under the
Declaration, the rights of the holders of the Trust Common Securities to
payment in respect of distributions and payments upon liquidation, redemption
and otherwise will be subordinated to the rights of the holders of the Trust
Preferred Securities. The Company will acquire Trust Common Securities having
an aggregate liquidation amount equal to a minimum of 3% of the total capital
of the Alcoa Trust. The Alcoa Trust will have a term of [40] years, but may
terminate earlier as provided in the Declaration. The Alcoa Trust's business
and affairs will be conducted by the Trustees. The holder of the Trust Common
Securities will be entitled to appoint, remove or replace any of, or increase
or reduce the number of, the Trustees of the Alcoa Trust. The duties and
obligations of the Trustees shall be governed by the Declaration of the Alcoa
Trust. At least one of the Trustees of the Alcoa Trust will be a person who is
an employee or officer of or who is affiliated with the Company (a "Regular
Trustee"). One Trustee of the Alcoa Trust will be a financial institution that
is not affiliated with the Company, which shall act as property trustee and as
indenture trustee for the purposes of the Trust Indenture Act of 1939, as
amended (the "Trust Indenture Act"), pursuant to the terms set forth in a
Prospectus Supplement (the "Property Trustee"). In addition, unless the
Property Trustee maintains a principal place of business in the State of
Delaware and otherwise meets the requirements of applicable law, one Trustee
of the Alcoa Trust will be a legal entity having a principal place of business
in, or an individual resident of, the State of Delaware (the "Delaware
Trustee" and, together with the Regular Trustee and the Property Trustee, the
"Trustees"). The Company will pay all fees and expenses related to the Alcoa
Trust and the offering of the Trust Preferred Securities. Unless otherwise set
forth in the Prospectus Supplement, the Property Trustee will be The Chase
Manhattan Bank, and the Delaware Trustee will be Chase Manhattan Bank
Delaware. The office of the Delaware Trustee in the State of Delaware is 1201
Market Street, Wilmington, Delaware 19801. The principal place of business of
the Alcoa Trust is c/o Aluminum Company of America, 425 Sixth Avenue, Alcoa
Building, Pittsburgh, Pennsylvania 15219-1850. Telephone: (412) 553-4545.
(Effective August 14, 1998, the principal executive offices of the Company
will be located at 201 Isabella Street, Pittsburgh, Pennsylvania 15212-5858.)
 
                                USE OF PROCEEDS
 
  Unless otherwise specified in the Prospectus Supplement, the net proceeds
from the sale of the Company Securities offered hereby will be used for
general corporate purposes, including repayment of borrowings, working
capital, capital expenditures, stock repurchase programs and acquisitions,
including borrowings under the Company's commercial paper program. Unless
otherwise specified in the Prospectus Supplement, the Alcoa Trust will use all
proceeds received from the sale of Trust Preferred Securities to purchase
Subordinated Debt Securities of the Company. Additional information on the use
of net proceeds from the sale of the Offered Securities offered hereby may be
set forth in the Prospectus Supplement relating to such Offered Securities.
 
                                       5
<PAGE>
 
                     DESCRIPTION OF SENIOR DEBT SECURITIES
 
  The following description of the terms of the Senior Debt Securities
summarizes certain general terms and provisions of the Senior Debt Securities
to which any Prospectus Supplement may relate. The particular terms of the
Senior Debt Securities and the extent, if any, to which such general
provisions may apply to any series of Senior Debt Securities will be described
in the Prospectus Supplement relating to such series.
 
  Senior Debt Securities may be issued, from time to time, in one or more
series under an Indenture, dated as of September 30, 1993 (the "Senior
Indenture"), between the Company and PNC Bank, National Association, as
trustee, or such other trustee as shall be named in a Prospectus Supplement
(the "Senior Trustee"). The Senior Indenture is filed with the Commission and
incorporated by reference as an exhibit to the Registration Statement of which
this Prospectus is a part. The following statements are subject to the
detailed provisions of the Senior Indenture. Wherever any particular
provisions of the Senior Indenture or terms defined therein are referred to,
such provisions and terms are incorporated by reference as a part of the
statements made herein and such statements are qualified in their entirety by
such references, including the definitions therein of certain terms.
References to particular sections of the Senior Indenture are noted below.
Capitalized terms used herein but not defined herein shall have the meanings
ascribed to them in the Senior Indenture.
 
GENERAL
 
  The Senior Indenture does not limit the aggregate amount of Senior Debt
Securities which may be issued thereunder and Senior Debt Securities may be
issued thereunder from time to time in separate series up to the aggregate
amount from time to time authorized by the Company for each series. The Senior
Debt Securities will be unsecured obligations of the Company and will rank on
a parity with all other unsecured and unsubordinated indebtedness of the
Company.
 
  The applicable Prospectus Supplement relating to the Senior Debt Securities
will describe the following terms of the Senior Debt Securities: (1) the title
of the Senior Debt Securities; (2) any limit on the aggregate principal amount
of the Senior Debt Securities; (3) whether the Senior Debt Securities are to
be issuable as Registered Securities or Bearer Securities or both, whether any
of the Senior Debt Securities are to be issuable initially in temporary global
form and whether any of the Senior Debt Securities are to be issuable in
permanent global form; (4) the price or prices (expressed as a percentage of
the aggregate principal amount thereof) at which the Senior Debt Securities
will be issued; (5) the date or dates on which the Senior Debt Securities will
mature; (6) the rate or rates per annum at which the Senior Debt Securities
will bear interest, if any, or the formula pursuant to which such rate or
rates shall be determined, and the date from which any such interest will
accrue; (7) the Interest Payment Dates on which any such interest on the
Senior Debt Securities will be payable, the Regular Record Date for any
interest payable on any Senior Debt Securities which are Registered Securities
on any Interest Payment Date and the extent to which, or the manner in which,
any interest payable on a temporary global Senior Debt Security on an Interest
Payment Date will be paid if other than in the manner described under "--
Temporary Global Securities" below; (8) the person to whom any interest on any
Registered Security of the series will be payable if other than the person in
whose name such Registered Security is registered at the close of business on
the Regular Record Date for such interest as described under "--Payment and
Paying Agents" below, and the manner in which any interest on any Bearer
Security will be paid if other than in the manner described under "--Payment
and Paying Agents" below; (9) any mandatory or optional sinking fund or
analogous provisions; (10) each office or agency where, subject to the terms
of the Senior Indenture as described below under "--Payment and Paying
Agents," the principal of and any premium and interest on the Senior Debt
Securities will be payable and each office or agency where, subject to the
terms of the Senior Indenture as described below under "--Form, Exchange,
Registration and Transfer," the Senior Debt Securities may be presented for
registration of transfer or exchange; (11) the date, if any, after which
 
                                       6
<PAGE>
 
and the price or prices at which the Senior Debt Securities may, pursuant to
any optional or mandatory redemption provisions, be redeemed, in whole or in
part, and the other detailed terms and provisions of any such optional or
mandatory redemption provisions; (12) the denominations in which any Senior
Debt Securities which are Registered Securities will be issuable, if other
than denominations of $1,000 and any integral multiple thereof, and the
denomination or denominations in which any Senior Debt Securities which are
Bearer Securities will be issuable, if other than the denomination of $5,000;
(13) the currency, currencies or currency units of payment of principal of and
any premium and interest on the Senior Debt Securities and the manner of
determining the U.S. dollar equivalent thereof for purposes of determining
Outstanding Senior Debt Securities of such series; (14) any index used to
determine the amount of payments of principal of and any premium and interest
on the Senior Debt Securities; (15) the portion of the principal amount of the
Senior Debt Securities if other than the principal amount thereof, payable
upon acceleration of maturity thereof; (16) if other than the Senior Trustee,
the Person who shall be the Security Registrar of Senior Debt Securities; (17)
if applicable, that the Senior Debt Securities shall be subject to defeasance
or covenant defeasance as described under "--Defeasance and Covenant
Defeasance;" (18) the terms and conditions, if any, pursuant to which the
Senior Debt Securities of the series are convertible into or exchangeable for
Common Stock of the Company; (19) if and as applicable, that the Senior Debt
Securities of the series shall be issuable in whole or in part in the form of
one or more Book-Entry Securities and, in such case, the Depository or
Depositories for such Book-Entry Debt Security or Book-Entry Securities and
any circumstances other than those set forth in the Senior Indenture in which
any such Book-Entry Security may be transferred to, and registered and
exchanged for Senior Debt Securities registered in the name of, a Person other
than the Depository for such Book-Entry Security or a nominee thereof and in
which any such transfer may be registered; and (20) any other terms of the
Senior Debt Securities not inconsistent with the provisions of the Senior
Indenture. (Section 301) Any such Prospectus Supplement will also describe any
special provisions for the payment of additional amounts with respect to the
Senior Debt Securities.
 
  Senior Debt Securities may be issued at a substantial discount below their
stated principal amount. Certain United States Federal income tax
considerations applicable to Senior Debt Securities issued at discount and to
Senior Debt Securities which are denominated in a currency other than United
States dollars will be described in the Prospectus Supplement relating
thereto.
 
  Senior Debt Securities may also be issued under the Senior Indenture upon
the exercise of Warrants issued by the Company. See "Description of Warrants."
United States Federal income tax consequences applicable to any Warrants will
be set forth in the Prospectus Supplement relating thereto.
 
FORM, EXCHANGE, REGISTRATION AND TRANSFER
 
  Senior Debt Securities of a series may be issuable in definitive form solely
as Registered Securities, solely as Bearer Securities or as both Registered
Securities and Bearer Securities. Unless otherwise indicated in an applicable
Prospectus Supplement, definitive Bearer Securities will have interest coupons
attached. (Section 201) The Senior Indenture also will provide that Senior
Debt Securities of a series may be issuable in temporary and permanent global
form. (Section 201) See "Permanent Global Securities."
 
  In connection with its sale during the restricted period (as defined in
United States Treasury Regulations Section 1.163-5(c)(2)(i)(D)(7)), no Bearer
Security (including a Senior Debt Security in permanent global form) shall be
mailed or otherwise delivered to any location in the United States or its
possessions. No Bearer Security other than a temporary global Bearer Security
may be delivered, nor may interest be paid on any Bearer Security unless the
Person entitled to receive such Bearer Security or such interest furnishes
written certification, in the form required by the Senior Indenture, to the
effect that such person (i) is not a United States person, (ii) is a foreign
branch of a United States
 
                                       7
<PAGE>
 
financial institution purchasing for its own account or for resale, or is a
United States person who acquired the Senior Debt Security through such a
financial institution and who holds the Senior Debt Security through such
financial institution on the date of certification, provided in either case
that such financial institution provides a certificate to the Company or the
distributor selling the Senior Debt Security to it stating that it agrees to
comply with the requirements of Section 165(j)(3)(A), (B) or (C) of the
Internal Revenue Code of 1986, as amended (the "Code"), and the United States
Treasury Regulations thereunder, or (iii) is a financial institution holding
for purposes of resale during the restricted period (as defined in United
States Treasury Regulations Section 1.163-5(c)(2)(i)(D)(7)). A financial
institution described in clause (iii) of the preceding sentence (whether or
not also described in clause (i) or (ii)) must certify that it has not
acquired the Senior Debt Security for purposes of resale directly or
indirectly to a United States person or to a person within the United States
or its possessions. In the case of a Bearer Security in permanent global form,
such certification must be given in connection with notation of a beneficial
owner's interest therein. (Section 303) See "--Temporary Global Securities."
 
  Registered Securities of any series will be exchangeable for other
Registered Securities of the same series and of a like aggregate principal
amount and tenor of different authorized denominations. In addition, if Senior
Debt Securities of any series are issuable as both Registered Securities and
Bearer Securities, at the option of the Holder upon request confirmed in
writing, and subject to the terms of the Senior Indenture, Bearer Securities
(with all unmatured coupons, except as provided below, and all matured coupons
in default) of such series will be exchangeable into Registered Securities of
the same series of any authorized denominations and of a like aggregate
principal amount and tenor. Bearer Securities surrendered in exchange for
Registered Securities between a Regular Record Date or a Special Record Date
and the relevant date for payment of interest shall be surrendered without the
coupon relating to such date for payment of interest and interest will not be
payable in respect of the Registered Security issued in exchange for such
Bearer Security, but will be payable only to the Holder of such coupon when
due in accordance with the terms of the Senior Indenture. Bearer Securities
will not be issued in exchange for Registered Securities. (Section 305) Each
Bearer Security other than a temporary global Bearer Security will bear a
legend substantially to the following effect: "Any United States Person who
holds this obligation will be subject to limitations under the United States
income tax laws, including the limitations provided in Sections 165(j) and
1287(a) of the Internal Revenue Code."
 
  Senior Debt Securities may be presented for exchange as provided above, and
Registered Securities may be presented for registration of transfer (with the
form of transfer endorsed thereon duly executed, if so required by the Company
or the Senior Trustee or any transfer agent), at the office of the Security
Registrar or at the office of any transfer agent designated by the Company for
such purpose with respect to any series of Senior Debt Securities and referred
to in an applicable Prospectus Supplement, without service charge and upon
payment of any taxes and other governmental charges as described in the Senior
Indenture. Such transfer or exchange will be effected upon the Security
Registrar or such transfer agent, as the case may be, being satisfied with the
documents of title and identity of the person making the request. (Section
305) If a Prospectus Supplement refers to any transfer agents (in addition to
the Security Registrar) initially designated by the Company with respect to
any series of Senior Debt Securities, the Company may at any time rescind the
designation of any such transfer agent or approve a change in the location
through which any such transfer agent acts, except that, if Senior Debt
Securities of a series are issuable solely as Registered Securities, the
Company will be required to maintain a transfer agent in each Place of Payment
for such series and, if Senior Debt Securities of a series are issuable as
Bearer Securities, the Company will be required to maintain (in addition to
the Security Registrar) a transfer agent in a Place of Payment for such series
located outside the United States. The Company may at any time designate
additional transfer agents with respect to any series of Senior Debt
Securities. (Section 1002)
 
                                       8
<PAGE>
 
  In the event of any redemption in part, the Company shall not be required to
(i) issue, register the transfer of or exchange Senior Debt Securities of any
series during a period beginning at the opening of business 15 days before any
selection of Senior Debt Securities of that series to be redeemed and ending
at the close of business on (A) if Senior Debt Securities of the series are
issuable only as Registered Securities, the day of mailing of the relevant
notice of redemption and (B) if Senior Debt Securities of the series are
issuable as Bearer Securities, the day of the first publication of the
relevant notice of redemption or, if Senior Debt Securities of the series are
also issuable as Registered Securities and there is no publication, the
mailing of the relevant notice of redemption; (ii) register the transfer of or
exchange any Registered Security, or portion thereof, called for redemption,
except the unredeemed portion of any Registered Security being redeemed in
part; or (iii) exchange any Bearer Security called for redemption, except to
exchange such Bearer Security for a Registered Security of that series and
like tenor which is immediately surrendered for redemption. (Section 305)
 
PAYMENT AND PAYING AGENTS
 
  Unless otherwise indicated in an applicable Prospectus Supplement, payment
of principal of and any premium and interest on Bearer Securities will be
payable, subject to any applicable laws and regulations, at the offices of
such Paying Agents outside the United States as the Company may designate from
time to time by check or by transfer, at the option of the Holder, to an
account maintained by the payee with a bank located outside the United States.
Unless otherwise indicated in an applicable Prospectus Supplement, payment of
interest on Bearer Securities on any Interest Payment Date will be made only
against surrender outside the United States, to the Paying Agent, of the
coupon relating to such Interest Payment Date. (Section 1001) No payment with
respect to any Bearer Security will be made at any office or agency of the
Company in the United States or by check mailed to any address in the United
States or by transfer to an account maintained with a bank located in the
United States. Notwithstanding the foregoing, payments of principal of and any
premium and interest on Bearer Securities denominated and payable in U.S.
dollars will be made at the office of the Company's Paying Agent in the
Borough of Manhattan, the City of New York, if (but only if) payment of the
full amount thereof in U.S. dollars at all offices or agencies outside the
United States is illegal or effectively precluded by exchange controls or
other similar restrictions. (Section 1002)
 
  Unless otherwise indicated in an applicable Prospectus Supplement, payment
of principal of and any premium and interest on Registered Securities will be
made at the office of such Paying Agent or Paying Agents as the Company may
designate from time to time, except that at the option of the Company, payment
of any interest may be made by check mailed to the address of the Person
entitled thereto as such address shall appear in the Security Register. Unless
otherwise indicated in an applicable Prospectus Supplement, payment of any
instalment of interest on Registered Securities will be made to the Person in
whose name such Registered Security is registered at the close of business on
the Regular Record Date for such interest. (Section 307)
 
  Unless otherwise indicated in an applicable Prospectus Supplement, the
Corporate Trust Office of the Senior Trustee in Pittsburgh, Pennsylvania, will
be designated as a Paying Agent for the Company for payments with respect to
Senior Debt Securities which are issuable solely as Registered Securities and
the Company will maintain a Paying Agent outside of the United States for
payments with respect to Senior Debt Securities (subject to the limitations
described above in the case of Bearer Securities) which are issuable solely as
Bearer Securities or as both Registered Securities and Bearer Securities. Any
Paying Agents outside the United States and any other Paying Agents in the
United States initially designated by the Company for the Senior Debt
Securities will be named in an applicable Prospectus Supplement. The Company
may at any time designate additional Paying Agents or rescind the designation
of any Paying Agent or approve a change in the office through which any Paying
Agent acts, except that, if Senior Debt Securities of a series are issuable
solely as Registered Securities, the Company will be required to maintain a
Paying Agent in each Place of Payment for such series and, if
 
                                       9
<PAGE>
 
Senior Debt Securities of a series are issuable as Bearer Securities, the
Company will be required to maintain (i) a Paying Agent in the Borough of
Manhattan, the City of New York for payments with respect to any Registered
Securities of the series (and for payments with respect to Bearer Securities
of the series in the circumstances described above, but not otherwise), and
(ii) a Paying Agent in a Place of Payment located outside the United States
where Senior Debt Securities of such series and any coupons appertaining
thereto may be presented and surrendered for payment; provided that if the
Senior Debt Securities of such series are listed on The Stock Exchange of the
United Kingdom and the Republic of Ireland or the Luxembourg Stock Exchange or
any other stock exchange located outside the United States and such stock
exchange shall so require, the Company will maintain a Paying Agent in London
or Luxembourg or any other required city located outside the United States, as
the case may be, for the Senior Debt Securities of such series. (Section 1002)
 
  All moneys paid by the Company to a Paying Agent for the payment of
principal of and any premium or interest on any Senior Debt Security which
remain unclaimed at the end of two years after such principal, premium or
interest shall have become due and payable will be repaid to the Company and
the Holder of such Senior Debt Security or any coupon will thereafter look
only to the Company for payment thereof. (Section 1003)
 
BOOK-ENTRY SECURITIES
 
  The Senior Debt Securities of a series may be issued in the form of one or
more Registered Securities that will be registered in the name of the
Depository or its nominee and bearing a legend as specified in the Senior
Indenture ("Book-Entry Security"). Unless otherwise indicated in the
applicable Prospectus Supplement, a Book-Entry Security may not be registered
for transfer or exchange to any Person other than the Depository or its
nominee unless (i) the Depository notifies the Company that it is unwilling to
continue as Depository or ceases to be a clearing agency registered under the
Exchange Act, (ii) the Company executes and delivers to the Senior Trustee a
Company Order that such Book-Entry Security shall be so exchangeable and the
transfer thereof so registrable, or (iii) there shall have occurred and be
continuing an Event of Default, or an event which after notice or lapse of
time, or both, would be an Event of Default, with respect to the Senior Debt
Securities evidenced by such Book-Entry Security. Upon the occurrence in
respect of any Book-Entry Security of any series of any one or more of the
conditions specified in clauses (i), (ii) or (iii) of the preceding sentence
or such other conditions as may be specified as contemplated by the Indentures
for such series, such Book-Entry Security may be exchanged for Senior Debt
Securities of such series registered in the names of, and the transfer of such
Book-Entry Security may be registered to, such Persons (including Persons
other than the Depository with respect to such series and its nominees) as
such Depository shall direct.
 
  The specific terms of the depositary arrangement with respect to any portion
of a series of Registered Book-Entry Securities to be represented by a Book-
Entry Security will be described in the applicable Prospectus Supplement. The
Company expects that the following provisions will apply to depositary
arrangements.
 
  Unless otherwise specified in the applicable Prospectus Supplement, Senior
Debt Securities which are to be represented by a Book-Entry Security to be
deposited with or on behalf of a Depository will be represented by a Book-
Entry Security registered in the name of such Depository or its nominee. Upon
the issuance of such Book-Entry Security, and the deposit of such Book-Entry
Security with or on behalf of the Depository for such Book-Entry Security, the
Depository will credit, on its book-entry registration and transfer system,
the respective principal amounts of the Senior Debt Securities represented by
such Book-Entry Security to the accounts of institutions that have accounts
with such Depository or its nominee ("participants"). The accounts to be
credited will be designated by the underwriters or agents of such Senior Debt
Securities or by the Company if such Senior Debt Securities are offered and
sold directly by the Company. Ownership of beneficial interests in such Book-
Entry Security will be limited to participants or Persons that may hold
interests through
 
                                      10
<PAGE>
 
participants. Ownership of beneficial interests by participants in such Book-
Entry Security will be shown on, and the transfer of that ownership interest
will be effected only through, records maintained by the Depository or its
nominee for such Book-Entry Security. Ownership of beneficial interests in
such Book-Entry Security by Persons that hold through participants will be
shown on, and the transfer of that ownership interest within such participant
will be effected only through, records maintained by such participant. The
laws of some jurisdictions require that certain purchasers of securities take
physical delivery of such securities in certificated form. The foregoing
limitations and such laws may impair the ability to transfer beneficial
interests in such Book-Entry Securities.
 
  So long as the Depository for a Book-Entry Security, or its nominee, is the
registered owner of such Book-Entry Security, such Depository or such nominee,
as the case may be, will be considered the sole owner or Holder of the Senior
Debt Securities represented by such Book-Entry Security for all purposes under
the Senior Indenture. Unless otherwise specified in the applicable Prospectus
Supplement, owners of beneficial interests in such Book-Entry Security will
not be entitled to have Senior Debt Securities of the series represented by
such Book-Entry Security registered in their names, will not receive or be
entitled to receive physical delivery of Senior Debt Securities of such series
in certificated form and will not be considered the Holders thereof for any
purposes under the Senior Indenture. (Sections 204 and 305) Accordingly, each
Person owning a beneficial interest in such Book-Entry Security must rely on
the procedures of the Depository and, if such Person is not a participant, on
the procedures of the participant through which such Person owns its interest,
to exercise any rights of a Holder under the Senior Indenture. The Senior
Indenture provides that the Depository may grant proxies and otherwise
authorize participants to give or take any request, demand, authorization,
direction, notice, consent, waiver or other action which a Holder is entitled
to give or take under the Senior Indenture. (Section 104) The Company
understands that under existing industry practices, if the Company requests
any action of Holders, or an owner of a beneficial interest in such Book-Entry
Security desires to give any notice or take any action a Holder is entitled to
give or take under the Senior Indenture, the Depository would authorize the
participants to give such notice or take such action, and participants would
authorize beneficial owners owning through such participants to give such
notice or take such action or would otherwise act upon the instructions of
beneficial owners owning through them.
 
TEMPORARY GLOBAL SECURITIES
 
  If so specified in an applicable Prospectus Supplement, all or any portion
of the Senior Debt Securities of a series which are issuable as Bearer
Securities will initially be represented by one or more temporary global
Senior Debt Securities, without interest coupons, to be deposited with a
common depositary in London for the Euroclear System ("Euroclear") and CEDEL
S.A. ("CEDEL") for credit to the designated accounts. On and after the date
determined as provided in any such temporary global Senior Debt Security and
described in an applicable Prospectus Supplement, each such temporary global
Senior Debt Security will be exchanged for an interest in a permanent global
Bearer Security as specified in an applicable Prospectus Supplement, but,
unless otherwise specified in an applicable Prospectus Supplement, only upon
receipt of written certification from Euroclear or CEDEL, as the case may be,
in the form and to the effect required by the Senior Indenture (a "Depository
Tax Certification") and upon receipt of written certification by Euroclear or
CEDEL from the person entitled to receive such Senior Debt Securities in the
form and to the effect described under "--Form, Exchange, Registration and
Transfer." No definitive Bearer Security (including a Senior Debt Security in
permanent global form that is either a Bearer Security or exchangeable for
Bearer Securities) delivered in exchange for a portion of a temporary or
permanent global Senior Debt Security shall be mailed or otherwise delivered
to any location in the United States in connection with such exchange.
(Section 304)
 
  Unless otherwise specified in an applicable Prospectus Supplement, interest
in respect of any portion of a temporary global Senior Debt Security payable
in respect of an Interest Payment Date
 
                                      11
<PAGE>
 
occurring prior to the issuance of securities in permanent global form will be
paid to each of Euroclear and CEDEL with respect to the portion of the
temporary global Senior Debt Security held for its account following the
receipt by the Company or its agent of a Depository Tax Certification. Each of
Euroclear and CEDEL will undertake in such circumstances to credit such
interest received by it in respect of a temporary global Senior Debt Security
to the respective accounts for which it holds such temporary global Senior
Debt Security only upon receipt in each case of certification in the form and
to the effect described under "--Form, Exchange, Registration and Transfer"
with respect to the portion of such temporary global Senior Debt Security on
which such interest is to be so credited. Receipt of the certification
described in the preceding sentence by Euroclear or CEDEL, as the case may be,
shall constitute irrevocable instructions to Euroclear or CEDEL to exchange
such portion of the temporary global Senior Debt Security with respect to
which such certification was received for an interest in a permanent global
Senior Debt Security.
 
PERMANENT GLOBAL SECURITIES
 
  If any Senior Debt Securities of a series are issuable in permanent global
form, the applicable Prospectus Supplement will describe the circumstances, if
any, under which beneficial owners of interests in any such permanent global
Senior Debt Security may exchange such interests for Senior Debt Securities of
such series and of like tenor and principal amount in any authorized form and
denomination. No Bearer Security delivered in exchange for a portion of a
permanent global Senior Debt Security shall be mailed or otherwise delivered
to any location in the United States in connection with such exchange.
(Section 305) A Person having a beneficial interest in a permanent global
Senior Debt Security will, except with respect to payment of principal of and
any premium and interest on such permanent global Senior Debt Security, be
treated as a Holder of such principal amount of Outstanding Senior Debt
Securities represented by such permanent global Senior Debt Security as shall
be specified in a written statement of the Holder of such permanent global
Senior Debt Security or, in the case of a permanent global Senior Debt
Security in bearer form, of the operator of Euroclear or CEDEL which is
produced to the Senior Trustee by such Person. (Section 203) Principal of and
any premium and interest on a permanent global Senior Debt Security will be
payable in the manner described in the applicable Prospectus Supplement.
 
CERTAIN LIMITATIONS
 
  The Senior Indenture contains the covenants and limitations summarized
below, which will be applicable (unless waived or amended) so long as any of
the Senior Debt Securities are outstanding, unless stated otherwise in the
Prospectus Supplement.
 
  Liens. The Company covenants in the Senior Indenture that it will not
create, incur, assume or guarantee, and will not permit any Restricted
Subsidiary to create, incur, assume or guarantee, any indebtedness for
borrowed money ("Debt") secured by a mortgage, security interest, pledge,
charge or similar encumbrance ("mortgages") upon any Principal Property of the
Company or any Restricted Subsidiary or upon any shares of stock or
indebtedness of any Restricted Subsidiary without equally and ratably securing
the Senior Debt Securities. The foregoing restriction, however, will not apply
to (a) mortgages on property, shares of stock or indebtedness of any
corporation existing at the time such corporation becomes a Restricted
Subsidiary; (b) mortgages on property existing at the time of acquisition of
such property by the Company or a Restricted Subsidiary or mortgages to secure
the payment of all or any part of the purchase price of such property upon the
acquisition or to secure any Debt incurred prior to, at the time of, or within
180 days after, the acquisition of such property for the purpose of financing
all or any part of the purchase price thereof, or mortgages to secure the cost
of improvements to such acquired property; (c) mortgages to secure Debt of a
Restricted Subsidiary to the Company or another Restricted Subsidiary; (d)
mortgages existing at the date of the Senior Indenture; (e) mortgages on
property of a corporation existing at the time such corporation is merged into
or consolidated with the Company or a Restricted Subsidiary or at the time of
a sale, lease, or
 
                                      12
<PAGE>
 
other disposition of the properties of a corporation as an entirety or
substantially as an entirety to the Company or a Restricted Subsidiary; (f)
certain mortgages in favor of governmental entities; or (g) extensions,
renewals or replacements of any mortgage referred to in the foregoing clauses
(a) through (f). (Section 1009)
 
  Notwithstanding the restrictions outlined in the preceding paragraph, the
Company or any Restricted Subsidiary will be permitted to create, incur,
assume or guarantee any Debt secured by a mortgage without equally and ratably
securing the Senior Debt Securities, provided that after giving effect
thereto, the aggregate amount of all debt so secured by mortgages (not
including mortgages permitted under clauses (a) through (g) above) does not
exceed 10% of Consolidated Net Tangible Assets. (Section 1009)
 
  Sale and Leaseback Arrangements. The Company covenants that it will not, nor
will it permit any Restricted Subsidiary to, enter into any arrangement with
any person that provides for the leasing to the Company or any Restricted
Subsidiary of Principal Property (other than any such transaction involving a
lease for a term of not more than three years or any such transaction between
the Company and a Restricted Subsidiary or between Restricted Subsidiaries)
which has been or is to be sold or transferred by the Company or such
Restricted Subsidiary to such person, unless either (a) the Company or such
Restricted Subsidiary would be entitled to create, incur, assume or guarantee
Debt secured by a mortgage on such Principal Property at least equal in amount
to the Attributable Debt with respect to such arrangement, without equally and
ratably securing the Senior Debt Securities, pursuant to the limitation in the
Senior Indenture on liens, or (b) the Company shall apply an amount equal to
the greater of the net proceeds of such sale or the Attributable Debt with
respect to such arrangement to the retirement of Debt that matures more than
twelve months after the creation of such Debt. (Section 1010)
 
  Highly leveraged transactions. The Senior Indenture does not contain
provisions which would afford protection to the Holders of the Senior Debt
Securities in the event of a highly leveraged transaction involving the
Company.
 
CERTAIN DEFINITIONS
 
  The term "Affiliate" of any specified Person shall mean any other Person
directly or indirectly controlling or controlled by or under direct or
indirect common control with such specified Person. For the purposes of this
definition, "control," when used with respect to any specified Person, means
the power to direct the management and policies of such Person, directly or
indirectly, whether through the ownership of voting securities, by contract or
otherwise; and the terms "controlling" and "controlled" have meanings
correlative to the foregoing.
 
  The term "Attributable Debt" when used in connection with a sale and
leaseback transaction referred to above shall mean, at the time of
determination, the lesser of (a) the fair value of such property (as
determined by the Board of Directors of the Company) or (b) the present value
(discounted at the annual rate of 9%, compounded semi-annually) of the
obligation of the lessee for net rental payments during the remaining term of
the lease (including any period for which such lease has been extended).
 
  The term "Bearer Security" means any Senior Debt Security established
pursuant to the Senior Indenture which is payable to bearer.
 
  The term "Board of Directors" means either the board of directors of the
Company or any duly authorized committee of that board.
 
                                      13
<PAGE>
 
  The term "Book-Entry Security" means a Registered Security bearing the
legend specified in Section 204 of the Senior Indenture, evidencing all or
part of a series of Senior Debt Securities, issued to the Depository for such
series or its nominee, and registered in the name of such Depository or
nominee. Book-Entry Securities shall not be deemed to be securities in global
form for purposes of Sections 201 and 203 and Article Three of the Senior
Indenture.
 
  The term "Common Stock" includes any stock of any class of the Company which
has no preference in respect of dividends or of amounts payable in the event
of any voluntary of involuntary liquidation, dissolution or winding-up of the
Company and which is not subject to redemption by the Company. However,
subject to the provisions of Section 1511 of the Senior Indenture, shares
issuable on conversion of Senior Debt Securities shall include only shares of
the class designated as Common Stock of the Company at the date of this
instrument or shares of any class or classes resulting from any
reclassification or reclassifications thereof and which have no preference in
respect of dividends or of amounts payable in the event of any voluntary or
involuntary liquidation, dissolution or winding-up of the Company and which
are not subject to redemption by the Company; provided that if at any time
there shall be more than one such resulting class, the shares of each such
class then so issuable shall be substantially in the proportion which the
total number of shares of each such class resulting from all such
reclassifications bears to the total number of shares of all such classes
resulting from all such reclassifications.
 
  The term "Company Request" or "Company Order" means a written request or
order signed in the name of the Company by its Chairman of the Board of
Directors, its Vice Chairman of the Board of Directors, its President or a
Vice President, and by its Treasurer, an Assistant Treasurer, its Secretary or
an Assistant Secretary and delivered to the Senior Trustee.
 
  The term "Corporate Trust Office" means the principal office of the Senior
Trustee in Pittsburgh, Pennsylvania, at which at any particular time its
corporate trust business shall be administered.
 
  The term "Consolidated Net Tangible Assets" shall mean, as of any particular
time, the aggregate amount of assets (less applicable reserves and other
properly deductible items) adjusted for inventories on the basis of cost
(before application of the "last-in first-out" method of determining cost) or
current market value, whichever is lower, and deducting therefrom (a) all
current liabilities except for (1) notes and loans payable, (2) current
maturities of long-term debt and (3) current maturities of obligations under
capital leases and (b) all goodwill, tradenames, trademarks, patents,
unamortized debt discount and expenses (to the extent included in said
aggregate amount of assets) and other like intangibles, all as set forth on
the most recent consolidated balance sheet of the Company and its consolidated
Subsidiaries and computed in accordance with generally accepted accounting
principles.
 
  The term "Defaulted Interest" shall mean any interest on any Registered
Security of any series which is payable, but is not punctually paid or duly
provided for on any Interest Payment Date.
 
  The term "Depository" means, with respect to the Senior Debt Securities of
any series issuable or issued in whole or in part in the form of one or more
Book-Entry Securities, the clearing agency registered under the Exchange Act
specified for that purpose as contemplated by Section 301 of the Senior
Indenture.
 
  The term "Exchange Act" means the Securities Exchange Act of 1934, each as
amended from time to time, and any statute successor thereto.
 
  The term "Holder," when used with respect to any Senior Debt Security, means
in the case of a Registered Security the Person in whose name the Senior Debt
Security is registered in the Security Register and in the case of a Bearer
Security the bearer thereof and, when used with respect to any coupon, means
the bearer thereof.
 
                                      14
<PAGE>
 
  The term "Indenture" means the Senior Indenture, as such indenture was
originally executed or as it may from time to time be supplemented or amended
by one or more indentures supplemental thereto entered into pursuant to the
applicable provisions thereof, including, for all purposes of that instrument
and any such supplemental indenture, the provisions of the Trust Indenture Act
that are deemed to be a part of and govern the indenture, and any such
supplemental indenture, respectively. The term "Indenture" shall also include
the terms of particular series of Senior Debt Securities established as
contemplated by Section 301 therein.
 
  The term "Interest Payment Date," when used with respect to any Senior Debt
Security, means the Stated Maturity of an installment of interest on such
Senior Debt Security.
 
  The term "Maturity," when used with respect to any Senior Debt Security,
means the date on which the principal of such Senior Debt Security or an
installment of principal becomes due and payable as therein or herein
provided, whether at the Stated Maturity or by declaration of acceleration,
call for redemption or otherwise.
 
  The term "Opinion of Counsel" means a written opinion of counsel, who may be
counsel for the Company and shall be acceptable to the Senior Trustee.
 
  The term "Original Issue Discount Security" means any Senior Debt Security
which provides for an amount less than the principal amount thereof to be due
and payable upon a declaration of acceleration of the Maturity thereof
pursuant to Section 502 of the Senior Indenture.
 
  The term "Outstanding," when used with respect to Senior Debt Securities,
means, as of the date of determination, all Senior Debt Securities theretofore
authenticated and delivered under the Senior Indenture, except:
 
    (1) Senior Debt Securities theretofore canceled by the Senior Trustee or
  delivered to the Senior Trustee for cancellation;
 
    (2) Senior Debt Securities for whose payment or redemption money in the
  necessary amount has been theretofore deposited with the Senior Trustee or
  any Paying Agent in trust or set aside and segregated in trust by the
  Company (if the Company shall act as its own Paying Agent) for the Holders
  of such Senior Debt Securities and any coupons appertaining thereto;
  provided that, if such Senior Debt Securities are to be redeemed, notice of
  such redemption has been duly given pursuant to the Senior Indenture or
  provision therefor satisfactory to the Senior Trustee has been made;
 
    (3) Senior Debt Securities as to which Defeasance has been effected
  pursuant to Section 1302 of the Senior Indenture (See also "--Defeasance
  and Covenant Defeasance" section herein); and
 
    (4) Senior Debt Securities which have been paid pursuant to Section 306
  of the Senior Indenture or in exchange for or in lieu of which other Senior
  Debt Securities have been authenticated and delivered pursuant to the
  Senior Indenture, other than any such Senior Debt Securities in respect of
  which there shall have been presented to the Senior Trustee proof
  satisfactory to it that such Senior Debt Securities are held by a bona fide
  purchaser in whose hands such Senior Debt Securities are valid obligations
  of the Company; provided, however, that in determining whether the Holders
  of the requisite principal amount of the Outstanding Senior Debt Securities
  have given any request, demand, authorization, direction, notice, consent
  or waiver hereunder or whether a quorum is present at a meeting of Holders
  of Senior Debt Securities (A) the principal amount of an Original Issue
  Discount Security that shall be deemed to be Outstanding shall be the
  amount of the principal thereof that would be due and payable as of the
  date of such determination upon acceleration of the Maturity thereof to
  such date pursuant to Section 502 of the Senior Indenture, (B) the
  principal amount of a Senior Debt Security
 
                                      15
<PAGE>
 
  denominated in one or more foreign currencies or currency units shall be
  the Dollar equivalent, determined in the manner provided as contemplated by
  Section 301 of the Senior Indenture on the date of original issuance of
  such Senior Debt Security, of the principal amount (or, in the case of an
  Original Issue Discount Security, the Dollar equivalent on the date of
  original issuance of such Senior Debt Security of the amount determined as
  provided in Clause (A) above), of such Senior Debt Security, and (C) Senior
  Debt Securities owned by the Company or any other obligor upon the Senior
  Debt Securities or any Affiliate of the Company or of such other obligor
  shall be disregarded and deemed not to be Outstanding, except that, in
  determining whether the Senior Trustee shall be protected in relying upon
  any such request, demand, authorization, direction, notice, consent or
  waiver, or upon any such determination as to the presence of a quorum, only
  Senior Debt Securities which the Senior Trustee knows to be so owned shall
  be so disregarded. Senior Debt Securities so owned which have been pledged
  in good faith may be regarded as Outstanding if the pledgee establishes to
  the satisfaction of the Senior Trustee the pledgee's right so to act with
  respect to such Senior Debt Securities and that the pledgee is not the
  Company or any other obligor upon the Senior Debt Securities or any
  Affiliate of the Company or of such other obligor.
 
  The term "Paying Agent" means any Person authorized by the Company to pay
the principal of or any premium or interest on any Senior Debt Securities on
behalf of the Company.
 
  The term "Person" means any individual, corporation, partnership, joint
venture, trust, unincorporated organization or government or any agency or
political subdivision thereof.
 
  The term "Place of Payment," when used with respect to the Senior Debt
Securities of any series, means the place or places where, subject to the
provisions of Section 1002 of the Senior Indenture, the principal of and any
premium and interest on the Senior Debt Securities of that series are payable
as specified as contemplated by Section 301 of the Senior Indenture.
 
  The term "Principal Property" shall mean any manufacturing plant or
manufacturing facility which is (i) owned by the Company or any Restricted
Subsidiary and (ii) located within the continental United States of America,
except any such plant which, in the opinion of the Board of Directors, is not
of material importance to the total business conducted by the Company and the
Restricted Subsidiaries taken as a whole.
 
  The term "Redemption Date," when used with respect to any Senior Debt
Security to be redeemed, means the date fixed for such redemption by or
pursuant to the Senior Indenture.
 
  The term "Registered Security" means any Senior Debt Security established
pursuant to the Senior Indenture which is registered in the Security Register.
 
  The term "Regular Record Date" for the interest payable on any Interest
Payment Date on the Registered Securities of any series means the date
specified for that purpose as contemplated by Section 301 of the Senior
Indenture.
 
  The term "Restricted Subsidiary" shall mean any Subsidiary substantially all
the property of which is located within the continental United States;
provided, however, that the term "Restricted Subsidiary" shall not include any
Subsidiary which is principally engaged in leasing or in financing
receivables, or which is principally engaged in financing the Company's
operations outside the continental United States, or which principally serves
as a partner in a partnership.
 
  The term "Security Register" and "Security Registrar" shall mean the Person
named in the applicable Prospectus Supplement.
 
                                      16
<PAGE>
 
  The term "Special Record Date" for the payment of any Defaulted Interest on
the Registered Securities of any series means a date fixed by the Senior
Trustee pursuant to Section 307 of the Senior Indenture.
 
  The term "Stated Maturity," when used with respect to any Senior Debt
Security or any installment of principal thereof or interest thereon, means
the date specified in such Senior Debt Security or a coupon representing such
installment of interest as the fixed date on which the principal of such
Senior Debt Security or such installment of principal or interest is due and
payable.
 
  The term "Subsidiary" shall mean any corporation of which at least a
majority of the outstanding stock having the voting power to elect a majority
of the board of directors of such corporation as at the time is owned,
directly or indirectly, by the Company or by one or more Subsidiaries, or by
the Company and one or more Subsidiaries.
 
  The term "Trading Day" means each Monday, Tuesday, Wednesday, Thursday and
Friday, other than any day on which the Common Stock is not traded on the New
York Stock Exchange, Inc. ("NYSE") or, if the Common Stock is not traded on
the NYSE on the principal exchange or market on which the Common Stock is
traded or quoted.
 
  The term "Trust Indenture Act" means the Trust Indenture Act of 1939 as in
force at the date as of which the Senior Indenture was executed, provided,
however, that in the event the Trust Indenture Act of 1939 is amended after
such date, "Trust Indenture Act" means, to the extent required by any such
amendment, the Trust Indenture Act of 1939 as so amended.
 
  The term "U.S. Government Obligations" shall mean (x) any security that is
(i) a direct obligation of the United States of America for the payment of
which full faith and credit of the United States of America is pledged or (ii)
an obligation of a Person controlled or supervised by or acting as an agent or
instrumentality of the United States of America the payment of which is
unconditionally guaranteed as a full faith and credit obligation by the United
States of America, which, in either case (i) or (ii), is not callable or
redeemable at the option of the issuer thereof, and (y) any depositary receipt
issued by a bank (as defined in Section 3(a)(2) of the Securities Act of 1933,
as amended) as custodian with respect to any U.S. Government Obligation
specified in Clause (x) and held by such custodian for the account of the
holder of such depositary receipt, or with respect to any specific payment of
principal of or interest on any such U.S. Government Obligation, provided that
(except as required by law) such custodian is not authorized to make any
deduction from the amount payable to the holder of such depositary receipt
from any amount received by the custodian in respect of the U.S. Government
Obligation or the specific payment of principal or interest evidenced by such
depositary receipt.
 
EVENTS OF DEFAULT
 
  Unless otherwise provided in the applicable Prospectus Supplement, any one
of the following events will constitute an Event of Default under the Senior
Indenture with respect to Senior Debt Securities of any series: (a) failure to
pay any interest on any Senior Debt Security of that series when due,
continued for 30 days; (b) failure to pay principal of or any premium on any
Senior Debt Security of that series when due; (c) failure to deposit any
sinking fund payment when due in respect of any Senior Debt Security of that
series, continued for 30 days; (d) failure to perform any other covenant of
the Company in the Senior Indenture (other than a covenant included in the
Senior Indenture solely for the benefit of a series of Senior Debt Securities
other than that series), continued for 90 days after written notice as
provided in the Senior Indenture; (e) default resulting in acceleration of any
indebtedness for money borrowed by the Company under the terms of the
instrument or instruments under which such indebtedness is issued or secured
if such acceleration is not rescinded or annulled within 10 days after written
notice as provided in the Senior Indenture (provided that, the resulting Event
of Default under the Senior Indenture will be cured or waived if such other
default is cured or
 
                                      17
<PAGE>
 
waived); (f) certain events in bankruptcy, insolvency or reorganization
involving the Company; and (g) any other Event of Default provided with
respect to Senior Debt Securities of that series. (Section 501)
 
  If an Event of Default with respect to Senior Debt Securities of any series
at the time Outstanding occurs and is continuing, either the Senior Trustee or
the Holders of at least 25% in aggregate principal amount of the Outstanding
Senior Debt Securities of that series by notice as provided in the Senior
Indenture may declare the principal amount (or, if the Senior Debt Securities
of that series are Original Issue Discount Securities, such portion of the
principal amount as may be specified in the terms of that series) of all the
Senior Debt Securities of that series to be due and payable immediately. At
any time after a declaration of acceleration with respect to Senior Debt
Securities of any series has been made, but before a judgment or decree for
payment of money has been obtained by the Senior Trustee, the Holders of a
majority in aggregate principal amount of the Outstanding Senior Debt
Securities of that series may, under certain circumstances, rescind and annul
such acceleration. (Section 502)
 
  The Senior Indenture will provide that, subject to the duty of the Senior
Trustee during default to act with the required standard of care, the Senior
Trustee will be under no obligation to exercise any of its rights or powers
under the Senior Indenture at the request or direction of any of the Holders,
unless such Holders shall have offered to the Senior Trustee reasonable
indemnity. (Sections 601 and 603) The Holders of a majority in aggregate
principal amount of the Outstanding Senior Debt Securities of any series will
have the right to direct the time, method and place of conducting any
proceeding for any remedy available to the Senior Trustee, or exercising any
trust or power conferred on the Senior Trustee, with respect to the Senior
Debt Securities of that series. (Section 512)
 
CONVERSION AND EXCHANGE RIGHTS
 
  The Senior Debt Securities of any series may be convertible into or
exchangeable for Common Stock of the Company on the terms and subject to the
conditions set forth in the Prospectus Supplement.
 
DEFEASANCE AND COVENANT DEFEASANCE
 
  Unless otherwise indicated in the applicable Prospectus Supplement with
respect to the Senior Debt Securities of a series, the Company, at its option,
(i) will be discharged from any and all obligations in respect of the Senior
Debt Securities of such series (except for certain obligations to issue
temporary Senior Debt Securities pending preparation of definitive Senior Debt
Securities, to register the transfer or exchange of Senior Debt Securities of
such series, to replace stolen, lost or mutilated Senior Debt Securities of
such series, and to maintain paying agents and hold moneys for payment in
trust) or (ii) need not comply with the covenants that are set forth under "--
Certain Limitations" and "--Consolidation, Merger and Sale of Assets," and the
occurrence of an event described under clause (d) of the "Events of Default"
with respect to any defeased covenant and Clauses (e) and (g) of "--Events of
Default" shall no longer be an Event of Default if, in each case, the Company
irrevocably deposits with the Senior Trustee, in trust, money and/or U.S.
Government Obligations that through the scheduled payment of interest thereon
and principal thereof in accordance with their terms will provide money in an
amount sufficient to pay all the principal of (and premium, if any) and any
interest on the Senior Debt Securities of such series on the dates such
payments are due (which may include one or more redemption dates designated by
the Company) in accordance with the terms of the Senior Indenture and such
Senior Debt Securities. Such a trust may only be established if, among other
things, (a) no Event of Default or event which with the giving of notice or
lapse of time, or both, would become an Event of Default under the Senior
Indenture shall have occurred and be continuing on the date of such deposit,
or with regard to any Event of Default or any such event described under
clause (f) of "--Events of Default" shall have occurred and be continuing at
any time during the period ending on the 91st day following such date of
deposit, and (b) the Company shall have delivered an Opinion of Counsel based,
in the event of a defeasance of the type
 
                                      18
<PAGE>
 
described in clause (i) above, upon a ruling from the Internal Revenue Service
or a change in applicable Federal income tax law from the date of the Senior
Indenture to the effect that the Holders of the Senior Debt Securities will
not recognize income, gain or loss for Federal income tax purposes as a result
of such deposit or defeasance and will be subject to Federal income tax in the
same manner as if such defeasance had not occurred. In the event the Company
omits to comply with its remaining obligations under the Senior Indenture
after a defeasance of the Senior Indenture with respect to the Senior Debt
Securities of any series as described under clause (ii) above and the Senior
Debt Securities of such series are declared due and payable because of the
occurrence of any undefeased Event of Default, the amount of money and/or U.S.
Government Obligations on deposit with the Senior Trustee may be insufficient
to pay amounts due on the Senior Debt Securities of such series at the time of
the acceleration resulting from such Event of Default. However, the Company
will remain liable in respect of such payments. (Article Thirteen)
 
MEETINGS, MODIFICATION AND WAIVER
 
  Modifications and amendments of the Senior Indenture may be made by the
Company and the Senior Trustee with the consent of the Holders of not less
than 66 2/3% in aggregate principal amount of the Outstanding Senior Debt
Securities of each series affected by such modification or amendment;
provided, however, that no such modification or amendment may, without the
consent of the Holder of each Outstanding Senior Debt Security affected
thereby, (a) change the Stated Maturity of the principal of, or any instalment
of principal of or interest on any Senior Debt Security, (b) reduce the
principal amount of, or premium or interest on, any Senior Debt Security, (c)
change any obligation of the Company to pay additional amounts, (d) reduce the
amount of principal of an Original Issue Discount Security payable upon
acceleration of the Maturity thereof, (e) change the coin or currency in which
any Senior Debt Security or any premium or interest thereon is payable, (f)
impair the right to institute suit for the enforcement of any payment on or
with respect to any Senior Debt Security, (g) reduce the percentage in
principal amount of Outstanding Senior Debt Securities of any series, the
consent of whose Holders is required for modification or amendment of the
Senior Indenture or for waiver of compliance with certain provisions of such
Senior Indenture or for waiver of certain defaults, (h) reduce the
requirements contained in such Senior Indenture for quorum or voting, (i)
change any obligation of the Company to maintain an office or agency in the
places and for the purposes required by such Senior Indenture, or (j) modify
any of the above provisions. (Section 902)
 
  The Holders of at least 66 2/3% of the outstanding Senior Debt Securities of
a series may waive compliance by the Company with certain restrictive
provisions of the Senior Indenture. (Section 1012) The Holders of not less
than a majority in aggregate principal amount of the Outstanding Senior Debt
Securities of each series may, on behalf of all Holders of Senior Debt
Securities of that series and any coupons appertaining thereto, waive any past
default under the Senior Indenture with respect to Senior Debt Securities of
that series, except a default (a) in the payment of principal of (or premium
if any) or any interest on any Senior Debt Security of such series, and (b) in
respect of a covenant or provision of the Senior Indenture which cannot be
modified or amended without the consent of the Holder of each Outstanding
Senior Debt Security of such series affected. (Section 513)
 
  The Senior Indenture provides that in determining whether the Holders of the
requisite principal amount of the Outstanding Senior Debt Securities have
given any request, demand, authorization, direction, notice, consent or waiver
thereunder or are present at a meeting of Holders of Senior Debt Securities
for quorum purposes, (i) the principal amount of an Original Issue Discount
Security that shall be deemed to be Outstanding shall be the amount of the
principal thereof that would be due and payable as of the date of such
determination upon acceleration of the Maturity thereof, (ii) the principal
amount of a Senior Debt Security denominated in a foreign currency or
currencies shall be the U.S. dollar equivalent, determined on the date of
original issuance of such Security, of the principal amount
 
                                      19
<PAGE>
 
of such Senior Debt Security (or, in the case of an Original Issue Discount
Security, the U.S. dollar equivalent, determined on the date of original
issuance of such Senior Debt Security, of the amount determined as provided in
(i) above), and (iii) Senior Debt Securities owned by the Company or an
Affiliate thereof shall not be deemed outstanding. (Section 101)
 
  The Senior Indenture contains provisions for convening meetings of the
Holders of Senior Debt Securities of a series if Senior Debt Securities of
that series are issuable as Bearer Securities. (Section 1401) A meeting may be
called at any time by the Senior Trustee, and also, upon request, by the
Company or the Holders of at least 10% in principal amount of the Outstanding
Senior Debt Securities of such series, in any such case upon notice given in
accordance with "--Notices" below. (Section 1402) To be entitled to vote at
any meeting of Holders of Senior Debt Securities of any series, a Person shall
be (1) a Holder of one or more Outstanding Senior Debt Securities of such
series, or (2) a person appointed by an instrument in writing as proxy of a
Holder or Holders, including proxies given to beneficial owners of Book-Entry
Securities by the Depository, or its nominee. (Section 1403) Except for any
consent which must be given by the Holder of each Outstanding Senior Debt
Security affected thereby, as described above, any resolution presented at a
meeting or adjourned meeting at which a quorum is present may be adopted by
the affirmative vote of the Holders of a majority in principal amount of the
Outstanding Senior Debt Securities of that series; provided, however, that,
except for any consent which must be given by the Holder of each Outstanding
Senior Debt Security affected thereby, as described above, any resolution with
respect to any consent or waiver which may be given by the Holders of not less
than 66 2/3% in principal amount of the Outstanding Senior Debt Securities of
a series may be adopted at a meeting or an adjourned meeting at which a quorum
is present only by the affirmative vote of 66 2/3% in principal amount of the
Outstanding Senior Debt Securities of that series; and provided, further,
that, except for any consent which must be given by the Holder of each
Outstanding Senior Debt Security affected thereby, as described above, any
resolution with respect to any request, demand, authorization, direction,
notice, consent, waiver or other action which may be made, given or taken by
the Holders of a specified percentage, which is less than a majority, in
principal amount of Outstanding Senior Debt Securities of a series may be
adopted at a meeting or adjourned meeting duly reconvened at which a quorum is
present by the affirmative vote of the Holders of such specified percentage in
principal amount of the Outstanding Senior Debt Securities of that series. Any
resolution passed or decision taken at any meeting of Holders of Senior Debt
Securities of any series duly held in accordance with the Senior Indenture
will be binding on all Holders of Senior Debt Securities of that series and
the related coupons. The quorum at any meeting called to adopt a resolution,
and at any reconvened meeting, will be persons holding or representing a
majority in principal amount of the Outstanding Senior Debt Securities of a
series; provided, however, that if any action is to be taken at such meeting
with respect to a consent or waiver which may be given by the Holders of not
less than 66 2/3% in principal amount of the Outstanding Senior Debt
Securities of a series, the persons holding or representing 66 2/3% in
principal amount of the Outstanding Senior Debt Securities of such series will
constitute a quorum. (Section 1404)
 
CONSOLIDATION, MERGER AND SALE OF ASSETS
 
  The Company, without the consent of the Holders of any of the Outstanding
Senior Debt Securities under the Senior Indenture, may consolidate or merge
with or into, or transfer or lease its assets substantially as an entirety to,
any Person which is a corporation, partnership or trust organized and validly
existing under the laws of any domestic jurisdiction, or may permit any such
Person to consolidate with or merge into the Company or convey, transfer or
lease its properties and assets substantially as an entirety to the Company,
provided that any successor Person assumes the Company's obligations on the
Senior Debt Securities and under the Senior Indenture, that after giving
effect to the transaction no Event of Default, and no event which, after
notice or lapse of time, would become an Event of Default, shall have occurred
and be continuing, and that certain other conditions are met. (Section 801)
 
                                      20
<PAGE>
 
NOTICES
 
  Except as otherwise provided in the Senior Indenture, notices to Holders of
Bearer Securities will be given by publication at least twice in a daily
newspaper in the City of New York and in such other city or cities as may be
specified in such Senior Debt Securities and described in the applicable
Prospectus Supplement. Notices to Holders of Registered Securities will be
given by mail to the addresses of such Holders as they appear in the Security
Register. (Sections 101 and 106)
 
TITLE
 
  Title to any Bearer Securities and any coupons appertaining thereto will
pass by delivery. The Company, the Senior Trustee and any agent of the Company
or the Senior Trustee may treat the bearer of any Bearer Security and the
bearer of any coupon and the registered owner of any Registered Security as
the absolute owner thereof (whether or not such Senior Debt Security or coupon
shall be overdue and notwithstanding any notice to the contrary) for the
purpose of making payment and for all other purposes. (Section 308)
 
REPLACEMENT OF SECURITIES AND COUPONS
 
  Any mutilated Senior Debt Security or a Senior Debt Security with a
mutilated coupon appertaining thereto will be replaced by the Company at the
expense of the Holder upon surrender of such Senior Debt Security to the
Security Registrar. Senior Debt Securities or coupons that become destroyed,
stolen or lost will be replaced by the Company at the expense of the Holder
upon delivery to the Senior Trustee of the Senior Debt Security and coupons or
evidence of the destruction, loss or theft thereof satisfactory to the Company
and the Senior Trustee; in the case of any coupon which becomes destroyed,
stolen or lost, such coupon will be replaced by issuance of a new Senior Debt
Security in exchange for the Senior Debt Security to which such coupon
appertains. In the case of a destroyed, lost or stolen Senior Debt Security or
coupon, an indemnity satisfactory to the Senior Trustee and the Company may be
required at the expense of the Holder of such Senior Debt Security or coupon
before a replacement Senior Debt Security will be issued. (Section 306)
 
GOVERNING LAW
 
  The Senior Indenture, the Senior Debt Securities and the coupons will be
governed by, and construed in accordance with, the laws of the Commonwealth of
Pennsylvania. (Section 113)
 
REGARDING THE SENIOR TRUSTEE
 
  PNC Bank, National Association is the trustee under the Senior Indenture.
The Company and certain of its subsidiaries maintain deposit accounts and
conduct other banking transactions, including borrowings in the ordinary
course of business, with PNC Bank, National Association.
 
                                      21
<PAGE>
 
                DESCRIPTION OF THE SUBORDINATED DEBT SECURITIES
 
  The following description of the terms of the Subordinated Debt Securities
summarizes certain general terms and provisions of the Subordinated Debt
Securities to which any Prospectus Supplement may relate. The particular terms
of the Subordinated Debt Securities and the extent, if any, to which such
general provisions may apply to the Subordinated Debt Securities will be
described in the Prospectus Supplement relating to such Subordinated Debt
Securities.
 
  The Subordinated Debt Securities may be issued under an indenture (the
"Subordinated Indenture") between the Company and The Chase Manhattan Bank, as
trustee, or such other trustee as shall be named in a Prospectus Supplement
(the "Subordinated Trustee"), the form of which has been filed with the
Commission as an exhibit to the Registration Statement of which this
Prospectus forms a part. This summary of certain terms and provisions of the
Subordinated Debt Securities and the Subordinated Indenture does not purport
to be complete and is subject to, and is qualified in its entirety by
reference to, the Subordinated Indenture. References to particular sections of
the Subordinated Indenture are noted below. Capitalized terms used herein but
not defined herein shall have the meanings ascribed to them in the
Subordinated Indenture.
 
GENERAL
 
  The Subordinated Debt Securities will be unsecured and will rank junior and
be subordinate in right of payment to all Senior Debt (as defined below) of
the Company. The Subordinated Indenture does not limit the incurrence or
issuance of other secured or unsecured debt of the Company, whether under the
Subordinated Indenture or any existing or other indenture that the Company may
enter into in the future or otherwise. See "--Subordination."
 
  Concurrently with the issuance of Trust Preferred Securities, the Alcoa
Trust will invest the proceeds thereof and the consideration paid by the
Company for the related Trust Common Securities in Subordinated Debt
Securities. The Subordinated Debt Securities will be in the principal amount
equal to the aggregate stated liquidation amount of the Trust Preferred
Securities plus the Company's concurrent investment in the related Trust
Common Securities.
 
  The Subordinated Debt Securities will not be subject to any sinking fund
provision.
 
  Reference is made to the Prospectus Supplement for the following terms of
the Subordinated Debt Securities being offered hereby (to the extent such
terms are applicable to the Subordinated Debt Securities): (i) the specific
designation of such Subordinated Debt Securities, aggregate principal amount
and purchase price; (ii) any limit on the aggregate principal amount of such
Subordinated Debt Securities; (iii) the date or dates on which the principal
of such Subordinated Debt Securities is payable and the right, if any, to
extend such date or dates; (iv) the rate or rates at which such Subordinated
Debt Securities will bear interest or the method of calculating such rate or
rates, if any; (v) the date or dates from which such interest shall accrue,
the interest payment dates on which such interest will be payable or the
manner of determination of such interest payment dates and the record dates
for the determination of holders to whom interest is payable on any such
interest payment dates; (vi) the right, if any, to defer payments of interest
on the Subordinated Debt Securities by extending the interest payment periods
and the duration of such extensions (each, an "Extension Period"); (vii) the
period or periods within which, the price or prices at which, and the terms
and conditions upon which, such Subordinated Debt Securities may be redeemed,
in whole or in part, at the option of the Company; (viii) the obligation, if
any, of the Company to redeem or purchase such Subordinated Debt Securities at
the option of the holder thereof and the period or periods within which, the
price or prices at which, and the terms and conditions upon which, such
Subordinated Debt Securities shall be redeemed or purchased, in whole or part,
pursuant to such obligation; (ix) any applicable United States Federal income
tax consequences, including whether and under what circumstances the Company
will pay additional amounts on the Subordinated Debt Securities held by a
person who is not a U.S. person in
 
                                      22
<PAGE>
 
respect of any tax, assessment or governmental charge withheld or deducted
and, if so, whether the Company will have the option to redeem such
Subordinated Debt Securities rather than pay such additional amounts; (x) the
form of such Subordinated Debt Securities; (xi) if other than denominations of
$50 or any integral multiple thereof, the denominations in which such
Subordinated Debt Securities shall be issuable; (xii) any and all other terms
with respect to such Subordinated Debt Securities, including any modification
of or additions to the events of default or covenants provided for with
respect to the Subordinated Debt Securities, and any terms which may be
required by or advisable under applicable laws or regulations not inconsistent
with the Subordinated Indenture; (xiii) the terms and conditions upon which
the Subordinated Debt Securities may be convertible into or exchanged for
Common Stock of the Company; and (xiv) whether such Subordinated Debt
Securities are issuable as a global security, and in such case, the identity
of the depositary.
 
  Unless otherwise indicated in the applicable Prospectus Supplement, the
Subordinated Debt Securities will be issued in United States dollars in fully
registered form without coupons in denominations of $50 or integral multiples
thereof. No service charge will be made for any transfer or exchange of any
Subordinated Debt Securities, but the Company may, except in certain specified
cases not involving any transfer, require payment of a sum sufficient to cover
any tax or other governmental charge payable in connection therewith. Unless
otherwise set forth in the applicable Prospectus Supplement, interest on
outstanding Subordinated Debt Securities will be paid to holders of record on
the date which is 15 days immediately prior to the date such interest is to be
paid.
 
GLOBAL SECURITIES
 
  If any Subordinated Debt Securities are represented by one or more Global
Securities, the applicable Prospectus Supplement will describe the
circumstances, if any, under which beneficial owners of interests in any such
Global Security may exchange such interests for Subordinated Debt Securities
and of like tenor and principal amount in any authorized form and
denomination. Principal of, and any premium and interest on, a Global Security
will be payable in the manner described in the applicable Prospectus
Supplement.
 
  The specific terms of the depositary arrangement with respect to any portion
of Subordinated Debt Securities to be represented by a Global Security will be
described in the applicable Prospectus Supplement.
 
PAYMENT AND PAYING AGENTS
 
  Payments on Subordinated Debt Securities represented by a Global Security
will be made to the depositary for the Subordinated Debt Securities. In the
event Subordinated Debt Securities are issued in definitive form, principal of
and premium, if any, and any interest on Subordinated Debt Securities will be
payable, the transfer of the Subordinated Debt Securities will be registrable,
and the Subordinated Debt Securities will be exchangeable for Subordinated
Debt Securities of other denominations of a like aggregate principal amount at
the corporate office of the Subordinated Trustee in the City of New York or at
the office of such Paying Agent or Paying Agents as the Company may designate,
except that at the option of the Company payment of any interest may be made
(i) by check mailed to the address of the Person entitled thereto as such
address shall appear in the Securities Register or (ii) by wire transfer to an
account maintained by the Person entitled thereto as specified in the
Securities Register, provided that proper transfer instructions have been
received by the Regular Record Date. Payment of any interest on Subordinated
Debt Securities will be made to the Person in whose name such Subordinated
Debt Securities are registered at the close of business on the Regular Record
Date for such interest, except in the case of Defaulted Interest. The Regular
Record Date for the interest payable on any Interest Payment Date shall be the
15th day (whether or not a Business Day) next preceding such Interest Payment
Date. The Company may at any time designate additional Paying Agents or
rescind the designation of any Paying Agent. (Section 2.3)
 
                                      23
<PAGE>
 
  Any monies deposited with the Subordinated Trustee or any Paying Agent or
then held by the Company in trust, for the payment of the principal of and
premium, if any, or interest on any Subordinated Debt Securities and remaining
unclaimed for two years after such principal and premium, if any, or interest
has become due and payable shall, at the request of the Company, be repaid to
the company and the holder of such Subordinated Debt Securities shall
thereafter look, as a general unsecured creditor, only to the Company for
payment thereof. (Section 10.3)
 
MODIFICATION OF INDENTURE
 
  From time to time, the Company and the Subordinated Trustee may, without the
consent of the holders of Subordinated Debt Securities, amend, waive or
supplement the Subordinated Indenture for specified purposes, including, among
other things, curing ambiguities, defects or inconsistencies (provided that
any such action does not materially adversely affect the interest of the
holders of the Subordinated Debt Securities, or the holders of the Trust
Preferred Securities so long as they remain outstanding) and qualifying, or
maintaining the qualification of, the Subordinated Indenture under the Trust
Indenture Act. The Subordinated Indenture contains provisions permitting the
Company and the Subordinated Trustee, with the consent of the holders of not
less than a majority in principal amount of the outstanding Subordinated Debt
Securities, to modify the Subordinated Indenture in a manner affecting the
rights of the holders of the Subordinated Debt Securities; provided that no
such modification may, without the consent of the holder of each outstanding
Subordinated Debt Security so affected, (i) change the stated maturity of the
Subordinated Debt Securities, or reduce the principal amount thereof, or
reduce the rate or extend the time of payment of interest thereon (other than
deferrals of the payments of interest during any Extension Period as described
in any applicable Prospectus Supplement) or reduce the premium payable upon
the redemption thereof, or impair any right to institute suit for the
enforcement of any such payment, or adversely affect the subordination
provisions of the Subordinated Indenture or any right to convert any
Subordinated Debt Securities or (ii) reduce the percentage of principal amount
of Subordinated Debt Securities, the holders of which are required to consent
to any such modification of the Subordinated Indenture, provided that, so long
as any of the Trust Preferred Securities remain outstanding, (a) no such
modification may be made that adversely affects the holders of such Trust
Preferred Securities in any material respect, and no termination of the
Subordinated Indenture may occur, and no waiver of any Subordinated Debt
Securities Event of Default or compliance with any covenant under the
Subordinated Indenture may be effective, without the prior consent of the
holders of at least a majority in aggregate liquidation amount of the Trust
Preferred Securities then outstanding unless and until the principal of and
any premium on the Subordinated Debt Securities and all accrued and unpaid
interest thereon has been paid in full and (b) where a consent under the
Subordinated Indenture would require the consent of each holder of
Subordinated Debt Securities, no such consent will be given by the Property
Trustee without the prior consent of each holder of the Trust Preferred
Securities. (Section 9.2)
 
SUBORDINATED DEBT SECURITIES EVENTS OF DEFAULT
 
  The Subordinated Indenture will provide that any one or more of the
following described events that has occurred and is continuing constitutes a
"Subordinated Debt Securities Event of Default" with respect to the
Subordinated Debt Securities:
 
    (i) failure for 30 days to pay any interest on the Subordinated Debt
  Securities, when due (subject to the deferral of any due date in the case
  of an Extension Period);
 
    (ii) failure to pay any principal or premium, if any, on the Subordinated
  Debt Securities when due whether at maturity, upon redemption by
  declaration or otherwise;
 
    (iii) failure by the Company to deliver shares of Common Stock upon an
  appropriate election by holders of Subordinated Debt Securities to convert
  such Subordinated Debt Securities;
 
                                      24
<PAGE>
 
    (iv) failure to observe or perform certain other covenants contained in
  the Subordinated Indenture for 90 days after written notice to the Company
  from the Subordinated Trustee or to the Subordinated Trustee and the
  Company from the holders of at least 25% in aggregate outstanding principal
  amount of such Subordinated Debt Securities; or
 
    (v) certain events in bankruptcy, insolvency or reorganization of the
  Company. (Section 5.1)
 
  The holders of a majority in aggregate outstanding principal amount of the
Subordinated Debt Securities have the right to direct the time, method and
place of conducting any proceeding for any remedy available to the
Subordinated Trustee or exercising any trust or power conferred on the
Subordinated Trustee consistent with the Subordinated Indenture. The
Subordinated Trustee or the holders of not less than 25% in aggregate
principal amount of the Subordinated Debt Securities then outstanding may
declare the principal due and payable immediately upon a Subordinated Debt
Securities Event of Default, and, should the Subordinated Trustee or the
holders of the Subordinated Debt Securities fail to make such declaration, the
holders of at least 25% in aggregate liquidation amount of the Trust Preferred
Securities then outstanding shall have such right. The holders of a majority
in aggregate outstanding principal amount of the Subordinated Debt Securities
may annul and rescind such declaration if the default (other than the non-
payment of the principal of the Subordinated Debt Securities which has become
due solely by such acceleration) has been cured or waived and a sum sufficient
to pay all matured installments of interest and principal due otherwise than
by acceleration has been deposited with the Subordinated Trustee and, should
the holders of the Subordinated Debt Securities fail to annul and rescind such
declaration, the holders of a majority in aggregate liquidation amount of the
Trust Preferred Securities then outstanding shall have such right. (Section
5.2)
 
  The holders of a majority in aggregate outstanding principal amount of the
Subordinated Debt Securities affected thereby may, on behalf of the holders of
all the Subordinated Debt Securities, waive any past default, except a default
in the payment of principal or interest (unless such default has been cured
and a sum sufficient to pay all matured installments of interest and principal
due otherwise than by acceleration has been deposited with the Subordinated
Trustee) or a default in respect of a covenant or provision which under the
Subordinated Indenture cannot be modified or amended without the consent of
the holder of each outstanding Subordinated Debt Security and, should the
holders of the Subordinated Debt Securities fail to annul such declaration and
waive such default, the holders of a majority in aggregate liquidation amount
of the Trust Preferred Securities shall have such right. (Sections 5.2 and
5.13) The Company is required to file annually with the Subordinated Trustee a
certificate as to whether or not the Company is in compliance with all the
conditions and covenants applicable to it under the Subordinated Indenture.
(Section 10.5)
 
  In case a Subordinated Debt Securities Event of Default shall occur and be
continuing as to the Subordinated Debt Securities, the Property Trustee will
have the right to declare the principal of and the interest on the
Subordinated Debt Securities and any other amounts payable under the
Subordinated Indenture to be forthwith due and payable and to enforce its
other rights as a creditor with respect to the Subordinated Debt Securities.
 
CONSOLIDATION, MERGER, SALE OF ASSETS AND OTHER TRANSACTIONS
 
  The Subordinated Indenture will provide that the Company shall not
consolidate with or merge into any other Person or convey, transfer or lease
its properties and assets substantially as an entirety to any Person, and no
Person shall consolidate with or merge into the Company or convey, transfer or
lease its properties and assets substantially as an entirety to the Company,
unless (i) in case the Company consolidates with or merges into another Person
or conveys, transfers or leases its properties and assets substantially as an
entirety to any Person, the successor Person is organized under the laws of
the United States or any state or the District of Columbia, and such successor
Person expressly assumes the Company's obligations on the Subordinated Debt
Securities and under
 
                                      25
<PAGE>
 
the Subordinated Indenture; (ii) immediately after giving effect thereto, no
Subordinated Debt Securities Event of Default, and no event which, after
notice or lapse of time or both, would become a Subordinated Debt Securities
Event of Default, shall have happened and be continuing; (iii) such
transaction is permitted under the Trust Agreement (as defined herein) and the
Trust Guarantee and does not give rise to any breach or violation of the Trust
Agreement or the Trust Guarantee; and (iv) certain other conditions as
prescribed in the Subordinated Indenture are met. (Section 8.1)
 
  The general provisions of the Subordinated Indenture do not afford holders
of the Subordinated Debt Securities protection in the event of a highly
leveraged or other transaction involving the Company that may adversely affect
holders of the Subordinated Debt Securities.
 
EXPENSES OF THE ALCOA TRUST
 
  Pursuant to the Subordinated Indenture, the Company will pay all of the
costs, expenses or liabilities of the Alcoa Trust, other than obligations of
the Alcoa Trust to pay to the holders of any Trust Preferred Securities or
Trust Common Securities the amounts due such holders pursuant to the terms of
the Trust Preferred Securities or Trust Common Securities. (Secion 10.9)
 
SATISFACTION AND DISCHARGE
 
  The Subordinated Indenture will provide that when, among other things, all
Subordinated Debt Securities not previously delivered to the Subordinated
Trustee for cancellation (i) have become due and payable or (ii) will become
due and payable at their stated maturity within one year or are to be properly
called for redemption within one year, and the Company deposits or causes to
be deposited with the Subordinated Trustee trust funds, in trust, for the
purpose and in an amount in the currency or currencies in which the
Subordinated Debt Securities are payable sufficient to pay and discharge the
entire indebtedness on the Subordinated Debt Securities not previously
delivered to the Subordinated Trustee for cancellation, for the principal and
premium, if any, and interest to the date of the deposit or to the stated
maturity, as the case may be, then the Subordinated Indenture will cease to be
of further effect (except as to the Company's obligations to pay all other
sums due pursuant to the Subordinated Indenture and to provide the officers'
certificates and opinions of counsel described therein), and the Company will
be deemed to have satisfied and discharged the Subordinated Indenture.
(Section 4.1)
 
SUBORDINATION
 
  In the Subordinated Indenture, the Company has covenanted and agreed that
any Subordinated Debt Securities issued thereunder will be subordinate and
junior in right of payment to all Senior Debt (as defined below) of the
Company whether now existing or hereinafter incurred. Upon any payment or
distribution of assets of the Company to creditors upon any liquidation,
dissolution, winding-up, reorganization, assignment for the benefit of
creditors, marshaling of assets or any bankruptcy, insolvency, debt
restructuring or similar proceedings in connection with any insolvency or
bankruptcy proceeding of the Company, the holders of Senior Debt will first be
entitled to receive payment in full of principal of and premium, if any, and
interest, if any, on such Senior Debt before the Property Trustee, on behalf
of the holders of the Subordinated Debt Securities, will be entitled to
receive or retain any payment in respect of the principal of and premium, if
any, or interest, if any, on the Subordinated Debt Securities. (Sections 12.1
and 12.2)
 
  In the event of the acceleration of the maturity of any Subordinated Debt
Securities, the holders of all Senior Debt outstanding at the time of such
acceleration will first be entitled to receive payment in full of all amounts
due thereon (including any amounts due upon acceleration) before the holders
of Subordinated Debt Securities will be entitled to receive or retain any
payment in respect of the principal of or premium, if any, or interest, if
any, on the Subordinated Debt Securities. (Section 12.1)
 
                                      26
<PAGE>
 
  No payments on account of principal (or premium, if any) or interest, if
any, in respect of the Subordinated Debt Securities may be made if there shall
have occurred and be continuing a default in any payment with respect to
Senior Debt, or an event of default with respect to any Senior Debt resulting
in the acceleration of the maturity thereof, or if any judicial proceeding
shall be pending with respect to any such default. (Section 12.3)
 
  "Debt" means, with respect to any Person, whether recourse is to all or a
portion of the assets of such Person and whether or not contingent, (i) every
obligation of such Person for money borrowed; (ii) every obligation of such
Person evidenced by bonds, Subordinated Debt Securities, notes or other
similar instruments, including obligations incurred in connection with the
acquisition of property, assets or businesses; (iii) every reimbursement
obligation of such Person with respect to letters of credit, bankers'
acceptances or similar facilities issued for the account of such Person; (iv)
every obligation of such Person issued or assumed as the deferred purchase
price of property or services (but excluding trade accounts payable or accrued
liabilities arising in the ordinary course of business); (v) every capital
lease obligation of such Person; and (vi) every obligation of the type
referred to in clauses (i) through (v) of another Person and all dividends of
another person the payment of which, in either case, such Person has
guaranteed or for which such Person is responsible or liable, directly or
indirectly, as obligor or otherwise.
 
  "Senior Debt" means the principal of (and premium, if any) and interest, if
any (including interest accruing on or after the filing of any petition in
bankruptcy or for reorganization relating to the Company whether or not such
claim for post-petition interest is allowed in such proceeding), on Debt of
the Company, whether incurred on or prior to the date of the Indenture or
thereafter incurred, unless, in the instrument creating or evidencing the same
or pursuant to which the same is outstanding, it is provided that such
obligations are not superior in right of payment to the Subordinated Debt
Securities.
 
  The Subordinated Indenture will place no limitation on the amount of
additional Senior Debt that may be incurred by the Company.
 
GOVERNING LAW
 
  The Subordinated Indenture and the Subordinated Debt Securities will be
governed by and construed in accordance with the laws of the State of New
York. (Section 1.12)
 
INFORMATION CONCERNING THE SUBORDINATED TRUSTEE
 
  The Chase Manhattan Bank is the trustee under the Subordinated Indenture.
The Subordinated Trustee is under no obligation to exercise any of the powers
vested in it by the Subordinated Indenture at the request of any holder of
Subordinated Debt Securities, unless offered reasonable indemnity by such
holder against the costs, expenses and liabilities which might be incurred
thereby. The Subordinated Trustee is not required to expend or risk its own
funds or otherwise incur personal financial liability in the performance of
its duties if the Subordinated Trustee reasonably believes that repayment or
adequate indemnity is not reasonably assured to it. The Company and certain of
its subsidiaries maintain deposit accounts and conduct other banking
transactions, including borrowing in the ordinary course of business, with The
Chase Manhattan Bank.
 
                                      27
<PAGE>
 
                            DESCRIPTION OF WARRANTS
 
  The Company may issue, together with any Senior Debt Securities offered by
any Prospectus Supplement or separately, Warrants for the purchase of other
Senior Debt Securities. The Warrants are to be issued under Warrant Agreements
(each a "Warrant Agreement") to be entered into between the Company and a bank
or trust company, as Warrant Agent (the "Warrant Agent"), all as set forth in
the Prospectus Supplement relating to the particular issue of Warrants. A copy
of the form of Warrant Agreement, including the form of Warrant Certificates
representing the Warrants (the "Warrant Certificates"), reflecting the
alternative provisions to be included in the Warrant Agreements that will be
entered into with respect to particular offerings of Warrants, is filed with
the Commission and incorporated by reference as an exhibit to the Registration
Statement. The following summaries of certain provisions of the Warrant
Agreement and the Warrant Certificates do not purport to be complete and are
subject to, and are qualified in their entirety by reference to, all the
provisions of the Warrant Agreement and the Warrant Certificates,
respectively.
 
  The Prospectus Supplement will describe the terms of the Warrants, the
Warrant Agreement relating to the Warrants and the Warrant Certificates
representing the Warrants, including the following: (1) the designation,
aggregate principal amount and terms of the Senior Debt Securities purchasable
upon exercise of the Warrants; (2) the designation and terms of any related
Senior Debt Securities with which the Warrants are issued and the number of
Warrants issued with each such Senior Debt Security; (3) the date, if any, on
and after which the Warrants and the related Senior Debt Securities will be
separately transferable; (4) the principal amount of Senior Debt Securities
purchasable upon exercise of one Warrant and the price at which such principal
amount of Senior Debt Securities may be purchased upon such exercise; (5) the
date on which the right to exercise the Warrants shall commence and the date
(the "Expiration Date") on which such right shall expire; and (6) whether the
Warrants represented by the Warrant Certificates will be issued in registered
or bearer form, and if registered, where they may be transferred and
registered.
 
  If the Senior Debt Securities purchasable upon exercise of the Warrants are
issuable in bearer form, such Warrants shall not be offered nor constitute an
offer to, and Bearer Senior Debt Securities issuable upon exercise of such
Warrants shall not be issued to, United States persons other than to offices
outside the United States of certain United States financial institutions.
 
  Warrant Certificates will be exchangeable for new Warrant Certificates of
different denominations and Warrants may be exercised at the corporate trust
office of the Warrant Agent or any other office indicated in the Prospectus
Supplement. Prior to the exercise of their Warrants, holders of Warrants will
not have any of the rights of Holders of the Senior Debt Securities
purchasable upon such exercise and will not be entitled to payments of
principal of (and premium, if any) or interest, if any, on the Senior Debt
Securities purchasable upon such exercise.
 
                                      28
<PAGE>
 
                        DESCRIPTION OF PREFERRED STOCK
 
  The Company's Articles of Incorporation, as amended (the "Articles"),
authorize the issuance of two classes of preferred stock, 660,000 shares of
$3.75 Cumulative Preferred Stock, par value $100.00 per share ("Class A
Stock") and 10,000,000 shares of Class B Serial Preferred Stock, par value
$1.00 per share ("Class B Stock"). As of June 29, 1998, there were 557,649
shares of Class A Stock outstanding and no shares of Class B Stock
outstanding. No additional shares of Class A Stock may be issued. The Company
initiated an ongoing program to purchase and retire shares of Class A Stock in
1989.
 
  The following description of Class B Stock sets forth certain general terms
and provisions of the series of Class B Stock to which any Prospectus
Supplement may relate. The specific terms of a particular series of Class B
Stock will be described in the Prospectus Supplement relating to such series
of the Class B Stock offered pursuant thereto. If so indicated in the
Prospectus Supplement relating thereto, the terms of any such series of Class
B Stock may differ from the terms set forth below. The description of Class B
Stock set forth below and the description of the terms of a particular series
of Class B Stock set forth in the Prospectus Supplement relating thereto do
not purport to be complete and are qualified in their entirety by reference to
the Company's Articles and the Statement with Respect to Shares relating to
such series of Class B Stock, which will be filed or incorporated by reference
as an exhibit to the Registration Statement of which this Prospectus is a
part.
 
GENERAL
 
  The Board of Directors of the Company has the authority to issue shares of
Class B Stock in one or more series and to fix the specific number of shares
and, subject to the Articles, the relative rights and preferences of any such
series so established; provided that all shares of preferred stock shall be
identical except as to the following relative rights and preferences, any of
which may vary between different series: (i) the rate of dividend (including
the date from which dividends shall be cumulative and, with respect to the
Class B Stock, whether such dividend rate shall be fixed or variable and the
methods, procedures and formulas for the recalculation or periodic resetting
of any variable dividend rate); (ii) the price at, and the terms and
conditions on, which shares may be redeemed; (iii) the amounts payable on
shares in the event of voluntary or involuntary liquidation; (iv) sinking fund
provisions for the redemption or purchase of shares in the event shares of any
series of preferred stock are issued with sinking fund provisions; and (v) the
terms and conditions on which the shares of any series may be converted in the
event the shares of any series are issued with the privilege of conversion.
Each share of any series of Class B Stock shall be identical with all other
shares of any such series, except as to the date from which dividends shall be
cumulative.
 
  The Prospectus Supplement will set forth the following specific terms
regarding the series of Class B Stock offered thereby: (i) the designation,
number of shares and liquidation preference per share; (ii) the initial public
offering price; (iii) the dividend rate or rates, or the method of determining
the dividend rate or rates; (iv) the index, if any, upon which the amount of
dividends, if any, is determined; (v) the dates on which dividends, if any,
will accrue and be payable, that such dividends will be cumulative, and the
designated record dates for determining the holders entitled to such
dividends; (vi) any redemption or sinking fund provisions; (vii) any
conversion or exchange provisions; (viii) provisions for issuance of global
securities; (ix) the currency (which may be composite currency) in which
payment of dividends, if any, shall be payable if other than United States
dollars; (x) voting rights, if any, (except as otherwise required by law); and
(xi) any additional terms, preferences or rights and qualifications,
limitations or restrictions thereof.
 
  The shares of Class B Stock will, when issued, be fully paid and
nonassessable and will have no preemptive rights.
 
  The transfer agent, registrar, dividend disbursing agent and redemption
agent for the Class B Stock will be specified in the Prospectus Supplement
relating thereto.
 
                                      29
<PAGE>
 
DIVIDENDS
 
  The holders of Class A Stock are entitled to receive, when and as declared
by the Board of Directors of the Company, out of funds legally available
therefor, cumulative cash dividends at the annual rate of $3.75 per share,
payable quarterly on the first day of January, April, July and October in each
year.
 
  The holders of the Class B Stock of each series will be entitled to receive,
when, as and if declared by the Board of Directors of the Company, out of
funds legally available therefor, cumulative cash or other dividends at such
rate or rates and on such dates as the Board of Directors determines in
respect of such series and will be set forth in the Prospectus Supplement
relating to such series of Class B Stock. Such rates may be fixed or variable
or both. No dividends may be declared in respect of any dividend period on any
series of Class B Stock, unless all accrued dividends and the current quarter
yearly dividend on Class A Stock shall have been paid in full or
contemporaneously are declared and set apart. In the event that full
cumulative dividends on shares of a series of Class B Stock have not been
declared and paid or set apart when due, dividends thereon shall be declared
and paid pro rata to the holders of such series entitled thereto. No interest
shall be payable in respect of any dividend payment on the Class A Stock or
the Class B Stock which may be in arrears.
 
  In the event that full cumulative dividends on any class or series of Class
A Stock or Class B Stock (including dividends for the current quarter yearly
dividend period for shares of Class A Stock) have not been declared and paid
or set apart when due, the Company may not declare or pay any dividends on, or
make other distributions on or make payment on account of the purchase,
redemption, or other retirement, of Common Stock. No restriction applies to
the repurchase or redemption of Class A Stock or Class B Stock by the Company
while there is any arrearage in the payment of dividends or any applicable
sinking fund installments on such stock.
 
REDEMPTION
 
  At the option of its Board of Directors at any time, the Company may redeem
the whole or any part of the Class A Stock, at par, plus accrued dividends.
Notice of redemption must be given by publication in daily newspapers of
general circulation in New York City and in Pittsburgh, Pennsylvania; and by
mail to each record holder not less than 30 days nor more than 60 days prior
to the date fixed for redemption. In case of a redemption of a part only of
the Class A Stock at the time outstanding, the shares to be redeemed shall be
selected pro rata or by lot as determined by the Board of Directors of the
Company.
 
  If notice of redemption has been given, from and after the redemption date
for the shares of Class A Stock called for redemption (unless default shall be
made by the Company in providing money for the payment of the redemption price
of the shares so called for redemption), dividends on the shares of Class A
Stock so called for redemption will cease to accrue, such shares will no
longer be deemed to be outstanding, and all rights of the holders thereof as
shareholders of the Company (except the right to receive the redemption price)
will cease. Upon surrender in accordance with such notice of the certificates
representing any shares so redeemed (properly endorsed or assigned for
transfer, if the Board of Directors of the Company will so require and the
notice shall so state), the redemption price referred to above will be paid
out of funds provided by the Company. If fewer than all of the shares
represented by any such certificate are redeemed, a new certificate will be
issued representing the unredeemed shares without cost to the holder thereof.
All shares of Class A Stock so redeemed shall be cancelled and shall not be
reissued.
 
  The terms and conditions under which the whole or any part of any series of
the Class B Stock may be redeemed shall be established by the Board of
Directors prior to the issuance thereof. Unless otherwise determined by the
Board of Directors, all shares of Class B Stock so redeemed or otherwise
acquired by the Company shall be returned to the status of authorized but
unissued shares.
 
                                      30
<PAGE>
 
LIQUIDATION PREFERENCE
 
  Upon any liquidation, dissolution or winding up of the Company, the holders
of Class A Stock shall be entitled to receive out of the assets of the Company
available for distribution to shareholders the full respective preferential
amounts to which they are entitled before any distribution of assets is made
to or set apart for the holders of Class B Stock. The holders of shares of
each series of Class B Stock shall be entitled to receive out of the assets of
the Company available for distribution to shareholders the full respective
preferential amounts to which they are entitled before any distribution of
assets is made to or set apart for the holders of Common Stock, with respect
to the Class B Stock, plus all dividends which have accrued on such series of
Class B Stock and have not been paid or declared and a sum sufficient for
payment thereof set apart, an amount described in the Prospectus Supplement
relating to such series of Class B Stock. If, in any case of any such
liquidation, dissolution or winding up of the Company, the assets of the
Company or the proceeds thereof shall be insufficient to pay in full the
amounts payable with respect to shares of each series of Class B Stock, the
holders of shares of such series of Class B Stock will share ratably in any
such distribution of assets of the Company in proportion to the full
respective preferential amounts to which they are entitled. After payment to
the holders of shares of such series of Class B Stock of the full preferential
amounts to which they are entitled, the holders of shares of such series of
Class B Stock will not be entitled to any further participation in any
distribution of assets by the Company, unless otherwise provided in the
Prospectus Supplement. A consolidation or merger of the Company with one or
more corporations shall not be deemed to be a liquidation, dissolution or
winding up of the Company.
 
CONVERSION AND EXCHANGE RIGHTS
 
  The terms, if any, on which shares of any series of Class B Stock are
convertible into or exchangeable for Common Stock will be set forth in the
Prospectus Supplement relating thereto. Such terms may include provisions for
conversion or exchange, either mandatory, at the option of the holder, or at
the option of the Company, in which the number of shares of Common Stock to be
received by the holders of Class B Stock would be calculated according to the
market price of Common Stock as of a time stated in the Prospectus Supplement.
 
VOTING RIGHTS
 
  Except as indicated below or in the Prospectus Supplement relating to a
particular series of the Class B Stock, or except as expressly required by
applicable law, the holders of Class B Stock will not be entitled to vote.
 
  Pennsylvania law requires that holders of outstanding shares of a particular
class or series be entitled to vote as a class on an amendment to the Articles
that would (i) authorize the Board of Directors to fix and determine the
relative rights and preferences as between series of any preferred stock or
special class of stock; (ii) change the preferences, limitations or other
special rights of the shares of a class or series adverse to that class or
series; (iii) authorize a new class or series of shares having a preference as
to dividends or assets which is senior to shares of a particular class or
series; or (iv) increase the number of authorized shares of any particular
class or series having a preference as to dividends or assets which is senior
in any respect to the shares of such class or series.
 
  The Board of Directors, pursuant to the Company's Articles, may limit or
eliminate the voting rights applicable to any series of Class B Stock prior to
the issuance of such series, except as otherwise required by law. Any one or
more series of the Class B Stock may be issued with such additional voting
rights, exercisable only during certain extended periods of dividend
arrearages, as the Board of Directors may determine to be required to qualify
the series for listing on a recognized stock exchange. Such rights may only be
granted if there are no shares of Class A Stock outstanding.
 
                                      31
<PAGE>
 
  On matters on which holders of such series and holders of any other series
of Class B Stock are entitled to vote as a single class, each full share of
any series of the Class B Stock shall be entitled to one vote. Therefore, the
voting power of such series will depend on the number of shares in such
series, not the liquidation preference or initial offering price of the shares
of such series of the Class B Stock.
 
  So long as any shares of Class A Stock or Class B Stock remain outstanding,
without the consent of the holders of at least a majority of the outstanding
Class A Stock and Class B Stock, voting as a class, the Company shall not (i)
authorize any additional class of stock or increase the authorized number of
shares of the Class A Stock or Class B Stock or any class of stock ranking on
a parity with the Class A Stock or Class B Stock, as the case may be, as to
dividends or assets or (ii) merge or consolidate with any other corporation if
the corporation surviving or resulting from such merger or consolidation would
have any authorized class of stock ranking senior to or on a parity with the
Class A Stock or Class B Stock except the same number of shares of stock with
the same rights and preferences as the authorized stock of the corporation
immediately preceding such merger or consolidation.
 
  So long as any shares of Class A Stock or Class B Stock remain outstanding,
without the consent of the holders of at least two-thirds of the outstanding
Class A Stock and Class B Stock, the Company shall not (i) make any change in
the rights and preferences of the Class A Stock or Class B Stock so as to
affect such stock adversely (provided, however, that if any such change would
affect any series of Class A Stock or Class B Stock adversely as compared with
the effect thereof upon any other series of Class A Stock or Class B Stock, no
such change shall be made without the additional consent of the holders of at
least two-thirds of the outstanding shares of such series of Class A Stock or
Class B Stock), (ii) authorize any additional class of stock or increase the
authorized number of shares of any class of stock ranking senior to the Class
A Stock or Class B Stock as to dividends or assets or (iii) sell or otherwise
part with control of all or substantially all of its property or business or
voluntarily liquidate, dissolve or wind up its affairs.
 
                          DESCRIPTION OF COMMON STOCK
 
  The Company is authorized to issue 600,000,000 shares of Common Stock, par
value $1.00 per share. As of June 29, 1998, there were 164,796,822 shares of
Common Stock outstanding. In addition, as of such date, there were 14,124,241
shares of Common Stock issued and held in the treasury of the Company and an
aggregate of 23,229,499 shares of Common Stock reserved for issuance under
various incentive plans.
 
DIVIDEND RIGHTS
 
  The holders of Common Stock are entitled to receive dividends, when and as
declared by the Board of Directors, but no dividend shall be declared or paid
on the Common Stock so long as any preferred stock remains outstanding, unless
all dividends accrued on all classes of the Company's preferred stock and the
current quarter yearly dividend on the Class A Stock shall have been paid or
declared and a sum sufficient for payment therefor set apart.
 
VOTING RIGHTS
 
  The holders of Common Stock are entitled to one vote per share.
 
                                      32
<PAGE>
 
LIQUIDATION RIGHTS
 
  Upon any liquidation, dissolution or winding up of the Company, whether
voluntary or involuntary, after payments to holders of preferred stock of such
amount as shall have been fixed by the Board of Directors, plus accrued
dividends, the remaining assets of the Company shall belong to and be divided
among the holders of Common Stock. The consolidation or merger of the Company
with or into any other corporation or corporations or a share exchange or
division involving the Company pursuant to applicable law will not be deemed a
liquidation, dissolution or winding up of the Company under the Company's
Articles.
 
PREEMPTIVE OR OTHER SUBSCRIPTION RIGHTS
 
  The holders of Common Stock have no right to participate in any right of
subscription to any increased or additional capital stock of the Company.
 
CONVERSION AND OTHER RIGHTS
 
  The Common Stock does not have any conversion, redemption or sinking fund
provisions applicable thereto and is not liable to further call or assessment
by the Company. All outstanding shares of Common Stock are fully paid and non-
assessable.
 
OTHER MATTERS
 
  The Articles of the Company provide for a classified Board of Directors with
staggered three year terms, establish special shareholder voting requirements
to remove directors and establish certain procedures relating to the
nomination of directors, filling of vacancies and the vote required to amend
or repeal any of these provisions. The Articles also prohibit the Company's
payment of "green-mail," that is, payment of a premium in purchasing shares of
its Common Stock from a present or recent holder of 5% or more of the Common
Stock, except with the approval of a majority of the disinterested
shareholders. This provision and the classified board provision may be amended
or repealed only with the affirmative vote of at least 80% of the Common
Stock. In addition, the Articles limit or eliminate to the fullest extent
permitted by Pennsylvania law as from time to time in effect the personal
liability of the Company's directors for monetary damages, and authorize the
Company, except as prohibited by law, to indemnify directors, officers,
employees and others against liabilities and expenses incurred by them in
connection with the performance of their duties to the Company. The classified
Board article provision and the anti-"greenmail" provision may have certain
anti-takeover effects.
 
  The Company is governed by certain "anti-takeover" provisions in the
Pennsylvania Business Corporation Law (the "PCBL"). Chapter 25 of the PBCL
contains several anti-takeover provisions that apply to registered
corporations such as the Company. Section 2538 of the PBCL provides that if an
interested shareholder of a registered corporation (together with others
acting jointly or in concert therewith and affiliates thereof) (i) is to be a
party to a merger or consolidation, a share exchange or certain sales of
assets involving such corporation or a subsidiary thereof; (ii) is to receive
a disproportionate amount of any of the securities of any corporation
surviving or resulting from a division of such corporation; (iii) is to be
treated differently from others holding shares of the same class in a
voluntary dissolution of such corporation; or (iv) is to have his or her
percentage of voting or economic share interest in such corporation materially
increased relative to substantially all other shareholders in a
reclassification, then the transactions being proposed must be approved by the
affirmative vote of the holders of shares representing at least a majority of
the votes that all shareholders (other than the interested shareholder) are
entitled to cast with respect to such transaction, excluding all such voting
shares beneficially owned by such interested shareholder. Such special voting
requirement does not apply if the transaction being proposed has been approved
in a prescribed manner by such corporation's board of directors or certain
other conditions (including the amount of consideration to be paid to certain
shareholders) are satisfied or the transaction involves certain subsidiaries.
 
                                      33
<PAGE>
 
  Section 2555 of the PBCL may apply to a transaction between a registered
corporation and an interested shareholder thereof, notwithstanding that
Section 2538 is also applicable. Section 2555 prohibits such a corporation
from engaging in a business combination with an interested shareholder unless:
(i) the board of directors of such corporation gives prior approval to the
proposed transaction or gives prior approval to the interested shareholder's
acquisition of 20% of the shares entitled to vote in an election of directors
of such corporation, (ii) the interested shareholder owns at least 80% of the
stock of such corporation entitled to vote in an election of directors and, no
earlier than three months after such interested shareholder reaches such 80%
level, the majority of the remaining shareholders approve the proposed
transaction and shareholders receive a minimum "fair price" for their shares
in the transaction and the other conditions of Section 2556 of the PBCL are
met, (iii) holders of all outstanding common stock approve the transaction,
(iv) no earlier than 5 years after the interested shareholder acquired the
20%, a majority of the remaining shares entitled to vote in an election of
directors approve the transaction, or (v) no earlier than 5 years after the
interested shareholder acquired the 20%, a majority of all the shares approve
the transaction, all shareholders receive a minimum fair price for their
shares, and certain other conditions are met.
 
  The Company's Articles also provide that the Company may not engage in any
stock repurchases at prices greater than the current fair market value from an
interested shareholder. Under the PBCL, when a person or group of persons
acting in concert holds 20% of the shares of a registered corporation entitled
to vote in the election of directors (a "Control Group"), on the occurrence of
the transaction that makes the group a control group, any other shareholder of
the registered corporation who objects can, under procedures set forth in the
statute, require the Control Group to purchase his or her shares at "fair
value," as defined in the PBCL.
 
  The PBCL also contains certain provisions applicable to a registered
corporation such as the Company which, under certain circumstances, permit a
corporation to redeem "control shares," as defined in the PBCL, remove the
voting rights of control shares and require the disgorgement of profits by a
"controlling person," as defined in the PBCL.
 
  The transfer agent and registrar for the Common Stock is First Chicago Trust
Company of New York.
 
                                      34
<PAGE>
 
         DESCRIPTION OF TRUST PREFERRED SECURITIES AND TRUST GUARANTEE
 
TRUST PREFERRED SECURITIES
 
  The Declaration pursuant to which the Alcoa Trust is organized will be
replaced by an Amended and Restated Trust Agreement (the "Trust Agreement")
which will authorize the Trustees of the Alcoa Trust to issue on behalf of the
Alcoa Trust one series of Trust Preferred Securities and one series of Trust
Common Securities (together, the "Trust Securities"). The Trust Preferred
Securities will be issued to the public pursuant to the Registration Statement
of which this Prospectus forms a part, and the Trust Common Securities will be
issued directly or indirectly to the Company.
 
  The Trust Preferred Securities will have such terms, including dividends,
redemption, voting, conversion, liquidation rights and such other preferred,
deferred or other special rights or such restrictions as shall be set forth in
the Trust Agreement or made part of the Trust Agreement by the Trust Indenture
Act. Reference is made to the applicable Prospectus Supplement relating to the
Trust Preferred Securities of the Alcoa Trust for specific terms, including
(i) the distinctive designation of Trust Preferred Securities, (ii) the number
of Trust Preferred Securities issued by the Alcoa Trust, (iii) the annual
dividend rate (or method of determining such rate) for Trust Preferred
Securities issued by the Alcoa Trust and the date or dates upon which such
dividends shall be payable, (iv) whether dividends on Trust Preferred
Securities issued by the Alcoa Trust shall be cumulative, and, in the case of
Trust Preferred Securities having such cumulative dividend rights, the date or
dates or method of determining the date or dates from which dividends on Trust
Preferred Securities issued by the Alcoa Trust shall be cumulative, (v) the
amount or amounts which shall be paid out of the assets of the Alcoa Trust to
the holders of Trust Preferred Securities of the Alcoa Trust upon voluntary or
involuntary dissolution, winding-up or termination of the Alcoa Trust, (vi)
the terms and conditions, if any, under which Trust Preferred Securities of
the Alcoa Trust may be converted into shares of capital stock of the Company,
including the conversion price per share and the circumstances, if any, under
which any such conversion right shall expire, (vii) the terms and conditions,
if any, upon which the related series of the Subordinated Debt Securities of
the Company may be distributed to holders of Trust Preferred Securities of the
Alcoa Trust, (ix) the obligation, if any, of the Alcoa Trust to purchase or
redeem Trust Preferred Securities issued by the Alcoa Trust and the price or
prices at which, the period or periods within which and the terms and
conditions upon which Trust Preferred Securities issued by the Alcoa Trust
shall be purchased or redeemed, in whole or in part, pursuant to such
obligation, (x) the voting rights, if any, of Trust Preferred Securities
issued by the Alcoa Trust in addition to those required by law, including the
number of votes per Trust Preferred Security and any requirement for the
approval by the holders of Trust Preferred Securities, as a condition to
specified action or amendments to the Trust Agreement, and (xi) any other
relevant rights, preferences, privileges, limitations or restrictions of Trust
Preferred Securities issued by the Alcoa Trust consistent with the Trust
Agreement or with applicable law. Pursuant to the Trust Agreement, the
Property Trustee will own the Subordinated Debt Securities of the Company
purchased by the Alcoa Trust for the benefit of the holders of the Trust
Preferred Securities and the Trust Common Securities. The payment of dividends
out of money held by the Alcoa Trust, and payments upon redemption of Trust
Preferred Securities or liquidation of the Alcoa Trust, will be guaranteed by
the Company to the extent described under "--Trust Guarantee."
 
  Certain United States Federal income tax considerations applicable to an
investment in Trust Preferred Securities will be described in the Prospectus
Supplement relating thereto.
 
  In connection with the issuance of Trust Preferred Securities, the Alcoa
Trust will also issue one series of Trust Common Securities. The Trust
Agreement will authorize the Regular Trustees of the Alcoa Trust to issue on
behalf of the Alcoa Trust one series of Trust Common Securities having such
terms, including dividends, conversion, redemption, voting, liquidation rights
or such restrictions as shall be set forth therein. Except as otherwise
provided in the Prospectus Supplement relating to the Trust Preferred
Securities, the terms of the Trust Common Securities issued by the Alcoa Trust
will be
 
                                      35
<PAGE>
 
substantially identical to the terms of the Trust Preferred Securities issued
by the Alcoa Trust, and the Trust Common Securities will rank pari passu, and
payments will be made thereon pro rata with the Trust Preferred Securities,
except that, upon an event of default under the Trust Agreement, the rights of
the holders of the Trust Common Securities to payment in respect of dividends
and payments upon liquidation, redemption and otherwise will be subordinated
to the rights of the holders of the Trust Preferred Securities. Except in
certain limited circumstances, the Trust Common Securities will also carry the
right to vote and appoint, remove or replace any of the Trustees of the Alcoa
Trust. All of the Trust Common Securities of the Alcoa Trust will be directly
or indirectly owned by the Company.
 
  The Company and certain of its subsidiaries maintain deposit accounts and
conduct other banking transactions, including borrowings in the ordinary
course of business, with the Property Trustee.
 
TRUST GUARANTEE
 
  Set forth below is a summary of information concerning the Trust Guarantee
which will be executed and delivered by the Company for the benefit of the
holders of Trust Preferred Securities. The accompanying Prospectus Supplement
will describe any significant differences between the actual terms of the
Trust Guarantee and the summary below. The following summary does not purport
to be complete and is subject in all respects to the provisions of, and is
qualified in its entirety by reference to, the Trust Guarantee, which is filed
with the Commission and incorporated by reference as an exhibit to the
Registration Statement of which this Prospectus forms a part.
 
  General. The Company will irrevocably and unconditionally agree, to the
extent set forth in the Trust Guarantee, to pay in full, to the holders of
Trust Preferred Securities, the Trust Guarantee Payments (as defined below)
(except to the extent paid by the Alcoa Trust), as and when due, regardless of
any defense, right of set-off or counterclaim which the Alcoa Trust may have
or assert. The following payments with respect to the Trust Preferred
Securities to the extent not paid by the Alcoa Trust (the "Trust Guarantee
Payments") will be subject to the Trust Guarantee (without duplication): (i)
any accrued and unpaid dividends which are required to be paid on the Trust
Preferred Securities, to the extent the Alcoa Trust shall have funds legally
available therefor, (ii) the redemption price, including all accrued and
unpaid dividends (the "Redemption Price"), payable out of funds legally
available therefor, with respect to any Trust Preferred Securities called for
redemption by the Alcoa Trust and (iii) upon a liquidation of the Alcoa Trust
(other than in connection with the distribution of Subordinated Debt
Securities of the Company to the holders of the Trust Preferred Securities or
the redemption of all of the Trust Preferred Securities issued by the Alcoa
Trust), the lesser of (a) the aggregate of the liquidation amount and all
accrued and unpaid dividends on the Trust Preferred Securities to the date of
payment and (b) the amount of assets of the Alcoa Trust remaining available
for distribution to holders of Trust Preferred Securities in liquidation of
the Alcoa Trust. The Company's obligation to make a Trust Guarantee Payment
may be satisfied by direct payment of the required amounts by the Company to
the holders of Trust Preferred Securities or by causing the Alcoa Trust to pay
such amounts to such holders.
 
  Covenants of the Company. In the Trust Guarantee, the Company will covenant
that, so long as any Trust Preferred Securities issued by the Alcoa Trust
remain outstanding, if there shall have occurred any event that would
constitute an event of default under the Trust Guarantee or the Trust
Agreement, then (a) the Company shall not declare or pay any dividend on, make
any distributions with respect to, or redeem, purchase or make a liquidation
payment with respect to, any of its Common Stock (other than (i) purchases or
acquisitions of shares of Common Stock in connection with the satisfaction by
the Company of its obligations under any employee benefit plan, (ii) as a
result of a reclassification of the Company's Common Stock or the exchange or
conversion of one class or series of the Company's Common Stock for another
class or series of the Company's Common Stock, (iii) the purchase of
fractional interests in shares of the Company's Common Stock pursuant to the
conversion
 
                                      36
<PAGE>
 
or exchange provisions of such Common Stock of the Company or the security
being converted or exchanged or (iv) purchases or acquisitions of shares of
Common Stock to be used in connection with acquisitions of Common Stock by
shareholders pursuant to the Company's dividend reinvestment plan) or make any
guarantee payments with respect to the foregoing and (b) the Company shall not
make any payment of principal or premium, if any, on or repurchase any debt
securities (including guarantees) other than at stated maturity issued by the
Company which rank pari passu with or junior to the Subordinated Debt
Securities.
 
  Amendment and Assignment. Except with respect to any changes which do not
adversely affect the rights of holders of Trust Preferred Securities (in which
case no vote will be required), the Trust Guarantee with respect to the Trust
Preferred Securities may be changed only with the prior approval of the
holders of not less than a majority in liquidation amount of the outstanding
Trust Preferred Securities. The manner of obtaining any such approval of
holders of the Trust Preferred Securities will be as set forth in an
accompanying Prospectus Supplement. All guarantees and agreements contained in
the Trust Guarantee shall bind the successors, assigns, receivers, trustees
and representatives of the Company and shall inure to the benefit of the
holders of the Trust Preferred Securities then outstanding.
 
  Termination of the Trust Guarantee. The Trust Guarantee will terminate as to
the Trust Preferred Securities issued by the Alcoa Trust (a) upon full payment
of the redemption price of all Trust Preferred Securities of the Alcoa Trust,
(b) upon distribution of the Subordinated Debt Securities of the Company held
by the Alcoa Trust to the holders of the Trust Preferred Securities of the
Alcoa Trust or (c) upon full payment of the amounts payable in accordance with
the Trust Agreement upon liquidation of the Alcoa Trust. The Trust Guarantee
will continue to be effective or will be reinstated, as the case may be, if at
any time any holder of Trust Preferred Securities issued by the Alcoa Trust
must restore payment of any sums paid under such Trust Preferred Securities or
such Trust Guarantee. The subordination provisions of the Subordinated Debt
Securities and the Trust Guarantee, respectively, will provide that in the
event payment is made on the Subordinated Debt Securities or the Trust
Guarantee in contravention of such provisions, such payments will be paid over
to the holders of Senior Debt.
 
  Ranking of the Trust Guarantee. The Trust Guarantee will constitute an
unsecured obligation of the Company and will rank (i) subordinate and junior
in right of payment to all other liabilities of the Company, (ii) pari passu
with the most senior preferred or preference stock, if any, hereafter issued
by the Company and with any guarantee hereafter entered into by the Company in
respect of any preferred or preference stock or interests of any affiliate of
the Company and (iii) senior to the Company's Common Stock. The Trust
Agreement will provide that each holder of Trust Preferred Securities by
acceptance thereof agrees to the subordination provisions and other terms of
the Trust Guarantee.
 
  The Trust Guarantee will constitute a guarantee of payment and not of
collection. The Trust Guarantee will be deposited with the Property Trustee to
be held for the benefit of the Trust Preferred Securities. The Property
Trustee will have the right to enforce the Trust Guarantee on behalf of the
holders of the Trust Preferred Securities. The holders of not less than a
majority in aggregate liquidation amount of the Trust Preferred Securities
will have the right to direct the time, method and place of conducting any
proceeding for any remedy available in respect of the Trust Guarantee,
including the giving of directions to the Property Trustee. If the Property
Trustee fails to enforce the Trust Guarantee as above provided, any holder of
Trust Preferred Securities may institute a legal proceeding directly against
the Company to enforce its rights under the Trust Guarantee, without first
instituting a legal proceeding against the Alcoa Trust, or any other person or
entity. The Trust Guarantee will not be discharged except by payment of the
Trust Guarantee Payments in full to the extent not paid by the Alcoa Trust,
and by complete performance of all obligations under the Trust Guarantee.
 
  Governing Law. The Trust Guarantee will be, governed by and construed in
accordance with, the laws of the State of New York.
 
                                      37
<PAGE>
 
                             PLAN OF DISTRIBUTION
 
  The Company and/or the Alcoa Trust, as the case may be, may sell Offered
Securities to one or more underwriters for public offering and sale by them or
may sell Offered Securities to investors directly or through agents. Any such
underwriter or agent involved in the offer and sale of the Offered Securities
will be named in an applicable Prospectus Supplement.
 
  Underwriters may offer and sell the Offered Securities at a fixed price or
prices, which may be changed, or from time to time at market prices prevailing
at the time of sale, at prices related to such prevailing market prices or at
negotiated prices. The Company and/or the Alcoa Trust, as the case may be,
also may, from time to time, authorize underwriters acting as the Company's
and/or the Alcoa Trust's agents to offer and sell the Offered Securities upon
the terms and conditions as shall be set forth in any Prospectus Supplement.
In connection with the sale of Offered Securities, underwriters may be deemed
to have received compensation from the Company and/or the Alcoa Trust in the
form of underwriting discounts or commissions and may also receive commissions
from purchasers of Offered Securities for whom they may act as agent.
Underwriters may sell Offered Securities to or through dealers, and such
dealers may receive compensation in the form of discounts, concessions or
commissions from the underwriters and/or commissions (which may be changed
from time to time) from the purchasers for whom they may act as agent.
 
  Any underwriting compensation paid by the Company and/or the Alcoa Trust to
underwriters or agents in connection with the offering of Offered Securities,
and any discounts, concessions or commissions allowed by underwriters to
participating dealers, will be set forth in an applicable Prospectus
Supplement. Underwriters, dealers and agents participating in the distribution
of the Offered Securities may be deemed to be underwriters, and any discounts
and commissions received by them and any profit realized by them on resale of
the Offered Securities may be deemed to be underwriting discounts and
commissions under the Securities Act. Underwriters, dealers and agents may be
entitled, under agreements with the Company and/or the Alcoa Trust, to
indemnification against and contribution toward certain civil liabilities,
including liabilities under the Act, and to reimbursement by the Company
and/or the Alcoa Trust for certain expenses.
 
  If so indicated in an applicable Prospectus Supplement, the Company and/or
the Alcoa Trust will authorize dealers acting as the Company's and/or the
Alcoa Trust's agents to solicit offers by certain institutions to purchase
Offered Securities from the Company and/or the Alcoa Trust at the public
offering price set forth in such Prospectus Supplement pursuant to Delayed
Delivery Contracts ("Contracts") providing for payment and delivery on the
date or dates stated in such Prospectus Supplement. Each Contract will be for
an amount not less than, and the aggregate amount of Offered Securities sold
pursuant to Contracts shall be not less nor more than, the respective amounts
stated in such Prospectus Supplement. Institutions with whom Contracts, when
authorized, may be made include commercial and savings banks, insurance
companies, pension funds, investment companies, educational and charitable
institutions and other institutions, but will in all cases be subject to the
approval of the Company and/or the Alcoa Trust. Contracts will not be subject
to any conditions except (i) the purchase by an institution of the Offered
Securities covered by its Contracts shall not at the time of delivery be
prohibited under the laws of any jurisdiction in the United States to which
such institution is subject, and (ii) if the Offered Securities are being sold
to underwriters, the Company and/or the Alcoa Trust shall have sold to such
underwriters the total principal amount of the Offered Securities less the
principal amount thereof covered by Contracts. Agents and underwriters will
have no responsibility in respect of the delivery or performance of Contracts.
 
  Each underwriter, dealer and agent participating in the distribution of any
Offered Securities which are issuable in bearer form will agree that it will
not offer, sell or deliver, directly or indirectly, Offered Securities in
bearer form in the United States or to United States persons (other than
qualifying
 
                                      38
<PAGE>
 
financial institutions) during the restricted period (as defined in United
States Treasury Regulations Section 1.163-5(c)(2)(i)(D)(7)).
 
  All Offered Securities will be a new issue of securities with no established
trading market. Any underwriters to whom Offered Securities are sold by the
Company and/or the Alcoa Trust for public offering and sale may make a market
in such Offered Securities, but such underwriters will not be obligated to do
so and may discontinue any market making at any time without notice. No
assurance can be given as to the liquidity of the secondary market for any
Offered Securities.
 
  Certain of the underwriters or agents and their associates may be customers
of, engage in transactions with and perform services for the Company and its
subsidiaries in the ordinary course of business.
 
                                LEGAL OPINIONS
 
  Unless otherwise indicated in the applicable Prospectus Supplement, the
validity of the Company Securities will be passed upon for the Company by
Denis A. Demblowski, Esq., Senior Counsel of the Company. The validity of the
Trust Preferred Securities will be passed upon for the Alcoa Trust by Skadden,
Arps, Slate, Meagher & Flom LLP, New York, New York, special counsel to the
Company and the Alcoa Trust. The validity of the Offered Securities will be
passed upon for any underwriters or agents by Cravath, Swaine & Moore, New
York, New York. Mr. Demblowski is a participant in the stock option plan and
various other employee benefit plans offered to employees of the Company.
 
                                    EXPERTS
 
  The consolidated financial statements and related schedules in the Company's
Annual Report on Form 10-K for the year ended December 31, 1997, incorporated
by reference in this Prospectus, have been incorporated herein by reference in
reliance upon the reports of PricewaterhouseCoopers LLP given upon their
authority as experts in auditing and accounting.
 
                                      39
<PAGE>
 
                PART II. INFORMATION NOT REQUIRED IN PROSPECTUS
 
ITEM 14. OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION:
 
  The expenses in connection with the issuance and distribution of the
securities being registered, other than underwriting compensation, are:
 
<TABLE>
     <S>                                                               <C>
     Registration Fee................................................. $309,750
     Rating Agency Fees...............................................  210,000
     Printing and Engraving...........................................   60,000
     Trustees' Fees and Expenses......................................   25,000
     Accountants' Fees and Expenses...................................   10,000
     Legal Fees and Expenses..........................................  100,000
     Miscellaneous....................................................   10,000
                                                                       --------
       Total.......................................................... $724,750
                                                                       ========
</TABLE>
 
ITEM 15. INDEMNIFICATION OF DIRECTORS AND OFFICERS.
 
THE COMPANY
 
  Article V of the ByLaws of the Company (the "ByLaws") provides that the
Company shall indemnify, under specified circumstances, persons who were or
are directors, officers or employees of the Company or who served or serve
other business entities at the request of the Company. Under these ByLaw
provisions, a person who is wholly successful in defending a claim will be
indemnified for any reasonable expenses. To the extent a person is not
successful in defending a claim, reasonable expenses of the defense and any
liability incurred are to be indemnified under these provisions only where
independent legal counsel or other disinterested person selected by the Board
of Directors determines that such person acted in good faith and in a manner
such person reasonably believed to be in, or not opposed to, the best
interests of the Company, and in addition with respect to any criminal action
or proceeding, had no reasonable cause to believe the conduct of such person
was unlawful. Any expense incurred with respect to any claim may be advanced
by the Company if the recipient agrees to repay such amount if it is
ultimately determined that such recipient is not to be indemnified pursuant to
Article V.
 
  The foregoing ByLaw provisions generally parallel Sections 1741 and 1745 of
the Pennsylvania Business Corporation Law ("PBCL"). Section 1746 and the
ByLaws both also provide that the indemnification provided for therein shall
not be deemed exclusive of any other rights to which those seeking
indemnification may otherwise be entitled.
 
  Section 1746 of the PBCL and the ByLaws provide for increased
indemnification protections for directors, officers and others.
Indemnification may be provided by Pennsylvania corporations in any case
except where the act or failure to act giving rise to the claim for
indemnification is determined by a court to have constituted willful
misconduct or recklessness.
 
  Section 1713 of the PBCL also sets forth a framework whereby Pennsylvania
corporations, with the approval of the shareholders, may limit the personal
liability of directors for monetary damages except where the act or omission
giving rise to a claim constitutes self-dealing, willful misconduct or
recklessness. The section does not apply to a director's responsibility or
liability under a criminal or tax statute and may not apply to liability under
Federal statutes, such as the Federal securities laws.
 
  The Company's Articles of Incorporation (the "Articles") and ByLaws were
amended by the shareholders to implement the increased protections made
available to directors under the PBCL as described in the preceding paragraph.
Article VIII of the ByLaws provides that, except as prohibited by
 
                                     II-1
<PAGE>
 
law, every director of the Company shall be entitled as of right to be
indemnified by the Company for expenses and any and all liability paid or
incurred by such person by reason of such person being or having been a
director of the Company. Expenses incurred with respect to any claim may be
advanced by the Company, subject to certain exceptions. The shareholders have
also approved a form of indemnity agreement. The Company has entered into such
an indemnity agreement with each of its current directors.
 
  The Company has purchased a one year liability insurance policy with an
aggregate limit of $100 million, with certain specified deductible amounts.
The policy provides coverage for various executive and corporate risks,
including liability of directors and officers and reimbursement to the Company
for indemnification provided to directors and officers. The policy has an
expiration date of October 1, 2000 and provides liability insurance and
reimbursement coverage for the Company, and its directors and officers, which
is permitted by Section 1747 of the PBCL.
 
  The Articles provide that except as prohibited by law, the Company may
indemnify any person who is or was a director, officer, employee or agent of
the Company or is or was serving at the request of the Company as a director,
officer, employee or agent of another corporation, partnership, joint venture,
trust or other enterprise (including, without limitation, any employee benefit
plan) and may take such steps as may be deemed appropriate by the Board of
Directors, including purchasing and maintaining insurance, entering into
contracts (including, without limitation, contracts of indemnification between
the Company and its directors and officers), creating a trust fund, granting
security interests or using other means (including, without limitation, a
letter of credit) to ensure the payment of such amounts as may be necessary to
effect such indemnification. The ByLaws provide for indemnification of such
persons to the fullest extent permitted by law.
 
  The Articles also provide that to the fullest extent that the laws of the
Commonwealth of Pennsylvania permit elimination or limitation of the liability
of directors, no director of the Company shall be personally liable for
monetary damages for any action taken, or any failure to take any action.
 
  Section (6)(b) of the Underwriting Agreement, relating to each of the Senior
Debt Securities and the Class B Stock (Exhibit (1)(a) and (1)(b),
respectively, hereto) and Section 7(b) of the Agency Agreement (Exhibit 1(c)
hereto) contain provisions relating to the indemnification by each Underwriter
and Agent, respectively, of the Company, officers and directors of the Company
and each person, if any, who controls the Company, and Section 6(a) of the
Underwriting Agreement, relating to each of the Senior Debt Securities and the
Class B Stock, and Section 7(a) of such Agency Agreement contain provisions
relating to the indemnification by the Company of each Underwriter and Agent,
respectively, and each person controlling the same, against liabilities
arising out of any untrue statement of any material fact contained in this
Registration Statement, or omission therefrom of any material fact. In
addition, Section 8(a) of the form of Underwriting Agreement, relating to the
Trust Preferred Securities (Exhibit (1)(d) hereto), contains provisions
relating to the indemnification by each Underwriter of the Company and the
Alcoa Trust, and Section 8(b) of the form of Underwriting Agreement, relating
to the Trust Preferred Securities, contains provisions relating to the
indemnification by the Company and the Alcoa Trust of each Underwriter,
against liabilities arising out of any untrue statement of any material fact
contained in this Registration Statement, or omission therefrom of any
material fact.
 
THE ALCOA TRUST
 
  The Trust Agreement pursuant to which the Alcoa Trust is organized will
provide that no Regular Trustee, or affiliate of any Regular Trustee, or
officer, director, shareholder, member, partner, employee, representative or
agent of any Regular Trustee or of any such affiliate, or employee or agent of
the Alcoa Trust or its affiliates (each an "Indemnified Person") shall be
liable, responsible or accountable in damages or otherwise to the Alcoa Trust
or any employee or agent of the Alcoa Trust or its affiliates for any loss,
damage or claim incurred by reason of any act or omission performed or
 
                                     II-2
<PAGE>
 
omitted by such Indemnified Person in good faith on behalf of the Alcoa Trust
and in a manner such Indemnified Person reasonably believed to be within the
scope of the authority conferred on such Indemnified Person by such Trust
Agreement or by law, except that an Indemnified Person shall be liable for
such loss, damage or claim incurred by reason of such Indemnified Person's
gross negligence or willful misconduct with respect to such act or omission.
The Trust Agreement also provides that to the fullest extent permitted by
applicable law, the Company shall indemnify and hold harmless each Indemnified
Person from and against any loss, damage or claim incurred by such Indemnified
Person by reason of any act or omission performed or omitted by such
Indemnified Person in good faith on behalf of the Alcoa Trust and in a manner
such Indemnified Person reasonably believed to be within the scope of
authority conferred on such Indemnified Person by such Trust Agreement, except
that no Indemnified Person shall be entitled to be indemnified in respect of
any loss, damage or claim incurred by such Indemnified Person by reason of
gross negligence or willful misconduct with respect to such act or omission.
The Trust Agreement further provides that, to the fullest extent permitted by
applicable law, expenses (including legal fees) incurred by an Indemnified
Person in defending any claim, demand, action, suit or proceeding shall, from
time to time, be advanced by the Company prior to the final disposition of
such claim, demand, action, suit or proceeding upon receipt of an undertaking
by or on behalf of the Indemnified Person to repay such amount if it shall be
determined that the Indemnified Person is not entitled to be indemnified for
the underlying cause of action as authorized by such Trust Agreement.
 
ITEM 16. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES.
 
  (a) Exhibits:
 
    A list of Exhibits filed herewith is contained on the Exhibit Index and
  is incorporated herein by reference.
 
  (b) Financial Statement Schedules:
 
    All schedules for which provision is made in the applicable accounting
  regulations of the Securities and Exchange Commission have been omitted
  because they are not required, amounts which would otherwise be required to
  be shown with respect to any item are not material, are inapplicable, or
  the required information has already been provided elsewhere in the
  registration statement.
 
ITEM 17. UNDERTAKINGS.
 
  The undersigned Registrants hereby undertake:
 
    (1) To file, during any period in which offers or sales are being made, a
  post-effective amendment to this Registration Statement:
 
      (i) To include any prospectus required by Section 10(a)(3) of the
    Securities Act of 1933;
 
      (ii) To reflect in the prospectus any facts or events arising after
    the effective date of the Registration Statement (or the most recent
    post-effective amendment thereof) which, individually or in the
    aggregate, represents a fundamental change in the information set forth
    in the Registration Statement; and
 
      (iii) To include any material information with respect to the plan of
    distribution not previously disclosed in the Registration Statement or
    material change to such information in the Registration Statement;
 
    (2) That, for the purpose of determining any liability under the
  Securities Act of 1933, each such post-effective amendment shall be deemed
  to be a new Registration Statement relating to the securities offered
  therein, and the securities offered therein, and the offering of such
  securities at that time shall be deemed to be the initial bona fide
  offering thereof.
 
                                     II-3
<PAGE>
 
    (3) To remove from registration by means of a post-effective amendment
  any of the securities being registered which remain unsold at the
  termination of the offering.
 
    (4) That, for purposes of determining any liability under the Securities
  Act of 1933, each filing of the Company's annual report pursuant to Section
  13(a) or Section 15(d) of the Securities Exchange Act of 1934 that is
  incorporated by reference in the Registration Statement shall be deemed to
  be a new Registration Statement relating to the securities offered therein,
  and the offering of such securities at that time shall be deemed to be the
  initial bona fide offering thereof.
 
    (5) For purposes of determining any liability under the Securities Act of
  1933, the information omitted from the form of prospectus filed as part of
  this registration statement in reliance upon Rule 430A and contained in a
  form of prospectus filed by the Registrants pursuant to Rule 424(b)(1) or
  (4) or 497(h) under the Securities Act shall be deemed to be part of this
  registration statement as of the time it was declared effective.
 
    (6) For the purpose of determining any liability under the Securities Act
  of 1933, each post-effective amendment that contains a form of prospectus
  shall be deemed to be a new registration statement relating to the
  securities offered therein, and the offering of such securities at that
  time shall be deemed to be the initial bona fide offering thereof.
 
  Insofar as indemnification for liabilities arising under the Securities Act
of 1933 may be permitted to directors, officers and controlling persons of the
Registrants pursuant to the foregoing provisions described in Item 15 above,
the Registrants have been informed that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Act and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
Registrants of expenses incurred or paid by a director, officer or controlling
person of the Registrants in the successful defense of any action, suit or
proceeding) is asserted by such director, officer or controlling person in
connection with the securities being registered, the Registrants will, unless
in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question whether
such indemnification by it is against public policy as expressed in the Act
and will be governed by the final adjudication of such issue.
 
                                     II-4
<PAGE>
 
                                  SIGNATURES
 
  PURSUANT TO THE REQUIREMENTS OF THE SECURITIES ACT OF 1933, THE REGISTRANT
CERTIFIES THAT IT HAS REASONABLE GROUNDS TO BELIEVE THAT IT MEETS ALL OF THE
REQUIREMENTS FOR FILING ON FORM S-3 AND HAS DULY CAUSED THIS REGISTRATION
STATEMENT OR AMENDMENT THERETO TO BE SIGNED ON ITS BEHALF BY THE UNDERSIGNED,
THEREUNTO DULY AUTHORIZED, IN THE CITY OF PITTSBURGH AND COMMONWEALTH OF
PENNSYLVANIA, ON THE 17TH DAY OF JULY, 1998.
 
                                          Aluminum Company of America
 
                                                   /s/ Richard B. Kelson
                                          By: _________________________________
                                                     RICHARD B. KELSON
                                               EXECUTIVE VICE PRESIDENT AND
                                                  CHIEF FINANCIAL OFFICER
 
  PURSUANT TO THE REQUIREMENTS OF THE SECURITIES ACT OF 1933, THIS
REGISTRATION STATEMENT OR AMENDMENT THERETO HAS BEEN SIGNED BELOW BY THE
FOLLOWING PERSONS IN THE CAPACITIES AND ON THE DATES INDICATED.
 
              SIGNATURE                        TITLE                 DATE
 
         /s/ Paul H. O'Neill           Chairman of the          July 17, 1998
- -------------------------------------   Board and Director
           PAUL H. O'NEILL              (Principal
                                        Executive Officer)
 
        /s/ Richard B. Kelson          Executive Vice           July 17, 1998
- -------------------------------------   President and Chief
          RICHARD B. KELSON             Financial Officer
                                        (Principal
                                        Financial Officer)
 
       /s/ Earnest J. Edwards          Senior Vice              July 17, 1998
- -------------------------------------   President and
         EARNEST J. EDWARDS             Controller
                                        (Principal
                                        Accounting Officer)
 
Kenneth W. Dam, Joseph T. Gorman, Judith M. Gueron, Sir Ronald Hampel, Hugh M.
Morgan, John P. Mulroney, Paul H. O'Neill, Henry B. Schacht, Franklin A.
Thomas and Marina v.N. Whitman, each as a Director, on July 17, 1998, by Denis
A. Demblowski, their attorney-in-fact.*
 
        /s/ Denis A. Demblowski
*By: ________________________________
          DENIS A. DEMBLOWSKI
           ATTORNEY-IN-FACT
 
                                     II-5
<PAGE>
 
                                  SIGNATURES
 
  PURSUANT TO THE REQUIREMENTS OF THE SECURITIES ACT OF 1933, ALCOA TRUST I
CERTIFIES THAT IT HAS REASONABLE GROUNDS TO BELIEVE THAT IT MEETS ALL OF THE
REQUIREMENTS FOR FILING ON FORM S-3 AND HAS DULY CAUSED THIS REGISTRATION
STATEMENT TO BE SIGNED ON ITS BEHALF BY THE UNDERSIGNED THEREUNTO DULY
AUTHORIZED, IN THE CITY OF PITTSBURGH AND THE COMMONWEALTH OF PENNSYLVANIA ON
THE 17TH DAY OF JULY, 1998.
 
                                          Alcoa Trust I,
                                           a Delaware business trust
 
                                          BY:Aluminum Company of America,
                                                as Depositor
 
                                                   /s/ Richard B. Kelson
                                          BY: _________________________________
                                                     RICHARD B. KELSON
                                               EXECUTIVE VICE PRESIDENT AND
                                                  CHIEF FINANCIAL OFFICER
 
                                     II-6
<PAGE>
 
                               INDEX TO EXHIBITS
 
<TABLE>
<CAPTION>
 EXHIBIT
 NUMBER                                  EXHIBIT
 -------                                 -------
 <C>     <S>
 (1)(a)  Form of Underwriting Agreement relating to the Senior Debt Securities
         and Warrants to Purchase Senior Debt Securities (incorporated by
         reference to Exhibit 1(a) to Registration Statement No.33-49997 on
         Form S-3).
 (1)(b)  Form of Underwriting Agreement relating to the Class B Stock
         (incorporated by reference to Exhibit 1(b) to Registration Statement
         No. 33-49997 on Form S-3).
 (1)(c)  Form of Proposed Agency Agreement relating to the Distribution of
         Medium-Term Notes (incorporated by reference to Exhibit 1(b) to Post-
         Effective Amendment No. 2 to Registration Statement No. 33-877 on Form
         S-3).
 (1)(d)  Form of Underwriting Agreement for Trust Preferred Securities.*
 (2)     Agreement and Plan of Merger among the Company, AMX Acquisition Corp.
         and Alumax Inc. dated as of March 8, 1998. The Registrant will furnish
         supplementally a copy of all omitted Schedules to Exhibit 2 upon the
         request of the Securities and Exchange Commission (incorporated herein
         by reference to Exhibit (2) to the Company's Quarterly Report on Form
         10-Q for the quarter ended March 31, 1998).
 (3)(a)  Articles of Incorporation of the Company (incorporated by reference to
         Exhibit 3(i) to Form 10-Q for the quarter ended June 30, 1993).
 (3)(b)  ByLaws of the Company (incorporated by reference to Exhibit 3 to Form
         10-Q for the quarter ended September 30, 1991).
 (4)(a)  Form of Indenture, dated as of September 30, 1993, between the Company
         and PNC Bank, National Association, as Trustee (undated form of
         Indenture incorporated by reference to Exhibit 4(a) to Registration
         Statement No. 33-49997 on Form S-3).
 (4)(b)  Form of proposed Warrants to Purchase Senior Debt Securities
         (incorporated by reference to Exhibit 4(c) to Registration Statement
         No. 2-78009 on Form S-3).
 (4)(c)  Form of proposed Warrant Agreement relating to the Warrants to
         Purchase Senior Debt Securities (incorporated by reference to Exhibit
         4(d) to Registration Statement No. 2-78009 on Form S-3).
 (4)(d)  Form of Registered Security which is not an Original Issue Discount
         Security (included in Exhibit 4(a) as Exhibit A).
 (4)(e)  Form of Registered Security which is an Original Issue Discount
         Security (included in Exhibit 4(a) as Exhibit B).
 (4)(f)  Form of Bearer Security which is not an Original Issue Discount
         Security and form of Related Coupon (included in Exhibit 4(a) as
         Exhibit C).
 (4)(g)  Form of Bearer Security which is an Original Issue Discount Security
         and form of Related Coupon (included in Exhibit 4(a) as Exhibit D).
 (4)(h)  Form of Certificate for Shares of Class B Stock (incorporated by
         reference to Exhibit 4(h) to Registration Statement No. 33-49997 on
         Form S-3).
 (4)(i)  Form of Certificate for Shares of Common Stock (incorporated by
         reference to Exhibit 4(i) to Registration Statement No. 33-49997 on
         Form S-3).
 (4)(j)  Form of Subordinated Indenture (including form of Subordinated Debt
         Security).**
</TABLE>
 
<PAGE>
 
<TABLE>
<CAPTION>
 EXHIBIT
 NUMBER                                  EXHIBIT
 -------                                 -------
 <C>     <S>
  (4)(k) Certificate of Trust of Alcoa Trust I.*
  (4)(l) Declaration of Trust of Alcoa Trust I.*
  (4)(m) Form of Amended and Restated Trust Agreement of Alcoa Trust I.*
  (4)(n) Form of Guarantee Agreement.*
  (5)(a) Opinion of Denis A. Demblowski, Esq., Senior Counsel of the Company.**
  (5)(b) Opinion of Skadden, Arps, Slate, Meagher & Flom LLP, special counsel
         to the Company and the Alcoa Trust.**
 (12)    Computation of Ratio of Earnings to Fixed Charges (incorporated by
         reference to Exhibit 12 to Form 10-K for the year ended December 31,
         1997 and to Exhibit 12 to Form 10-Q for the quarter ended March 31,
         1998).
 (21)    Subsidiaries of Aluminum Company of America.*
 (23)(a) Consent of PricewaterhouseCoopers LLP.*
 (23)(b) Consent of PricewaterhouseCoopers LLP.*
 (23)(c) Consent of Denis A. Demblowski, Esq., counsel to the Company.**
 (23)(d) Consent of Skadden, Arps, Slate, Meagher & Flom LLP, counsel to the
         Company.**
 (24)    Powers of Attorney of certain officers and directors.
 (25)(a) Form T-1 Statement of Eligibility under the Trust Indenture Act of
         1939 of PNC Bank, National Association, as trustee under the Senior
         Indenture (incorporated by reference to Exhibit 25 to Registration
         Statement No. 33-64353 on Form S-3).
 (25)(b) Form T-1 Statement of Eligibility under the Trust Indenture Act of
         1939 of The Chase Manhattan Bank, as trustee under the Subordinated
         Indenture.*
 (25)(c) Form T-1 Statement of Eligibility under the Trust Indenture Act of
         1939 of The Chase Manhattan Bank, as trustee under the Amended and
         Restated Trust Agreement of Alcoa Trust I.*
 (25)(d) Form T-1 Statement of Eligibility under the Trust Indenture Act of
         1939 of The Chase Manhattan Bank, as trustee under the Guarantee of
         the Company for the benefit of the holders of Trust Preferred
         Securities of the Alcoa Trust I.*
</TABLE>
- --------
*Filed herewith.
**To be filed by amendment.

<PAGE>
 
                                                                    EXHIBIT 1(D)


                          ALUMINUM COMPANY OF AMERICA

                                 ALCOA TRUST I

                             PREFERRED SECURITIES

                                  __________

                            UNDERWRITING AGREEMENT
                            ----------------------

                                                                          [DATE]


TO THE REPRESENTATIVES OF THE
 SEVERAL UNDERWRITERS NAMED IN THE
 RESPECTIVE PRICING AGREEMENTS
 HEREINAFTER DESCRIBED.

Ladies and Gentlemen:

     From time to time Aluminum Company of America, a Pennsylvania corporation
(the "Company") and Alcoa Trust I (the "Trust"), propose to enter into one or
more Pricing Agreements (each a "Pricing Agreement") in the form of Annex I
hereto, with such additions and deletions as the parties thereto may determine,
and, subject to the terms and conditions stated herein and therein, to issue and
sell to the firms named in Schedule I to the applicable Pricing Agreement (such
firms constituting the "Underwriters" with respect to such Pricing Agreement and
the securities specified therein) certain trust preferred securities of the
Trust (the "Securities") specified in Schedule II to such Pricing Agreement
(with respect to such Pricing Agreement, the "Designated Securities").

     The terms and rights of any particular issuance of Designated Securities
shall be as specified in the Pricing Agreement relating thereto.  Each series of
Designated Securities will represent undivided beneficial interests in the
assets of the Trust, guaranteed (the "Guarantee") by the Company as to the
payment of distributions, and as to payments on liquidation or redemption, to
the extent set forth in a guarantee agreement (the "Guarantee Agreement")
between the Company and [                ], as trustee (the "Guarantee
Trustee").  The proceeds of the sale of the Designated Securities and common
securities (liquidation amount $50 per common security) (the "Common
Securities") by the Trust are to be invested in [Convertible] Subordinated
Debentures (the "Subordinated Debentures") of the Company, to be issued pursuant
to an Indenture (the "Indenture") between the Company and [                 ],
as Trustee (the "Debenture Trustee").  [Designated Securities are convertible
into shares of the Company's common stock, par value $1.00 per share ("Common
Stock")].

     1.   Particular sales of Designated Securities may be made from time to
time to the Underwriters of such Designated Securities, for whom the firms
designated as representatives of the Underwriters of such Designated Securities
in the Pricing Agreement relating thereto will act as representatives (the
"Representatives").  The term "Representatives" also refers to a single firm
<PAGE>
 
acting as sole representative of the Underwriters and to an Underwriter or
Underwriters who act without any firm being designated as its or their
representatives. This Underwriting Agreement shall not be construed as an
obligation of the Company or the Trust to sell any of the Securities or as an
obligation of any of the Underwriters to purchase the Designated Securities. The
obligation of the Trust to issue and sell any of the Designated Securities and
the obligation of any of the Underwriters to purchase any of the Designated
Securities shall be evidenced by the Pricing Agreement with respect to the
Designated Securities specified therein. Each Pricing Agreement shall specify
the aggregate liquidation amount of such Designated Securities, the initial
public offering price of such Designated Securities, the purchase price to the
Underwriters of such Designated Securities, the names of the Underwriters of
such Designated Securities, the names of the Representatives of such
Underwriters and the liquidation amount of such Designated Securities to be
purchased by each Underwriter and shall set forth the date, time and manner of
delivery of such Designated Securities and payment therefor. The Pricing
Agreement shall also specify (to the extent not set forth in the registration
statement and prospectus or prospectus supplement with respect thereto) the
terms of such Designated Securities. A Pricing Agreement shall be in the form of
an executed writing (which may be in counterparts), and may be evidenced by an
exchange of telegraphic communications or any other rapid transmission device
designed to produce a written record of communications transmitted. The
obligations of the Underwriters under this Agreement and each Pricing Agreement
shall be several and not joint.

     2.   The Company and the Trust jointly and severally represent and warrant
to, and agree with, each of the Underwriters that:

          (a)  Two registration statements on Form S-3 (File No. 33-64353 and
     File No. 333-[     ]) (the "Initial Registration Statement") in respect of
     certain securities including the Securities have been filed with the
     Securities and Exchange Commission (the "Commission"); the Initial
     Registration Statement and any post-effective amendment thereto, each in
     the form heretofore delivered or to be delivered to the Representatives
     and, excluding exhibits to the Initial Registration Statement, but
     including all documents incorporated by reference in the prospectus
     contained therein, to the Representatives for each of the other
     Underwriters, have been declared effective by the Commission in such form;
     other than a registration statement, if any, increasing the size of the
     offering (a "Rule 462(b) Registration Statement"), filed pursuant to Rule
     462(b) under the Securities Act of 1933, as amended (the "Act"), which
     became effective upon filing, no other document with respect to the Initial
     Registration Statement or document incorporated by reference therein has
     heretofore been filed or transmitted for filing with the Commission (other
     than prospectuses filed pursuant to Rule 424(b) of the rules and
     regulations of the Commission under the Act, each in the form heretofore
     delivered to the Representatives); and to the best knowledge of the Company
     and the Trust, no stop order suspending the effectiveness of the Initial
     Registration Statement, any post-effective amendment thereto or the Rule
     462(b) Registration Statement, if any, has been issued and no proceeding
     for that purpose has been initiated or threatened by the Commission (any
     preliminary prospectus included in the Initial Registration Statement or
     filed with the Commission pursuant to Rule 424(a) under the Act, is
     hereinafter called a "Preliminary Prospectus"; the various parts of the
     Initial Registration Statement, any post-effective amendment thereto and
     the Rule 462(b) Registration Statement, if any, including all exhibits
     thereto and the documents incorporated by reference in the prospectus
     contained in the Initial Registration Statement at the time such part of
     the Initial Registration Statement became effective but excluding Form T-1,
     each as amended at the time such part of the 

                                       2
<PAGE>
 
     Initial Registration Statement became effective or such part of the Rule
     462(b) Registration Statement, if any, became or hereafter becomes
     effective, are hereinafter collectively called the "Registration
     Statement"; the prospectus relating to the Securities, in the form in which
     it has most recently been filed, or transmitted for filing, with the
     Commission on or prior to the date of this Agreement, being hereinafter
     called the "Prospectus"; any reference herein to any Preliminary Prospectus
     or the Prospectus shall be deemed to refer to and include the documents
     incorporated by reference therein pursuant to the applicable form under the
     Act, as of the date of such Preliminary Prospectus or Prospectus, as the
     case may be; any reference to any amendment or supplement to any
     Preliminary Prospectus or the Prospectus shall be deemed to refer to and
     include any documents filed after the date of such Preliminary Prospectus
     or Prospectus, as the case may be, under the Securities Exchange Act of
     1934, as amended (the "Exchange Act"), and incorporated by reference in
     such Preliminary Prospectus or Prospectus, as the case may be; any
     reference to any amendment to the Initial Registration Statement shall be
     deemed to refer to and include any annual report of the Company filed
     pursuant to Sections 13(a) or 15(d) of the Exchange Act after the effective
     date of the Initial Registration Statement that is incorporated by
     reference in the Registration Statement; and any reference to the
     Prospectus as amended or supplemented shall be deemed to refer to the
     Prospectus as amended or supplemented in relation to the applicable
     Designated Securities in the form in which it is filed with the Commission
     pursuant to Rule 424(b) under the Act in accordance with Section 5(a)
     hereof, including any documents incorporated by reference therein as of the
     date of such filing);

          (b)  The documents incorporated by reference in the Prospectus, when
     they became effective or were filed with the Commission, as the case may
     be, conformed in all material respects to the requirements of the Act or
     the Exchange Act, as applicable, and the rules and regulations of the
     Commission thereunder, and none of such documents contained an untrue
     statement of a material fact or omitted to state a material fact required
     to be stated therein or necessary to make the statements therein not
     misleading; and any further documents so filed and incorporated by
     reference in the Prospectus or any further amendment or supplement thereto,
     when such documents become effective or are filed with the Commission, as
     the case may be, will conform in all material respects to the requirements
     of the Act or the Exchange Act, as applicable, and the rules and
     regulations of the Commission thereunder and will not contain an untrue
     statement of a material fact or omit to state a material fact required to
     be stated therein or necessary to make the statements therein not
     misleading; provided, however, that this representation and warranty shall
     not apply to any statements or omissions made in reliance upon and in
     conformity with information furnished in writing to the Company or the
     Trust by an Underwriter of Designated Securities through the
     Representatives expressly for use in the Registration Statement or the
     Prospectus as amended or supplemented relating to such Designated
     Securities;

          (c)  The Registration Statement and the Prospectus conform, and any
     further amendments or supplements to the Registration Statement or the
     Prospectus will conform, in all material respects to the requirements of
     the Act and the Trust Indenture Act of 1939, as amended (the "Trust
     Indenture Act"), and the rules and regulations of the Commission thereunder
     and do not and will not, as of the applicable effective date as to the
     Registration 

                                       3
<PAGE>
 
     Statement and any amendment thereto and as of the applicable filing date as
     to the Prospectus and any amendment or supplement thereto, contain an
     untrue statement of a material fact or omit to state a material fact
     required to be stated therein or necessary to make the statements therein
     not misleading; provided, however, that this representation and warranty
     shall not apply to any statements or omissions made in reliance upon and in
     conformity with information furnished in writing to the Company or the
     Trust by an Underwriter of Designated Securities through the
     Representatives expressly for use in the Registration Statement or the
     Prospectus as amended or supplemented relating to such Designated
     Securities;

          (d)  The Trust has been duly created and is validly existing as a
     statutory business trust in good standing under the Delaware Business Trust
     Act with the power and authority to own its properties and conduct its
     business as described in the Prospectus, and the Trust has conducted no
     business to date other than as contemplated by the Prospectus and this
     Agreement, and it will conduct no business in the future that would be
     inconsistent with the Trust Agreement (as defined below) and the
     description of the Trust set forth in the Prospectus; the Trust is not a
     party to or bound by any agreement or instrument other than this Agreement,
     the Amended and Restated Trust Agreement (the "Trust Agreement") among the
     Company, the trustees named therein (the "Trustees") and the holders of the
     Designated Securities (the "Securityholders") issued thereunder, and the
     agreements and instruments contemplated by the Trust Agreement; the Trust
     has no liabilities or obligations other than those arising out of the
     transactions contemplated by this Agreement and the Trust Agreement and
     described in the Prospectus; based on expected operations and current law,
     the Trust is not and will not be classified as an association taxable as a
     corporation for United States federal income tax purposes; and the Trust is
     not a party to or subject to any action, suit or proceeding of any nature;

          (e)  The Designated Securities have been duly and validly authorized
     by the Trust, and, when issued and delivered against payment therefor as
     provided herein, will be duly and validly issued and fully paid and non-
     assessable undivided beneficial interests in the assets of the Trust and
     will conform to the description of the Designated Securities contained in
     the Prospectus; the issuance of the Designated Securities is not subject to
     preemptive or other similar rights; the Designated Securities will have the
     rights set forth in the Trust Agreement, and the terms of the Designated
     Securities are valid and binding on the Trust; the holders of the
     Designated Securities will be entitled to the same limitation of personal
     liability extended to stockholders of private corporations for profit
     organized under the General Corporation Law of the State of Delaware;

          (f)  The Common Securities of the Trust have been duly and validly
     authorized by the Trust and upon delivery by the Trust to the Company
     against payment therefor as described in the Prospectus, will be duly and
     validly issued undivided beneficial interests in the assets of the Trust
     and will conform in all material respects to the description thereof
     contained in the Prospectus; the issuance of the Common Securities is not
     subject to preemptive or other similar rights; and at the Time of Delivery
     (as defined herein), all of the issued and outstanding Common Securities of
     the Trust will be directly owned by the Company free and clear of any
     security interest, mortgage, pledge, lien, encumbrance, claim or equity;

                                       4
<PAGE>
 
          (g)  The Guarantee, the Subordinated Debentures, the Trust Agreement
     and the Indenture (the Guarantee, the Subordinated Debentures, the Trust
     Agreement and the Indenture being collectively referred to as the
     "Guarantor Agreements"), when validly executed and delivered by the Company
     and, in the case of the Guarantee, by the Guarantee Trustee, in the case of
     the Trust Agreement, by the Trustees and, in the case of the Indenture, by
     the Debenture Trustee, will constitute valid and legally binding
     obligations of the Company, enforceable in accordance with their respective
     terms, subject, as to enforcement, to bankruptcy, insolvency,
     reorganization, moratorium and similar laws of general applicability
     relating to or affecting creditors' rights and to general equity
     principles; the Subordinated Debentures are entitled to the benefits of the
     Indenture; and the Guarantor Agreements will conform to the descriptions
     thereof in the Prospectus;

          (h)  The Trust is not, and after giving effect to the offering and
     sale of the Designated Securities will not be, an "investment company", or
     an entity "controlled" by an "investment company", as such terms are
     defined in the United States Investment Company Act of 1940, as amended
     (the "Investment Company Act");

     3.   Upon the execution of the Pricing Agreement applicable to any
Designated Securities and authorization by the Representatives of the release of
such Designated Securities, the several Underwriters propose to offer such
Designated Securities for sale upon the terms and conditions set forth in the
Prospectus as amended or supplemented.

     4.   Designated Securities to be purchased by each Underwriter pursuant to
the Pricing Agreement relating thereto, in the form specified in such Pricing
Agreement, and in such authorized denominations and registered in such names as
the Representatives may request upon at least forty-eight hours' prior notice to
the Company, shall be delivered by or on behalf of the Company and the Trust to
the Representatives for the account of such Underwriter, against payment by such
Underwriter or on its behalf of the purchase price therefor by wire transfer of
Federal (same-day) funds to the account specified by the Company to the
Representatives at least forty-eight hours in advance or at such other place and
time and date as the Representatives and the Company may agree upon in writing,
such time and date being herein called the "Time of Delivery" for such
Securities.

     5.   The Company and the Trust jointly and severally agree with each of the
Underwriters of any Designated Securities:

          (a) To prepare the Prospectus as amended or supplemented in relation
     to the Designated Securities in a form approved by the Representatives,
     which approval shall not be unreasonably withheld, and to file such
     Prospectus pursuant to Rule 424(b) under the Act not later than the
     Commission's close of business on the second business day following the
     execution and delivery of the Pricing Agreement relating to the Designated
     Securities or, if applicable, such earlier time as may be required by Rule
     424(b); to make no further amendment or any supplement to the Registration
     Statement or Prospectus as amended or supplemented after the date of the
     Pricing Agreement relating to such Designated Securities and prior to the
     Time of Delivery for such Designated Securities which shall be disapproved
     by the Representatives for such Designated Securities promptly after
     reasonable notice thereof; to advise the Representatives promptly of any
     such amendment or supplement after 

                                       5
<PAGE>
 
     such Time of Delivery and furnish the Representatives with copies thereof;
     to file promptly all reports and any definitive proxy or information
     statements required to be filed by the Company or the Trust with the
     Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange
     Act for so long as the delivery of a prospectus is required in connection
     with the offering or sale of such Designated Securities, and during such
     same period to advise the Representatives, promptly after the Company or
     the Trust, as the case may be, receives notice thereof, of the time when
     any amendment to the Registration Statement has been filed or becomes
     effective or any supplement to the Prospectus or any amended Prospectus has
     been filed with the Commission, of the issuance by the Commission of any
     stop order or of any order preventing or suspending the use of any
     prospectus relating to the Designated Securities, of the suspension of the
     qualification of such Designated Securities for offering or sale in any
     jurisdiction, of the initiation or threatening of any proceeding for any
     such purpose, or of any request by the Commission for the amending or
     supplementing of the Registration Statement or Prospectus or for additional
     information; and, in the event of the issuance of any such stop order or of
     any such order preventing or suspending the use of any prospectus relating
     to the Designated Securities or suspending any such qualification, to
     promptly use their best efforts to obtain the withdrawal of such order;

          (b)  Promptly from time to time to take such action in cooperation
     with the Underwriters as the Representatives may reasonably request to
     qualify such Designated Securities for offering and sale under the
     securities laws of such jurisdictions as the Representatives may request
     and to comply with such laws so as to permit the continuance of sales and
     dealings therein in such jurisdictions for as long as may be necessary to
     complete the distribution of such Designated Securities, provided that in
     connection therewith the Company and the Trust shall not be required to
     qualify as a foreign corporation or to file a general consent to service of
     process in any jurisdiction;

          (c)  Prior to 10:00 a.m., New York City time, on the New York business
     day next succeeding the date of this Agreement and from time to time, to
     furnish the Underwriters with copies of the Prospectus in New York City as
     amended or supplemented in such quantities as the Representatives may
     reasonably request, and, if the delivery of a prospectus is required at any
     time in connection with the offering or sale of the Designated Securities
     and if at such time any event shall have occurred as a result of which the
     Prospectus as then amended or supplemented would include an untrue
     statement of a material fact or omit to state any material fact necessary
     in order to make the statements therein, in the light of the circumstances
     under which they were made when such Prospectus is delivered, not
     misleading, or, if for any other reason it shall be necessary during such
     same period to amend or supplement the Prospectus or to file under the
     Exchange Act any document incorporated by reference in the Prospectus in
     order to comply with the Act, the Exchange Act or the Trust Indenture Act,
     to notify the Representatives and upon their request to file such document
     and to prepare and furnish without charge to each Underwriter and to any
     dealer in Designated Securities as many copies as the Representatives may
     from time to time reasonably request of an amended Prospectus or a
     supplement to the Prospectus which will correct such statement or omission
     or effect such compliance;

          (d)  To make generally available to their securityholders as soon as
     practicable, but in any event not later than eighteen months after the
     effective date of the Registration 

                                       6
<PAGE>
 
     Statement (as defined in Rule 158(c) under the Act), an earnings statement
     of the Company and its subsidiaries (and the Trust if required by the
     Commission) (which need not be audited) complying with Section 11(a) of the
     Act and the rules and regulations of the Commission thereunder (including,
     at the option of the Company, Rule 158);

          (e)  During the period from the date hereof and continuing to and
     including the date  90 days after the date of the Prospectus, not to offer,
     sell, contract to sell or otherwise dispose of, except as provided
     hereunder, any securities of the Company that are substantially similar to
     the Designated Securities or the Common Stock, including but not limited to
     any securities that are convertible into or exchangeable for, or that
     represent the right to receive, Common Stock or any such substantially
     similar securities (other than pursuant to employee stock option plans
     existing on, or upon the conversion or exchange of convertible or
     exchangeable securities outstanding as of, the date of this Agreement),
     without your prior written consent;

          (f)  If the Company and the Trust elect to rely upon Rule 462(b), the
     Company and the Trust shall file a Rule 462(b) Registration Statement with
     the Commission in compliance with Rule 462(b) by 10:00 P.M., Washington,
     D.C. time, on the date of this Agreement, and the Company and the Trust
     shall at the time of filing either pay to the Commission the filing fee for
     the Rule 462(b) Registration Statement or give irrevocable instructions for
     the payment of such fee pursuant to Rule 111(b) under the Act; and

          (g)  To issue the Guarantee and the Subordinated Debentures
     concurrently with the issue and sale of the Designated Securities as
     contemplated in the Pricing Agreement relating to such Designated
     Securities.

     6.   The Company and the Trust jointly and severally covenant and agree
with the several Underwriters that the Company and the Trust will pay or cause
to be paid the following: (i) the fees, disbursements and expenses of the
Company's and Trust's counsel and accountants in connection with the
registration of the Securities under the Act and all other expenses in
connection with the preparation, printing and filing of the Registration
Statement, any Preliminary Prospectus and the Prospectus and amendments and
supplements thereto and the mailing and delivering of copies thereof to the
Underwriters; (ii) the cost of printing or producing any Agreement among
Underwriters, this Agreement, any Pricing Agreement, any Guarantor Agreement,
any Blue Sky Survey, closing documents (including any compilations thereof) and
any other documents in connection with the offering, purchase, sale and delivery
of the Designated Securities; (iii) all expenses in connection with the
qualification of the Designated Securities for offering and sale under state
securities laws as provided in Section 5(b) hereof, including the fees and
disbursements of counsel for the Underwriters in connection with such
qualification and in connection with the Blue Sky Survey; (iv) any fees charged
by securities rating services for rating the Securities; (v) any filing fees
incident to, and the fees and disbursements of counsel for the Underwriters in
connection with, any required review by the National Association of Securities
Dealers, Inc. of the terms of the sale of the Designated Securities; (vi) the
cost of preparing the Designated Securities and the Subordinated Debentures;
(vii) the fees and expenses of the Trustees, the Guarantee Trustee and Debenture
Trustee and any agent of the Trustees, the Guarantee Trustee and the Debenture
Trustee, the fees and disbursements of counsel for the Trustees in connection
with the Trust Agreement and the Designated Securities, counsel for the
Guarantee Trustee in connection with the Guarantee and 

                                       7
<PAGE>
 
counsel for the Debenture Trustee in connection with the Indenture and the
Subordinated Debentures; and (viii) all other costs and expenses incident to the
performance of their respective obligations hereunder which are not otherwise
specifically provided for in this Section. It is understood, however, that,
except as provided in this Section, and Sections 8 and 11 hereof, the
Underwriters will pay all of their own costs and expenses, including the fees of
their counsel, transfer taxes on resale of any of the Designated Securities by
them, and any advertising expenses connected with any offers they may make.

     7.   The obligations of the Underwriters of any Designated Securities under
the Pricing Agreement relating to such Designated Securities shall be subject,
in the discretion of the Representatives, to the condition that all
representations and warranties and other statements of the Trust and the Company
in or incorporated by reference in the Pricing Agreement relating to such
Designated Securities are, at and as of the Time of Delivery for such Designated
Securities, true and correct, the condition that the Company and the Trust shall
have performed all of their respective obligations hereunder theretofore to be
performed, and the following additional conditions:

     (a)  The Prospectus as amended or supplemented in relation to the
applicable Designated Securities shall have been filed with the Commission
pursuant to Rule 424(b) within the applicable time period prescribed for such
filing by the rules and regulations under the Act and in accordance with Section
5(a) hereof; if the Company and the Trust have elected to rely upon Rule 462(b),
the Rule 462(b) Registration Statement shall have become effective by 10:00
P.M., Washington, D.C. time, on the date of the relevant Pricing Agreement; no
stop order suspending the effectiveness of the Registration Statement or any
part thereof shall have been issued and no proceeding for that purpose shall
have been initiated or threatened by the Commission; and all requests for
additional information on the part of the Commission shall have been complied
with to the Representatives' reasonable satisfaction;

     (b)  Cravath, Swaine & Moore, counsel for the Underwriters shall have
furnished to the Representatives such written opinion or opinions, dated the
Time of Delivery for such Designated Securities, with respect to such matters as
the Representatives may reasonably request, and such counsel shall have received
such papers and information as they may reasonably request to enable them to
pass upon such matters;

     (c)  The General Counsel, an Assistant General Counsel or a Senior Counsel
for the Company or Skadden, Arps, Slate, Meagher & Flom LLP, special Delaware
counsel to the Trust and special counsel to the Company, shall have furnished to
the Representatives a written opinion or opinions relating to the Company, dated
the Time of Delivery for such Designated Securities, in form and substance
reasonably satisfactory to the Representatives set forth in Exhibit [  ] to the
Pricing Agreement.

     Such opinions shall be limited to New York, Pennsylvania, Delaware and
Federal law.  In giving such opinions, such counsel may rely, as to all matters
governed by the laws of jurisdictions in which such counsel is not qualified,
upon opinions of other counsel, who shall be counsel satisfactory to counsel for
the Representatives, in which case the opinions shall state that they believe
you and they are entitled to rely on such opinions;

                                       8
<PAGE>
 
     (d)  At the Time of Delivery for such Designated Securities, the
independent accountants of the Company who have certified the financial
statements of the Company and its subsidiaries included or incorporated by
reference in the Registration Statement, shall have furnished to the
Representatives a letter, dated such Time of Delivery, to the effect set forth
in Annex II hereto, and as to such other matters as the Representatives may
reasonably request and in form and substance satisfactory to the
Representatives;

     (e)  Since the respective dates as of which information is given in the
Prospectus as amended prior to the date of the Pricing Agreement relating to the
Designated Securities there shall not have been any change, or any development
involving a prospective change, in or affecting the general affairs, management,
financial position, stockholders' equity or results of operations of the Company
and its subsidiaries, otherwise than as set forth or contemplated in the
Prospectus as amended prior to the date of the Pricing Agreement relating to the
Designated Securities, the effect of which, in any such case, is in the judgment
of the Representatives so material and adverse as to make it impracticable or
inadvisable to proceed with the public offering or the delivery of the
Designated Securities on the terms and in the manner contemplated in the
Prospectus as first amended or supplemented relating to the Designated
Securities;

     (f)  On or after the date of the Pricing Agreement relating to the
Designated Securities (i) no downgrading shall have occurred in the rating
accorded the Company's debt securities by Standard and Poor's Corporation or
Moody's Investors Service, Inc. and (ii) no such organization shall have
publicly announced that it has under surveillance or review, with possible
negative implications, its rating of any of the Company's debt securities;

     (g)  On or after the date of the Pricing Agreement relating to the
Designated Securities there shall not have occurred any of the following: (i) a
suspension or material limitation in trading in securities generally on the New
York Stock Exchange; (ii) a suspension or material limitation in trading in the
Company's securities on the New York Stock Exchange; (iii) a general moratorium
on commercial banking activities declared by either Federal or New York State
authorities; or (iv) the outbreak or escalation of hostilities involving the
United States or the declaration by the United States of a national emergency or
war, if the effect of any such event specified in this Clause (iv) in the
judgment of the Representatives makes it impracticable or inadvisable to proceed
with the public offering or the delivery of the Designated Securities on the
terms and in the manner contemplated in the Prospectus as first amended or
supplemented relating to the Designated Securities;

     (h)  The Company shall have complied with the provisions of Section 5(c)
hereof with respect to the furnishing of prospectuses on the New York business
day next succeeding the date of this Agreement;

     (i)  The Company and the Trust shall have furnished or caused to be
furnished to the Representatives at the Time of Delivery for the Designated
Securities a certificate or certificates of officers of the Company and the
Trust, based on their best knowledge after reasonable investigation,
satisfactory to the Representatives as to the accuracy of the representations
and warranties of the Company and the Trust herein at and as of such Time of
Delivery, as to the performance by the Company and the Trust of all of their
respective obligations hereunder to be performed at or prior to such Time of
Delivery, as to the matters set forth in subsections (a) and (e) of this Section
7 and as to such other matters as the Representatives may reasonably request;
and

                                       9
<PAGE>
 
     (j)  The Representatives shall have received at the Time of Delivery the
opinion of Skadden, Arps, Slate, Meagher & Flom LLP, special Delaware Counsel
for the Trust and the Company, relating to the Trust, dated the Time of
Delivery, to the effect set forth in Exhibit [  ] to the Pricing Agreement.

     (k)  Skadden, Arps, Slate, Meagher & Flom LLP, special tax counsel for the
Company and the Trust, shall have furnished to the Representatives their written
opinion, dated the Time of Delivery, in form and substance satisfactory to you,
to the effect that such firm confirms its opinion set forth in the Prospectus
under the caption ["Certain Federal Income Tax Consequences"].

     8.   (a)  The Company and the Trust jointly and severally will indemnify
and hold harmless each Underwriter against any losses, claims, damages or
liabilities, joint or several, to which such Underwriter may become subject,
under the Act or otherwise, insofar as such losses, claims, damages or
liabilities (or actions in respect thereof) arise out of or are based upon an
untrue statement or alleged untrue statement of a material fact contained in any
Preliminary Prospectus, any preliminary prospectus supplement, the Registration
Statement, the Prospectus as amended or supplemented and any other prospectus
relating to the Securities, or any amendment or supplement thereto, or arise out
of or are based upon the omission or alleged omission to state therein a
material fact required to be stated therein or necessary to make the statements
therein not misleading, and will reimburse each Underwriter for any legal or
other expenses reasonably incurred by such Underwriter in connection with
investigating or defending any such action or claim as such expenses are
incurred; provided, however, that the Company and the Trust shall not be liable
in any such case to the extent that any such loss, claim, damage or liability
arises out of or is based upon an untrue statement or alleged untrue statement
or omission or alleged omission made in any Preliminary Prospectus, any
preliminary prospectus supplement, the Registration Statement, the Prospectus as
amended or supplemented and any other prospectus relating to the Designated
Securities, or any such amendment or supplement in reliance upon and in
conformity with written information furnished to the Company or the Trust by any
Underwriter of Designated Securities through the Representatives expressly for
use in the Prospectus as amended or supplemented relating to such Designated
Securities.

     (b)  Each Underwriter will indemnify and hold harmless the Company and the
Trust against any losses, claims, damages or liabilities to which the Company or
the Trust may become subject, under the Act or otherwise, insofar as such
losses, claims, damages or liabilities (or actions in respect thereof) arise out
of or are based upon an untrue statement or alleged untrue statement of a
material fact contained in any Preliminary Prospectus, any preliminary
prospectus supplement, the Registration Statement, the Prospectus as amended or
supplemented and any other prospectus relating to the Designated Securities, or
any amendment or supplement thereto, or arise out of or are based upon the
omission or alleged omission to state therein a material fact required to be
stated therein or necessary to make the statements therein not misleading, in
each case to the extent, but only to the extent, that such untrue statement or
alleged untrue statement or omission or alleged omission was made in any
Preliminary Prospectus, any preliminary prospectus supplement, the Registration
Statement, the Prospectus as amended or supplemented and any other prospectus
relating to the Designated Securities, or any such amendment or supplement in
reliance upon and in conformity with written information furnished to the
Company or the Trust by such Underwriter through the Representatives expressly 
for use therein; and will reimburse the Company or the Trust

                                      10
<PAGE>
 
for any legal or other expenses reasonably incurred by the Company or the Trust
in connection with investigating or defending any such action or claim as such
expenses are incurred.

     (c)  Promptly after receipt by an indemnified party under subsection (a) or
(b) above of notice of the commencement of any action, such indemnified party
shall, if a claim in respect thereof is to be made against the indemnifying
party under such subsection, notify the indemnifying party in writing of the
commencement thereof; but the omission so to notify the indemnifying party shall
not relieve it from any liability which it may have to any indemnified party
otherwise than under such subsection.  In case any such action shall be brought
against any indemnified party and it shall notify the indemnifying party of the
commencement thereof, the indemnifying party shall be entitled to participate
therein and, to the extent that it shall wish, jointly with any other
indemnifying party similarly notified, to assume the defense thereof, with
counsel satisfactory to such indemnified party (who shall not, except with the
consent of the indemnified party, be counsel to the indemnifying party, which
consent shall not be unreasonably withheld), and, after notice from the
indemnifying party to such indemnified party of its election so to assume the
defense thereof, the indemnifying party shall not be liable to such indemnified
party under such subsection for any legal expenses of other counsel or any other
expenses, in each case subsequently incurred by such indemnified party, in
connection with the defense thereof other than reasonable costs of
investigation.  No indemnifying party shall, without the written consent of the
indemnified party, effect the settlement or compromise of, or consent to the
entry of any judgment with respect to, any pending or threatened action or claim
in respect of which indemnification or contribution may be sought hereunder
(whether or not the indemnified party is an actual or potential party to such
action or claim) unless such settlement, compromise or judgment (i) includes an
unconditional release of the indemnified party from all liability arising out of
such action or claim and (ii) does not include a statement as to or an admission
of fault, culpability or a failure to act, by or on behalf of any indemnified
party.

     (d)  If the indemnification provided for in this Section 8 is unavailable
to or insufficient to hold harmless an indemnified party under subsection (a) or
(b) above in respect of any losses, claims, damages or liabilities (or actions
in respect thereof) referred to therein, then each indemnifying party shall
contribute to the amount paid or payable by such indemnified party as a result
of such losses, claims, damages or liabilities (or actions in respect thereof)
in such proportion as is appropriate to reflect the relative benefits received
by the Company on the one hand and the Underwriters of the Designated Securities
on the other from the offering of the Designated Securities to which such loss,
claim, damage or liability (or action in respect thereof) relates. If, however,
the allocation provided by the immediately preceding sentence is not permitted
by applicable law or if the indemnified party failed to give the notice required
under subsection (c) above, then each indemnifying party shall contribute to
such amount paid or payable by such indemnified party in such proportion as is
appropriate to reflect not only such relative benefits but also the relative
fault of the Company and the Trust on the one hand and the Underwriters of the
Designated Securities on the other in connection with the statements or
omissions which resulted in such losses, claims, damages or liabilities (or
actions in respect thereof), as well as any other relevant equitable
considerations. The relative benefits received by the Company and the Trust on
the one hand and such Underwriters of the Designated Securities on the other
shall be deemed to be in the same proportion as the total net proceeds from such
offering (before deducting expenses) received by the Company and the
Trust bear to the total underwriting discounts and commissions received by such
Underwriters.  The relative fault shall be determined by reference to, among
other things, whether the untrue or alleged untrue statement of a material fact
or the omission or alleged omission to state a material fact relates 

                                      11
<PAGE>
 
to information supplied by the Company and the Trust on the one hand or such
Underwriters of the Designated Securities on the other and the parties' relative
intent, knowledge, access to information and opportunity to correct or prevent
such statement or omission. The Company, the Trust and the Underwriters agree
that it would not be just and equitable if contribution pursuant to this
subsection (d) were determined by pro rata allocation (even if the Underwriters
were treated as one entity for such purpose) or by any other method of
allocation which does not take account of the equitable considerations referred
to above in this subsection (d). The amount paid or payable by an indemnified
party as a result of the losses, claims, damages or liabilities (or actions in
respect thereof) referred to above in this subsection (d) shall be deemed to
include any legal or other expenses reasonably incurred by such indemnified
party in connection with investigating or defending any such action or claim.
Notwithstanding the provisions of this subsection (d), no Underwriter shall be
required to contribute any amount in excess of the amount by which the total
price at which the Designated Securities underwritten by it and distributed to
the public were offered to the public exceeds the amount of any damages which
such Underwriter has otherwise been required to pay by reason of such untrue or
alleged untrue statement or omission or alleged omission. No person guilty of
fraudulent misrepresentation (within the meaning of Section 11(f) of the Act)
shall be entitled to contribution from any person who was not guilty of such
fraudulent misrepresentation. The obligations of the Underwriters of Designated
Securities in this subsection (d) to contribute are several in proportion to
their respective underwriting obligations with respect to such Designated
Securities and not joint.

     (e)  The obligations of the Company and the Trust under this Section 8
shall be in addition to any liability which the Company and the Trust may
otherwise have and shall extend, upon the same terms and conditions, to each
person, if any, who controls any Underwriter within the meaning of the Act; and
the obligations of the Underwriters under this Section 8 shall be in addition to
any liability which the respective Underwriters may otherwise have and shall
extend, upon the same terms and conditions, to each officer and director of the
Company and the Trust and to each person, if any, who controls the Company and
the Trust within the meaning of the Act.

     9.   (a)  If any Underwriter shall default in its obligation to purchase
the Designated Securities which it has agreed to purchase under the Pricing
Agreement relating to such Designated Securities, the Representatives may in
their reasonable judgment arrange for themselves or another party or other
parties acceptable to the Company to purchase such Designated Securities on the
terms contained herein.  If within thirty-six hours after such default by any
Underwriter the Representatives do not arrange for the purchase of such
Designated Securities, then the Company shall be entitled to a further period of
thirty-six hours within which to procure another party or other parties
reasonably satisfactory to the Representatives to purchase such Designated
Securities on such terms.  In the event that, within the respective prescribed
period, the Representatives notify the Company that they have so arranged for
the purchase of such Designated Securities, or the Company notifies the
Representatives that it has so arranged for the purchase of such Designated
Securities, the Representatives or the Company shall have the right to postpone
the Time of Delivery for such Designated Securities for a period of not more
than seven days, in order to effect whatever changes may thereby be made
necessary in the Registration Statement or the Prospectus as amended or
supplemented, or in any other documents or arrangements, and the Company agrees
to file promptly any amendments or supplements to the Registration Statement or
the Prospectus which in the reasonable opinion of the Representatives may
thereby be made necessary.  The term "Underwriter" as used in this Agreement
shall include any person substituted under this Section with 

                                      12
<PAGE>
 
like effect as if such person had originally been a party to the Pricing
Agreement with respect to such Designated Securities.

     (b) If, after giving effect to any arrangements for the purchase of the
Designated Securities of a defaulting Underwriter or Underwriters by the
Representatives and the Company as provided in subsection (a) above, the
aggregate liquidation amount of such Designated Securities which remains
unpurchased does not exceed one-eleventh of the aggregate liquidation amount of
the Designated Securities, then the Company shall have the right to require each
non-defaulting Underwriter to purchase the liquidation amount of Designated
Securities which such Underwriter agreed to purchase under the Pricing Agreement
relating to such Designated Securities and, in addition, to require each non-
defaulting Underwriter to purchase its pro rata share (based on the liquidation
amount of Designated Securities which such Underwriter agreed to purchase under
such Pricing Agreement) of the Designated Securities of such defaulting
Underwriter or Underwriters for which such arrangements have not been made; but
nothing herein shall relieve a defaulting Underwriter from liability for its
default.

     (c) If, after giving effect to any arrangements for the purchase of the
Designated Securities of a defaulting Underwriter or Underwriters by the
Representatives and the Company as provided in subsection (a) above, the
aggregate liquidation amount of Designated Securities which remains unpurchased
exceeds one-eleventh of the aggregate liquidation amount of the Designated
Securities, as referred to in subsection (b) above, or if the Company shall not
exercise the right described in subsection (b) above to require non-defaulting
Underwriters to purchase Designated Securities of a defaulting Underwriter or
Underwriters, then the Pricing Agreement relating to such Designated Securities
shall thereupon terminate, without liability on the part of any non-defaulting
Underwriter or the Company, except for the expenses to be borne by the Company
and the Underwriters as provided in Section 6 hereof and the indemnity and
contribution agreements in Section 8 hereof; but nothing herein shall relieve a
defaulting Underwriter from liability for its default.

     10. The respective indemnities, agreements, representations, warranties
and other statements of the Company, the Trust and the several Underwriters, as
set forth in this Agreement or made by or on behalf of them, respectively,
pursuant to this Agreement, shall remain in full force and effect, regardless of
any investigation (or any statement as to the results thereof) made by or on
behalf of any Underwriter or any controlling person of any Underwriter, the
Company or the Trust, or any officer or director or controlling person of the
Company or the Trust, and shall survive delivery of and payment for the
Designated Securities.

     11. If any Pricing Agreement shall be terminated pursuant to Section 9
hereof, the Company and the Trust shall not then be under any liability to any
Underwriter with respect to the Designated Securities covered by such Pricing
Agreement except as provided in Sections 6 and 8 hereof; but, if for any other
reason Designated Securities are not delivered by or on behalf of the Company
and the Trust as provided herein, the Company or the Trust will reimburse the
Underwriters through the Representatives for all out-of-pocket expenses approved
in writing by the Representatives, including fees and disbursements of counsel,
reasonably incurred by the Underwriters in making preparations for the purchase,
sale and delivery of such Designated Securities, but the Company or the Trust
shall then be under no further liability to any Underwriter with respect to such
Designated Securities except as provided in Sections 6 and 8 hereof.

                                       13
<PAGE>
 
     12.  In all dealings hereunder, the Representatives of the Underwriters of
Designated Securities shall act on behalf of each of such Underwriters, and the
parties hereto shall be entitled to act and rely upon any statement, request,
notice or agreement on behalf of any Underwriter made or given by such
Representatives jointly or by such of the Representatives, if any, as may be
designated for such purpose in the Pricing Agreement.

     All statements, requests, notices and agreements hereunder shall be in
writing, and if to the Underwriters shall be delivered or sent by mail, telex or
facsimile transmission to the address of the Representatives as set forth in the
Pricing Agreement; and if to the Company or the Trust shall be delivered or sent
by mail, telex or facsimile transmission to the address of the Company set forth
in the Registration Statement: Attention: Treasurer; provided, however, that any
notice to an Underwriter pursuant to Section 8(c) hereof shall be delivered or
sent by mail, telex or facsimile transmission to such Underwriter at its address
set forth in its Underwriters' Questionnaire, or telex constituting such
Questionnaire, which address will be supplied to the Company by the
Representatives upon request.  Any such statements, requests, notices or
agreements shall take effect upon receipt thereof.

     13.  This Agreement and each Pricing Agreement shall be binding upon, and
inure solely to the benefit of, the Underwriters, the Company, the Trust and, to
the extent provided in Sections 8 and 10 hereof, the officers and directors of
the Company and the Trust and each person who controls the Company, the Trust or
any Underwriter, and their respective heirs, executors, administrators,
successors and assigns, and no other person shall acquire or have any right
under or by virtue of this Agreement or any such Pricing Agreement. No purchaser
of any of the Designated Securities from any Underwriter shall be deemed a
successor or assign by reason merely of such purchase.

     14.  Time shall be of the essence of each Pricing Agreement.  As used
herein, "business day" shall mean any day when the Commission's office in
Washington, D.C. is open for business.

     15.  THIS AGREEMENT AND EACH PRICING AGREEMENT SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

     16.  This Agreement and each Pricing Agreement may be executed by any one
or more of the parties hereto and thereto in any number of counterparts, each of
which shall be deemed to be an original, but all such respective counterparts
shall together constitute one and the same instrument.

                                       14
<PAGE>
 
     IF THE FOREGOING IS IN ACCORDANCE WITH YOUR UNDERSTANDING, PLEASE SIGN AND
RETURN TO US EIGHT COUNTERPARTS HEREOF.

                                 Very truly yours,

                                 Aluminum Company of America

                                 By:............................
                                   Name:
                                   Title:


                                 Alcoa Trust I

                                 By: Aluminum Company of America,
                                     as Depositor


                                 By:............................

                                 Name:
                                 Title:


Accepted as of the date hereof:

[underwriters]


BY: ................................

                                       15
<PAGE>
 
                                                                         ANNEX I

                               PRICING AGREEMENT
                               -----------------



[NAMES OF CO-REPRESENTATIVE(S),]
 As Representatives of the several
   Underwriters named in Schedule I hereto,

[Address]

                                                             ............., 19..

Ladies and Gentlemen:

     Aluminum Company of America, a Pennsylvania corporation as depositor of the
Trust (as defined herein) and as guarantor (the "Company") and Alcoa Trust I, a
statutory business trust created under the Business Trust Act of the State of
Delaware (the "Trust"), propose, subject to the terms and conditions stated
herein and in the Underwriting Agreement, dated . . . . . . . . . . . ., 19 . .
(the "Underwriting Agreement"), among the Company and the Trust on the one hand
and [names of Co-Representatives named therein] on the other hand, to issue and
sell to the Underwriters named in Schedule I hereto (the "Underwriters") the
Securities specified in Schedule II hereto (the "Designated Securities").  Each
of the provisions of the Underwriting Agreement is incorporated herein by
reference in its entirety, and shall be deemed to be a part of this Agreement to
the same extent as if such provisions had been set forth in full herein; and
each of the representations and warranties set forth therein shall be deemed to
have been made at and as of the date of this Pricing Agreement, except that each
representation and warranty which refers to the Prospectus in Section 2 of the
Underwriting Agreement shall be deemed to be a representation or warranty as of
the date of the Underwriting Agreement in relation to the Prospectus (as therein
defined), and also a representation and warranty as of the date of this Pricing
Agreement in relation to the Prospectus as amended or supplemented relating to
the Designated Securities which are the subject of this Pricing Agreement.  Each
reference to the Representatives herein and in the provisions of the
Underwriting Agreement so incorporated by reference shall be deemed to refer to
you.  Unless otherwise defined herein, terms defined in the Underwriting
Agreement are used herein as therein defined.  The Representatives designated to
act on behalf of the Representatives and on behalf of each of the Underwriters
of the Designated Securities pursuant to Section 12 of the Underwriting
Agreement and the address of the Representatives referred to in such Section 12
are set forth at the end of Schedule II hereto.

     An amendment to the Registration Statement, or a supplement to the
Prospectus, as the case may be, relating to the Designated Securities, in the
form heretofore delivered to you is now proposed to be filed with the
Commission.

     Subject to the terms and conditions set forth herein and in the
Underwriting Agreement incorporated herein by reference, the Trust agrees to
issue and sell to each of the Underwriters, and each of the Underwriters agrees,
severally and not jointly, to purchase from the Trust, at the time 

                                       16
<PAGE>
 
and place and at the purchase price to the Underwriters set forth in Schedule II
hereto, the liquidation amount of Designated Securities set forth opposite the
name of such Underwriter in Schedule I hereto.

     If the foregoing is in accordance with your understanding, please sign and
return to us [                   ] counterparts hereof, and upon acceptance 
hereof by you, on behalf of each of the Underwriters, this letter and such
acceptance hereof, including the provisions of the Underwriting Agreement
incorporated herein by reference, shall constitute a binding agreement among
each of the Underwriters, the Trust and the Company. It is understood that your
acceptance of this letter on behalf of each of the Underwriters is or will be
pursuant to the authority set forth in a form of Agreement among Underwriters,
the form of which shall be submitted to the Company for examination upon
request, but without warranty on the part of the Representatives as to the
authority of the signers thereof.

                                    Very truly yours,

                                    Aluminum Company of America


                                    By:........................
                                       Name:
                                       Title:

                                    Alcoa Trust I


                                    By:........................
                                       Name:
                                       Title:


Accepted as of the date hereof:

[NAME(S) OF CO-REPRESENTATIVE(S)]

BY:.................................



          On behalf of each of the Underwriters

                                       2
<PAGE>
 
                                  SCHEDULE I

<TABLE> 
<CAPTION> 
                                                         LIQUIDATION    
                                                         AMOUNT OF      
                                                         DESIGNATED     
                                                         SECURITIES     
                                                           TO BE          
                    UNDERWRITER                          PURCHASED      
                    -----------                          ---------
<S>                                                      <C>                    
 ......................................................   $              
[NAME(S) OF CO-REPRESENTATIVE(S)].....................
[NAMES OF OTHER UNDERWRITERS].........................
                                                                        




                                                          ------              
     Total ...........................................   $  
</TABLE>                                                  ======              

                                       3
<PAGE>
 
                                  SCHEDULE II

TITLE OF DESIGNATED SECURITIES:

     [  %] [Floating Rate] [Convertible] Preferred Securities
     (liquidation amount $50 per Preferred Security)

AGGREGATE LIQUIDATION AMOUNT:

     [$]

PRICE TO PUBLIC:

     % of the liquidation amount of the Designated Securities, plus accrued
     interest[, if any,] from         to                     [and accrued
     amortization[, if any,] from                 to           ]

PURCHASE PRICE BY UNDERWRITERS:

     % of the liquidation amount of the Designated Securities, plus accrued
     interest from
            to          [and accrued amortization[, if any,] from
     to                    ]

FORM OF DESIGNATED SECURITIES:

     [Definitive form to be made available for checking and packaging at least
     twenty-four hours prior to the Time of Delivery at the office of [The
     Depository Trust Company or its designated custodian] [the
     Representatives]]

     [Book-entry only form represented by one or more global securities
     deposited with The Depository Trust Company ("DTC") or its designated
     custodian, to be made available for checking by the Representatives at
     least twenty-four hours prior to the Time of Delivery at the office of
     DTC.]

SPECIFIED FUNDS FOR PAYMENT OF PURCHASE PRICE:

     Federal (same day) funds

TIME OF DELIVERY:

     a.m. (New York City time),                      , 19

CUMULATIVE CASH DISTRIBUTION RATE:

     [   %] [Zero Coupon] [See Floating Rate Provisions]

                                       4
<PAGE>
 
DISTRIBUTION DATES:

     [months and dates, commencing ....................., 19..]

REDEMPTION PROVISIONS:

     [Describe]

EXTENSION PERIOD PROVISIONS:

[Describe]

     [If Designated Securities are floating rate debt securities, insert--

FLOATING RATE PROVISIONS:

     Initial annual cash distribution rate will be       % through          [and
     thereafter will be adjusted [monthly] [on each          ,         ,
     and       ] [to an annual rate of      % above the average rate for
     -year [month][securities][certificates of deposit] issued by
            and        [insert names of banks].] [and the annual cash
     distribution rate [thereafter] [from          through         ] will be the
     interest yield equivalent of the weekly average per annum market discount
     rate for             -month Treasury bills plus         % of Interest
     Differential (the excess, if any, of (i) the then current weekly average
     per annum secondary market yield for         -month certificates of deposit
     over (ii) the then current interest yield equivalent of the weekly average
     per annum market discount rate for         -month Treasury bills); [from
     and thereafter the rate will be the then current interest yield equivalent
     plus  % of Interest Differential].]

CONVERSION PROVISIONS

CLOSING LOCATION FOR DELIVERY OF DESIGNATED SECURITIES:


ADDITIONAL CLOSING CONDITIONS:



NAMES AND ADDRESSES OF REPRESENTATIVES:

     Designated Representatives:
     Address for Notices, etc.:

[OTHER TERMS:]

                                       5
<PAGE>
 
                                                                        ANNEX II

     Pursuant to Section 7(d) of the Underwriting Agreement, the accountants
shall furnish letters to the Underwriters to the effect that:

          (i)   They are independent certified public accountants with respect
     to the Company and its subsidiaries within the meaning of the Act and the
     applicable published rules and regulations thereunder;

          (ii)  In their opinion, the financial statements and any supplementary
     financial information and schedules audited (and, if applicable, financial
     forecasts and/or pro forma financial information) examined by them and
     included or incorporated by reference in the Registration Statement or the
     Prospectus comply as to form in all material respects with the applicable
     accounting requirements of the Act or the Exchange Act, as applicable, and
     the related published rules and regulations thereunder; and, if applicable,
     they have made a review in accordance with standards established by the
     American Institute of Certified Public Accountants of the consolidated
     interim financial statements, selected financial data, pro forma financial
     information, financial forecasts and/or condensed financial statements
     derived from audited financial statements of the Company for the periods
     specified in such letter, as indicated in their reports thereon, copies of
     which have been separately furnished to the representative or
     representatives of the Underwriters (the "Representatives") such term to
     include an Underwriter or Underwriters who act without any firm being
     designated as its or their representatives;

          (iii) They have made a review in accordance with standards
     established by the American Institute of Certified Public Accountants of
     the unaudited condensed consolidated statements of income, consolidated
     balance sheets and consolidated statements of cash flows included in the
     Prospectus and/or included in the Company's quarterly report on Form 10-Q
     incorporated by reference into the Prospectus as indicated in their reports
     thereon copies of which have been separately furnished to the
     Representatives; and on the basis of specified procedures including
     inquiries of officials of the Company who have responsibility for financial
     and accounting matters regarding whether the unaudited condensed
     consolidated financial statements referred to in paragraph (vi)(A)(i) below
     comply as to form in all material respects with the applicable accounting
     requirements of the Act and the Exchange Act and the related published
     rules and regulations, nothing came to their attention that caused them to
     believe that the unaudited condensed consolidated financial statements do
     not comply as to form in all material respects with the applicable
     accounting requirements of the Act and the Exchange Act and the related
     published rules and regulations;

          (iv)  The unaudited selected financial information with respect to the
     consolidated results of operations and financial position of the Company
     for the five most recent fiscal years included in the Prospectus and
     included or incorporated by reference in Item 6 of the Company's Annual
     Report on Form 10-K for the most recent fiscal year agrees with the
     corresponding amounts (after restatement where applicable) in the audited
     consolidated financial statements for five such fiscal years which were
     included or incorporated by reference in the Company's Annual Reports on
     Form 10-K for such fiscal years;
<PAGE>
 
          (v)  They have compared the information in the Prospectus under
     selected captions with the disclosure requirements of Regulation S-K and on
     the basis of limited procedures specified in such letter nothing came to
     their attention as a result of the foregoing procedures that caused them to
     believe that this information does not conform in all material respects
     with the disclosure requirements of Items 301, 302, 402 and 503(d),
     respectively, of Regulation S-K;

          (vi) On the basis of limited procedures, not constituting an
     examination in accordance with generally accepted auditing standards,
     consisting of a reading of the unaudited financial statements and other
     information referred to below, a reading of the latest available interim
     financial statements of the Company and its subsidiaries, inspection of the
     minute books of the Company and its subsidiaries since the date of the
     latest audited financial statements included or incorporated by reference
     in the Prospectus, inquiries of officials of the Company and its
     subsidiaries responsible for financial and accounting matters and such
     other inquiries and procedures as may be specified in such letter, nothing
     came to their attention that caused them to believe that:

               (A) (i) the unaudited condensed consolidated statements of
          income, consolidated balance sheets and consolidated statements of
          cash flows included in the Prospectus and/or included or incorporated
          by reference in the Company's Quarterly Reports on Form 10-Q
          incorporated by reference in the Prospectus do not comply as to form
          in all material respects with the applicable accounting requirements
          of the Exchange Act and the related published rules and regulations,
          or (ii) to the extent not covered in their reports filed as part of
          the Company's Quarterly Reports on Form 10-Q, any material
          modifications should be made to the unaudited condensed consolidated
          statements of income, consolidated balance sheets and consolidated
          statements of cash flows included in the Prospectus or included in the
          Company's Quarterly Reports on Form 10-Q incorporated by reference in
          the Prospectus for them to be in conformity with generally accepted
          accounting principles;

               (B) any other unaudited income statement data and balance sheet
          items included in the Prospectus do not agree with the corresponding
          items in the unaudited consolidated financial statements from which
          such data and items were derived, and any such unaudited data and
          items were not determined on a basis substantially consistent with the
          basis for the corresponding amounts in the audited consolidated
          financial statements included or incorporated by reference in the
          Company's Annual Report on Form 10-K for the most recent fiscal year;

               (C) the unaudited financial statements which were not included in
          the Prospectus but from which were derived the unaudited condensed
          financial statements referred to in clause (A) and any unaudited
          income statement data and balance sheet items included in the
          Prospectus and referred to in Clause (B) were not determined on a
          basis substantially consistent with the basis for the audited
          financial statements included or incorporated by reference in the
          Company's Annual Report on Form 10-K for the most recent fiscal year;

               (D) any unaudited pro forma consolidated condensed financial
          statements included or incorporated by reference in the Prospectus do
          not comply as to form in 

                                       2
<PAGE>
 
          all material respects with the applicable accounting requirements of
          the Act and the published rules and regulations thereunder or the pro
          forma adjustments have not been properly applied to the historical
          amounts in the compilation of those statements;

               (E) as of a specified date not more than five days prior to the
          date of such letter, there have been any changes in the consolidated
          capital stock (other than issuances of capital stock upon exercise of
          options and stock appreciation rights, upon earn-outs of performance
          shares and upon conversions of convertible securities, in each case
          which were outstanding on the date of the latest balance sheet
          included or incorporated by reference in the Prospectus) or any
          increase in the consolidated long-term debt of the Company and its
          subsidiaries, or any decreases in consolidated net current assets or
          stockholders' equity or other items specified by the Representatives,
          or any increases in any items specified by the Representatives, in
          each case as compared with amounts shown in the latest balance sheet
          included or incorporated by reference in the Prospectus, except in
          each case for changes, increases or decreases which the Prospectus
          discloses have occurred or may occur or which are described in such
          letter; and


               (F) for the period from the date of the latest financial
          statements included or incorporated by reference in the Prospectus to
          the specified date referred to in Clause (E) there were any decreases
          in consolidated net revenues or operating profit or the total or per
          share amounts of consolidated net income or other items specified by
          the Representatives, or any increases in any items specified by the
          Representatives, in each case as compared with the comparable period
          of the preceding year and with any other period of corresponding
          length specified by the Representatives, except in each case for
          increases or decreases which the Prospectus discloses have occurred or
          may occur or which are described in such letter; and

          (vii) In addition to the audit referred to in their report(s)
     included or incorporated by reference in the Prospectus and the limited
     procedures, inspection of minute books, inquiries and other procedures
     referred to in paragraphs (iii) and (vi) above, they have carried out
     certain specified procedures, not constituting an audit in accordance with
     generally accepted auditing standards, with respect to certain amounts,
     percentages and financial information specified by the Representatives
     which are derived from the general accounting records of the Company and
     its subsidiaries, which appear in the Prospectus (excluding documents
     incorporated by reference), or in Part II of, or in exhibits and schedules
     to, the Registration Statement specified by the Representatives or in
     documents incorporated by reference in the Prospectus specified by the
     Representatives, and have compared certain of such amounts, percentages and
     financial information with the accounting records of the Company and its
     subsidiaries and have found them to be in agreement.

     All references in this Annex II to the Prospectus shall be deemed to refer
to the Prospectus (including the documents incorporated by reference therein) as
defined in the Underwriting Agreement as of the date of the letter delivered on
the date of the Pricing Agreement for purposes of such letter and to the
Prospectus as amended or supplemented (including the documents 

                                       3
<PAGE>
 
incorporated by reference therein) in relation to the applicable Designated
Securities for purposes of the letter delivered at the Time of Delivery for such
Designated Securities.

                                       4

<PAGE>
 
                                                                    EXHIBIT 4(K)
 
                             CERTIFICATE OF TRUST

          The undersigned, the trustees of Alcoa Trust I, desiring to form a
business trust pursuant to Delaware Business Trust Act, 12 Del. C. (S) 3810 et
                                                           ---- --          --
seq., hereby certify as follows:
- ----                            

          (a)  The name of the business trust being formed hereby (the "Trust")
               is "Alcoa Trust I."

          (b)  The name and business address of the trustee of the Trust which
               has its principal place of business in the State of Delaware is
               as follows:

               Chase Manhattan Bank Delaware
               1201 Market St.
               Wilmington, DE 19801
               Attention: Trust Department

          (c)  This Certificate of Trust shall be effective as of the date of
               filing.

Dated:  July 10, 1998
                                /S/ Cynthia E. Holloway
                               -----------------------------------
                               CYNTHIA E. HOLLOWAY
                               Regular Trustee


                                /S/ Robert G. Wennemer
                               ----------------------------------
                               ROBERT G. WENNEMER
                               Regular Trustee


                                /S/ Richard B. Kelson
                               ----------------------------------
                               RICHARD B. KELSON
                               Regular Trustee


                               CHASE MANHATTAN BANK DELAWARE, as
                                Delaware Trustee


                               By: /S/ Denis Kelly
                                  -------------------------------
                                  Denis Kelly
                                  Trust Officer
 

                               THE CHASE MANHATTAN BANK, as
                                Institutional Trustee

                               By: /S/ Joanne Adamis
                                  -------------------------------
                                  Joanne Adamis
                                  Assistant Vice President


<PAGE>
 
                                                                    EXHIBIT 4(L)
 
                       ================================


                             DECLARATION OF TRUST

                                 Alcoa Trust I

                           Dated as of July 10, 1998


                       ================================
<PAGE>
 
                               TABLE OF CONTENTS

<TABLE> 
<CAPTION> 
                                                                        Page
                                                                        ----

                                   ARTICLE I
                                  DEFINITIONS
<S>                                                                     <C>    
SECTION 1.1  Definitions..................................................  1
             -----------

                                  ARTICLE II
                                 ORGANIZATION

SECTION 2.1  Name.........................................................  4
             ----
SECTION 2.2  Office.......................................................  4
             ------
SECTION 2.3  Purpose......................................................  4
             -------
SECTION 2.4  Authority....................................................  5
             ---------
SECTION 2.5  Title to Property of the Trust...............................  5
             ------------------------------
SECTION 2.6  Powers of the Trustees.......................................  5
             ----------------------
SECTION 2.7  Filing of Certificate of Trust...............................  6
             ------------------------------
SECTION 2.8  Duration of Trust............................................  7
             -----------------
SECTION 2.9  Responsibilities of the Sponsor..............................  7
             -------------------------------
SECTION 2.10 Declaration Binding on Securities Holders....................  7
             -----------------------------------------

                                  ARTICLE III
                                   TRUSTEES

SECTION 3.1  Trustees.....................................................  8
             --------
SECTION 3.2  Regular Trustees.............................................  8
             ----------------
SECTION 3.3  Delaware Trustee.............................................  8
             ----------------
SECTION 3.4  Institutional Trustee........................................  9
             ---------------------
SECTION 3.5  Not Responsible for Recitals or Sufficiency 
              of Declaration..............................................  9

                                  ARTICLE IV
                          LIMITATION OF LIABILITY OF
                   HOLDERS OF SECURITIES, TRUSTEES OR OTHERS

SECTION 4.1  Exculpation..................................................  9
             -----------
SECTION 4.2  Fiduciary Duty............................................... 10
             --------------
SECTION 4.3  Indemnification.............................................. 11
             ---------------
SECTION 4.4  Outside Businesses........................................... 14
             ------------------

                                   ARTICLE V
                    AMENDMENTS, TERMINATION, MISCELLANEOUS

SECTION 5.1  Amendments................................................... 15
             ----------
SECTION 5.2  Termination of Trust......................................... 15
             --------------------
SECTION 5.3  Governing Law................................................ 16
             -------------
SECTION 5.4  Headings..................................................... 16
             --------
SECTION 5.5  Successors and Assigns....................................... 16
             ----------------------
</TABLE> 
    
                                       i
<PAGE>
 
<TABLE> 
<S>                                                                        <C> 
SECTION 5.6  Partial Enforceability....................................... 16
             ----------------------
SECTION 5.7  Counterparts................................................. 16
             ------------
</TABLE> 
                                      ii
<PAGE>
 
                             DECLARATION OF TRUST
                                      OF
                                 Alcoa Trust I

                                 July 10, 1998


          DECLARATION OF TRUST ("Declaration") dated and effective as of July
10, 1998 by the Trustees (as defined herein), the Sponsor (as defined herein),
and by the holders, from time to time, of undivided beneficial interests in the
Trust to be issued pursuant to this Declaration;

          WHEREAS, the Trustees and the Sponsor desire to establish a trust (the
"Trust") pursuant to the Delaware Business Trust Act for the purpose of issuing
and selling certain securities representing undivided beneficial interests in
the assets of the Trust and investing the proceeds thereof in certain Debentures
of the Debenture Issuer (as defined herein);

          NOW, THEREFORE, it being the intention of the parties hereto that the
Trust constitute a business trust under the Business Trust Act and that this
Declaration constitute the governing instrument of such business trust, the
Trustees declare that all assets contributed to the Trust will be held in trust
for the exclusive benefit of the holders, from time to time, of the securities
representing undivided beneficial interests in the assets of the Trust issued
hereunder, subject to the provisions of this Declaration.


                                   ARTICLE I
                                  DEFINITIONS

 SECTION 1.1   Definitions.
               ----------- 

           Unless the context otherwise requires:

     (a)   Capitalized terms used in this Declaration 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 Declaration has the same meaning
           throughout;

     (c)   all references to "the Declaration" or "this Declaration" are to
           this Declaration of Trust as modified, supplemented or amended from
           time to time;
<PAGE>
 
     (d)   all references in this Declaration to Articles and Sections are to
           Articles and Sections of this Declaration unless otherwise specified;
           and

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

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

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

           "Business Trust Act" means Chapter 38 of Title 12 of the Delaware
            ------------------                                              
Code, 12 Del. C. (S) 3801 et seq., as it may be amended from time to time, or
      ------- --          -- ---                                             
any successor legislation.

           "Commission" means the Securities and Exchange Commission.
            ----------                                                

           "Common Securities" means securities representing undivided
            -----------------
beneficial ownership interests in the assets of the Trust with such terms as may
be set out in any amendment to this Declaration.

           "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 Securities.

           "Debenture Issuer" means the Parent in its capacity as the issuer of
            ----------------                                                   
the Debentures under the Indenture.

           "Debentures" means the series of Debentures to be issued by the
            ----------                                                    
Debenture Issuer and acquired by the Trust.

           "Debenture Trustee" means the trustee under the Indenture until a
            -----------------                                                
successor is appointed thereunder, and thereafter means such successor trustee.

           "Delaware Trustee" has the meaning set forth in Section 3.1.
            ----------------                                           

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

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

                                       2
<PAGE>
 
           "Indemnified Person" means a Parent Indemnified Person or a Fiduciary
            ------------------                                                  
Indemnified Person.

           "Indenture" means the indenture to be entered into between the Parent
            ---------                                                           
and the Debenture Trustee and any indenture supplemental thereto pursuant to
which the Debentures are to be issued.

           "Institutional Trustee" has the meaning set forth in Section 3.4.
            ---------------------                                           

           "Parent" means Aluminum Company of America, a Pennsylvania         
            ------                                                    
corporation or any successor entity in a merger.

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

           "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.

           "Preferred Securities" means securities representing undivided
            --------------------                                         
beneficial ownership interests in the assets of the Trust with such terms as may
be set out in any amendment to this Declaration.
 
           "Regular Trustee" means any Trustee other than the Delaware Trustee
            ---------------                                                   
and the Institutional Trustee (as hereinafter defined).

           "Securities" means the Common Securities and the Preferred 
            ----------           
Securities.

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

           "Sponsor" means the Parent in its capacity as sponsor of the Trust.
            -------                                                           

           "Trustee" or "Trustees" means each Person who has signed this
            -------      --------                                       
Declaration as a trustee, so long as such Person shall continue in office 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.

                                       3
<PAGE>
 
                                  ARTICLE II
                                 ORGANIZATION

SECTION 2.1    Name.
               ---- 

          The Trust created by this Declaration is named "Alcoa Trust I." The
Trust's activities may be conducted under the name of the Trust or any other
name deemed advisable by the Regular Trustees.

SECTION 2.2    Office.
               ------ 

          The address of the principal office of the Trust is c/o Aluminum
Company of America, 425 Sixth Avenue, Alcoa Building, Pittsburgh, Pennsylvania
15219-1850. (Effective August 14, 1998, the address of the principal office of
the Trust will be c/o Aluminum Company of America, 201 Isabella Street,
Pittsburgh, Pennsylvania 15212-5858.) At any time, the Regular Trustees may
designate another principal office.

SECTION 2.3    Purpose.
               ------- 

          It is the intention of the parties hereto that the Trust created
hereby constitute a business trust under the Business Trust Act, and that this
Declaration constitute the governing instrument of the Trust. The Trustees are
hereby authorized and directed to execute and file a certificate of trust in the
office of the Secretary of State of the State of Delaware in the form attached
hereto. The Trust is hereby established by the Sponsor and the Trustees for the
purposes of (i) issuing Preferred Securities and investing the proceeds thereof
in Debentures, (ii) issuing and selling Common Securities to the Sponsor in
exchange for cash and investing the proceeds thereof in additional Debentures
and (iii) engaging in such other activities as are necessary, convenient or
incidental thereto. The Trust shall not borrow money, issue debt or reinvest
proceeds derived from investments, pledge any of its assets, or otherwise
undertake (or permit to be undertaken) any activity that would cause the Trust
not to be classified for United States federal income tax purposes as a grantor
trust.

          Concurrent with the first issuance of any Securities by the Trust, the
Sponsor and the Trustees intend to enter into an amended and restated
Declaration of Trust or Trust agreement, satisfactory to each such party and
substantially in the form included as an exhibit to the Securities Act
Registration Statement referred to below at the time such registration statement
becomes effective under the

                                       4
<PAGE>
 
Securities Act, to provide for the contemplated operation of the Trust created
hereby and the issuance of the Preferred Securities and the Common Securities
referred to therein. Prior to the execution and delivery of such amended and
restated Declaration of Trust or Trust agreement, the Trustees shall not have
any duty or obligation hereunder or with respect to the trust estate, except as
otherwise required by applicable law or, in the case of the Regular Trustees, as
may be necessary to obtain, prior to such execution and delivery, any licenses,
consents or approvals required by applicable law or otherwise.

SECTION 2.4    Authority.
               --------- 

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

SECTION 2.5    Title to Property of the Trust.
               ------------------------------ 

          Legal title to all assets of the Trust shall be vested in the Trust.

SECTION 2.6    Powers of the Trustees.
               ---------------------- 

          The Regular Trustees shall have the exclusive power and authority to
cause the Trust to engage in the following activities:

          (a)  to issue and sell the Preferred Securities and the Common
     Securities in accordance with this Declaration; provided, however, that the
                                                     --------  -------          
     Trust may issue no more than one series of Preferred Securities and no more
     than one series of Common Securities, and, provided further, that there
                                                -------- -------            
     shall be no interests in the Trust other than the Securities and the
     issuance of the Securities shall be limited to a one-time, simultaneous
     issuance of both Preferred Securities and Common Securities;

          (b)  in connection with the issue and sale of the Preferred
     Securities, at the direction of the Sponsor, to:

               (i)  execute and file with the Commission a registration
          statement on Form S-3 prepared by the Sponsor (the "Registration
          Statement"), including any amendments thereto in relation to the
          registration of the Preferred Securities under the Securities Act;

                                       5
<PAGE>
 
              (ii)  execute and file any documents prepared by the Sponsor, or
          take any acts as determined by the Sponsor to be necessary in order to
          qualify or register all or part of the Preferred Securities in any
          State in which the Sponsor has determined to qualify or register such
          Preferred Securities for sale;

             (iii)  execute and file on behalf of the Trust, with the New York
          Stock Exchange or any other national stock exchange or the Nasdaq
          National Market for listing or quotation upon notice of issuance of
          any Preferred Securities a listing application and all other
          applications, statements, certificates, agreements and other
          instruments as shall be necessary or desirable to cause the Preferred
          Securities to be listed on such exchange or national market, as the
          case may be;

               (iv) execute and file with the Commission a registration
          statement on Form 8-A, including any amendments thereto, prepared by
          the Sponsor relating to the registration of the Preferred Securities
          under Section 12(b) or 12(g) of the Exchange Act, if the Sponsor in
          its sole discretion determines that such a filing is necessary or
          appropriate; and

               (v)  negotiate the terms of, and execute and enter into, on
          behalf of the Trust, an underwriting agreement and pricing agreement
          providing for the sale of the Preferred Securities substantially in
          the form included as an exhibit to the Registration Statement at the
          time it becomes effective under the Securities Act;

          (c)  to employ or otherwise engage employees and agents (who may be
     designated as officers with titles) and managers, contractors, advisors and
     consultants and provide for reasonable compensation for such services;

          (d)  to incur expenses that are necessary or incidental to carry out
     any of the purposes of this Declaration; and

          (e)  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.

SECTION 2.7    Filing of Certificate of Trust.
               ------------------------------ 

          On or after the date of execution of this Declaration, the Trustees
shall cause the filing of the Certificate of Trust for the Trust in the form
attached hereto as Exhibit A with the Secretary of State of the State of
Delaware.

                                       6
<PAGE>
 
SECTION 2.8    Duration of Trust.
               ----------------- 

          The Trust, absent termination pursuant to the provisions of Section
5.2, shall have existence for forty (40) years from the date hereof.

SECTION 2.9    Responsibilities of the Sponsor.
               ------------------------------- 

          In connection with the issue and sale of the Preferred Securities, the
Sponsor shall have the exclusive right and responsibility to engage in the
following activities:

          (a)  to prepare for filing by the Trust with the Commission a
     registration statement on Form S-3 in relation to the Preferred Securities,
     including any amendments thereto;

          (b)  to determine the States in which to take appropriate action to
     qualify or register for sale all or part of the Preferred Securities and to
     do any and all such acts, other than actions which must be taken by the
     Trust, and advise the Trust of actions it must take, and prepare for
     execution and filing of any documents to be executed and filed by the
     Trust, as the Sponsor deems necessary or advisable in order to comply with
     the applicable laws of any such States;

          (c)  at the sole discretion of the Sponsor, to prepare for filing by
     the Trust of an application to the New York Stock Exchange or any other
     national stock exchange or the Nasdaq National Market for listing or
     quotation upon notice of issuance of any Preferred Securities;

          (d)  to prepare for filing by the Trust with the Commission a
     registration statement on Form 8-A relating to the registration of the
     class of Preferred Securities under Section 12(b) or 12(g) of the Exchange
     Act, including any amendments thereto, if the Sponsor in its sole
     discretion determines that such a filing is necessary or appropriate; and

          (e)  to negotiate the terms of an underwriting agreement and pricing
     agreement providing for the sale of the Preferred Securities.

SECTION 2.10   Declaration Binding on Securities Holders.
               ----------------------------------------- 

          Every Person by virtue of having become a holder of a Security or any
interest therein in accordance with the terms of this Declaration, shall be
deemed to have expressly assented and agreed to the terms of, and shall be bound
by, this Declaration.

                                       7
<PAGE>
 
                                  ARTICLE III
                                   TRUSTEES

SECTION 3.1    Trustees.
               -------- 

          The number of Trustees initially shall be five (5), and thereafter the
number of Trustees shall be such number as shall be fixed from time to time by a
written instrument signed by the Sponsor. The Sponsor is entitled to appoint or
remove without cause any Trustee at any time; provided, however that the number
                                              --------  -------                
of Trustees shall in no event be less than two (2); provided  further that one
                                                    -------- --------         
Trustee, in the case of a natural person, shall be a person who is a resident of
the State of Delaware or that, if not a natural person, is an entity that has
its principal place of business in the State of Delaware (the "Delaware
Trustee"); provided further that there shall be at least one trustee who is an
employee or officer of, or is affiliated with the Parent (a "Regular Trustee").

SECTION 3.2    Regular Trustees.
               ---------------- 

          The initial Regular Trustees shall be:

                     Cynthia E. Holloway
                     Robert G. Wennemer
                     Richard B. Kelson

          (a)  Except as expressly set forth in this Declaration, any power of
the Regular Trustees may be exercised by, or with the consent of, any one such
Regular Trustee.

          (b)  Unless otherwise determined by the Regular Trustees, and except
as otherwise required by the Business Trust Act, any Regular Trustee is
authorized to execute on behalf of the Trust any documents that the Regular
Trustees have the power and authority to cause the Trust to execute pursuant to
Section 2.6; and

          (c)  a Regular Trustee may, by power of attorney consistent with
applicable law, delegate to any other natural person over the age of 21 his or
her power for the purposes of signing any documents that the Regular Trustees
have power and authority to cause the Trust to execute pursuant to Section 2.6.

                                       8
<PAGE>
 
SECTION 3.3    Delaware Trustee.
               ---------------- 

          The initial Delaware Trustee shall be:

               Chase Manhattan Bank Delaware
               1201 Market St.
               Wilmington, DE 19801
               Attention:  Corporate Trust Department

          Notwithstanding any other provision of this Declaration, the Delaware
Trustee shall not be entitled to exercise any of the powers, nor shall the
Delaware Trustee have any of the duties and responsibilities of the Trustees
(except as required by the Business Trust Act) described in this Declaration.
The Delaware Trustee shall be a Trustee for the sole and limited purpose of
fulfilling the requirements of Section 3807 of the Business Trust Act.
Notwithstanding anything herein to the contrary, the Delaware Trustee shall not
be liable for the acts or omissions to act of the Trust or of the Regular
Trustees except such acts as the Delaware Trustee is expressly obligated or
authorized to undertake under this Declaration or the Business Trust Act and
except for the negligence or willful misconduct of the Delaware Trustee. The 
Delaware Trustee may resign as a Trustee of the Trust by giving not less than 30
days written notice of resignation to any Regular Trustee; provided, however, 
that no such resignation of the Delaware Trustee shall be effective until a 
successor Delaware Trustee has been appointed and has accepted such appointment 
by instrument executed by such successor Delaware Trustee and delivered to the 
Trust, the Sponsor and the resigning Delaware Trustee.

SECTION 3.4    Institutional Trustee.
               --------------------- 

          The Sponsor hereby appoints The Chase Manhattan Bank as the trustee
meeting the requirements of an eligible trustee under the Trust Indenture Act of
1939, as amended (the "Institutional Trustee").

          Notwithstanding any other provision of this Declaration, the
Institutional Trustee shall not be entitled to exercise any of the powers, nor
shall the Institutional Trustee have any of the duties and responsibilities of
the Trustees (except as required by the Business Trust Act) described in this
Declaration. Notwithstanding anything herein to the contrary, the Institutional
Trustee shall not be liable for the acts or omissions to act of the Trust or of
the Regular Trustees except such acts as the Institutional Trustee is expressly
obligated or authorized to undertake under this Declaration or the Business
Trust Act and except for the negligence or willful misconduct of the
Institutional Trustee. The Institutional Trustee may resign as a Trustee of the 
Trust by giving not less than 30 days written notice of resignation to any 
Regular Trustee; provided, however that no such resignation of the Institutional
Trustee shall be effective until a successor Institutional Trustee has been 
appointed and has accepted such appointment by instrument executed by such 
successor Institutional Trustee and delivered to the Trust, the Sponsor and the 
resigning Institutional Trustee.

SECTION 3.5    Not Responsible for Recitals or Sufficiency of Declaration.
               ---------------------------------------------------------- 

          The recitals contained in this Declaration shall be taken as the
statements of the Sponsor, and the Trustees do not assume any responsibility for
their correctness. The Trustees make no representations as to the value or
condition of the property of the Trust or any part thereof. The Trustees make no

                                       9
<PAGE>
 
representations as to the validity or sufficiency of this Declaration.


                                  ARTICLE IV
                          LIMITATION OF LIABILITY OF
                   HOLDERS OF SECURITIES, TRUSTEES OR OTHERS

SECTION 4.1    Exculpation.
               ----------- 

          (a)  No Indemnified Person shall be liable, responsible or accountable
in damages or otherwise to the Trust or any Covered Person for any loss, damage
or claim incurred by reason of any act or omission performed or omitted by such
Indemnified Person in good faith on behalf of the Trust and in a manner such
Indemnified Person reasonably believed to be within the scope of the authority
conferred on such Indemnified Person by this Declaration or by law, except that
an Indemnified Person shall be liable for any such loss, damage or claim
incurred by reason of such Indemnified Person's negligence or willful misconduct
with respect to such acts or omissions; and

          (b)  an Indemnified Person shall be fully protected in relying in good
faith upon the records of the Trust and upon such information, opinions, reports
or statements presented to the Trust by any Person as to matters the Indemnified
Person reasonably believes are within such other Person's professional or expert
competence and who has been selected with reasonable care by or on behalf of the
Trust, including information, opinions, reports or statements as to the value
and amount of the assets, liabilities, profits, losses, or any other facts
pertinent to the existence and amount of assets from which distributions to
holders of Securities might properly be paid.

SECTION 4.2    Fiduciary Duty.
               -------------- 

          (a)  To the extent that, at law or in equity, an Indemnified Person
has duties (including fiduciary duties) and liabilities relating thereto to the
Trust or to any other Covered Person, an Indemnified Person acting under this
Declaration shall not be liable to the Trust or to any other Covered Person for
its good faith reliance on the provisions of this Declaration. The provisions of
this Declaration, to the extent that they restrict the duties and liabilities of
an Indemnified Person otherwise existing at law or in equity, are agreed by the
parties hereto to replace such other duties and liabilities of such Indemnified
Person;

          (b)  unless otherwise expressly provided herein:

                                      10
<PAGE>
 
               (i)  whenever a conflict of interest exists or arises between
          Covered Persons; or

               (ii) whenever this Declaration or any other agreement
          contemplated herein or therein provides that an Indemnified Person
          shall act in a manner that is, or provides terms that are, fair and
          reasonable to the Trust or any holder of Securities,

the Indemnified Person shall resolve such conflict of interest, take such action
or provide such terms, considering in each case the relative interest of each
party (including its own interest) to such conflict, agreement, transaction or
situation and the benefits and burdens relating to such interests, any customary
or accepted industry practices, and any applicable generally accepted accounting
practices or principles. In the absence of bad faith by the Indemnified Person,
the resolution, action or term so made, taken or provided by the Indemnified
Person shall not constitute a breach of this Declaration or any other agreement
contemplated herein or of any duty or obligation of the Indemnified Person at
law or in equity or otherwise; and

          (c)  whenever in this Declaration an Indemnified Person is permitted
or required to make a decision:

               (i)  in its "discretion" or under a grant of similar authority,
          the Indemnified Person shall be entitled to consider such interests
          and factors as it desires, including its own interests, and shall have
          no duty or obligation to give any consideration to any interest of or
          factors affecting the Trust or any other Person; or

               (ii) in its "good faith" or under another express standard, the
          Indemnified Person shall act under such express standard and shall not
          be subject to any other or different standard imposed by this
          Declaration or by applicable law.

SECTION 4.3    Indemnification.
               --------------- 

          (a)  (i)  The Sponsor shall indemnify, to the full extent permitted by
     law, any Parent Indemnified Person who was or is a party or is threatened
     to be made a party to any threatened, pending or contemplated action, suit
     or proceeding, whether civil, criminal, administrative or investigative
     (other than an action by or in the right of the Trust) by reason of the
     fact that he is or was a Parent Indemnified Person against expenses
     (including attorneys' fees), judgments, fines and amounts paid in
     settlement actually and reasonably incurred by him in connection with such
     action, suit or proceeding if he acted in good faith

                                      11
<PAGE>
 
     and in a manner he reasonably believed to be in or not opposed to the best
     interests of the Trust, and, with respect to any criminal action or
     proceeding, had no reasonable cause to believe his conduct was unlawful.
     The termination of any action, suit or proceeding by judgment, order, 
     settlement, conviction, or upon a plea of nolo contendere or its
     equivalent, shall not, of itself, create a presumption that the Parent
     Indemnified Person did not act in good faith and in a manner which he
     reasonably believed to be in or not opposed to the best interests of the
     Trust, and, with respect to any criminal action or proceeding, had
     reasonable cause to believe that his conduct was unlawful.

               (ii) The Sponsor shall indemnify, to the full extent permitted by
     law, any Parent Indemnified Person who was or is a party or is threatened
     to be made a party to any threatened, pending or contemplated action or
     suit by or in the right of the Trust to procure a judgment in its favor by
     reason of the fact that he is or was a Parent Indemnified Person against
     expenses (including attorneys' fees) actually and reasonably incurred by
     him in connection with the defense or settlement of such action or suit if
     he acted in good faith and in a manner he reasonably believed to be in or
     not opposed to the best interests of the Trust and except that no such
     indemnification shall be made in respect of any claim, issue or matter as
     to which such Parent Indemnified Person shall have been adjudged to be
     liable to the Trust unless and only to the extent that the Court of
     Chancery of Delaware or the court in which such action or suit was brought
     shall determine upon application that, despite the adjudication of
     liability but in view of all the circumstances of the case, such Person is
     fairly and reasonably entitled to indemnity for such expenses that such
     Court of Chancery or such other court shall deem proper.

             (iii)  Any indemnification under paragraphs (i) and (ii) of this
     Section 4.3(a) (unless ordered by a court) shall be made by the Sponsor
     only as authorized in the specific case upon a determination that
     indemnification of the Parent Indemnified Person is proper in the
     circumstances because he has met the applicable standard of conduct set
     forth in paragraphs (i) and (ii). Such determination shall be made (1) by
     the Regular Trustees by a majority vote of a quorum consisting of such
     Regular Trustees who were not parties to such action, suit or proceeding,
     (2) if such a quorum is not obtainable, or, even if obtainable, if a quorum
     of disinterested Regular Trustees so directs, by independent legal counsel
     in a written opinion, or (3) by the holder(s) of the Common Securities of
     the Trust.

                                      12
<PAGE>
 
              (iv)  Expenses (including attorneys' fees) incurred by a Parent
     Indemnified Person in defending a civil, criminal, administrative or
     investigative action, suit or proceeding referred to in paragraphs (i) and
     (ii) of this Section 4.3(a) shall be paid by the Sponsor in advance of the
     final disposition of such action, suit or proceeding upon receipt of an
     undertaking by or on behalf of such Parent Indemnified Person to repay such
     amount if it shall ultimately be determined that he is not entitled to be
     indemnified by the Sponsor as authorized in this Section 4.3(a).
     Notwithstanding the foregoing, no advance shall be made by the Sponsor if a
     determination is reasonably and promptly made (i) by the Regular Trustees
     by a majority vote of a quorum of disinterested Regular Trustees, (ii) if
     such a quorum is not obtainable, or, even if obtainable, if a quorum of
     disinterested Regular Trustees so directs, by independent legal counsel in
     a written opinion or (iii) the holder(s) of the Common Securities of the
     Trust, that, based upon the facts known to the Regular Trustees,
     independent legal counsel or the holder(s) of the Common Securities of the
     Trust at the time such determination is made, such Parent Indemnified
     Person acted in bad faith or in a manner that such Person did not believe
     to be in or not opposed to the best interests of the Trust, or, with
     respect to any criminal proceeding, that such Parent Indemnified Person
     believed or had reasonable cause to believe his conduct was unlawful. In no
     event shall any advance be made in instances where the Regular Trustees,
     independent legal counsel or the holder(s) of the Common Securities of the
     Trust reasonably determine that such Person deliberately breached his duty
     to the Trust or to the holder(s) of its Common Securities or Preferred
     Securities.

               (v)  The indemnification and advancement of expenses provided by,
     or granted pursuant to, the other paragraphs of this Section 4.3(a) shall
     not be deemed exclusive of any other rights to which those seeking
     indemnification and advancement of expenses may be entitled under any
     agreement, vote of shareholders or disinterested directors of the Sponsor
     or of the holder(s) of the Preferred Securities of the Trust or otherwise,
     both as to action in his official capacity and as to action in another
     capacity while holding such office. All rights to indemnification under
     this Section 4.3(a) shall be deemed to be provided by a contract between
     the Sponsor and each Parent Indemnified Person who serves in such capacity
     at any time while this Section 4.3(a) is in effect. Any repeal or
     modification of this Section 4.3(a) shall not affect any rights or
     obligations then existing.

              (vi)  The Sponsor or the Trust may purchase and maintain insurance
     on behalf of any Person who is

                                      13
<PAGE>
 
     or was a Parent Indemnified Person against any liability asserted against
     him and incurred by him in any such capacity, or arising out of his status
     as such, whether or not the Sponsor would have the power to indemnify him
     against such liability under the provisions of this Section 4.3(a).

          (vii)  For purposes of this Section 4.3(a), references to "the Trust"
     shall include, in addition to the resulting or surviving entity, any
     constituent entity (including any constituent of a constituent) absorbed in
     a consolidation or merger, so that any Person who is or was a director,
     trustee, officer or employee of such constituent entity, or is or was
     serving at the request of such constituent entity as a director, trustee,
     officer, employee or agent of another entity, shall stand in the same
     position under the provisions of this Section 4.3(a) with respect to the
     resulting or surviving entity as he would have with respect to such
     constituent entity if its separate existence had continued.

          (viii) The indemnification and advancement of expenses provided by, or
     granted pursuant to, this Section 4.3(a) shall, unless otherwise provided
     when authorized or ratified, continue as to a Person who has ceased to be a
     Parent Indemnified Person and shall inure to the benefit of the heirs,
     executors and administrators of such a Person.

     (b)  The Sponsor agrees to indemnify (i) the Delaware Trustee and the
Institutional Trustee, (ii) any Affiliate of the Delaware Trustee or the
Institutional Trustee, and (iii) any officers, directors, stockholders, members,
partners, employees, representatives, nominees, custodians or agents of the
Delaware Trustee or the Institutional Trustee (each of the Persons in (i)
through (iii) being referred to as a "Fiduciary Indemnified Person") for, and to
hold each Fiduciary Indemnified Person harmless against, any loss, liability or
expense incurred without negligence or bad faith on its part, arising out of or
in connection with the acceptance or administration of the trust or trusts
hereunder, including the costs and expenses (including reasonable legal fees and
expenses) of defending itself against, or investigating, any claim or liability
in connection with the exercise or performance of any of its powers or duties
hereunder. The provisions of this Section 4.3(b) shall survive the termination
of this Declaration or the resignation or removal of the Delaware Trustee or
Institutional Trustee.

                                      14
<PAGE>
 
SECTION 4.4    Outside Businesses.
               ------------------ 

          Any Covered Person, the Sponsor, the Delaware Trustee and the
Institutional Trustee may engage in or possess an interest in other business
ventures of any nature or description, independently or with others, similar or
dissimilar to the business of the Trust, and the Trust and the holders of
Securities shall have no rights by virtue of this Declaration in and to such
independent ventures or the income or profits derived therefrom and the pursuit
of any such venture, even if competitive with the business of the Trust, shall
not be deemed wrongful or improper. None of any Covered Person, the Sponsor, the
Delaware Trustee or the Institutional Trustee shall be obligated to present any
particular investment or other opportunity to the Trust even if such opportunity
is of a character that, if presented to the Trust, could be taken by the Trust,
and any Covered Person, the Sponsor, the Delaware Trustee and the Institutional
Trustee shall have the right to take for its own account (individually or as a
partner or fiduciary) or to recommend to others any such particular investment
or other opportunity. Any Covered Person, the Delaware Trustee and the
Institutional Trustee may engage or be interested in any financial or other
transaction with the Sponsor or any Affiliate of the Sponsor, or may act as
depositary, trustee or agent for, or may act on any committee or body of holders
of, securities or other obligations of the Sponsor or its Affiliates.


                                   ARTICLE V
                    AMENDMENTS, TERMINATION, MISCELLANEOUS

SECTION 5.1   Amendments.
              ---------- 

          At any time before the issue of any Securities, this Declaration may
be amended by, and only by, a written instrument executed by all of the Regular
Trustees and the Sponsor; provided, however, that if the amendment effects the 
rights, powers, duties, obligations or immunities of the Delaware Trustee or the
Institutional Trustee, the amendment shall also be approved in writing by the 
Delaware Trustee or the Institutional Trustee, as the case may be.

SECTION 5.2   Termination of Trust.
              -------------------- 

          (a)  The Trust shall dissolve and be of no further force or effect:
 
               (i)    upon the bankruptcy of the Sponsor;

               (ii)   upon the filing of a certificate of dissolution or its
          equivalent with respect to the Sponsor or the revocation of the
          Sponsor's charter or of the Trust's certificate of trust;

               (iii)  upon the entry of a decree of judicial dissolution of the
          Sponsor, or the Trust; and


                                      15
<PAGE>
 
               (iv)   before the issue of any Securities, with the consent of
          all of the Regular Trustees and the Sponsor; and

          (b)  As soon as is practicable after the occurrence of an event
referred to in Section 5.2(a), the Trustees shall file, after satisfaction of
all liabilities of the Trust in accordance with applicable law, a certificate of
cancellation with the Secretary of State of the State of Delaware and the Trust
shall terminate.

SECTION 5.3    Governing Law.
               ------------- 

          This Declaration and the rights of the parties hereunder shall be
governed by and interpreted in accordance with the laws of the State of Delaware
and all rights and remedies shall be governed by such laws without regard to
principles of conflict of laws.

SECTION 5.4    Headings.
               -------- 

          Headings contained in this Declaration are inserted for convenience of
reference only and do not affect the interpretation of this Declaration or any
provision hereof.

SECTION 5.5    Successors and Assigns.
               ---------------------- 

          Whenever in this Declaration any of the parties hereto is named or
referred to, the successors and assigns of such party shall be deemed to be
included, and all covenants and agreements in this Declaration by the Sponsor
and the Trustees shall bind and inure to the benefit of their respective
successors and assigns, whether or not so expressed.

SECTION 5.6    Partial Enforceability.
               ---------------------- 

          If any provision of this Declaration, or the application of such
provision to any Person or circumstance, shall be held invalid, the remainder of
this Declaration, or the application of such provision to Persons or
circumstances other than those to which it is held invalid, shall not be
affected thereby.

SECTION 5.7    Counterparts.
               ------------ 

          This Declaration may contain more than one counterpart of the
signature page and this Declaration may be executed by the affixing of the
signature of each of the Trustees to one of such counterpart signature pages.
All of such counterpart signature pages shall be read as though one, and they
shall have the same force and effect as though all of the signers had signed a
single signature page.

                                      16


<PAGE>
 
          IN WITNESS WHEREOF, the undersigned have caused these presents to be
executed as of the day and year first above written.

                              /S/ Cynthia E. Holloway
                              -----------------------------------
                              CYNTHIA E. HOLLOWAY
                              Regular Trustee


                              /S/ Robert G. Wennemer
                              -----------------------------------
                              ROBERT G. WENNEMER
                              Regular Trustee


                              /S/ Richard B. Kelson
                              -----------------------------------
                              RICHARD B. KELSON
                              Regular Trustee


                              CHASE MANHATTAN BANK DELAWARE, as 
                               Delaware Trustee


                              By: /S/ Denis Kelly
                                 --------------------------------
                                  Denis Kelly
                                  Trust Officer


                              THE CHASE MANHATTAN BANK, as
                               Institutional Trustee


                              By: /S/ Joanne Adamis
                                 --------------------------------
                                  Joanne Adamis
                                  Assistant Vice President


                              ALUMINUM COMPANY OF AMERICA, as      
                               Sponsor


                              By: /S/ Cynthia E. Holloway
                                 --------------------------------
                                  Cynthia E. Holloway
                                  Assistant Treasurer

                                      17
<PAGE>
 
                                   EXHIBIT A

                             (begins on next page)
<PAGE>
 
                             CERTIFICATE OF TRUST

          The undersigned, the trustees of Alcoa Trust I, desiring to form a
business trust pursuant to Delaware Business Trust Act, 12 Del. C. (S) 3810 et
                                                           ---- --          --
seq., hereby certify as follows:
- ----                            

          (a)  The name of the business trust being formed hereby (the "Trust")
               is "Alcoa Trust I."

          (b)  The name and business address of the trustee of the Trust which
               has its principal place of business in the State of Delaware is
               as follows:

               Chase Manhattan Bank Delaware
               1201 Market St.
               Wilmington, DE 19801
               Attention: Trust Department

          (c)  This Certificate of Trust shall be effective as of the date of
               filing.

Dated:  
        
                               -----------------------------------
        
                               Regular Trustee


        
                               ----------------------------------
        
                               Regular Trustee


        
                               ----------------------------------
        
                               Regular Trustee


        
                                Delaware Trustee


                               By: 
                                  -------------------------------

                                  Trust Officer
 


                                Institutional Trustee

                               By: 
                                  -------------------------------



  

<PAGE>
 
                                                                    EXHIBIT 4(M)


                             AMENDED AND RESTATED

                                TRUST AGREEMENT

                                     AMONG

                          ALUMINUM COMPANY OF AMERICA
                                 AS DEPOSITOR,

                           THE CHASE MANHATTAN BANK
                             AS PROPERTY TRUSTEE,

                         CHASE MANHATTAN BANK DELAWARE
                             AS DELAWARE TRUSTEE,

                                      AND

                   THE ADMINISTRATIVE TRUSTEES NAMED HEREIN

                              DATED AS OF [DATE]

                                 ALCOA TRUST I

================================================================================
<PAGE>
 
                               TABLE OF CONTENTS
                               
<TABLE>
<CAPTION>
                                                                                 PAGE
                                                                                 ----
<S>                                                                              <C>
ARTICLE 1
     DEFINED TERMS
     SECTION 1.1.   Definitions.................................................  2

ARTICLE 2
     ESTABLISHMENT OF THE TRUST
     SECTION 2.1.   Name........................................................ 14
     SECTION 2.2.   Office of the Delaware Trustee;
                         Principal Place of Business............................ 14
     SECTION 2.3.   Organizational Expenses..................................... 15
     SECTION 2.4.   Issuance of the Preferred
                         Securities............................................. 15
     SECTION 2.5.   Subscription and Purchase of
                         Debentures; Issuance of the
                         Common Securities...................................... 15
     SECTION 2.6.   Declaration of Trust........................................ 16
     SECTION 2.7.   Authorization to Enter into
                         Certain Transactions................................... 16
     SECTION 2.8.   Assets of Trust............................................. 21
     SECTION 2.9.   Title to Trust Property..................................... 21

ARTICLE 3
     PAYMENT ACCOUNT
     SECTION 3.1.   Payment account............................................. 22

ARTICLE 4
     DISTRIBUTIONS; REDEMPTION; EXCHANGE; CONVERSION
     SECTION 4.1.   Distributions............................................... 22
     SECTION 4.2.   Redemption.................................................. 23
     SECTION 4.3.   Conversion.................................................. 26
     SECTION 4.4.   Special Event Exchange or
                         Redemption............................................. 29
     SECTION 4.5.   Subordination of Common
                         Securities............................................. 32
     SECTION 4.6.   Payment Procedures.......................................... 32
     SECTION 4.7.   Tax Returns and Reports..................................... 32
     SECTION 4.8.   Payment of Taxes, Duties, Etc.,
                         of the Trust........................................... 33
     SECTION 4.9.   Payments under Indenture.................................... 33


ARTICLE 5
     TRUST SECURITIES CERTIFICATES
     SECTION 5.1.   Initial Ownership........................................... 33
     SECTION 5.2.   The Trust Securities Certificates........................... 33
     SECTION 5.3.   Delivery of Trust Securities
                         Certificates........................................... 34
 </TABLE>

                                       i
<PAGE>
 
<TABLE>
<CAPTION> 
                                                                                   Page
                                                                                   ----
<S>                                                                                <C>
     SECTION 5.4.   Registration of Transfer and
                         Exchange of Preferred
                         Securities; Restrictions on
                         Transfer................................................. 35
     SECTION 5.5.   Mutilated, Destroyed, Lost or
                         Stolen Trust Securities
                         Certificates............................................. 36
     SECTION 5.6.   Persons Deemed Securityholders................................ 36
     SECTION 5.7.   Access to List of Securityholders'
                         Names and Addresses...................................... 36
     SECTION 5.8.   Maintenance of Office or Agency............................... 37
     SECTION 5.9.   Appointment of Paying Agent................................... 37
     SECTION 5.10.  Ownership of Common Securities by
                         Depositor................................................ 38
     SECTION 5.11.  Global Securities; Non-Global
                         Securities; Common Securities
                         Certificate.............................................. 38
     SECTION 5.12.  Notices to Clearing Agency.................................... 40
     SECTION 5.13.  Definitive Preferred Securities
                         Certificates............................................. 40
     SECTION 5.14.  Rights of Securityholders..................................... 41


ARTICLE 6
     ACT OF SECURITYHOLDERS; MEETINGS; VOTING..................................... 42
     SECTION 6.1.   Limitations on Voting Rights.................................. 45
     SECTION 6.2.   Notice of Meetings
     SECTION 6.3.   Meetings of Preferred......................................... 45
                         Securityholders.......................................... 45
     SECTION 6.4.   Voting Rights................................................. 46
     SECTION 6.5.   Proxies, Etc
     SECTION 6.6.   Securityholder Action by Written.............................. 46
                         Consent
     SECTION 6.7.   Record Date for Voting and Other.............................. 46
                         Purposes................................................. 47
     SECTION 6.8.   Acts of Securityholders....................................... 48
     SECTION 6.9.   Inspection of Records

ARTICLE 7
     REPRESENTATIONS AND WARRANTIES
     SECTION 7.1.   Representations and Warranties of
                         the Property Trustee and the............................. 49
                         Delaware Trustee
     SECTION 7.2.   Representations and Warranties of
                         Depositor................................................ 50
</TABLE>

                                      ii
<PAGE>
 
<TABLE>
<CAPTION> 
                                                                                  Page
                                                                                  ----
<S>                                                                              <C>
ARTICLE 8
     THE TRUSTEES
     SECTION 8.1.   Certain Duties and
                         Responsibilities.......................................    51
     SECTION 8.2.   Notice of Defaults..........................................    54
     SECTION 8.3.   Certain Rights of Property Trustee..........................    56
     SECTION 8.4.   Not Responsible for Recitals or
                         Issuance of Securities.................................    59
     SECTION 8.5.   May Hold Securities.........................................    59
     SECTION 8.6.   Compensation; Indemnity, Fees...............................    60
     SECTION 8.7.   Property Trustee Required;
                         Eligibility of Trustees................................    61
     SECTION 8.8.   Conflicting Interests.......................................    61
     SECTION 8.9.   Resignation and Removal,
                         Appointment of Successor...............................    61
     SECTION 8.10.  Acceptance of Appointment by
                         Successor..............................................    64
     SECTION 8.11.  Merger, Conversion, Consolidation
                         or Succession to Business..............................    65
     SECTION 8.12.  Preferential Collection of Claims
                         Against Depositor or Trust.............................    65
     SECTION 8.13.  Reports by Property Trustee.................................    65
     SECTION 8.14.  Reports to the Property Trustee.............................    65
     SECTION 8.15.  Evidence of Compliance with
                         Conditions Precedent...................................    65
     SECTION 8.16.  Number of Trustees..........................................    66
     SECTION 8.17.  Delegation of Power.........................................    66

ARTICLE 9
     DISSOLUTION, LIQUIDATION AND MERGER
     SECTION 9.1.   Dissolution upon Expiration Date............................    67
     SECTION 9.2.   Early Dissolution...........................................    67
     SECTION 9.3.   Dissolution.................................................    67
     SECTION 9.4.   Liquidation.................................................    68
     SECTION 9.5.   Mergers, Consolidations,
                         Amalgamations or Replacements
                         of the Trust...........................................    69

ARTICLE 10
     MISCELLANEOUS PROVISIONS
     SECTION 10.1.  Limitation of Rights of
                         Securityholders........................................    71
     SECTION 10.2.  Amendment...................................................    71
     SECTION 10.3.  Separability................................................    73
     SECTION 10.4.  Governing Law...............................................    73
     SECTION 10.5.  Payments Due on Non-Business Day............................    73
     SECTION 10.6.  Successors..................................................    74
     SECTION 10.7.  Headings....................................................    74
</TABLE>

                                      iii
<PAGE>
 
<TABLE>
<CAPTION> 
                                                                                  Page
                                                                                  ----
<S>                                                                              <C>
     SECTION 10.8.  Reports, Notices and Demands................................    74
     SECTION 10.9.  Agreement Not to Petition...................................    74
     SECTION 10.10. Trust Indenture Act; Conflict with
                         Trust Indenture Act....................................    75
     SECTION 10.11. Acceptance of Terms of Trust
                         Agreement, Guarantee and
                         Indenture..............................................    75
     SECTION 10.12. Counterparts................................................    76
 </TABLE>

EXHIBIT A - Certificate of Trust of Alcoa Trust I

EXHIBIT B - Form of Certificate Depositary Agreement

EXHIBIT C - Form of Common Securities of Alcoa Trust I

EXHIBIT D - Form of Preferred Securities of Alcoa Trust I

EXHIBIT E - Notice of Conversion

                                      iv
<PAGE>
 
                                ALCOA TRUST I*

                   Certain Sections of this Trust Agreement
                     relating to Sections 310 through 318
                      of the Trust Indenture Act of 1939:

<TABLE>
<CAPTION>
TRUST INDENTURE                                                       TRUST AGREEMENT
ACT SECTION                                                           SECTION
<S>                                                                   <C>
Section 310        (a)(1)      .............................          8.7
                   (a)(2)      .............................          8.7
                   (a)(3)      .............................          Not Applicable
                   (a)(4)      .............................          2.7(a)(ii)
                   (b)         .............................          8.8
Section 311        (a)         .............................          8.12
                   (b          .............................          8.12
Section 312        (a)         .............................          5.7
                   (b)         .............................          5.7
                   (c)         .............................          5.7
Section 313        (a)         .............................          8.13(a)
                   (c)         .............................          10.8
                   (d)         .............................          8.13(c)
                   (a)(4)      .............................          8.13(b)
                   (b)         .............................          8.13(b)
Section 314        (a)         .............................          8.14
                   (b)         .............................          Not Applicable
                   (c)(1)      .............................          8.15
                   (c)(2)      .............................          8.15
                   (c)(3)      .............................          Not Applicable
                   (d)         .............................          Not Applicable
                   (e)         .............................          1.1, 8.15
Section 315        (a)         .............................          8.1(a), 8.3(a)
                   (b)         .............................          8.2, 10.8
                   (c)         .............................          8.1(a)
                   (d)         .............................          8.1, 8.3
                   (e)         .............................          Not Applicable
Section 316        (a)         .............................          Not Applicable
                   (a)(1)(A)   .............................          Not Applicable
                   (a)(1)(B)   .............................          Not Applicable
                   (a)(2)      .............................          Not Applicable
                   (b)         .............................          Not Applicable
                   (c)         .............................          6.7
Section 317        (a)(1)      .............................          Not Applicable
                   (b)         .............................          5.9
Section 318        (a)         .............................          10.10
</TABLE>

____________________

Note:  This reconciliation and tie sheet shall not, for any purpose, be deemed
to be a part of the Trust Agreement.

                                       v
<PAGE>
 
          AMENDED AND RESTATED TRUST AGREEMENT, dated as of [             ]
among (i) Aluminum Company of America, a Pennsylvania corporation, (including
any successors or assigns, the "Depositor'), (ii) The Chase Manhattan Bank, a
New York banking corporation, as property trustee (in such capacity, the
"Property Trustee" and, in its personal capacity and not in its capacity as
Property Trustee, the "Bank"), (iii) Chase Manhattan Bank Delaware, a
corporation duly organized and existing under the laws of the State of Delaware,
as Delaware trustee (in such capacity, the "Delaware Trustee"), (iv) [AT], an
individual, [AT], an individual, and [AT], an individual, each of whose address
is c/o Aluminum Company of America, 201 Isabella Street, Pittsburgh, PA  15212-
5858, each, an "Administrative Trustee" and, collectively, the "Administrative
Trustees" and, collectively with the Property Trustee and Delaware Trustee, the
"Trustees") and (iv) the several Holders as hereinafter defined.


                             W I T N E S S E T H:

          WHEREAS, the Depositor and certain of the Trustees have heretofore
duly declared and created a business trust pursuant to the Delaware Business
Trust Act by the entering into of that certain Declaration of Trust, dated as of
[                ] (the "Original Trust Agreement"), and by the execution and
filing by certain of the Trustees with the Secretary of State of the State of
Delaware of the Certificate of Trust, filed on [              ], attached as
Exhibit A, for the sole purpose of issuing and selling certain securities
representing undivided beneficial interests in the assets of the Trust (as
defined herein) and investing the proceeds thereof in the Debentures (as defined
herein); and

          WHEREAS, the parties hereto desire to amend and restate the Original
Trust Agreement in its entirety as set forth herein to provide for, among other
things, (i) the issuance and sale of the Common Securities (as defined herein)
by the Trust to the Depositor, (ii) the issuance and sale of the Preferred
Securities (as defined herein) by the Trust pursuant to the Underwriting
Agreement (as defined herein) and (iii) the acquisition by the Trust from the
Depositor of all of the right, title and interest in the Debentures;

          NOW, THEREFORE, in consideration of the agreements and obligations set
forth herein and for other good and valuable consideration, the sufficiency of
which is hereby
<PAGE>
 
acknowledged, each party, for the benefit of the other parties and for the
benefit of the Holders of the Preferred Securities, hereby amends and restates
the Original Trust Agreement in its entirety and agrees as follows:


                                   ARTICLE 1
                                 DEFINED TERMS

          SECTION 1.1.  Definitions.  For all purposes of this Trust Agreement,
                        ------------                                           
except as otherwise expressly provided or unless the context otherwise requires:

          (a)  the terms defined in this Article have the meanings assigned to
them in this Article and include the plural as well as the singular;

          (b) all other terms used herein that are defined in the Trust
Indenture Act, either directly or by reference therein, have the meanings
assigned to them therein;

          (c) unless the context otherwise requires, any reference to an
"Article" or a "Section" refers to an Article or a Section, as the case may be,
of this Trust Agreement; and

          (d) the words "herein", "hereof" and "hereunder" and other words of
similar import refer to this Trust Agreement as a whole and not to any
particular Article, Section or other subdivision.

          "Act" has the meaning specified in Section 6.8.

          ["Additional Amount" means, with respect to the Trust Securities, the
amount of Additional Interest (as defined in the Indenture) paid by the
Depositor on the Debentures.]

          ["Additional Sums" means, with respect to the Trust Securities, the
amount of Additional Sums (as defined in the Indenture) paid by the Depositor on
the Debentures.]

          "Administrative Trustee" means each of [           ,         and
  ], each solely in his capacity as Administrative Trustee of the Trust and not
in his individual capacity, or such Administrative Trustee's successor in
interest in such capacity, or any successor in interest in such capacity, or any
successor administrative trustee appointed as herein provided.

                                       2
<PAGE>
 
          "Affiliate" of any specified Person means any other Person directly or
indirectly controlling or controlled by or under direct or indirect common
control with such specified Person, provided, however that an Affiliate of the
Depositor shall be deemed not to include the Trust.  For the purposes of this
definition, "control" when used with respect to any specified Person means the
power to direct the management and policies of such Person, directly or
indirectly, whether through the ownership of voting securities, by contract or
otherwise; and the terms "controlling" and "controlled" have meanings
correlative to the foregoing.

          ["Applicable Procedures" means, with respect to any transfer or
transaction involving a Global Certificate or beneficial interest therein, the
rules and procedures of Euroclear and Cedel, and of the Clearing Agency for such
security, in each case to the extent applicable to such transaction and as in
effect from time to time.]

          "Bank" has the meaning specified in the preamble to this Trust
Agreement.

          "Bankruptcy Event" means, with respect to any Person:

          (a)  the entry of a decree or order by a court having jurisdiction in
     the premises judging such Person as bankrupt or insolvent, or approving as
     properly filed a petition seeking reorganization, arrangement, adjudication
     or composition of or in respect of such Person under any applicable Federal
     or State bankruptcy, insolvency, reorganization or other similar law, or
     appointing a receiver, liquidator, assignee, trustee, sequestrator (or
     other similar official) of such Person or of substantially all of its
     property or ordering the winding-up or liquidation of its affairs, and the
     continuance of any such decree or order unstayed and in effect for a period
     of 60 consecutive days; or

          (b)  the institution by such Person of proceedings to be adjudicated
     as bankrupt or insolvent, or the consent by it to the institution of
     bankruptcy or insolvency proceedings against it, or the filing by it of a
     petition or answer or consent seeking reorganization or relief under any
     applicable Federal or State bankruptcy, insolvency, reorganization or other
     similar law, or the consent by it to the filing of any such petition or to
     the appointment of a receiver, liquidator, assignee, trustee, sequestrator

                                       3
<PAGE>
 
     (or similar official) of such Person or of substantially all of its
     property, or the making by it of an assignment for the benefit of
     creditors, or the admission by it in writing of its inability to pay its
     debts generally as they become due and its willingness to be adjudicated a
     bankrupt, or the taking of corporate action by such Person in furtherance
     of any such action.

          "Bankruptcy Laws" has the meaning specified in Section 10.9.

          "Board of Directors" means either the board of directors of the
Depositor or any committee of that board duly authorized to act hereunder.

          "Book-Entry Preferred Securities Certificates" means a beneficial
interest in the Preferred Securities Certificates, ownership and transfers of
which shall be made through book entries by a Clearing Agency as described in
Section 5.11.

          "Business Day" means any day other than a Saturday or Sunday or a day
on which banking institutions in The City of New York are authorized or required
by law or executive order to remain closed or a day on which the Corporate Trust
Office of the Property Trustee or the corporate trust office of the Debenture
Trustee, is closed for business.

          "Certificate Depository Agreement" means the agreement among the
Trust, the Depositor and The Depository Trust Company, as the initial Clearing
Agency, dated as of the Closing Date, relating to the Trust Securities
Certificates substantially in the form attached as Exhibit B, as the same may be
amended and supplemented from time to time.

          "Clearing Agency" means an organization registered as a "clearing
agency" pursuant to Section 17A of the Securities Exchange Act of 1934, as
amended.  The Depository Trust Company will be the initial Clearing Agency.

          "Clearing Agency Participant" means a broker, dealer, bank, other
financial institution or other Person for whom from time to time a Clearing
Agency effects book-entry transfers and pledges of securities deposited with the
Clearing Agency.

          "Closing Date" means the first Time of Delivery (as defined in the
Underwriting Agreement), which date is

                                       4
<PAGE>
 
also the date of execution and delivery of this Trust Agreement.

          "Commission" means the Securities and Exchange Commission, as from
time to time constituted, created under the Securities Exchange Act of 1934, as
amended, or, if at any time after the execution of this instrument such
Commission is not existing and performing the duties now assigned to it under
the Trust Indenture Act, then the body performing such duties at such time.

          "Common Securities Certificate" means a certificate evidencing
ownership of Common Securities, substantially in the form attached as Exhibit C.

          "Common Security" means an undivided beneficial interest in the assets
of the Trust, having a Liquidation Amount with respect to the assets of the
Trust of $50 and having the rights provided therefor in this Trust Agreement,
including the right to receive Distributions and a Liquidation Distribution as
provided herein.

          "Common Stock" means common stock, $1.00 par value per share, of the
Depositor.

          "Conversion Agent" has the meaning specified in Section 4.3.

          "Conversion Date" has the meaning specified in Section 4.3.

          "Conversion Price" has the meaning specified in Section 4.3.

          "Corporate Trust Office" means the principal corporate trust office of
the Property Trustee at which at any particular time its corporate trust
business shall be administered, which office at the date hereof is located at
450 West 33rd Street, New York, New York 10001  Attention: Global Trust
Services.

          "Current Market Price", with respect to Common Stock, means for any
day the last reported sale price, regular way, on such day, or, if no sale takes
place on such day, the average of the reported closing bid and asked prices on
such day, regular way, in either case as reported on the New York Stock Exchange
Composite Transactions Tape, or, if Common Stock is not listed or admitted to
trading on the New York Stock Exchange on such day, on the principal national
securities exchange on which Common Stock is listed or admitted to trading, if
Common Stock is listed on a

                                       5
<PAGE>
 
national securities exchange, or the Nasdaq National Market, or, if Common Stock
is not quoted or admitted to trading on such quotation system, on the principal
quotation system on which Common Stock may be listed or admitted to trading or
quoted, or, if not listed or admitted to trading or quoted on any national
securities exchange or quotation system, the average of the closing bid and
asked prices of Common Stock in the over-the-counter market on the day in
question as reported by the National Quotation Bureau Incorporated, or a similar
generally accepted reporting service, or, if not so available in such manner, as
furnished by any New York Stock Exchange member firm selected from time to time
by the Board of Directors for that purpose or, if not so available in such
manner, as otherwise determined in good faith by the Board of Directors.

          "Debenture Event of Default" means an "Event of Default" as defined in
the Indenture.

          "Debenture Redemption Date" means, with respect to any Debentures to
be redeemed under the Indenture, the date fixed for redemption thereof under the
Indenture.

          "Debenture Trustee" means [T], a [          ] banking corporation, as
trustee under the Indenture.

          "Debentures" means all of the Depositor's [     ] [junior] convertible
subordinated debentures, $[           ] aggregate principal amount, issued
pursuant to the Indenture.

          "Definitive Preferred Securities Certificates" means either or both
(as the context requires) of (x) Preferred Securities Certificates issued in
certificated, fully registered form as provided in Section 5.11(b) and (y)
Preferred Securities Certificates issued in certificated, fully registered form
as provided in Section 5.13.

          "Delaware Business Trust Act" means Chapter 38 of Title 12 of the
Delaware Code, 12 Del. C. ((S)) 3801, et seq., as it may be amended from time to
time.

          "Delaware Trustee" means the Person identified as the "Delaware
Trustee" in the preamble to this Trust Agreement solely in its capacity as
Delaware Trustee of the Trust and not in its individual capacity, or its
successor in interest in such capacity, or any successor Delaware trustee
appointed as herein provided.

                                       6
<PAGE>
 
          "Depositor" has the meaning specified in the preamble to this Trust
Agreement.

          "Direct Action" has the meaning specified in Section 6.8.

          "Distribution Date" has the meaning specified in Section 4.1(a).

          "Distributions" means amounts payable in respect of the Trust
Securities as provided in Section 4.1.

          "Early Dissolution Event" has the meaning specified in Section 9.2.

          "Event of Default" means the occurrence of a Debenture Event of
Default, whatever the reason for such Debenture Event of Default and whether it
shall be voluntary or involuntary or be effected by operation of law or pursuant
to any judgment, decree or order of any court or any order, rule or regulation
of any administrative or governmental body.

          "Exchange Notice" has the meaning specified in Section 4.4(b).

          "Expiration Date" has the meaning specified in Section 9.1.

          "Global Certificate" means a Preferred Security that is registered in
the Securities Register in the name of a Clearing Agency or a nominee thereof.

          "Guarantee" means the Guarantee Agreement executed and delivered by
the Depositor and The Chase Manhattan Bank, a New York banking corporation, as
guarantee trustee, contemporaneously with the execution and delivery of this
Trust Agreement, for the benefit of the Holders of the Preferred Securities, as
amended from time to time.

          "Holder" means a Person in whose name a Trust Securities Certificate
representing a Trust Security is registered, such Person being a beneficial
owner within the meaning of the Delaware Business Trust Act.

          "Indenture" means the Junior Convertible Subordinated Indenture, dated
as of [           , 1998] between the Depositor and the Debenture Trustee, as
amended or supplemented from time to time.

                                       7
<PAGE>
 
          "Investment Company Event" means the receipt by the Property Trustee,
on behalf of the Trust, of an Opinion of Counsel, rendered by a law firm having
a national tax and securities practice (which Opinion of Counsel shall not have
been rescinded by such law firm), to the effect that, as a result of the
occurrence of a change in law or regulation or a change in interpretation or
application of law or regulation by any legislative body, court, governmental
agency or regulatory authority (a "Change in 1940 Act Law"), there is more than
an insubstantial risk that the Trust is or will be considered an "investment
company" that is required to be registered under the 1940 Act, which Change in
1940 Act Law becomes effective on or after the date of original issuance of the
Preferred Securities under this Trust Agreement.

          "Lien" means any lien, pledge, charge, encumbrance, mortgage, deed of
trust, adverse ownership interest, hypothecation, assignment, security interest
or preference, priority or other security agreement or preferential arrangement
of any kind or nature whatsoever.

          "Liquidation Amount" means an amount with respect to the assets of the
Trust equal to $50 per Trust Security.

          "Liquidation Date" means each date on which Debentures or cash are to
be distributed to Holders of Trust Securities in connection with a dissolution
and liquidation of the Trust pursuant to Section 9.4(a).

          "Liquidation Distribution" has the meaning specified in Section
9.4(d).

          "1940 Act" means the Investment Company Act of 1940, as amended.

          "Notice of Conversion" means the notice given by a Holder of Preferred
Securities to the Conversion Agent directing the Conversion Agent to exchange
such Preferred Securities for Debentures and to convert such Debentures into
Common Stock on behalf of such holder.  Such notice is substantially in the form
set forth in Exhibit E.

          "Officers' Certificate" means a certificate signed by (i) the Chairman
of the Board, Vice Chairman of the Board, the President or a Vice President, and
by (ii) the Treasurer, an Assistant Treasurer, the Secretary or an Assistant
Secretary, the Controller, or an Assistant Controller, of the Depositor, and
delivered to the Trustee. One of the officers signing an Officers' Certificate
given pursuant to Section 8.15 shall be the principal executive,

                                       8
<PAGE>
 
financial or accounting officer of the Depositor.  Any Officers' Certificate
delivered with respect to compliance with a condition or covenant provided for
in this Trust Agreement shall include:

          (a)  a statement that each officer signing the Officers' Certificate
     has read the covenant or condition and the definitions relating thereto;

          (b)  a brief statement of the nature and scope of the examination or
     investigation undertaken by each officer in rendering the Officers'
     Certificate;

          (c)  a statement that each officer has made such examination or
     investigation as, in such officer's opinion, is necessary to enable such
     officer to express an informed opinion as to whether or not such covenant
     or condition has been complied with; and

          (d)  a statement as to whether, in the opinion of each such officer,
     such condition or covenant has been complied with.

          "Opinion of Counsel" means a written opinion of counsel, who may be
counsel for the Trust, the Property Trustee or the Depositor, and who may be an
employee of any thereof, and who shall be reasonably acceptable to the Property
Trustee.  Any Opinion of Counsel delivered with respect to compliance with a
condition or covenant provided for in this Trust Agreement shall include:

          (a)  a statement that the counsel signing the Opinion of Counsel has
     read the covenant or condition and the definitions relating thereto;

          (b)  a brief statement of the nature and scope of the examination or
     investigation undertaken by such counsel in rendering the Opinion of
     Counsel;

          (c)  a statement that such counsel has made such examination or
     investigation as is necessary to enable such counsel to express an informed
     opinion as to whether or not such covenant or condition has been complied
     with; and

          (d)  a statement as to whether, in the opinion of each such counsel,
     such condition or covenant has been complied with.

          "Optional Redemption Price" means with respect to the Preferred
Securities (except as set forth below with

                                       9
<PAGE>
 
respect to redemption upon the occurrence of a Tax Event), the following
percentages of the Liquidation Amounts thereof, plus accumulated and unpaid
Distributions, if any, to the date fixed for redemption if redeemed during the
twelve-month period commencing [          ] in each of the following years
indicated:

<TABLE>
<CAPTION>
Year      Redemption Price          Year        Redemption Price   
- ----      ----------------          ----        ----------------  
<S>       <C>                     <C>           <C> 
[    ]       [     ]%              [     ]         [        ]%  
                                                                
[    ]       [     ]%              [     ]         [        ]%  
                                                                
[    ]       [     ]%             [     ] and      [        ]%  
                                  thereafter                    

[    ]       [     ]%
</TABLE> 

          In the event of a redemption of Trust Securities upon the occurrence
of a Tax Event, Trust Securities shall be redeemed at the redemption price of
$50 per Trust Security and all accumulated and unpaid Distributions, if any, to
the date fixed for redemption.

          "Original Trust Agreement" has the meaning specified in the recitals
to this Trust Agreement.

          "Outstanding", when used with respect to Trust Securities, means, as
of the date of determination, all Trust Securities theretofore executed and
delivered under this Trust Agreement, except:

          (a)  Trust Securities theretofore cancelled by the Securities
     Registrar or delivered to the Securities Registrar for cancellation or
     tendered for conversion;

          (b)  Trust Securities for whose payment or redemption money in the
     necessary amount has been theretofore deposited with the Property Trustee
     or any Paying Agent for the Holders of such Trust Securities; provided
     that, if such Trust Securities are to be redeemed, notice of such
     redemption has been duly given pursuant to this Trust Agreement;

          (c)  Trust Securities which have been exchanged for Debentures
     pursuant to Section 4.4; and

          (d)  Trust Securities which have been paid or in exchange for or in
     lieu of which other Trust Securities have been executed and delivered
     pursuant to Section 5.5;

                                      10
<PAGE>
 
provided, however, that in determining whether the Holders of the requisite
- --------  -------                                                          
Liquidation Amount of the Outstanding Trust Securities have given any request,
demand, authorization, direction, notice, consent or waiver hereunder, Trust
Securities owned by the Depositor, any Trustee or any Affiliate of the Depositor
or any Trustee shall be disregarded and deemed not to be Outstanding, except
that (a) in determining whether any Trustee shall be fully protected in relying
upon any such request, demand, authorization, direction, notice, consent or
waiver, only Trust Securities that a Responsible Officer of the Property Trustee
or the Delaware Trustee, or an individual Administrative Trustee, as the case
may be, actually knows to be so owned shall be so disregarded and (b) the
foregoing shall not apply at any time when all of the Outstanding Trust
Securities are owned by the Depositor, one or more of the Administrative
Trustees and/or any such Affiliate. Trust Securities so owned which have been
pledged in good faith may be regarded as Outstanding if the pledgee establishes
to the satisfaction of the Securities Registrar the pledgee's right so to act
with respect to such Trust Securities and that the pledgee is not the Depositor
or any Affiliate of the Depositor.

          "Owner" means each Person who is the beneficial owner of a Book-Entry
Preferred Securities Certificate as reflected in the records of the Clearing
Agency or, if a Clearing Agency Participant is not the Owner, then as reflected
in the records of a Person maintaining an account with such Clearing Agency
(directly or indirectly, in accordance with the rules of such Clearing Agency).

          "Paying Agent" means any paying agent or co-paying agent appointed
pursuant to Section 5.9.

          "Payment Account" means a segregated non-interest bearing corporate
trust account maintained by the Property Trustee with the Bank in its trust
department for the benefit of the Securityholders in which all amounts paid in
respect of the Debentures will be held and from which the Property Trustee shall
make payments to the Securityholders in accordance with Section 4.1.

          "Person" means any individual, corporation, partnership, joint
venture, association, joint stock company, trust, limited liability company or
corporation, unincorporated organization or government or any agency or
political subdivision thereof.

                                      11
<PAGE>
 
          "Preferred Securities Certificate" means a certificate evidencing
ownership of Preferred Securities, substantially in the form attached as Exhibit
D.

          "Preferred Security" means an undivided beneficial interest in the
assets of the Trust, having a Liquidation Amount with respect to the assets of
the Trust of $50 and having the rights provided therefor in this Trust
Agreement, including the right to receive Distributions and a Liquidation
Distribution as provided herein.

          "Property Trustee" means the commercial bank or trust company
identified as the "Property Trustee" in the preamble to this Trust Agreement
solely in its capacity as Property Trustee of the Trust and not in its
individual capacity, or its successor in interest in such capacity, or any
successor property trustee appointed as herein provided.

          "Redemption Date" means, with respect to any Trust Security to be
redeemed, each Debenture Redemption Date.

          "Redemption Price" means, with respect to any Trust Security, $50 per
Trust Security, plus accumulated and unpaid Distributions (including any
Additional Sums) to the date of redemption.

          "Relevant Trustee" has the meaning specified in Section 8.9.

          "Responsible Officer" means, with respect to the Property Trustee or
the Delaware Trustee, any officer, including any managing director, vice
president, assistant vice president, assistant treasurer, assistant secretary or
any other officer of the Property Trustee or the Delaware Trustee, as the case
may be, customarily performing functions similar to those performed by any of
the above designated officers and having direct responsibility for the
administration of this Trust Agreement, and also, with respect to a particular
matter, any other officer, to whom such matter is referred because of such
officer's knowledge of and familiarity with the particular subject.

          "Securities Register" and "Securities Registrar" have the respective
meanings specified in Section 5.4.

          "Securityholder" or "Holder" means a Person in whose name a Trust
Security or Securities is registered in the Securities Register; any such Person
shall be deemed to be a beneficial owner within the meaning of the Delaware
Business Trust Act.

                                      12
<PAGE>
 
          "Special Event" means a Tax Event or an Investment Company Event.

          "Successor Property Trustee" has the meaning specified in Section 8.9.

          "Successor Delaware Trustee" has the meaning specified in Section 8.9.

          "Successor Securities" has the meaning specified in Section 9.5.

          "Super Majority" has the meaning specified in Section 8.2.

          "Tax Event" means the receipt by the Property Trustee, on behalf of
the Trust, of an Opinion of Counsel, rendered by a law firm having a national
tax and securities practice (which Opinion of Counsel shall not have been
rescinded by such law firm), to the effect that, as a result of any amendment
to, or change (including any announced prospective change) in, the laws (or any
regulations thereunder) of the United States or any political subdivision or
taxing authority thereof or therein affecting taxation, or as a result of any
official administrative pronouncement or judicial decision interpreting or
applying such laws or regulations, which amendment or change is effective or
such pronouncement or decision is announced on or after the date of issuance of
the Preferred Securities under this Trust Agreement and does not pertain to the
use of the proceeds of the issuance of the Debentures, there is more than an
insubstantial risk in each case after the date thereof that (i) the Trust is, or
will be within 90 days after the date thereof, subject to United State Federal
income tax with respect to income received or accrued on the Debentures, (ii)
interest payable by the Depositor on the Debentures is not, or will not be,
within 90 days after the date thereof, deductible, in whole or in part, for
United States Federal income tax purposes or (iii) the Trust is, or will be
within 90 days after the date thereof, subject to more than de minimus amount of
                                                            -- -------          
other taxes, duties, assessments or other governmental charges.

          "Trust" means the Delaware business trust continued hereby and
identified on the cover page of this Trust Agreement.

          "Trust Agreement" means this Amended and Restated Trust Agreement, as
the same may be modified, amended or supplemented in accordance with the
applicable provisions hereof, including all exhibits hereto, including, for all

                                      13
<PAGE>
 
purposes of this Trust Agreement any such modification, amendment or supplement,
the provisions of the Trust Indenture Act that are deemed to be a part of and
govern this Trust Agreement and any such modification, amendment or supplement,
respectively.

          "Trust Indenture Act" means the Trust Indenture Act of 1939 as in
force at the date as of which this instrument was executed; provided, however,
                                                            --------  ------- 
that in the event the Trust Indenture Act of 1939 is amended after such date,
"Trust Indenture Act" means, to the extent required by any such amendment, the
Trust Indenture Act of 1939 as so amended.

          "Trust Property" means (a) the Debentures, (b) any cash on deposit in,
or owing to, the Payment Account and (c) all proceeds and rights in respect of
the foregoing to be held by the Property Trustee pursuant to the terms of this
Trust Agreement for the benefit of the Securityholders.

          "Trust Security" means any one of the Common Securities or the
Preferred Securities.

          "Trust Securities Certificate" means any one of the Common Securities
Certificates, the Global Certificates or the Definitive Preferred Securities
Certificates.

          "Trustees" means, collectively, the Property Trustee, the Delaware
Trustee and the Administrative Trustees.

          "Underwriting Agreement" means the Underwriting Agreement, dated as of
[                 ], including the Pricing Agreement dated [           ], among
the Trust, the Depositor and the Underwriters named therein.


                                   ARTICLE 2
                          ESTABLISHMENT OF THE TRUST

          SECTION 2.1.  Name.  The Trust continued hereby shall be known as
                        ----                                               
"Alcoa Trust [  ], as such name may be modified from time to time by the
Administrative Trustees following written notice to the Holders of Trust
Securities and the other Trustees, in which name the Trustees may conduct the
business of the Trust, make and execute contracts and other instruments on
behalf of the Trust and sue and be sued.

          SECTION 2.2.  Office of the Delaware Trustee; Principal Place of
                        --------------------------------------------------
Business.  The address of the Delaware
- ---------                             

                                      14
<PAGE>
 
Trustee in the State of Delaware is 1201 Market Street, Wilmington, Delaware
19801, Attention:  Corporate Trust Department, or such other address in the
State of Delaware as the Delaware Trustee may designate by written notice to the
Securityholders and the Depositor.  The principal executive office of the Trust
is 201 Isabella Street, Pittsburgh, PA  15212-5858.

          SECTION 2.3.  Organizational Expenses.  The Depositor shall pay
                        ------------------------                         
organizational expenses of the Trust as they arise or shall, upon request of any
Trustee, promptly reimburse such Trustee for any such expenses paid by such
Trustee.  The Depositor shall make no claim upon the Trust Property for the
payment of such expenses.

          SECTION 2.4.  Issuance of the Preferred Securities.  On [         ],
                        ------------------------------------- 
the Depositor on behalf of the Trust executed and delivered the Underwriting
Agreement. Contemporaneously with the execution and delivery of this Trust
Agreement, an Administrative Trustee, on behalf of the Trust, shall execute in
accordance with Section 5.2 and deliver to the Underwriters named in the
Underwriting Agreement Preferred Securities Certificates, in an aggregate amount
of [          ] Preferred Securities having an aggregate Liquidation Amount of
$[              ], against receipt of the aggregate purchase price of such
Preferred Securities of $[           ], which amount the Administrative Trustees
shall promptly deliver, or cause to be delivered, to the Property Trustee.

          SECTION 2.5.  Subscription and Purchase of Debentures; Issuance of the
                        --------------------------------------------------------
Common Securities. Contemporaneously with the execution and delivery of this
- ------------------                                                          
Trust Agreement, the Administrative Trustees, on behalf of the Trust, shall
subscribe to and purchase from the Depositor Debentures, registered in the name
of the Property Trustee (in its capacity as such) and having an aggregate
principal amount equal to $[           ], and, in satisfaction of the purchase
price for such Debentures, the Property Trustee, on behalf of the Trust, shall
deliver to the Depositor the sum of $[            ].  Contemporaneously
therewith, an Administrative Trustee, on behalf of the Trust, shall execute in
accordance with Section 5.2 and deliver to the Depositor Common Securities
Certificates registered in the name of the Depositor, in an aggregate amount of
[       ] Common Securities having an aggregate Liquidation Amount of $[      ]
against receipt by the Property Trustee of the aggregate purchase price of
such Common Securities from the Depositor of the sum of $[          ].

                                      15
<PAGE>
 
          SECTION 2.6.  Declaration of Trust.  The exclusive purposes and
                        ---------------------                            
functions of the Trust are (a) to issue and sell Trust Securities and use the
proceeds from such sale to acquire the Debentures, (b) to distribute the Trust's
income as provided in this Trust Agreement and (c) to engage in only those other
activities necessary or incidental thereto. The Trust shall not borrow money,
issue debt or reinvest proceeds derived from investments, mortgage or pledge any
of its assets or otherwise undertake (or permit to be undertaken) any activity
that would cause the Trust not to be classified for United States Federal income
tax purposes as a grantor trust.  The Depositor hereby appoints the Trustees as
trustees of the Trust, to have all the rights, powers and duties to the extent
set forth herein, and the Trustees hereby accept such appointment, subject to
the terms and conditions hereof.  The Property Trustee hereby declares that it
will hold the Trust Property in trust upon and subject to the conditions set
forth herein for the benefit of the Trust and the Securityholders.  The
Administrative Trustees shall have all rights, powers and duties set forth
herein and in accordance with applicable law with respect to accomplishing the
purposes of the Trust. The Delaware Trustee shall not be entitled to exercise
any powers, nor shall the Delaware Trustee have any of the duties and
responsibilities, of the Property Trustee or the Administrative Trustees set
forth herein.  The Delaware Trustee shall be one of the Trustees of the Trust
for the sole and limited purpose of fulfilling the requirements of Section 3807
of the Delaware Business Trust Act.  In the event the Delaware Trustee shall at
any time be required to take any action or perform any duty hereunder, the
Delaware Trustee shall be entitled to the benefits of Section 8.1(c) and Section
8.3.  No implied covenants or obligations shall be read into this Trust
Agreement against the Delaware Trustee.

          SECTION 2.7.  Authorization to Enter into Certain Transactions.  (a)
                        -------------------------------------------------      
The Trustees shall conduct the affairs of the Trust in accordance with the terms
of this Trust Agreement.  Subject to the limitations set forth in Section 2.6
and paragraph (b) of this Section, and in accordance with the following
provisions (i) and (ii), the Trustees shall have the exclusive power, duty and
the authority to cause the Trust to engage in the following activities:

          (i)  As among the Trustees, each Administrative Trustee shall have the
     exclusive power and authority to

                                      16
<PAGE>
 
     act on behalf of the Trust with respect to the following matters:

               (A)  to issue and sell the Trust Securities, provided, however,
                                                            --------  ------- 
          that the Trust may issue no more than one series of Preferred
          Securities and no more than one series of Common Securities, and,
          provided, further, that there shall be no interests in the Trust other
          than the Trust Securities, and the issuance of Trust Securities shall
          be limited to simultaneous issuance of both Preferred Securities and
          Common Securities on the Closing Date and any other date Preferred
          Securities and Common Securities are sold pursuant to the over-
          allotment option granted to the Underwriters named in the Underwriting
          Agreement, subject to the issuance of Trust Securities pursuant to
          Section 5.5 and Successor Securities pursuant to Section 9.5;

               (B)  to cause the Trust to enter into, and to execute, deliver
          and perform on behalf of the Trust, the Certificate Depository
          Agreement and such other agreements as may be necessary or incidental
          to the purposes and function of the Trust;

               (C)  to assist in the registration of the Preferred Securities
          under the Securities Act of 1933, as amended, and under state
          securities or blue sky laws, and the qualification of this Trust
          Agreement as a trust indenture under the Trust Indenture Act;

               (D)  to assist in the listing of the Preferred Securities upon
          such securities exchange or exchanges, if any, as shall be determined
          by the Depositor and the registration of the Preferred Securities
          under the Securities Exchange Act of 1934, as amended, and the
          preparation and filing of all periodic and other reports and other
          documents pursuant to the foregoing (only to the extent that such
          listing or registration is requested by the Depositor);

               (E)  to appoint a Paying Agent, a Securities Registrar and an
          authenticating agent in accordance with this Trust Agreement;

               (F)  to the extent provided in this Trust Agreement, to wind up
          the affairs of and liquidate

                                      17
<PAGE>
 
          the Trust and prepare, execute and file the certificate of
          cancellation with the Secretary of State of the State of Delaware;

               (G)  unless otherwise required by the Delaware Business Trust Act
          or the Trust Indenture Act, to execute on behalf of the Trust (either
          acting alone or together with any other Administrative Trustees) any
          documents that the Administrative Trustees have the power to execute
          pursuant to this Trust Agreement; and

               (H)  to take any action incidental to the foregoing as the
          Trustees may from time to time determine is necessary or advisable to
          give effect to the terms of this Trust Agreement including, but not
          limited to:

                    (i)   causing the Trust not to be deemed to be an Investment
               Company required to be registered under the 1940 Act;

                    (ii)  causing the Trust to be classified for United States
               Federal income tax purposes as a grantor trust; and

                    (iii) cooperating with the Depositor to ensure that the
               Debentures will be treated as indebtedness of the Depositor for
               United States Federal income tax purposes;

          provided that such action does not adversely affect in any material
          --------                                                           
          respect the interests of Securityholders except as otherwise provided
          in Section 10.2(a).

               (I)  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.

          (ii) As among the Trustees, the Property Trustee shall have the
     power, duty and authority to act on behalf of the Trust with respect to the
     following matters:

               (A)  the establishment of the Payment Account;

               (B)  the receipt of and taking title to the Debentures;

                                      18
<PAGE>
 
               (C)  the collection of interest, principal and any other payments
          made in respect of the Debentures in the Payment Account;

               (D)  the distribution from the Trust Property of amounts owed to
          the Securityholders in respect of the Trust Securities;

               (E)  the exercise of all of the rights, powers and privileges of
          a holder of the Debentures;

               (F)  the sending of notices of default, other notices and other
          information regarding the Trust Securities and the Debentures to the
          Securityholders in accordance with this Trust Agreement;

               (G)  the distribution of the Trust Property in accordance with
          the terms of this Trust Agreement;

               (H)  to the extent provided in this Trust Agreement, the winding
          up of the affairs of and liquidation of the Trust;

               (I)  after an Event of Default of which a Responsible Officer of
          the Property Trustee has knowledge, the taking of any action
          incidental to the foregoing as the Property Trustee may from time to
          time determine is necessary or advisable to give effect to the terms
          of this Trust Agreement and protect and conserve the Trust Property
          for the benefit of the Securityholders (without consideration of the
          effect of any such action on any particular Securityholder);

               (J)  subject to this Section 2.7(a)(ii), the Property Trustee
          shall have none of the duties, liabilities, powers or the authority of
          the Administrative Trustees set forth in Section 2.7(a)(i); and

               (K)  to act as Paying Agent and/or Securities Registrar to the
          extent appointed as such hereunder.

          (b)  So long as this Trust Agreement remains in effect, the Trust (or
the Trustees acting on behalf of the Trust) shall not undertake any business,
activities or transaction except as expressly provided herein or contemplated
hereby.  In particular, the Trust shall not, and the Trustees shall not and
shall not cause the Trust to

                                      19
<PAGE>
 
(i)  invest any proceeds received by the Trust from holding the Debentures
(rather, the Trustees shall distribute all such proceeds to the Securityholders
pursuant to the terms of this Trust Agreement and the Trust Securities), acquire
any investments or engage in any activities not authorized by this Trust
Agreement, (ii) sell, assign, transfer, exchange, mortgage, pledge, set-off or
otherwise dispose of any of the Trust Property or interests therein, including
to Securityholders, except as expressly provided herein, (iii) take any action
that would cause the Trust to fail or cease to qualify as a "grantor trust" for
United States Federal income tax purposes, (iv) make any loans or incur any
indebtedness for borrowed money or issue any other debt, (v) take or consent to
any action that would result in the placement of a Lien on any of the Trust
Property, (vi) possess any power or otherwise act in such a way as to vary the
Trust assets or the terms of the Trust Securities in any way whatsoever except
as permitted by the terms of this Trust Agreement, or (vii) issue any securities
or other evidences of beneficial ownership of, or beneficial interest in, the
Trust other than the Trust Securities.  The Administrative Trustees shall defend
all claims and demands of all Persons at any time claiming any Lien on any of
the Trust Property adverse to the interest of the Trust or the Securityholders
in their capacity as Securityholders.

          (c)  In connection with the issue and sale of the Preferred
Securities, the Depositor shall have the right and responsibility to assist the
Trust with respect to, or effect on behalf of the Trust, the following actions
(and any actions taken by the Depositor in furtherance of the following prior to
the date of this Trust Agreement are hereby ratified and confirmed in all
respects):

          (i)  to file by the Trust with the Commission and to execute on behalf
     of the Trust a registration statement on the appropriate form in relation
     to the Preferred Securities, including any amendments thereto;

          (ii) to determine the States and foreign jurisdictions in which to
     take appropriate action to qualify or register for resale all or part of
     the Preferred Securities and to do any and all such acts, other than
     actions which must be taken by or on behalf of the Trust, and advise the
     Trustees of actions they must take on behalf of the Trust, and prepare for
     execution and filing any documents to be executed and filed by the Trust or
     on behalf of the Trust, as the Depositor deems necessary or advisable in
     order to comply with the applicable laws of any such States and foreign
     jurisdictions;

                                      20
<PAGE>
 
          (iii) to the extent necessary, to prepare for filing by the Trust with
     the Commission and to execute on behalf of the Trust a registration
     statement on Form 8-A relating to the registration of the Preferred
     Securities under Section 12(b) or 12(g) of the Securities Exchange Act of
     1934, as amended, including any amendments thereto (it being understood
     that neither the Trust nor the Depositor has any obligation under the
     Indenture, the Underwriting Agreement or the Trust Agreement to register
     any Trust Securities under the Securities Exchange Act of 1934, as amended,
     or to list any Trust Securities on any securities exchange);

          (iv)  to negotiate, and to execute and deliver, on behalf of the
     Trust, the Underwriting Agreement; and

          (v)   any other actions necessary or incidental to carry out any of
     the foregoing activities.

          (d)   Notwithstanding anything herein to the contrary, the
Administrative Trustees are authorized and directed to conduct the affairs of
the Trust and to operate the Trust so that the Trust will not be deemed to be an
"investment company" required to be registered under the 1940 Act, or taxed as a
corporation for United States Federal income tax purposes and so that the
Debentures will be treated as indebtedness of the Depositor for United States
Federal income tax purposes.  In this connection, the Depositor and the
Administrative Trustees are authorized to take any action, not inconsistent with
applicable law, the Certificate of Trust or this Trust Agreement, that each of
the Depositor and the Administrative Trustees determines in their discretion to
be necessary or desirable for such purposes, so long as such action does not
adversely affect in any material respect the interests of the Holders of the
Preferred Securities except as otherwise provided in Section 10.2(a).

          SECTION 2.8.  Assets of Trust.  The assets of the Trust shall consist
                        ----------------                                       
of only the Trust Property.

          SECTION 2.9.  Title to Trust Property.  Legal title to all Trust
                        ------------------------                          
Property shall be vested at all times in the Property Trustee (in its capacity
as such) and shall be held and administered by the Property Trustee for the
benefit of the Trust and the Securityholders in accordance with this Trust
Agreement.  The Securityholders shall not have legal title to any part of the
assets of the Trust, but shall have an undivided beneficial interest in the
assets of the Trust.

                                      21
<PAGE>
 
                                   ARTICLE 3
                                PAYMENT ACCOUNT

          SECTION 3.1.  Payment Account.  (a)  On or prior to the Closing Date,
                        ----------------                                       
the Property Trustee shall establish the Payment Account.  The Property Trustee
and any agent of the Property Trustee shall have exclusive control and sole
right of withdrawal with respect to the Payment Account for the purpose of
making deposits in and withdrawals from the Payment Account in accordance with
this Trust Agreement. All monies and other property deposited or held from time
to time in the Payment Account shall be held by the Property Trustee in the
Payment Account for the exclusive benefit of the Securityholders and for
distribution as herein provided, including (and subject to) any priority of
payments provided for herein.

          (b)  The Property Trustee shall deposit in the Payment Account,
promptly upon receipt, all payments of principal of or interest on, and any
other payments or proceeds with respect to, the Debentures.  Amounts held in the
Payment Account shall not be invested by the Property Trustee pending
distribution thereof.


                                   ARTICLE 4
                DISTRIBUTIONS; REDEMPTION; EXCHANGE; CONVERSION

          SECTION 4.1.  Distributions.  (a)  Distributions on the Trust
                        --------------                                 
Securities shall be cumulative, and shall accrue from the date of original
issuance, or the most recent Distribution Date (as defined herein) and, except
in the event that the Depositor exercises its right to defer the payment of
interest on the Debentures pursuant to the Indenture, shall be payable quarterly
in arrears on [        ], [      ], [           ] and [          ] of each year,
commencing on [             ] (which dates correspond to the interest payment
dates on the Debentures), when, as and if available for payment by the Property
Trustee, as further described in paragraph (c) of this Section 4.1.  If any date
on which Distributions are otherwise payable on the Trust Securities is not a
Business Day, then the payment of such Distributions shall be made on the next
succeeding day which is a Business Day (and no interest shall accrue for the
period from and after such date until the next succeeding Business Day) with the
same force and effect as if made on such date (each date on which Distributions
are payable in accordance with this Section 4.1(a), a "Distribution Date").

                                      22
<PAGE>
 
          (b)  The Trust Securities represent undivided beneficial interests in
the Trust Property, and the Distributions on the Trust Securities shall be
payable at a rate of [     ]% per annum of the Liquidation Amount of the Trust
Securities, such rate being the rate of interest payable on the Debentures to be
held by the Property Trustee.  The amount of Distributions payable for any
period shall be computed on the basis of a 360-day year of twelve 30-day months.
For periods less than a full month, Distributions shall reflect interest on
Debentures computed on the basis of the actual number of elapsed days based on a
360-day year.  The amount of Distributions payable for any period shall include
the Additional Amounts, if any.

          (c)  Distributions on the Trust Securities shall be made by the
Property Trustee from the Payment Account and shall be payable on each
Distribution Date only to the extent that the Trust has funds then on hand and
available in the Payment Account for the payment of such Distributions.

          (d)  Distributions on the Trust Securities with respect to a
Distribution Date shall be payable to the Holders thereof as they appear on the
Securities Register for the Trust Securities on the relevant record date, which
shall be the date which is the fifteenth day (whether or not a Business Day)
next preceding such Distribution Date.

          SECTION 4.2.  Redemption.  (a)  Upon an optional redemption (as set
                        -----------                                          
forth in the Indenture) of Debentures, the proceeds from such redemption shall
be applied to redeem Trust Securities having an aggregate Liquidation Amount
equal to the aggregate principal amount of the Debentures so redeemed by the
Depositor, including pursuant to Section 4.4, at the Optional Redemption Price,
and upon a mandatory redemption (as set forth in the Indenture) of Debentures,
the proceeds from such redemption shall be applied to redeem Trust Securities,
having an aggregate Liquidation Amount equal to the aggregate principal amount
of the Debentures so redeemed by the Depositor, at the Redemption Price.  The
Trust may not redeem fewer than all the Outstanding Trust Securities unless all
accrued and unpaid Distributions have been paid on all Trust Securities for all
quarterly Distribution periods terminating on or prior to the date of
redemption.

          (b)  Notice of redemption (which notice will be irrevocable) shall be
given by the Property Trustee by first-class mail, postage prepaid, mailed not
less than 30 nor more than 60 days prior to the Redemption Date to the Depositor
and each Holder of Trust Securities to be

                                      23
<PAGE>
 
redeemed, at such Holder's address as it appears in the Securities Register.
All notices of redemption shall state:

          (i)    the Redemption Date;

          (ii)   the Redemption Price or the Optional Redemption Price, as the
     case may be;

          (iii)  the record date for the determination of Holders entitled to
     receive payment of the Redemption Price or Optional Redemption Price, as
     the case may be, as provided in Section 4.2(d);

          (iv)   the CUSIP number;

          (v)    if less than all of the Outstanding Trust Securities are to be
     redeemed, the identification and the aggregate Liquidation Amount of the
     particular Trust Securities to be redeemed;

          [(vi)  the Conversion Price and that a Holder of Preferred Securities
     who desires to convert such Preferred Securities called for redemption must
     satisfy the requirements for conversion contained in Section 4.3 below;]

          (vii)  that on the Redemption Date, the Redemption Price or the
     Optional Redemption Price, as the case may be, will become due and payable
     upon each such Trust Security to be redeemed and that Distributions thereon
     will cease to accrue on and after said date; and

          (viii) the place or places where such Trust Securities are to be
     surrendered for payment of the Redemption Price or the Optional Redemption
     Price, as the case may be.

          (c)    The Trust Securities redeemed on each Redemption Date shall be
redeemed at the Redemption Price or the Optional Redemption Price, as the case
may be, with the proceeds from the contemporaneous redemption of Debentures.
Redemptions of the Trust Securities shall be made and the Redemption Price or
the Optional Redemption Price, as the case may be, shall be payable on each
Redemption Date only to the extent that the Trust has funds then on hand and
available in the Payment Account for the payment of such Redemption Price or the
Optional Redemption Price, as the case may be.

          (d)    If the Property Trustee gives a notice of redemption in respect
of any Preferred Securities, then, by

                                      24
<PAGE>
 
12:00 noon, New York City time, on the Redemption Date, subject to Section
4.2(c), the Property Trustee will, so long as and to the extent the Preferred
Securities are in book-entry-only form, irrevocably deposit with the Clearing
Agency for the Preferred Securities funds sufficient to pay the applicable
Redemption Price. If the Preferred Securities are no longer in book-entry-only
form, the Property Trustee, subject to Section 4.2(c), will irrevocably deposit
with the Paying Agent funds sufficient to pay the applicable Redemption Price or
Optional Redemption Price, as the case may be, on such Preferred Securities held
in certificated form and will give the Paying Agent irrevocable instructions and
authority to pay the Redemption Price or the Optional Redemption Price, as the
case may be, to the Holders thereof upon surrender of their Preferred Securities
Certificates. Notwithstanding the foregoing, Distributions payable on or prior
to the Redemption Date for any Trust Securities called for redemption shall be
payable to the Holders of such Trust Securities as they appear on the Securities
Register for the Trust Securities on the relevant record dates for the related
Distribution Dates. If notice of redemption shall have been given and funds
deposited as required, then, upon the date of such deposit, all rights of
Securityholders holding Trust Securities so called for redemption will cease,
except (i) the right of such Securityholders to receive the Redemption Price or
the Optional Redemption Price, as the case may be, but without interest, and
(ii) the right to convert such Preferred Securities into Common Stock in the
manner provided in Section 4.3 through the close of business on the Redemption
Date; and such Trust Securities will cease to be Outstanding. In the event that
any date on which any Redemption Price or the Optional Redemption Price, as the
case may be, is payable is not a Business Day, then payment of the Redemption
Price or the Optional Redemption Price, as the case may be, payable on such date
will be made on the next succeeding day which is a Business Day (and without any
interest or other payment in respect of any such delay), except that, if such
Business Day is in the next succeeding calendar year, such payment shall be made
on the immediately preceding Business Day, in each case, with the same force and
effect as if made on such date. Payment of the Redemption Price or the Optional
Redemption Price, as the case may be, shall be made to the Holders of such Trust
Securities as they appear on the Securities Register for the Trust Securities on
the relevant record date, which shall be the date which is the fifteenth day
(whether or not a Business Day) preceding such Redemption Date.

          (e)  If less than all the Outstanding Trust Securities are to be
redeemed on a Redemption Date, then the

                                      25
<PAGE>
 
aggregate Liquidation Amount of Trust Securities to be redeemed shall be
allocated on a pro rata basis (based on Liquidation Amounts) among the Common
               --------
Securities and the Preferred Securities that are to be redeemed. The particular
Preferred Securities to be redeemed shall be selected not more than 60 days
prior to the Redemption Date by the Property Trustee from the Outstanding
Preferred Securities not previously called for redemption, by lot or by such
other method as the Property Trustee shall deem fair and appropriate and which
may provide for the selection for redemption of portions (equal to $50 or an
integral multiple of $50 in excess thereof) of the Liquidation Amount of the
Preferred Securities. The Property Trustee shall promptly notify the Securities
Registrar and the Conversion Agent in writing of the Preferred Securities
selected for redemption and, in the case of any Preferred Securities selected
for partial redemption, the Liquidation Amount thereof to be redeemed; it being
understood that, in the case of Preferred Securities registered in the name of
and held of record by the Clearing Agency (or any successor) or any nominee, the
distribution of the proceeds of such redemption will be made in accordance with
the procedures of the Clearing Agency or its nominee. For all purposes of this
Trust Agreement, unless the context otherwise requires, all provisions relating
to the redemption of Preferred Securities shall relate, in the case of any
Preferred Securities redeemed or to be redeemed only in part, to the portion of
the Liquidation Amount of Preferred Securities which has been or is to be
redeemed. In the event of any redemption in part, the Trust shall not be
required to (i) issue, register the transfer of or exchange of any Preferred
Security during a period beginning at the opening of business 15 days before any
selection for redemption of Preferred Securities and ending at the close of
business on the earliest date in which the relevant notice of redemption is
deemed to have been given to all Holders of Preferred Securities to be so
redeemed or (ii) register the transfer of or exchange of any Preferred
Securities so selected for redemption, in whole or in part, except for the
unredeemed portion of any Preferred Securities being redeemed in part.

          (f)  In the event of any redemption, the Trust shall not be required
to issue, register the transfer of or register the exchange of any Preferred
Security during a period beginning at the opening of business 15 days before any
Redemption Date and ending at the close of business on such Redemption Date.

          [SECTION 4.3.  Conversion.  The Holders of Trust Securities, subject
                         -----------                                          
to the limitations set forth in this Section, shall have the right, at their
option, to cause the

                                      26
<PAGE>
 
Conversion Agent to convert Trust Securities, on behalf of the converting
Holders, into shares of Common Stock in the manner described herein on and
subject to the following terms and conditions:

          (i)  The Trust Securities will be convertible into fully paid and
     nonassessable shares of Common Stock pursuant to the Holders direction to
     the Conversion Agent to exchange such Trust Securities for a portion of the
     Debentures having a principal amount equal to the aggregate Liquidation
     Amount of such Trust Securities, and promptly convert such amount of
     Debentures into fully paid and nonassessable shares of Common Stock at an
     initial rate of [     ] shares of Common Stock for each Trust Security 
     (which is equivalent to a conversion price of approximately $[     ] per 
     $50 principal amount of Debentures), subject to certain adjustments set 
     forth in the Indenture (as so adjusted, the "Conversion Price").

         (ii)  In order to convert Trust Securities into Common Stock, the
     Holder of such Trust Securities shall submit to the Conversion Agent an
     irrevocable Notice of Conversion to convert Trust Securities on behalf of
     such Holder, together, if the Trust Securities are in certificated form,
     with such certificates. The Notice of Conversion shall (i) set forth the
     number of Trust Securities to be converted and the name or names, if other
     than the Holder, in which the shares of Common Stock should be issued and
     (ii) direct the Conversion Agent (a) to exchange such Trust Securities for
     a portion of the Debentures held by the Property Trustee (at the rate of
     exchange specified in the preceding paragraph) and (b) to promptly convert
     such Debentures, on behalf of such Holder, into Common Stock (at the
     conversion rate specified in the preceding paragraph). The Conversion Agent
     shall notify the Property Trustee in writing of the Holder's election to
     exchange Trust Securities for a portion of the Debentures held by the
     Property Trustee and the Property Trustee shall, upon receipt of such
     written notice, deliver to the Conversion Agent the appropriate principal
     amount of Debentures for exchange in accordance with this Section. The
     Conversion Agent shall thereupon notify the Depositor of the Holder's
     election to convert such Debentures into shares of Common Stock. Holders of
     Trust Securities at the close of business on a Distribution payment record
     date will be entitled to receive the Distribution paid on such Trust
     Securities on the corresponding Distribution Date notwithstanding the
     conversion of such Trust Securities on or following

                                      27
<PAGE>
 
     such record date but prior to such distribution Date. Except as provided
     above, neither the Trust nor the Depositor will make, or be required to
     make, any payment, allowance or adjustment upon any conversion on account
     of any accumulated and unpaid Distributions whether or not in arrears
     accrued on the Trust Securities surrendered for conversion, or on account
     of any accumulated and unpaid dividends on the shares of Common Stock
     issued upon such conversion. Trust Securities submitted for conversion
     prior to the expiration of conversion rights as provided in Section
     4.3(iii) shall be deemed to have been converted immediately prior to the
     close of business on the day on which an irrevocable Notice of Conversion
     relating to such Trust Securities is received by the Conversion Agent in
     accordance with the foregoing provision (the "Conversion Date"). The Person
     or Persons entitled to receive the Common Stock issuable upon conversion of
     the Debentures shall be treated for all purposes as the record holder or
     holders of such Common Stock on the Conversion Date of conversion. As
     promptly as practicable on or after the Conversion Date, the Depositor
     shall issue and deliver at the office of the Conversion Agent a certificate
     or certificates for the number of full shares of Common Stock issuable upon
     such conversion, together with the cash payment, if any, in lieu of any
     fraction of any share to the Person or Persons entitled to receive the
     same, unless otherwise directed by the Holder in the notice of conversion
     and the Conversion Agent shall distribute such certificate or certificates
     to such Person or Persons.

        (iii)  The conversion rights of holders of the Debentures and the
     corresponding conversion rights of Holders of Trust Securities shall expire
     at the close of business on the date set for redemption of the Trust
     Securities upon the mandatory or optional redemption of the Debentures.

         (iv)  Each Holder of a Trust Security by its acceptance thereof 
     initially appoints [                     ] not in its individual capacity
     but solely as conversion agent (the "Conversion Agent") for the purpose of
     effecting the conversion of Trust Securities in accordance with this
     Section. In effecting the conversion and transactions described in this
     Section, the Conversion Agent shall be acting as agent of the Holders of
     Trust Securities directing it to effect such conversion transactions. The
     Conversion Agent is hereby authorized (i) to exchange Trust Securities from

                                      28
<PAGE>
 
     time to time for Debentures held by the Trust in connection with the
     conversion of such Trust Securities in accordance with this Section and
     (ii) to convert all or a portion of the Debentures into Common Stock and
     thereupon to deliver such shares of Common Stock in accordance with the
     provisions of this Section and to deliver to the Property Trustee any new
     Debenture or Debentures for any resulting unconverted principal amount
     delivered to the Conversion Agent by the Debenture Trustee.

          (v)  No fractional shares of Common Stock will be issued as a result
     of conversion, but, in lieu thereof, such fractional interest will be paid
     in cash by the Depositor to the Conversion Agent in an amount equal to the
     Current Market Price of the fractional share of the Common Stock, and the
     Conversion Agent will in turn make such payment to the Holder or Holders of
     Trust Securities so converted.

         (vi)  Nothing in this Section 4.3 shall limit the requirement of the
     Trust to withhold taxes pursuant to the terms of the Trust Securities or as
     set forth in this Trust Agreement or otherwise required of the Property
     Trustee or the Trust to pay any amounts on account of such withholdings.]

          SECTION 4.4.  Special Event Exchange or Redemption.  (a)  If a Special
                        -------------------------------------                   
Event shall occur and be continuing, the Property Trustee shall direct the
Conversion Agent to exchange all Outstanding Trust Securities for Debentures
having a principal amount equal to the aggregate Liquidation Amount of the Trust
Securities to be exchanged and with accrued interest in an amount equal to any
unpaid Distribution (including any Additional Amounts) on the Trust Securities;
provided, however, that, in the case of a Tax Event, the Depositor shall have
- --------  -------                                                            
the right to (i) direct that less than all, or none, as appropriate, of the
Trust Securities be so exchanged if and for so long as the Depositor shall have
elected to pay any Additional Sums (as defined in the Indenture) such that the
amount received by Holders of Trust Securities not so exchanged in respect of
Distributions and other distributions are not reduced as a result of such Tax
Event, and shall not have revoked any such election or failed to make such
payments or (ii) cause the Trust Securities to be redeemed in the manner set
forth below.  If a Tax Event shall occur and be continuing, the Depositor shall
have the right, upon not less than 30 nor more than 60 days' notice, to redeem
the Debentures, in whole or in part, for cash upon the later of (i) 90 days
following the occurrence of such Tax Event or

                                      29
<PAGE>
 
(ii) [                ].  Promptly following such redemption, Trust Securities
with an aggregate Liquidation Amount equal to the aggregate principal amount of
the Debentures so redeemed will be redeemed by the Trust at the Optional
Redemption Price applicable in the event of a redemption upon the occurrence of
a Tax Event on a pro rata basis.
                 --------       

          (b)  Notice of any exchange pursuant to this Section 4.4 (an "Exchange
Notice") of the Trust Securities, which Exchange Notice shall be irrevocable,
will be given by the Property Trustee by first-class mail to the Depositor and
to each record Holder of Trust Securities to be exchanged not fewer than 30 nor
more than 60 days prior to the date fixed for exchange thereof. For purposes of
the calculation of the date of exchange and the dates on which notices are given
pursuant to this paragraph (b), an Exchange Notice shall be deemed to be given
on the day such notice is first mailed by first-class mail, postage prepaid, to
each Holder. Each Exchange Notice shall be addressed to each Holder of Trust
Securities at the address of such Holder appearing in the Securities Register.
Each Exchange Notice shall state: (A) the exchange date; (B) the aggregate
Liquidation Amount and any unpaid Distributions (including any Additional
Amounts) on the Trust Securities to be exchanged and the aggregate principal
amount and any accrued interest on the Debentures to be exchanged therefor; (C)
that on the exchange date the Trust Securities to be so exchanged shall be
exchanged for Debentures and that Distributions on the Trust Securities so
exchanged will cease to accumulate on and after said date; (D) the record date
for the determination of Holders of Trust Securities to be exchanged as provided
in Section 4.4(g); and (E) the identity of the Conversion Agent, if any, and the
place or places where each Trust Certificate to be exchanged is to be
surrendered in exchange for Debentures. No defect in the Exchange Notice or in
the mailing thereof with respect to any Trust Security shall affect the validity
of the exchange proceedings for any other Trust Security.

          (c)  In the event that fewer than all the Outstanding Preferred
Securities are to be exchanged, then, on the exchange date, (i) if all of the
Outstanding Preferred Securities are represented by Definitive Preferred
Securities Certificates, the particular Preferred Securities to be exchanged
will be selected by the Property Trustee from the Outstanding Preferred
Securities not previously called for redemption or exchange on a pro rata basis,
                                                                 --------
and (ii) if all of the Outstanding Preferred Securities are represented by Book-
Entry Preferred Securities Certificates, the Property Trustee shall provide for
the selection for

                                      30
<PAGE>
 
exchange of a portion of the Global Certificate representing the Book-Entry
Preferred Securities Certificates on a pro rata basis.  In the case of clause
                                       --------                              
(ii) above, the particular Book-Entry Preferred Securities Certificates to be
exchanged shall be selected in accordance with the applicable rules and
procedures for the Clearing Agency in whose name, or whose nominee's name, such
Global Certificate is then held. Any Preferred Securities Certificate that is to
be exchanged only in part shall be surrendered with due endorsement or by a
written instrument of transfer fully executed by the Holder thereof (or its
attorney duly authorized in writing) and the Trust shall prepare and deliver to
such Holder, without service charge, a new Preferred Securities Certificate or
Certificates in aggregate stated Liquidation Amount equal to, and in exchange
for, the unredeemed portion of the Preferred Securities Certificate so
surrendered. The Common Securities shall be exchanged in a similar manner.

          (d)  In the event of an exchange pursuant to this Section 4.4, on the
date fixed for any such exchange, (i) if the Preferred Securities are
represented by Book-Entry Preferred Securities Certificates, the Clearing Agency
or its nominee, as the record Holder of the Preferred Securities, will exchange
through the Conversion Agent the Global Certificate representing the Preferred
Securities to be exchanged for a registered Global Certificate or certificates
representing the Debentures to be delivered upon such exchange, (ii) if the
Preferred Securities are represented by Definitive Preferred Securities
Certificates, the certificates representing the Preferred Securities to be so
exchanged will be deemed to represent Debentures having a principal amount equal
to the aggregate stated Liquidation Amount of such Preferred Securities until
such certificates are presented to the Conversion Agent for exchange for
definitive certificates representing Debentures and (iii) all rights of the
Holders of the Preferred Securities so exchanged will cease, except for the
right of such Holders to receive Debentures. The Common Securities shall be
exchanged in a similar manner.

          (e)  Each Holder, by becoming a party to this Trust Agreement pursuant
to Section 10.11 of this Trust Agreement, will be deemed to have agreed to be
bound by these exchange provisions in regard to the exchange of Trust Securities
for Debentures pursuant to the terms described above.

          (f)  Nothing in this Section 4.4 shall limit the requirement of the
Trust to withhold taxes pursuant to the terms of the Trust Securities or as set
forth in this Trust

                                      31
<PAGE>
 
Agreement or otherwise require the Property Trustee or the Trust to pay any
amounts on account of such withholdings.

          (g)  An exchange of Trust Securities for Debentures pursuant to this
Section 4.4 shall be made to Holders of Trust Securities as they appear on the
Securities Register for Trust Securities on the relevant record date, which
shall be the date which is the fifteenth day (whether or not a Business Day)
preceding the exchange date.

          SECTION 4.5.  Subordination of Common Securities. Payment of
                        -----------------------------------           
Distributions (including Additional Amounts, if applicable) on, and the 
Redemption Price of, the Trust Securities, as applicable, shall be made pro rata
                                                                        --------
based on the Liquidation Amount of the Trust Securities; provided, however, that
                                                         --------  -------      
if on any Distribution Date or Redemption Date an Event of Default shall have
occurred and be continuing, no payment of any Distribution (including Additional
Amounts, if applicable) on, or the Redemption Price of, any Common Security, and
no other payment on account of the redemption, liquidation or other acquisition
of Common Securities, shall be made unless payment in full in cash of all
accumulated and unpaid Distributions (including Additional Amounts, if
applicable) on all Outstanding Preferred Securities for all Distribution periods
terminating on or prior thereto, or in the case of payment of the Redemption
Price the full amount of such Redemption Price on all Outstanding Preferred
Securities to be redeemed, shall have been made or provided for, and all funds
immediately available to the Property Trustee shall first be applied to the
payment in full in cash of all Distributions (including Additional Amounts, if
applicable) on, or the Redemption Price of, Preferred Securities then due and
payable.

          SECTION 4.6.  Payment Procedures.  Payments in respect of the
                        -------------------                            
Preferred Securities shall be made by check mailed to the address of the Person
entitled thereto as such address shall appear on the Securities Register or, if
the Preferred Securities are held by a Clearing Agency, such Distributions shall
be made to the Clearing Agency in immediately available funds, in accordance
with the Certificate Depositary Agreement on the applicable Distribution Dates.
Payments in respect of the Common Securities shall be made in such manner as
shall be mutually agreed between the Property Trustee and the Holder of the
Common Securities.

          SECTION 4.7.  Tax Returns and Reports.  The Administrative Trustees
                        ------------------------                             
shall prepare (or cause to be prepared), at the Depositor's expense, and file
all United

                                      32
<PAGE>
 
States Federal, State and local tax and information returns and reports required
to be filed by or in respect of the Trust. In this regard, the Administrative
Trustees shall (a) prepare and file (or cause to be prepared or filed) Form 1041
or the appropriate Internal Revenue Service form required to be filed in respect
of the Trust in each taxable year of the Trust and (b) prepare and furnish (or
cause to be prepared and furnished) to each Securityholder a Form 1099 or the
appropriate Internal Revenue Service form required to be furnished to such
Securityholder or the information required to be provided on such form. The
Administrative Trustees shall provide the Depositor with a copy of all such
returns, reports and schedules promptly after such filing or furnishing. The
Trustees shall comply with United States Federal withholding and backup
withholding tax laws and information reporting requirements with respect to any
payments to Securityholders under the Trust Securities.

          SECTION 4.8.  Payment of Taxes, Duties, Etc., of the Trust.  Upon
                        ---------------------------------------------      
receipt under the Debentures of Additional Sums, the Property Trustee, upon
receipt of written notice from the Depositor or the Administrative Trustees,
shall promptly pay from such Additional Sums any taxes, duties or governmental
charges of whatsoever nature (other than withholding taxes) imposed on the Trust
by the United States or any other taxing authority.

          SECTION 4.9.  Payments under Indenture.  Any amount payable hereunder
                        -------------------------                              
to any Holder of Preferred Securities shall be reduced by the amount of any
corresponding payment such Holder (or any Owner with respect thereto) has
directly received pursuant to Section [5.8] of the Indenture in accordance with
the terms of Section 6.8 hereof.


                                   ARTICLE 5
                         TRUST SECURITIES CERTIFICATES

          SECTION 5.1.  Initial Ownership.  Upon the creation of the Trust and
                        ------------------                                    
until the issuance of the Trust Securities, and at any time during which no
Trust Securities are Outstanding, the Depositor shall be the sole beneficial
owner of the Trust.

          SECTION 5.2.  The Trust Securities Certificates. The Preferred
                        ----------------------------------              
Securities Certificates shall be issued in minimum denominations of $50
Liquidation Amount and integral multiples of $50 in excess thereof, and the
Common Securities Certificates shall be issued in denominations of

                                      33
<PAGE>
 
$50 Liquidation Amount and integral multiples thereof. The consideration
received by the Trust for the issuance of the Trust Securities shall constitute
a contribution to the capital of the Trust and shall not constitute a loan to
the Trust. The Trust Securities Certificates shall be executed on behalf of the
Trust by manual or facsimile signature of at least one Administrative Trustee
and authenticated by the Property Trustee. Preferred Securities initially will
be represented by one or more certificates in registered global form (the
"Global Certificates"). Trust Securities Certificates bearing the manual or
facsimile signatures of individuals who were, at the time when such signatures
shall have been affixed, authorized to sign on behalf of the Trust, shall be
validly issued and entitled to the benefit of this Trust Agreement,
notwithstanding that such individuals or any of them shall have ceased to be so
authorized prior to the delivery of such Trust Securities Certificates or did
not hold such offices at the date of delivery of such Trust Securities
Certificates. A transferee of a Trust Securities Certificate shall become a
Securityholder, and shall be entitled to the rights and subject to the
obligations of a Securityholder hereunder, upon due registration of such Trust
Securities Certificate in such transferee's name pursuant to Section 5.4.

          SECTION 5.3.  Delivery of Trust Securities Certificates.  On the
                        ------------------------------------------        
Closing Date, the Administrative Trustees shall cause Trust Securities
Certificates, in an aggregate Liquidation Amount as provided in Sections 2.4 and
2.5, to be executed on behalf of the Trust and delivered to or upon the written
order of the Depositor, signed by its Chairman of the Board, any Vice Chairman,
its President, any Senior Vice President or any Vice President, Treasurer or
Assistant Treasurer or Controller without further corporate action by the
Depositor, in authorized denominations.

          A Trust Security Certificate shall not be valid until authenticated by
the manual signature of an authorized signatory of the Property Trustee.  The
signature shall be conclusive evidence that the Trust Security Certificate has
been authenticated under this Trust Agreement.  Upon a written order of the
Trust signed by one Administrative Trustee, the Property Trustee shall
authenticate the Trust Security Certificates for original issue.

          The Property Trustee may appoint an authenticating agent acceptable to
the Administrative Trustees to authenticate Trust Security Certificates.  An
authenticating agent may authenticate Trust Security Certificates whenever the
Property Trustee may do so.  Each reference in this Trust Agreement to
authentication by the Property Trustee

                                      34
<PAGE>
 
includes authentication by such agent. An authenticating agent has the same
rights as the Property Trustee to deal with the Depositor or an Affiliate with
respect to the authentication of Trust Securities.

          SECTION 5.4.  Registration of Transfer and Exchange of Preferred
                        --------------------------------------------------
Securities; Restrictions on Transfer. The Securities Registrar shall keep or
- -------------------------------------                                       
cause to be kept, at the office or agency maintained pursuant to Section 5.8, a
Securities Register in which, subject to such reasonable regulations as it may
prescribe, the Securities Registrar shall provide for the registration of
Preferred Securities Certificates and Common Securities Certificates (subject to
Section 5.10 in the case of the Common Securities Certificates) and registration
of transfers and exchanges of Preferred Securities Certificates as herein
provided. The Property Trustee shall be the initial Securities Registrar.

          Upon surrender for registration of transfer of any Preferred Security
at an office or agency of the Securities Registrar designated pursuant to
Section 5.8 for such purpose, an Administrative Trustee shall execute on behalf
of the Trust by manual or facsimile signature, and the Property Trustee shall
authenticate and deliver, in the name of the designated transferee or
transferees, one or more new Preferred Securities of any authorized
denominations and of a like aggregate Liquidation Amount.

          At the option of the Holder, and subject to the other provisions of
this Section 5.4, Preferred Securities may be exchanged for other Preferred
Securities of any authorized denomination and of a like Liquidation Amount, upon
surrender of the Preferred Securities to be exchanged at any such office or
agency.  Whenever any Preferred Securities are so surrendered for exchange, an
Administrative Trustee shall execute on behalf of the Trust by manual or
facsimile signature, and the Property Trustee shall authenticate and deliver,
the Preferred Securities which the Holder making the exchange is entitled to
receive.

          All Preferred Securities issued upon any registration of transfer or
exchange of Preferred Securities shall be entitled to the same benefits under
this Trust Agreement as the Preferred Securities surrendered upon such
registration of transfer or exchange.

          Every Preferred Security presented or surrendered for registration of
transfer or for exchange shall (if so requested by the Depositor or the
Securities Registrar) be duly endorsed, or be accompanied by a written
instrument of transfer in form satisfactory to the Depositor and the

                                      35
<PAGE>
 
Securities Registrar duly executed, by the Holder thereof or his attorney duly
authorized in writing.

          No service charge shall be made for any registration of transfer or
exchange of Preferred Securities Certificates, but the Securities Registrar may
require payment of a sum sufficient to cover any tax or governmental charge that
may be imposed in connection with any transfer or exchange of Preferred
Securities Certificates.

          SECTION 5.5.  Mutilated, Destroyed, Lost or Stolen Trust Securities
                        -----------------------------------------------------
Certificates.  If (a) any mutilated Trust Securities Certificate shall be
- -------------                                                            
surrendered to the Securities Registrar, or if the Securities Registrar shall
receive evidence to its satisfaction of the destruction, loss or theft of any
Trust Securities Certificate and (b) there shall be delivered to the Securities
Registrar and the Administrative Trustees such security or indemnity as may be
required by them to save each of them harmless, then in the absence of notice
that such Trust Securities Certificate shall have been acquired by a bona fide
purchaser, the Administrative Trustees, or any one of them, on behalf of the
Trust shall execute and make available for authentication and delivery, in
exchange for or in lieu of any such mutilated, destroyed, lost or stolen Trust
Securities Certificate, a new Trust Securities Certificate of like denomination.
In connection with the issuance of any new Trust Securities Certificate under
this Section, the Securities Registrar may require the payment of a sum
sufficient to cover any tax or other governmental charge that may be imposed in
connection therewith. Any duplicative Trust Securities Certificate issued
pursuant to this Section shall constitute conclusive evidence of an undivided
beneficial interest in the assets of the Trust, as if originally issued, whether
or not the lost, stolen or destroyed Trust Securities Certificate shall be found
at any time.

          SECTION 5.6.  Persons Deemed Securityholders. Each Trustee and the
                        -------------------------------                     
Securities Registrar shall treat the Person in whose name any Trust Securities
Certificate shall be registered in the Securities Register as the owner of such
Trust Securities Certificate for the purpose of receiving Distributions and for
all other purposes whatsoever, and none of the Trustees nor the Securities
Registrar shall be bound by any notice to the contrary.

          SECTION 5.7.  Access to List of Securityholders' Names and Addresses.
                        ------------------------------------------------------- 
The Administrative Trustees or the Depositor shall furnish or cause to be
furnished (unless the Property Trustee is acting as Securities Registrar with

                                      36
<PAGE>
 
respect to the Trust Securities under the Trust Agreement) a list, in such form
as the Property Trustee may reasonably require, of the names and addresses of
the Securityholders as of the most recent record date (a) to the Property
Trustee, quarterly at least five Business Days before each Distribution Date,
and (b) to the Property Trustee, promptly after receipt by the Depositor of a
written request therefor from the Property Trustee in order to enable the
Property Trustee to discharge its obligations under this Trust Agreement, in
each case to the extent such information is in the possession or control of the
Administrative Trustees or the Depositor and is not identical to a previously
supplied list or has not otherwise been received by the Property Trustee in its
capacity as Securities Registrar. The rights of Securityholders to communicate
with other Securityholders with respect to their rights under this Trust
Agreement or under the Trust Securities, and the corresponding rights of the
Trustee shall be as provided in the Trust Indenture Act, except to the extent
Section 3819 of the Delaware Business Trust Act would require greater access to
such information, in which case the latter shall apply. Each Holder, by
receiving and holding a Trust Securities Certificate, and each Owner shall be
deemed to have agreed not to hold the Depositor, the Property Trustee or the
Administrative Trustees accountable by reason of the disclosure of its name and
address, regardless of the source from which such information was derived.

          SECTION 5.8.  Maintenance of Office or Agency. The Securities
                        --------------------------------               
Registrar shall maintain in The City of New York an office or offices or agency
or agencies where Preferred Securities Certificates may be surrendered for
registration of transfer, exchange or conversion and where notices and demands
to or upon the Trustees in respect of the Trust Securities Certificates may be
served.  The Securities Registrar initially designates [                    ,
New York, New York [   ], Attention: [                              ], as its
principal corporate trust office for such purposes.  The Securities Registrar
shall give prompt written notice to the Depositor and to the Securityholders of
any change in the location of the Securities Register or any such office or
agency.

          SECTION 5.9.  Appointment of Paying Agent.  In the event that the
                        ----------------------------                       
Preferred Securities are not in book-entry form only, the Trust shall maintain
in the Borough of Manhattan, City of New York, an office or agency (the "Paying
Agent") where the Preferred Securities may be presented for payment. The Paying
Agent shall make Distributions to Securityholders from the Payment Account and
shall report the amounts of such Distributions to the

                                      37
<PAGE>
 
Property Trustee and the Administrative Trustees.  Any Paying Agent shall have
the revocable power to withdraw funds from the Payment Account for the purpose
of making the Distributions referred to above.  The Administrative Trustees may
revoke such power and remove the Paying Agent if such Trustees determine in
their sole discretion that the Paying Agent shall have failed to perform its
obligations under this Trust Agreement in any material respect.  The Paying
Agent shall initially be the Property Trustee, and any co-paying agent chosen by
the Property Trustee and acceptable to the Administrative Trustees and the
Depositor. Any Person acting as Paying Agent shall be permitted to resign as
Paying Agent upon 30 days' written notice to the Property Trustee and the
Depositor; provided, however, that no such resignation of the Paying Agent shall
           --------  -------                                                    
be effective until a successor Paying Agent has been appointed and has accepted
such appointment by instrument executed by such successor Paying Agent and
delivered to the Trust, the Depositor and the resigning Paying Agent.  In the
event that the Property Trustee shall no longer be the Paying Agent or a
successor Paying Agent shall resign or its authority to act be revoked, the
Administrative Trustees shall appoint a successor that is acceptable to the
Property Trustee and the Depositor to act as Paying Agent (which shall be a bank
or trust company).  Each successor Paying Agent or any additional Paying Agent
shall agree with the Trustees that, as Paying Agent, such successor Paying Agent
or additional Paying Agent will hold all sums, if any, held by it for payment to
the Securityholders in trust for the benefit of the Securityholders entitled
thereto until such sums shall be paid to each Securityholder.  The Paying Agent
shall return all unclaimed funds to the Property Trustee and upon removal of a
Paying Agent such Paying Agent shall also return all funds in its possession to
the Property Trustee. The provisions of Sections 8.1, 8.3 and 8.6 shall apply to
the Property Trustee also in its role as Paying Agent, for so long as the
Property Trustee shall act as Paying Agent and, to the extent applicable, to any
other paying agent appointed hereunder.  Any reference in this Agreement to the
Paying Agent shall include any co-paying agent unless the context requires
otherwise.

          SECTION 5.10.  Ownership of Common Securities by Depositor.  Upon the
                         --------------------------------------------          
issuance of Common Securities as provided for in Section 2.5, the Depositor
shall acquire beneficial and record ownership of the Common Securities. The
Depositor has covenanted in the Indenture to maintain directly or indirectly
100% ownership of the Common Securities, provided that any permitted successor
of the Company under the Indenture may succeed to the Company's ownership of the
Common Securities. To the fullest extent

                                      38
<PAGE>
 
permitted by law, any attempted transfer of the Common Securities in violation
of that covenant shall be void. The Administrative Trustees shall cause each
Common Securities Certificate to contain a legend stating, "THIS CERTIFICATE IS
NOT TRANSFERABLE EXCEPT TO AN ENTITY WHOLLY OWNED BY ALUMINUM COMPANY OF AMERICA
OR TO CERTAIN SUCCESSORS OF ALUMINUM COMPANY OF AMERICA"

          SECTION 5.11.  Global Securities; Non-Global Securities; Common
                         ------------------------------------------------
Securities Certificate.  (a)  Each Global Certificate authenticated under this
- -----------------------                                                       
Trust Agreement shall be registered in the name of the Clearing Agency
designated by the Depositor for such Global Certificate or a nominee thereof and
delivered to such Clearing Agency or a nominee thereof or custodian therefor,
and each such Global Certificate shall constitute a Preferred Security for all
purposes of this Trust Agreement.

          (b)  If a Global Certificate is to be exchanged for Definitive
Preferred Securities Certificates or canceled in whole, it shall be surrendered
by or on behalf of the Clearing Agency, its nominee or custodian to the Property
Trustee, as Securities Registrar, for exchange or cancellation as provided in
this Article 5. If any Global Certificate is to be exchanged for Definitive
Preferred Securities Certificates or cancelled in part, or if another Preferred
Security is to be exchanged in whole or in part for a beneficial interest in any
Global Certificate, in each case, as provided in Section 5.4, then either (i)
such Global Certificate shall be so surrendered for exchange or cancellation as
provided in this Article 5 or (ii) the Liquidation Amount thereof (or number of
Preferred Securities represented thereby) shall be reduced or increased by an
amount equal to the portion, thereof to be so exchanged or cancelled, or equal
to the Liquidation Amount of (or number of securities represented by) such
Definitive Preferred Security Certificates to be so exchanged for a beneficial
interest therein, as the case may be, by means of an appropriate adjustment made
on the records of the Property Trustee, as Securities Registrar, whereupon the
Property Trustee, in accordance with the Applicable Procedures, shall instruct
the Clearing Agency or its authorized representative to make a corresponding
adjustment to its records. Upon any such surrender or adjustment of a Global
Certificate, an Administrative Trustee shall execute on behalf of the Trust by
manual or facsimile signature, and the Property Trustee shall, subject to
Section 5.4 and as otherwise provided in this Article 5, authenticate and
deliver any Preferred Securities issuable in exchange for such Global
Certificate (or any portion thereof) to or upon the written order of, and
registered in

                                      39
<PAGE>
 
such names as may be directed by, the Clearing Agency or its authorized
representative.  Upon the request of the Property Trustee in connection with the
occurrence of any of the events specified in this paragraph, the Depositor shall
promptly make available to the Property Trustee a reasonable supply of Preferred
Securities that are not in the form of Global Certificates.  The Property
Trustee shall be entitled to conclusively rely upon any order, direction or
request of the Clearing Agency or its authorized representative which is given
or made pursuant to this Article 5 if such order, direction or request is given
or made in accordance with the Applicable Procedures.

          (c)  Every Preferred Security authenticated and delivered upon
registration of transfer of, or in exchange for or in lieu of, a Global
Certificate or any portion thereof, whether pursuant to this Article 5 or
otherwise, shall be authenticated and delivered in the form of, and shall be, a
Global Certificate, unless such Preferred Security is registered in the name of
a Person other than the Clearing Agency for such Global Certificate or a nominee
thereof.

          (d)  The Clearing Agency or its nominee, as registered owner of a
Global Certificate, shall be the Holder of such Global Certificate for all
purposes under this Trust Agreement and the Preferred Securities, and owners of
beneficial interests in a Global Certificate shall hold such interests pursuant
to the Applicable Procedures. Accordingly, any such Owner's beneficial interest
in a Global Certificate will be shown only on, and the transfer of such interest
shall be effected only through, records maintained by the Clearing Agency or its
nominee or its participants and such owners of beneficial interests in a Global
Certificate will not be considered the owners or Holders of such Global
Certificate for any purpose of this Trust Agreement or the Preferred Securities.

          (e)  A single Common Securities Certificate representing the Common
Securities shall initially be issued to the Depositor in the form of a
definitive Common Securities Certificate.

          SECTION 5.12.  Notices to Clearing Agency.  To the extent that a
                         ---------------------------                      
notice or other communication to the Owners is required under this Trust
Agreement, unless and until Definitive Preferred Securities Certificates shall
have been issued to Owners pursuant to Section 5.13, the Trustees shall give all
such notices and communications specified herein to be given to Owners to the
Clearing Agency, and

                                      40
<PAGE>
 
shall have no obligations to provide notices directly to the Owners.

          SECTION 5.13.  Definitive Preferred Securities Certificates.
                         --------------------------------------------- 
Notwithstanding any other provision in this Trust Agreement, no Global
Certificate may be exchanged in whole or in part for Preferred Securities
registered, and no transfer of a Global Certificate in whole or in part may be
registered, in the name of any Person other than the Clearing Agency for such
Global Certificate or a nominee thereof unless (i) such Clearing Agency (A) has
notified the Trust and the Depositor that it is unwilling or unable to continue
as Clearing Agency for such Global Certificate or (B) has ceased to be a
clearing agency registered as such under the Securities Exchange Act of 1934, as
amended, and in either case the Trust and the Depositor thereupon fail to
appoint a successor Clearing Agency, (ii) the Trust and the Depositor, at their
option, notify the Property Trustee in writing that it elects to cause the
issuance of the Preferred Securities in certificated form or (iii) there shall
have occurred and be continuing an Event of Default or any event which after
notice or lapse of time or both would be an Event of Default. In all cases,
Definitive Preferred Securities Certificates delivered in exchange for any
Global Certificate or beneficial interests therein will be registered in the
names, and issued in any approved denominations, requested by or on behalf of
the Clearing Agency (in accordance with its customary procedures).

          SECTION 5.14.  Rights of Securityholders.  The legal title to the
                         --------------------------                        
Trust Property is vested exclusively in the Property Trustee (in its capacity as
such) in accordance with Section 2.9, and the Securityholders shall not have any
right or title therein other than the undivided beneficial interest in the
assets of the Trust conferred by their Trust Securities and they shall have no
right to call for any partition or division of property, profits or rights of
the Trust except as described below. The Trust Securities shall be personal
property giving only the rights specifically set forth therein and in this Trust
Agreement.  The Trust Securities shall have no preemptive or similar rights and,
when issued and delivered to Securityholders against payment of the purchase
price therefor, will be fully paid and nonassessable undivided beneficial
interests in the assets of the Trust.  The Holders of the Trust Securities, in
their capacities as such, shall be entitled to the same limitation of personal
liability extended to stockholders of private corporations for profit organized
under the General Corporation Law of the State of Delaware, provided, however,
                                                            --------  ------- 
the Holders of Trust Securities may be obligated, pursuant to the terms of this
Trust Agreement, to (i) provide

                                      41
<PAGE>
 
indemnity and/or security in connection with and pay taxes or governmental
charges arising from transfers of Trust Securities and (ii) provide security and
indemnity in connection with the requests of or directions to the Property
Trustee to exercise its rights and powers under the Trust Agreement.

                                   ARTICLE 6
                   ACT OF SECURITYHOLDERS; MEETINGS; VOTING

          SECTION 6.1.  Limitations on Voting Rights. (a)  Except as provided in
                        -----------------------------                           
this Section, in Section 8.2 and 10.2 and in the Indenture and as otherwise
required by law, no Holder of Preferred Securities shall have any right to vote
or in any manner otherwise control the administration, operation and management
of the Trust or the obligations of the parties hereto, nor shall anything herein
set forth, or contained in the terms of the Trust Securities Certificates, be
construed so as to constitute the Securityholders from time to time as partners
or members of an association.

          (b)  Subject to Section 8.2 hereof, if an Event of Default with
respect to the Preferred Securities has occurred and been subsequently cured,
waived or otherwise eliminated, the provisions of Section 6.1(b)(ii) hereof
shall apply.  During (x) the period commencing on the date of the occurrence of
an Event of Default with respect to the Preferred Securities and ending on the
date when such Event of Default is cured, waived or otherwise eliminated, or (y)
any period not described in either the preceding sentence or the preceding
clause (x), the provisions of Section 6.1(b)(i) shall apply.

          (i)  The Holders of a majority in aggregate Liquidation Amount of the
     Preferred Securities will have the right to direct the time, method and
     place of conducting any proceeding for any remedy available to the Property
     Trustee or to exercise any trust or power conferred upon the Property
     Trustee under this Trust Agreement, including the right to direct the
     Property Trustee to exercise the remedies available to it as a holder of
     the Debentures but excluding the right to direct the Property Trustee to
     consent to an amendment, modification or termination of the Indenture
     (which shall be as provided below).  So long as any Debentures are held by
     the Property Trustee, the Trustees shall not (A) direct the time, method
     and place of conducting any proceeding for any remedy available to the
     Debenture Trustee, or executing any trust or power

                                      42
<PAGE>
 
     conferred on the Debenture Trustee with respect to such Debentures, (B)
     waive any past default which is waivable under Section [5.13] of the
     Indenture, (C) exercise any right to rescind or annul a declaration that
     the principal of all the Debentures shall be due and payable or (D) consent
     to any amendment, modification or termination of the Indenture or the
     Debentures, where such consent shall be required, without, in each case,
     obtaining the prior approval of the Holders of a majority in aggregate
     Liquidation Amount of all Outstanding Preferred Securities (except in the
     case of clause (D), which consent, in the event that no Event of Default
     shall occur and be continuing, shall be of the Holders of a majority in
     aggregate Liquidation Amount of all Trust Securities, voting together as a
     single class); provided, however, that where a consent under the Indenture
                    --------  -------                                          
     would require the consent of each holder of Debentures affected thereby, no
     such consent shall be given by the Property Trustee without the prior
     written consent of each Holder of Preferred Securities.  The Trustees shall
     not revoke any action previously authorized or approved by a vote of the
     Holders of the Preferred Securities, except by a subsequent vote of the
     Holders of the Preferred Securities.  The Property Trustee shall notify all
     Holders of record of the Preferred Securities of any notice of default
     received from the Debenture Trustee with respect to the Debentures.  In
     addition to obtaining the foregoing approvals of the Holders of the
     Preferred Securities, prior to taking any of the foregoing actions, the
     Trustees shall, at the expense of the Depositor, obtain an Opinion of
     Counsel experienced in such matters to the effect that the Trust will not
     be classified as an association taxable as a corporation or partnership for
     United States Federal income tax purposes on account of such action.

          (ii)  Subject to Section 8.2 of this Trust Agreement and only after
     the Event of Default with respect to the Preferred Securities has been
     cured, waived, or otherwise eliminated, the Holders of a majority in
     aggregate Liquidation Amount of the Common Securities will have the right
     to direct the time, method and place of conducting any proceeding for any
     remedy available to the Property Trustee or to exercise any trust or power
     conferred upon the Property Trustee under this Trust Agreement, including
     the right to direct the Property Trustee to exercise the remedies available
     to it as a holder of the Debentures but excluding the right to direct the
     Property Trustee to

                                      43
<PAGE>
 
     consent to an amendment, modification or termination of the Indenture
     (which shall be as provided below).  So long as any Debentures are held by
     the Property Trustee, the Trustees shall not (A) direct the time, method
     and place of conducting any proceeding for any remedy available to the
     Debenture Trustee, or executing any trust or power conferred on the
     Debenture Trustee with respect to such Debentures, (B) waive any past
     default which is waivable under Section 5.13 of the Indenture, (C) exercise
     any right to rescind or annul a declaration that the principal of all the
     Debentures shall be due and payable or (D) consent to any amendment,
     modification or termination of the Indenture or the Debentures, where such
     consent shall be required, without, in each case, obtaining the prior
     approval of the Holders of a majority in aggregate Liquidation Amount of
     all Common Securities (except in the case of clause (D), which consent, in
     the event that no Event of Default shall occur and be continuing, shall be
     of the Holders of a majority in aggregate Liquidation Amount of all Trust
     Securities, voting together as a single class); provided, however, that
                                                     --------  -------      
     where a consent under the Indenture would require the consent of each
     holder of Debentures affected thereby, no such consent shall be given by
     the Property Trustee without the prior written consent of each Holder of
     Common Securities.  The Trustees shall not revoke any action previously
     authorized or approved by a vote of the Holders of the Common Securities,
     except by a subsequent vote of the Holders of the Common Securities.  The
     Property Trustee shall notify all Holders of record of the Common
     Securities of any notice of default received from the Debenture Trustee
     with respect to the Debentures.  In addition to obtaining the foregoing
     approvals of the Holders of the Common Securities, prior to taking any of
     the foregoing actions, the Trustees shall, at the expense of the Depositor,
     obtain an Opinion of Counsel experienced in such matters to the effect that
     the Trust will not be classified as an association taxable as a corporation
     or partnership for United States Federal income tax purposes on account of
     such action.

          (iii)  The provisions of this Section 6.1(b) and Section 6.1(a) of
     this Trust Agreement shall be in lieu of (S) 316(a)(1)(A) of the Trust
     Indenture Act, and such (S) 316(a)(1)(A) is hereby expressly excluded from
     this Trust Agreement and the Preferred Securities, as permitted by the
     Trust Indenture Act.

                                      44
<PAGE>
 
          (c)  If any proposed amendment to this Trust Agreement provides for,
or the Trustees otherwise propose to effect, the dissolution, winding-up or
termination of the Trust, other than pursuant to the terms of this Trust
Agreement, then the Holders of Outstanding Preferred Securities as a class will
be entitled to vote on such amendment or proposal and such amendment or proposal
shall not be effective except with the approval of the Holders of a majority in
aggregate Liquidation Amount of the Outstanding Preferred Securities.

          SECTION 6.2.  Notice of Meetings.  Notice of all meetings of the
                        -------------------                               
Holders of the Preferred Securities, stating the time, place and purpose of the
meeting, shall be given by the Property Trustee pursuant to Section 10.8 to each
Preferred Securityholder of record, at its registered address, at least 15 days
and not more than 90 days before the meeting.  At any such meeting, any business
properly before the meeting may be so considered whether or not stated in the
notice of the meeting.  Any adjourned meeting may be held as adjourned without
further notice.

          SECTION 6.3.  Meetings of Preferred Securityholders.  No annual
                        --------------------------------------           
meeting of Securityholders is required to be held.  The Administrative Trustees,
however, shall call a meeting of Securityholders to vote on any matter upon the
written request of the Preferred Securityholders of record of 25% of the
Preferred Securities (based upon their Liquidation Amount), and the
Administrative Trustees or the Property Trustee may, at any time in their
discretion, call a meeting of the Holders of Preferred Securities to vote on any
matters as to which such Holders are entitled to vote.

          Holders of record of a majority of the Preferred Securities (based
upon their Liquidation Amount), present in person or by proxy, shall constitute
a quorum at any meeting of Securityholders.

          If a quorum is present at a meeting, an affirmative vote by the
Holders of record of Preferred Securities present, in person or by proxy,
holding a majority of the Preferred Securities (based upon their Liquidation
Amount) held by Holders of record of Preferred Securities present, either in
person or by proxy, at such meeting shall constitute the action of the
Securityholders, unless this Trust Agreement requires a greater number of
affirmative votes.

          SECTION 6.4.  Voting Rights.  Securityholders shall be entitled to one
                        --------------                                          
vote for each $50 of Liquidation

                                      45
<PAGE>
 
Amount represented by their Trust Securities in respect of any matter as to
which such Securityholders are entitled to vote.  Notwithstanding that Holders
of Preferred Securities are entitled to vote or consent under any of the
circumstances described above, any of the Preferred Securities that are owned at
such time by the Depositor, the Trustees or any affiliate of any Trustee shall,
for purposes of such vote or consent, be treated as if such Preferred Securities
were not outstanding.

          SECTION 6.5.  Proxies, Etc.  At any meeting of Securityholders, any
                        -------------                                        
Securityholders entitled to vote thereat may vote by proxy, provided that no
proxy shall be voted at any meeting unless it shall have been placed on file
with the Administrative Trustees, or with such other officer or agent of the
Trust as the Administrative Trustees may direct, for verification prior to the
time at which such vote shall be taken.  Pursuant to a resolution of the
Property Trustee, proxies may be solicited in the name of the Property Trustee
or one or more officers of the Property Trustee.  Only Securityholders of record
shall be entitled to vote.  When Trust Securities are held jointly by several
Persons, any one of them may vote at any meeting in person or represented by
proxy in respect of such Trust Securities, but if more than one of them shall be
present at such meeting in person or by proxy, and such joint owners or their
proxies so present disagree as to any vote to be cast, such vote shall not be
received in respect of such Trust Securities.  A proxy purporting to be executed
by or on behalf of a Securityholder shall be deemed valid unless challenged at
or prior to its exercise, and the burden of proving invalidity shall rest on the
challenger.  No proxy shall be valid more than three years after its date of
execution.

          SECTION 6.6.  Securityholder Action by Written Consent.  Any action
                        -----------------------------------------            
which may be taken by Securityholders at a meeting may be taken without a
meeting if Securityholders holding a majority of all Outstanding Trust
Securities (based upon their Liquidation Amount) entitled to vote in respect of
such action (or such larger proportion thereof as shall be required by any
express provision of this Trust Agreement) shall consent to the action in
writing.

          SECTION 6.7.  Record Date for Voting and Other Purposes.  For the
                        ------------------------------------------         
purposes of determining the Securityholders who are entitled to notice of and to
vote at any meeting or by written consent, or to participate in any Distribution
on the Trust Securities in respect of which a record date is not otherwise
provided for in this Trust

                                      46
<PAGE>
 
Agreement, or for the purpose of any other action, the Property Trustee may from
time to time fix a date, not more than 90 days prior to the date of any meeting
of Securityholders or the payment of Distributions or other action, as the case
may be, as a record date for the determination of the identity of the
Securityholders of record for such purposes.

          SECTION 6.8.  Acts of Securityholders.  Any request, demand,
                        ------------------------                      
authorization, direction, notice, consent, waiver or other action provided or
permitted by this Trust Agreement to be given, made or taken by Securityholders
or Owners may be embodied in and evidenced by one or more instruments of
substantially similar tenor signed by such Securityholders or Owners in person
or by an agent duly appointed in writing; and, except as otherwise expressly
provided herein, such action shall become effective when such instrument or
instruments are delivered to an Administrative Trustee.  Such instrument or
instruments (and the action embodied therein and evidenced thereby) are herein
sometimes referred to as the "Act" of the Securityholders or Owners signing such
instrument or instruments.  Proof of execution of any such instrument or of a
writing appointing any such agent shall be sufficient for any purpose of this
Trust Agreement and (subject to Section 8.1) conclusive in favor of the
Trustees, if made in the manner provided in this Section.

          The fact and date of the execution by any Person of any such
instrument or writing may be proved by the affidavit of a witness of such
execution or by a certificate of a notary public or other officer authorized by
law to take acknowledgments of deeds, certifying that the individual signing
such instrument or writing acknowledged to him the execution thereof.  Where
such execution is by a signer acting in a capacity other than his individual
capacity, such certificate or affidavit shall also constitute sufficient proof
of his authority.  The fact and date of the execution of any such instrument or
writing, or the authority of the Person executing the same, may also be proved
in any other manner which any Trustee receiving the same deems sufficient.

          The ownership of Preferred Securities shall be proved by the
Securities Register.

          Any request, demand, authorization, direction, notice, consent, waiver
or other Act of the Securityholder of any Trust Security shall bind every future
Securityholder of the same Trust Security and the Securityholder of every Trust
Security issued upon the registration of transfer

                                      47
<PAGE>
 
thereof or in exchange therefor or in lieu thereof in respect of anything done,
omitted or suffered to be done by the Trustees or the Trust in reliance thereon,
whether or not notation of such action is made upon such Trust Security.

          Without limiting the foregoing, a Securityholder entitled hereunder to
take any action hereunder with regard to any particular Trust Security may do so
with regard to all or any part of the Liquidation Amount of such Trust Security
or by one or more duly appointed agents each of which may do so pursuant to such
appointment with regard to all or any part of such Liquidation Amount.

          If any dispute shall arise between the Securityholders and the
Administrative Trustees or among such Securityholders or Administrative Trustees
with respect to the authenticity, validity or binding nature of any request,
demand, authorization, direction, consent, waiver or other Act of such
Securityholder or Trustee under this Article 6, then the determination of such
matter by the Property Trustee shall be conclusive with respect to such matter.

          Upon the occurrence and continuation of an Event of Default, the
Holders of Preferred Securities shall rely on the enforcement by the Property
Trustee of its rights as holder of the Debentures against the Depositor.  If the
Property Trustee fails to enforce its rights as holder of the Debentures after a
request therefor by a Holder of Preferred Securities, such holder may proceed to
enforce such rights directly against the Depositor.  Notwithstanding the
foregoing, if an Event of Default has occurred and is continuing and such event
is attributable to the failure of the Depositor to pay interest or principal on
the Debentures on the date such interest or principal is otherwise payable (or
in the case of redemption, on the Redemption Date), then a Holder of Preferred
Securities shall have the right to institute a proceeding directly against the
Depositor, for enforcement of payment to such holder of the principal amount of
or interest on Debentures having a principal amount equal to the aggregate
Liquidation Amount of the Preferred Securities of such Holder after the
respective due date specified in the Debentures (a "Direct Action").  In
connection with any such Direct Action, the rights of the Depositor will be
subrogated to the rights of any Holder of the Preferred Securities to the extent
of any payment made by the Depositor to such Holder of Preferred Securities as a
result of such Direct Action.

                                      48
<PAGE>
 
          SECTION 6.9.  Inspection of Records.  Upon reasonable notice to the
                        ----------------------                               
Administrative Trustees and the Property Trustee, the records of the Trust shall
be open to inspection by Securityholders during normal business hours for any
purpose reasonably related to such Securityholder's interest as a
Securityholder.


                                   ARTICLE 7
                         REPRESENTATIONS AND WARRANTIES

          SECTION 7.1.  Representations and Warranties of the Property Trustee
                        ------------------------------------------------------
and the Delaware Trustee.
- -------------------------

          (a) The Property Trustee hereby represents and warrants for the
     benefit of the Depositor and the Securityholders that:

               (i)    the Property Trustee is a banking corporation duly
          organized, validly existing and in good standing under the laws of the
          State of New York;

               (ii)   the Property Trustee has full corporate power, authority
          and legal right to execute, deliver and perform its obligations under
          this Trust Agreement and has taken all necessary action to authorize
          the execution, delivery and performance by it of this Trust Agreement;

               (iii)  this Trust Agreement has been duly authorized, executed
          and delivered by the Property Trustee and constitutes the valid and
          legally binding agreement of the Property Trustee enforceable against
          it in accordance with its terms, subject to bankruptcy, insolvency,
          fraudulent transfer, reorganization, moratorium and similar laws of
          general applicability relating to or affecting creditors' rights and
          to general equity principles; and

               (iv)   the execution, delivery and performance by the Property
          Trustee of this Trust Agreement have been duly authorized by all
          necessary corporate or other action on the part of the Property
          Trustee and do not require any approval of stockholders of the
          Property Trustee and such execution, delivery and performance will not
          (a) violate the Property Trustee's charter or by-laws or (b) violate
          any law, governmental rule or regulation of the United States or the
          State of

                                      49
<PAGE>
 
          New York, as the case may be, governing the banking, corporate, or
          trust powers of the Property Trustee, or any order, judgment or decree
          applicable to the Property Trustee.

          (b) The Delaware Trustee hereby represents and warrants for the
     benefit of the Depositor and the Securityholders that:

              (i)   the Delaware Trustee is a banking corporation duly
          organized, validly existing and in good standing under the laws of the
          State of Delaware;

              (ii)  the Delaware Trustee has full corporate power, authority and
          legal right to execute, deliver and perform its obligations under this
          Trust Agreement and has taken all necessary action to authorize the
          execution, delivery and performance by it of this Trust Agreement;

              (iii) this Trust Agreement has been duly authorized, executed and
          delivered by the Delaware Trustee and constitutes the valid and
          legally binding agreement of the Delaware Trustee enforceable against
          it in accordance with its terms, subject to bankruptcy, insolvency,
          fraudulent transfer, reorganization, moratorium and similar laws of
          general applicability relating to or affecting creditors' rights and
          to general equity principles; and

              (iv)  the execution, delivery and performance by the Delaware
          Trustee of this Trust Agreement have been duly authorized by all
          necessary corporate or other action on the part of the Delaware
          Trustee and do not require any approval of stockholders of the
          Delaware Trustee or the Delaware Trustee and such execution, delivery
          and performance will not (a) violate the Delaware Trustee's charter or
          by-laws or (b) violate any law, governmental rule or regulation of the
          United States or the State of Delaware, as the case may be, governing
          the banking, corporate, or trust powers of the Delaware Trustee, or
          any order, judgment or decree applicable to the Delaware Trustee.

                                      50
<PAGE>
 
          SECTION 7.2.  Representations and Warranties of Depositor.  The
                        --------------------------------------------     
Depositor hereby represents and warrants for the benefit of the Property
Trustee, the Delaware Trustee and the Securityholders that:

          (a) the Trust Securities Certificates issued on the Closing Date on
     behalf of the Trust have been duly authorized and will have been duly and
     validly executed, issued and delivered by the Trustees pursuant to the
     terms and provisions of, and in accordance with the requirements of, this
     Trust Agreement and the Securityholders will be, as of such date, entitled
     to the benefits of this Trust Agreement; and

          (b) there are no taxes, fees or other governmental charges payable by
     the Trust (or the Trustees on behalf of the Trust) under the laws of the
     State of Delaware or any political subdivision thereof in connection with
     the execution, delivery and performance by the Property Trustee or the
     Delaware Trustee, as the case may be, of this Trust Agreement.


                                   ARTICLE 8
                                  THE TRUSTEES

          SECTION 8.1.  Certain Duties and Responsibilities. (a)  The duties and
                        ------------------------------------                    
responsibilities of the Trustees shall be as provided by this Trust Agreement
and, in the case of the Property Trustee, by the Trust Indenture Act.  The
Property Trustee, before the occurrence of any Event of Default and after the
curing or waiving of all Events of Default that may have occurred, shall
undertake to perform only such duties and obligations as are specifically set
forth in this Trust Agreement and the Trust Indenture Act and no implied
covenants shall be read into this Trust Agreement against the Property Trustee.
In case an Event of Default has occurred (that has not been cured or waived
pursuant to Section 8.2) of which a Responsible Officer of the Property Trustee
has actual knowledge, the Property Trustee shall exercise such rights and powers
vested in it by this Trust Agreement and the Trust Indenture Act, and use the
same degree of care and skill in its exercise, as a prudent individual would
exercise or use under the circumstances in the conduct of his or her own
affairs. Notwithstanding the foregoing, no provision of this Trust Agreement
shall require the Trustees to expend or risk their own funds or otherwise incur
any financial liability in the performance of any of their duties hereunder, or
in the exercise of any of their rights or powers, if they shall have reasonable
grounds for believing that repayment of such

                                      51
<PAGE>
 
funds or adequate indemnity against such risk or liability is not reasonably
assured to it.  Whether or not therein expressly so provided, every provision of
this Trust Agreement relating to the conduct or affecting the liability of or
affording protection to the Trustees shall be subject to the provisions of this
Section.  Nothing in this Trust Agreement shall be construed to release the
Administrative Trustees from liability for their own grossly negligent action,
their own grossly negligent failure to act, or their own willful misconduct.  To
the extent that, at law or in equity, an Administrative Trustee has duties
(including fiduciary duties) and liabilities relating thereto to the Trust or to
the Securityholders, such Administrative Trustee shall not be liable to the
Trust or to any Securityholder for such Administrative Trustee's good faith
reliance on the provisions of this Trust Agreement.  The provisions of this
Trust Agreement, to the extent that they restrict the duties and liabilities of
the Administrative Trustees otherwise existing at law or in equity, are agreed
by the Depositor and the Securityholders to replace such other duties and
liabilities of the Administrative Trustees.

          (b)  All payments made by the Property Trustee or a Paying Agent in
respect of the Trust Securities shall be made only from the revenue and proceeds
from the Trust Property and only to the extent that there shall be sufficient
revenue or proceeds from the Trust Property to enable the Property Trustee or a
Paying Agent to make payments in accordance with the terms hereof.  Each
Securityholder, by its acceptance of a Trust Security, agrees that it will look
solely to the revenue and proceeds from the Trust Property to the extent legally
available for distribution to it as herein provided and that the Trustees are
not personally liable to it for any amount distributable in respect of any Trust
Security or for any other liability in respect of any Trust Security.  This
Section 8.1(b) does not limit the liability of the Trustees expressly set forth
elsewhere in this Trust Agreement or, in the case of the Property Trustee, in
the Trust Indenture Act.

          (c)  No provision of this Trust Agreement shall be construed to
relieve the Property Trustee from liability for its own negligent action, its
own negligent failure to act, or its own willful misconduct, except that:

          (i) the Property Trustee shall not be liable for any error of judgment
     made in good faith by an authorized officer of the Property Trustee, unless
     it shall be proved that the Property Trustee was negligent in ascertaining
     the pertinent facts;

                                      52
<PAGE>
 
          (ii)   the Property Trustee shall not be liable with respect to any
     action taken or omitted to be taken by it in good faith in accordance with
     the direction of the Holders of a majority in aggregate Liquidation Amount
     of the Trust Securities relating to the time, method and place of
     conducting any proceeding for any remedy available to the Property Trustee,
     or exercising any trust or power conferred upon the Property Trustee under
     this Trust Agreement;

          (iii)  the Property Trustee's sole duty with respect to the custody,
     safekeeping and physical preservation of the Debentures and the Payment
     Account shall be to deal with such property as fiduciary assets, subject to
     the protections and limitations on liability afforded to the Property
     Trustee under this Trust Agreement and the Trust Indenture Act;

          (iv)   the Property Trustee shall not be liable for any interest on
     any money received by it except as it may otherwise agree, in writing, with
     the Depositor and money held by the Property Trustee need not be segregated
     from other funds held by it except in relation to the Payment Account
     maintained by the Property Trustee pursuant to Section 3.1 and except to
     the extent otherwise required by law;

          (v)    the Property Trustee shall not be responsible for monitoring
     the compliance by the Administrative Trustees or the Depositor with their
     respective duties under this Trust Agreement, nor shall the Property
     Trustee be liable for the default or misconduct of the Administrative
     Trustees or the Depositor;

          (vi)   the Property Trustee shall have no duty or liability with
     respect to the value, genuineness, existence or sufficiency of the
     Debentures or the payment of any taxes or assessments thereon or in
     connection therewith;

          (vii)  the duties and obligations of the Property Trustee shall be
     determined solely by the express provisions of this Trust Agreement and in
     the Preferred Securities and the Common Securities and the Property Trustee
     shall not be liable except for the performance of such duties and
     obligations as are specifically set forth in this Trust Agreement and in
     the Preferred Securities and the Common Securities, and no implied
     covenants or obligations shall be read into this Trust Agreement against
     the Property Trustee; and

                                      53
<PAGE>
 
          (viii)  no provision of this Trust Agreement shall require the
     Property Trustee to expend or risk its own funds or otherwise incur
     personal financial liability in the performance of any of its duties or in
     the exercise of any of its rights or powers, if it shall have reasonable
     grounds for believing that the repayment of such funds or liability is not
     reasonably assured to it under the terms of this Trust Agreement or
     indemnity reasonably satisfactory to the Property Trustee against such risk
     or liability is not reasonably assured to it.

          SECTION 8.2.  Notice of Defaults.  (a)  Within ten days after the
                        -------------------                                
occurrence of any Event of Default actually known to a Responsible Officer of
the Property Trustee, the Property Trustee shall transmit, in the manner and to
the extent provided in Section 10.8, notice of such Event of Default to the
Holders of Preferred Securities, the Administrative Trustees and the Depositor,
unless such Event of Default shall have been cured or waived, provided that,
                                                              --------      
except for a default in the payment of principal of (or premium, if any) or
interest on any of the Debentures, the Property Trustee shall be fully protected
in withholding such notice if and so long as the Board of Directors, the
executive committee, or a trust committee of directors and/or Responsible
Officers of the Property Trustee in good faith determines that the withholding
of such notice is in the interests of the Holders of the Preferred Securities.

          (b)  Within ten days after the receipt of notice of the Depositor's
exercise of its right to extend the interest payment period for the Debentures
pursuant to the Indenture, the Property Trustee shall transmit, in the manner
and to the extent provided in Section 10.8, notice of such exercise to the
Securityholders, unless such exercise shall have been revoked.

          (c)  The Holders of a majority in Liquidation Amount of Preferred
Securities may, by vote, on behalf of the Holders of all of the Preferred
Securities, waive any past Event of Default in respect of the Preferred
Securities and its consequences, provided that, if the underlying Debenture
                                 --------                                  
Event of Default:

               (i)  is not waivable under the Indenture, the Event of Default
     under this Trust Agreement shall also not be waivable; or

               (ii) requires the consent or vote of greater than a majority in
     principal amount of the holders of the Debentures, including the consent or
     vote of all

                                      54
<PAGE>
 
     such holders, (a "Super Majority") to be waived under the Indenture, the
     Event of Default under this Trust Agreement may only be waived by the vote
     of the Holders of the same proportion in Liquidation Amount of the
     Preferred Securities that the relevant Super Majority represents of the
     aggregate principal amount of the Debentures outstanding.

          The provisions of Section 6.1(b) and this Section 8.2(c) shall be in
lieu of (S) 316(a)(1)(B) of the Trust Indenture Act and such (S) 316(a)(1)(B) of
the Trust Indenture Act is hereby expressly excluded from this Trust Agreement
and the Preferred Securities, as permitted by the Trust Indenture Act.  Upon
such waiver, any such default shall cease to exist, and any Event of Default
with respect to the Preferred Securities arising therefrom shall be deemed to
have been cured, for every purpose of this Trust Agreement, but no such waiver
shall extend to any subsequent or other default or an Event of Default with
respect to the Preferred Securities or impair any right consequent thereon. Any
waiver by the Holders of the Preferred Securities of an Event of Default with
respect to the Preferred Securities shall also be deemed to constitute a waiver
by the Holders of the Common Securities of any such Event of Default with
respect to the Common Securities for all purposes of this Trust Agreement
without any further act, vote, or consent of the Holders of the Common
Securities.

          (d)  The Holders of a majority in Liquidation Amount of the Common
Securities may, by vote, on behalf of the Holders of all of the Common
Securities, waive any past Event of Default with respect to the Common
Securities and its consequences, provided that, if the underlying Debenture
                                 --------                                  
Event of Default:

               (i)   is not waivable under the Indenture, except where the
     Holders of the Common Securities are deemed to have waived such Event of
     Default under the Trust Agreement as provided below in this Section 8.2(d),
     the Event of Default under this Trust Agreement shall also not be waivable;
     or

               (ii)  requires the consent or vote of a Super Majority to be
     waived, except where the Holders of the Common Securities are deemed to
     have waived such Event of Default under this Trust Agreement as provided
     below in this Section 8.2(d), the Event of Default under this Trust
     Agreement may only be waived by the vote of the Holders of the same
     proportion in Liquidation Amount of the Common Securities that the relevant
     Super Majority

                                      55
<PAGE>
 
     represents of the aggregate principal amount of the Debentures outstanding;

provided further, that each Holder of Common Securities will be deemed to have
waived any such Event of Default and all Events of Default with respect to the
Common Securities and its consequences until all Events of Default with respect
to the Preferred Securities have been cured, waived or otherwise eliminated, and
until such Events of Default have been so cured, waived or otherwise eliminated,
the Property Trustee will be deemed to be acting solely on behalf of the Holders
of the Preferred Securities and only the Holders of the Preferred Securities
will have the right to direct the Property Trustee in accordance with the terms
of the Securities.  The provisions of Section 6.1(b) and this Section 8.2(d)
shall be in lieu of (S) 316(a)(1)(B) of the Trust Indenture Act and such (S)
316(a)(1)(B) of the Trust Indenture Act is hereby expressly excluded from this
Trust Agreement and the Preferred Securities, as permitted by the Trust
Indenture Act.  Subject to the foregoing provisions of this Section 8.2(d), upon
such waiver, any such default shall cease to exist and any Event of Default with
respect to the Common Securities arising therefrom shall be deemed to have been
cured for every purpose of this Trust Agreement, but no such waiver shall extend
to any subsequent or other default or Event of Default with respect to the
Common Securities or impair any right consequent thereon.

          (e)  A waiver of a Debenture Event of Default by the Property Trustee
at the direction of the Holders of the Preferred Securities, constitutes a
waiver of the corresponding Event of Default under this Trust Agreement. The
foregoing provisions of this Section 8.2(e) shall be in lieu of (S) 316(a)(1)(B)
of the Trust Indenture Act and such (S) 316(a)(1)(B) of the Trust Indenture Act
is hereby expressly excluded from this Trust Agreement and the Preferred
Securities, as permitted by the Trust Indenture Act.

          SECTION 8.3.  Certain Rights of Property Trustee. Subject to the
                        -----------------------------------               
provisions of Section 8.1:

          (a)  the Property Trustee may conclusively rely and shall be fully
     protected in acting or refraining from acting in good faith upon any
     resolution, Opinion of Counsel, certificate, written representation of a
     Holder or transferee such as of a certificate presented for transfer,
     certificate of auditors or any other certificate, statement, instrument,
     opinion, report, notice, request, consent, order, appraisal, bond,
     debenture, note, other evidence of indebtedness or

                                      56
<PAGE>
 
     other paper or document believed by it to be genuine and to have been
     signed or presented by the proper party or parties;

          (b) if no Event of Default has occurred and is continuing and, (i) in
     performing its duties under this Trust Agreement the Property Trustee is
     required to decide between alternative courses of action or (ii) in
     construing any of the provisions in this Trust Agreement the Property
     Trustee finds the same ambiguous or inconsistent with any other provisions
     contained herein or (iii) the Property Trustee is unsure of the application
     of any provision of this Trust Agreement, then, except as to any matter as
     to which the Holders of Preferred Securities are entitled to vote under the
     terms of this Trust Agreement, the Property Trustee shall deliver a notice
     to the Depositor requesting written instructions of the Depositor as to the
     course of action to be taken and the Property Trustee shall take such
     action, or refrain from taking such action, as the Property Trustee shall
     be instructed in writing to take, or to refrain from taking, by the
     Depositor; provided, however, that if the Property Trustee does not receive
                --------  -------                                               
     such instructions of the Depositor within ten Business Days after it has
     delivered such notice, or such reasonably shorter period of time set forth
     in such notice (which to the extent practicable shall not be less than two
     Business Days), it may, but shall be under no duty to, take or refrain from
     taking such action not inconsistent with this Trust Agreement as it shall
     deem advisable and in the best interests of the Securityholders, in which
     event the Property Trustee shall have no liability except for its own bad
     faith, negligence or willful misconduct;

          (c) any direction or act of the Depositor or the Administrative
     Trustees contemplated by this Trust Agreement shall be sufficiently
     evidenced by an Officers' Certificate;

          (d) whenever in the administration of this Trust Agreement, the
     Property Trustee shall deem it desirable that a matter be established
     before undertaking, suffering or omitting any action hereunder, the
     Property Trustee (unless other evidence is herein specifically prescribed)
     may, in the absence of bad faith on its part, request and conclusively rely
     upon an Officers' Certificate and an Opinion of Counsel which, upon receipt
     of such request, shall be promptly delivered by the Depositor or the
     Administrative Trustees;

                                      57
<PAGE>
 
          (e) the Property Trustee shall have no duty to accomplish any
     recording, filing or registration of any instrument (including any
     financing or continuation statement or any filing under tax or securities
     laws) or any rerecording, refiling or reregistration thereof;

          (f) the Property Trustee may consult with counsel at the Depositor's
     expense (which counsel may be counsel to the Depositor or any of its
     Affiliates, and may include any of its employees) and the advice of such
     counsel or any Opinion of Counsel shall be full and complete authorization
     and protection in respect of any action taken, suffered or omitted by it
     hereunder in good faith and in reliance thereon and in accordance with such
     advice; and the Property Trustee shall have the right at any time to seek
     instructions concerning the administration of this Trust Agreement from any
     court of competent jurisdiction;

          (g) the Property Trustee shall be under no obligation to exercise any
     of the rights or powers vested in it by this Trust Agreement at the request
     or direction of any of the Securityholders pursuant to this Trust
     Agreement, unless such Securityholders shall have offered to the Property
     Trustee reasonable security or indemnity satisfactory to it against the
     costs, expenses (including attorneys' fees and expenses and the expenses of
     the Property Trustee's agents, custodians or nominees) and liabilities
     which might be incurred by it in compliance with such request or direction;

          (h) the Property Trustee shall not be bound to make any investigation
     into the facts or matters stated in any resolutions, certificate,
     statement, instrument, opinion, report, notice, request, consent, order,
     approval, bond, debenture, note or other evidence of indebtedness or other
     paper or document, but the Property Trustee may make such further inquiry
     or investigation into such facts or custodian or nominee matters as it may
     see fit;

          (i) the Property Trustee may execute any of the trusts or powers
     hereunder or perform any duties hereunder either directly or by or through
     its agents, custodians or nominees, attorneys or an Affiliate, provided
     that the Property Trustee shall not be responsible for the negligence or
     recklessness on the part of any agent, attorney, custodian or nominee
     appointed by it with due care hereunder;

                                      58
<PAGE>
 
          (j) whenever in the administration of this Trust Agreement the
     Property Trustee shall deem it desirable to receive instructions with
     respect to enforcing any remedy or right or taking any other action
     hereunder, the Property Trustee (i) may request instructions from the
     Holders of the Trust Securities, which instructions may only be given by
     the Holders of the same proportion in Liquidation Amount of the Trust
     Securities as would be entitled to direct the Property Trustee under the
     terms of the Trust Securities in respect of such remedy, right or action,
     (ii) may refrain from enforcing such remedy or right or taking such other
     action until such instructions are received, and (iii) shall be fully
     protected in conclusively relying on or acting in accordance with such
     instructions;

          (k) except as otherwise expressly provided by this Trust Agreement,
     the Property Trustee shall not be under any obligation to take any action
     that is discretionary under the provisions of this Trust Agreement;

          (1) the Property Trustee shall not be liable for any action taken,
     suffered, or omitted to be taken by it in good faith and reasonably
     believed by it to be authorized or within the discretion or rights or
     powers conferred upon it by this Trust Agreement; and

          (m) in the event that the Property Trustee is also acting as a Paying
     Agent, Conversion Agent, and/or Securities Registrar hereunder, the rights
     and protections afforded to the Property Trustee pursuant to this Article 8
     shall also be afforded to such Paying Agent, Conversion Agent, and/or
     Securities Registrar.

          No provision of this Trust Agreement shall be deemed to impose any
duty or obligation on the Property Trustee to perform any act or acts or
exercise any right, power, duty or obligation conferred or imposed on it, in any
jurisdiction in which it shall be illegal, or in which the Property Trustee
shall be unqualified or incompetent in accordance with applicable law, to
perform any such act or acts, or to exercise any such right, power, duty or
obligation.  No permissive power or authority available to the Property Trustee
shall be construed to be a duty.

          Section 8.4.  Not Responsible for Recitals or Issuance of Securities.
                        ------------------------------------------------------- 
The recitals contained herein and in the Trust Securities Certificates shall not
be taken as the statements of the Trustees, and the Trustees do not assume any
responsibility for their correctness.  The

                                      59
<PAGE>
 
Trustees shall not be accountable for the use or application by the Depositor of
the proceeds of the Debentures.

          SECTION 8.5.  May Hold Securities.  Except as provided in the
                        --------------------                           
definition of the term "Outstanding" in Article 1, any Trustee or any other
agent of any Trustee or the Trust, in its individual or any other capacity, may
become the owner or pledgee of Trust Securities and, subject to Section 8.8 and
8.12, may otherwise deal with the Trust with the same rights it would have if it
were not a Trustee or such other agent.

          SECTION 8.6.  Compensation; Indemnity; Fees.
                        ------------------------------

     The Depositor agrees:

          (a) to pay the Trustees from time to time reasonable compensation for
     all services rendered by them hereunder (which compensation shall not be
     limited by any provision of law in regard to the compensation of a trustee
     of an express trust);

          (b) except as otherwise expressly provided herein, to reimburse the
     Trustees upon request for all reasonable expenses, disbursements and
     advances incurred or made by the Trustees in accordance with any provision
     of this Trust Agreement (including the reasonable compensation and the
     expenses and disbursements of its agents and counsel), except any such
     expense, disbursement or advance as may be attributable to its negligence
     or bad faith;

          (c) to the fullest extent permitted by applicable law, to indemnify
     and hold harmless (i) each Trustee, (ii) any Affiliate of any Trustee,
     (iii) any officer, director, shareholder, employee, representative or agent
     of any Trustee, and (iv) any employee or agent of the Trust or its
     Affiliates (referred to herein as an "Indemnified Person") from and against
     any loss, damage, liability, tax, penalty, expense or claim of any kind or
     nature whatsoever incurred by such Indemnified Person by reason of the
     creation, operation, dissolution or termination of the Trust or in
     connection with the administration of the Trust or any act or omission
     performed or omitted by such Indemnified Person in good faith on behalf of
     the Trust and in a manner such Indemnified Person reasonably believed to be
     within the scope of authority conferred on such Indemnified Person by this
     Trust Agreement, except that no Indemnified Person shall be entitled to be
     indemnified in respect of any loss, damage or claim

                                      60
<PAGE>
 
     incurred by such Indemnified Person by reason of negligence or willful
     misconduct with respect to such acts or omissions; and

          (d) no Trustee may claim any lien or charge on any Trust Property as a
     result of any amount due pursuant to this Section 8.6.

          SECTION 8.7.  Property Trustee Required; Eligibility of Trustees.  (a)
                        ---------------------------------------------------  
There shall at all times be a Property Trustee hereunder with respect to the
Trust Securities.  The Property Trustee shall be a Person that is eligible
pursuant to the Trust Indenture Act to act as such and has a combined capital
and surplus of at least $50,000,000.  If any such Person publishes reports of
condition at least annually, pursuant to law or to the requirements of its
supervising or examining authority, then for the purposes of this Section, the
combined capital and surplus of such Person shall be deemed to be its combined
capital and surplus as set forth in its most recent report of condition so
published.  If at any time the Property Trustee with respect to the Trust
Securities shall cease to be eligible in accordance with the provisions of this
Section, it shall resign immediately in the manner and with the effect
hereinafter specified in this Article.

          (b)  There shall at all times be one or more Administrative Trustees
hereunder with respect to the Trust Securities. Each Administrative Trustee
shall be either a natural person who is at least 21 years of age or a legal
entity that shall act through one or more persons authorized to bind that
entity.

          (c)  There shall at all times be a Delaware Trustee with respect to
the Trust Securities.  The Delaware Trustee shall either be (i) a natural person
who is at least 21 years of age and a resident of the State of Delaware or (ii)
a legal entity with its principal place of business in the State of Delaware and
that otherwise meets the requirements of applicable Delaware law that shall act
through one or more persons authorized to bind such entity.

          SECTION 8.8.  Conflicting Interests.  If the Property Trustee has or
                        ----------------------                                
shall acquire a conflicting interest within the meaning of the Trust Indenture
Act, the Property Trustee shall either eliminate such interest or resign, to the
extent and in the manner provided by, and subject to the provisions of, the
Trust Indenture Act and this Trust Agreement.

                                      61
<PAGE>
 
          SECTION 8.9.  Resignation and Removal; Appointment of Successor.  (a)
                        --------------------------------------------------      
Subject to Sections 8.9(b) and 8.9(c), Trustees (the "Relevant Trustee") may be
appointed or removed without cause at any time:

               (i)  until the issuance of any Trust Securities, by written
     instrument executed by the Depositor; and

               (ii) after the issuance of any Securities, by vote of the Holders
     of a majority in Liquidation Amount of the Common Securities voting as a
     class.

          (b)  The Trustee that acts as Property Trustee shall not be removed in
accordance with Section 8.9(a) until a successor possessing the qualifications
to act as a Property Trustee under Section 8.7 (a "Successor Property Trustee")
has been appointed and has accepted such appointment by instrument executed by
such Successor Property Trustee and delivered to the Trust, the Depositor and
the removed Property Trustee.

          (c)  The Trustee that acts as Delaware Trustee shall not be removed in
accordance with Section 8.9(a) until a successor possessing the qualifications
to act as Delaware Trustee under Section 8.7 (a "Successor Delaware Trustee")
has been appointed and has accepted such appointment by instrument executed by
such Successor Delaware Trustee and delivered to the Trust, the Depositor and
the removed Delaware Trustee.

          (d)  A Trustee appointed to office shall hold office until his, her or
its successor shall have been appointed or until his, her or its death, removal,
resignation, dissolution or liquidation.  Any Trustee may resign from office
(without need for prior or subsequent accounting) by an instrument in writing
signed by the Trustee and delivered to the Depositor and the Trust, which
resignation shall take effect upon such delivery or upon such later date as is
specified therein; provided, however, that:
                   --------  -------       

               (i) No such resignation of the Trustee that acts as the Property
     Trustee shall be effective:

                    (a) until a Successor Property Trustee has been appointed
          and has accepted such appointment by instrument executed by such
          Successor Property Trustee and delivered to the Trust, the Depositor
          and the resigning Property Trustee; or

                                      62
<PAGE>
 
                    (b) until the assets of the Trust have been completely
          liquidated and the proceeds thereof distributed to the Holders of the
          Securities;

               (ii)  no such resignation of the Trustee that acts as the
     Delaware Trustee shall be effective until a Successor Delaware Trustee has
     been appointed and has accepted such appointment by instrument executed by
     such Successor Delaware Trustee and delivered to the Trust, the Depositor
     and the resigning Delaware Trustee; and

               (iii) no appointment of a successor Property Trustee or Delaware
     Trustee shall be effective until all fees, charges, and expenses of the
     retiring Property Trustee or retiring Delaware Trustee, as the case may be,
     have been paid.

          (e)  The Holders of the Common Securities shall use their best efforts
to promptly appoint a Successor Property Trustee or Successor Delaware Trustee,
as the case may be, if the Property Trustee or the Delaware Trustee delivers an
instrument of resignation in accordance with Section 8.9(d).

          (f)  If no Successor Property Trustee or Successor Delaware Trustee
shall have been appointed and accepted appointment as provided in this Section
8.9 within 60 days after delivery pursuant to this Section 8.9 of an instrument
of resignation or removal, the Property Trustee or Delaware Trustee resigning or
being removed, as applicable, may petition any court of competent jurisdiction
for appointment of a Successor Property Trustee or Successor Delaware Trustee.
Such court may thereupon, after prescribing such notice, if any, as it may deem
proper and prescribe, appoint a Successor Property Trustee or Successor Delaware
Trustee, as the case may be.

          (g)  No Property Trustee or Delaware Trustee shall be liable for the
acts or omissions to act of any Successor Property Trustee or Successor Delaware
Trustee, as the case may be.

          (h)  The Property Trustee shall give notice of each resignation and
each removal of a Trustee and each appointment of a successor Trustee to all
Securityholders in the manner provided in Section 10.8 and shall give notice to
the Depositor. Each notice shall include the name of the successor Relevant
Trustee and the address of its Corporate Trust Office if it is the Property
Trustee.

                                      63
<PAGE>
 
          (i)  Notwithstanding the foregoing or any other provision of this
Trust Agreement, in the event any Administrative Trustee or a Delaware Trustee
who is a natural person dies or becomes, in the opinion of the Depositor,
incompetent or incapacitated, the vacancy created by such death, incompetence or
incapacity may be filled by (a) the unanimous act of the remaining
Administrative Trustees if there are at least two of them or (b) otherwise by
the Depositor (with the successor in each case being a Person who satisfies the
eligibility requirement for Administrative Trustees or the Delaware Trustee, as
the case may be, set forth in Section 8.7).

          The indemnity provided to a Trustee under Section 8.6 shall survive
any Trustee's resignation or removal or termination of this Trust Agreement.

          SECTION 8.10.  Acceptance of Appointment by Successor.  In case of the
                         ---------------------------------------                
appointment hereunder of a successor Relevant Trustee, the retiring Relevant
Trustee and each successor Relevant Trustee shall execute and deliver an
amendment hereto wherein each successor Relevant Trustee shall accept such
appointment and which (a) shall contain such provisions as shall be necessary or
desirable to transfer and confirm to, and to vest in, each successor Relevant
Trustee all the rights, powers, trusts and duties of the retiring Relevant
Trustee and (b) shall add to or change any of the provisions of this Trust
Agreement as shall be necessary to provide for or facilitate the administration
of the trusts hereunder by more than one Relevant Trustee, it being understood
that nothing herein or in such amendment shall constitute such Relevant Trustees
as co-trustees and upon the execution and delivery of such amendment the
resignation or removal of the retiring Relevant Trustee shall become effective
to the extent provided therein and each such successor Relevant Trustee, without
any further act, deed or conveyance, shall become vested with all the rights,
powers, trusts and duties of the retiring Relevant Trustee; but, on request of
the Trust or any successor Relevant Trustee, such retiring Relevant Trustee
shall duly assign, transfer and deliver to such successor Relevant Trustee all
Trust Property, all proceeds thereof and money held by such retiring Relevant
Trustee hereunder.

          Upon request of any such successor Relevant Trustee, the Trust shall
execute any and all instruments for more fully and certainly vesting in and
confirming to such successor Relevant Trustee all such rights, powers and trusts
referred to in the first or second preceding paragraph, as the case may be.

                                      64
<PAGE>
 
          No successor Relevant Trustee shall accept its appointment unless at
the time of such acceptance such successor Relevant Trustee shall be qualified
and eligible under this Article.

          SECTION 8.11.  Merger, Conversion, Consolidation or Succession to
                         --------------------------------------------------
Business.  Any Person into which the Property Trustee, the Delaware Trustee or
- ---------                                                                     
any Administrative Trustee that is not a natural person may be merged or
converted or with which it may be consolidated, or any Person resulting from any
merger, conversion or consolidation to which such Relevant Trustee shall be a
party, or any corporation succeeding to all or substantially all the corporate
trust business of such Relevant Trustee, shall be the successor of such Relevant
Trustee hereunder, provided such Person shall be otherwise qualified and
eligible under this Article, without the execution or filing of any paper or any
further act on the part of any of the parties hereto.

          SECTION 8.12.  Preferential Collection of Claims Against Depositor or
                         ------------------------------------------------------
Trust.  If and when the Property Trustee shall be or become a creditor of the
- ------                                                                       
Depositor or the Trust (or any other obligor upon the Debentures or the Trust
Securities), the Property Trustee shall be subject to and shall take all actions
necessary in order to comply with the provisions of the Trust Indenture Act
regarding the collection of claims against the Depositor or Trust (or any such
other obligor).

          SECTION 8.13.  Reports by Property Trustee. Within 60 days after May
                         ----------------------------                         
15 of each year, commencing with the first May 15, after the first issuance of
Preferred Securities, the Property Trustee shall provide to the Holders of the
Preferred Securities such reports as are required by (S) 313 of the Trust
Indenture Act, if any, in the form and in the manner provided by (S) 313 of the
Trust Indenture Act.  The Property Trustee shall also comply with the
requirements of (S) 313(d) of the Trust Indenture Act.

          SECTION 8.14.  Reports to the Property Trustee. The Depositor and the
                         --------------------------------                      
Administrative Trustees on behalf of the Trust shall provide to the Property
Trustee such documents, reports and information as are required by Section 314
of the Trust Indenture Act (if any) and the compliance certificate required by
Section 314(a) of the Trust Indenture Act in the form, in the manner and at the
times required by Section 314 of the Trust Indenture Act.

          SECTION 8.15.  Evidence of Compliance with Conditions Precedent.  Each
                         -------------------------------------------------      
of the Depositor and the

                                      65
<PAGE>
 
Administrative Trustees on behalf of the Trust shall provide to the Property
Trustee such evidence of compliance with any conditions precedent, if any,
provided for in this Trust Agreement that relate to any of the matters set forth
in Section 314(c) of the Trust Indenture Act.  Any certificate or opinion
required to be given by an officer pursuant to Section 314(c)(1) of the Trust
Indenture Act shall be given in the form of an Officers' Certificate.

          SECTION 8.16.  Number of Trustees.  (a) The number of Trustees shall
                         -------------------                                  
be five, provided that the Holder of all of the Common Securities by written
instrument may increase or decrease the number of Administrative Trustees.  The
Property Trustee and the Delaware Trustee may be the same Person.

          (b)  If a Trustee ceases to hold office for any reason and the number
of Administrative Trustees is not reduced pursuant to Section 8.16(a), or if the
number of Trustees is increased pursuant to Section 8.16(a), a vacancy shall
occur.

          (c)  The death, resignation, retirement, removal, bankruptcy,
incompetence or incapacity to perform the duties of a Trustee shall not operate
to dissolve, terminate or annul the Trust. Whenever a vacancy in the number of
Administrative Trustees shall occur, until such vacancy is filled by the
appointment of an Administrative Trustee in accordance with Section 8.9, the
Administrative Trustees in office, regardless of their number (and
notwithstanding any other provision of this Agreement), shall have all the
powers granted to the Administrative Trustees and shall discharge all the duties
imposed upon the Administrative Trustees by this Trust Agreement.

          SECTION 8.17.  Delegation of Power.  (a)  Any Administrative Trustee
                         --------------------                                 
may, by power of attorney consistent with applicable law, delegate to any other
natural person over the age of 21 his or her power for the purpose of executing
any documents contemplated in Section 2.7(a), including any registration
statement or amendment thereof filed with the Commission, or making any other
governmental filing.

          (b)  The Administrative Trustees shall have power to delegate from
time to time to such of their number or to the Depositor the doing of such
things and the execution of such instruments either in the name of the Trust or
the names of the Administrative Trustees or otherwise as the Administrative
Trustees may deem expedient, to the extent such delegation is not prohibited by
applicable law or

                                      66
<PAGE>
 
contrary to the provisions of the Trust, as set forth herein.


                                   ARTICLE 9
                      DISSOLUTION, LIQUIDATION AND MERGER

          SECTION 9.1.  Dissolution upon Expiration Date. Unless earlier
                        ---------------------------------               
dissolved, the Trust shall automatically dissolve on [                ] (the
"Expiration Date").

          Section 9.2.  Early Dissolution.  The first to occur of any of the
                        ------------------                                  
following events is an "Early Dissolution Event":

          (a) the occurrence of a Bankruptcy Event in respect of, or the
dissolution or liquidation of, the Depositor;

          (b) the occurrence of a Special Event except in the case of a Tax
Event following which the Depositor has elected (i) to pay any Additional Sums
(in accordance with Section 4.4) such that the net amount received by Holders of
Preferred Securities in respect of Distributions are not reduced as a result of
such Tax Event and the Depositor has not revoked any such election or failed to
make such payments or (ii) to redeem all or some of the Debentures pursuant to
Section 4.4(a);

          (c) the redemption, conversion or exchange of all of the Trust
Securities;

          (d) an order for dissolution of the Trust shall have been entered by a
court of competent jurisdiction; and

          (e) receipt by the Property Trustee of written notice from the
Depositor at any time (which direction is optional and wholly within the
discretion of the Depositor) of its intention to dissolve the Trust and
distribute the Debentures in exchange for the Preferred Securities.

          SECTION 9.3.  Dissolution.  The respective obligations and
                        ------------                                
responsibilities of the Trustees and the Trust created and continued hereby
shall terminate upon the latest to occur of the following:  (a) the distribution
by the Property Trustee to Securityholders upon the liquidation of the Trust
pursuant to Section 9.4, or upon the redemption of all of the Trust Securities
pursuant to Section 4.2, of all amounts required to be distributed hereunder
upon the final payment of the Trust Securities; (b) the payment of all expenses
owed by the Trust; and (c) the discharge of all

                                      67
<PAGE>
 
administrative duties of the Administrative Trustees, including the performance
of any tax reporting obligations with respect to the Trust or the
Securityholders.

          SECTION 9.4.  Liquidation.  (a)  If an Early Dissolution Event
                        ------------                                    
specified in clause (a), (b), (d) or (e) of Section 9.2 occurs or upon the
Expiration Date, the Trust shall be liquidated by the Trustees as expeditiously
as the Trustees determine to be possible by distributing, after satisfaction of
liabilities to creditors of the Trust as provided by applicable law, to each
Securityholder an aggregate principal amount of Debentures equal to the
aggregate Liquidation Amount of Trust Securities held by such Holder, subject to
Section 9.4(d). Notice of liquidation shall be given by the Property Trustee by
first-class mail, postage prepaid, mailed not later than 30 nor more than 60
days prior to the Liquidation Date to each Holder of Trust Securities at such
Holder's address as it appears in the Securities Register. All notices of
liquidation shall be prepared by the Administrative Trustees and shall:

          (i) state the Liquidation Date;

          (ii) state that, from and after the Liquidation Date, the Trust
     Securities will no longer be deemed to be Outstanding and any Trust
     Securities Certificates not surrendered for exchange will be deemed to
     represent an aggregate principal amount of Debentures equal to the
     aggregate Liquidation Amount of Preferred Securities held by such Holder;
     and

          (iii) provide such information with respect to the mechanics by which
     Holders may exchange Trust Securities Certificates for Debentures, or, if
     Section 9.4(d) applies, receive a Liquidation Distribution, as the
     Administrative Trustees or the Property Trustee shall deem appropriate.

          (b) Except where Section 9.2(c) or 9.4(d) applies, in order to effect
the liquidation of the Trust and distribution of the Debentures to
Securityholders, the Property Trustee shall establish a record date for such
distribution (which shall be not more than 45 days prior to the Liquidation Date
and, unless the Property Trustee determines otherwise, shall be the date which
is the fifteenth day (whether or not a Business Day) next preceding the
Liquidation Date) and, either itself acting as exchange agent or through the
appointment of a separate exchange agent, shall establish such procedures as it
shall deem

                                      68
<PAGE>
 
appropriate to effect the distribution of Debentures in exchange for the
Outstanding Trust Securities Certificates.

          (c) Except where Section 9.2(c) or 9.4(d) applies, after the
Liquidation Date, (i) the Trust Securities will no longer be deemed to be
Outstanding, (ii) the Clearing Agency or its nominee, as the record holder of
such Trust Securities, will receive a registered global certificate or
certificates representing the Debentures to be delivered upon such distribution
and (iii) any Trust Securities Certificates not held by the Clearing Agency will
be deemed to represent an aggregate principal amount of Debentures equal to the
aggregate Liquidation Amount of Preferred Securities held by such Holders, and
bearing accrued and unpaid interest in an amount equal to the accrued and unpaid
Distributions on such Trust Securities until such certificates are presented to
the Property Trustee for transfer or reissuance.

          (d) In the event that, notwithstanding the other provisions of this
Section 9.4, whether because of an order for dissolution entered by a court of
competent jurisdiction or otherwise, distribution of the Debentures in the
manner provided herein is determined by the Property Trustee not to be
practicable, the Trust Property shall be liquidated, and the Trust shall be
wound-up or terminated, by the Property Trustee in such manner as the Property
Trustee determines, and an Administrative Trustee shall prepare, execute and
file the certificate of cancellation with the Secretary of State of the State of
Delaware. In such event, Securityholders will be entitled to receive out of the
assets of the Trust available for distribution to Securityholders, after
satisfaction of liabilities to creditors of the Trust as provided by applicable
law, an amount equal to the Liquidation Amount per Trust Security plus accrued
and unpaid Distributions thereon to the date of payment (such amount being the
"Liquidation Distribution"). If, upon any such winding-up or termination, the
Liquidation Distribution can be paid only in part because the Trust has
insufficient assets available to pay in full the aggregate Liquidation
Distribution, then, subject to the next succeeding sentence, the amounts payable
by the Trust on the Trust Securities shall be paid on a pro rata basis (based
                                                        --------             
upon Liquidation Amounts).  The Holder of the Common Securities will be entitled
to receive Liquidation Distributions upon any such winding-up or termination pro
                                                                             ---
rata (determined as aforesaid) with Holders of Preferred Securities, except
- ----                                                                       
that, if a Debenture Event of Default has occurred and is continuing, the
Preferred Securities shall have a priority over the Common Securities.

                                      69
<PAGE>
 
          SECTION 9.5.  Mergers, Consolidations, Amalgamations or Replacements
                        ------------------------------------------------------
of the Trust.  The Trust may not merge with or into, consolidate, amalgamate, or
- -------------                                                                   
be replaced by, or convey, transfer or lease its properties and assets
substantially as an entirety to any Person, except pursuant to this Section 9.5
or Section 9.4. At the request of the Depositor, with the consent of the
Administrative Trustees and without the consent of the Property Trustee, the
Delaware Trustee or the Holders of the Preferred Securities, the Trust may merge
with or into, consolidate, amalgamate, be replaced by or convey, transfer or
lease its properties and assets substantially as an entirety to a trust
organized as such under the laws of any State; provided, that (i) such successor
entity either (a) expressly assumes all of the obligations of the Trust with
respect to the Preferred Securities or (b) substitutes for the Preferred
Securities other securities having substantially the same terms as the Preferred
Securities (the "Successor Securities") so long as the Successor Securities rank
the same as the Preferred Securities rank in priority with respect to
Distributions and payments upon liquidation, redemption and otherwise, (ii) the
Depositor expressly appoints a trustee of such successor entity possessing the
same powers and duties as the Property Trustee as the holder of the Debentures,
(iii) the Successor Securities are listed, or any Successor Securities will be
listed upon notification of issuance, on any national securities exchange or
other organization on which the Preferred Securities are then listed, if any,
(iv) such merger, consolidation, amalgamation, replacement, conveyance, transfer
or lease does not cause the Preferred Securities (including any Successor
Securities) to be downgraded by any nationally recognized statistical rating
organization, (v) such merger, consolidation, amalgamation, replacement,
conveyance, transfer or lease does not adversely affect the rights, preferences
and privileges of the Holders of the Preferred Securities (including any
Successor Securities) in any material respect (other than with respect to any
dilution of the Holder's interest in the new entity), (vi) such successor entity
has a purpose substantially identical to that of the Trust, (vii) prior to such
merger, consolidation, amalgamation, replacement, conveyance, transfer or lease
the Depositor has received an Opinion of Counsel to the effect that (a) such
merger, consolidation, amalgamation, replacement, conveyance, transfer or lease
does not adversely affect the rights, preferences and privileges of the Holders
of the Preferred Securities (including any Successor Securities) in any material
respect (other than with respect to any dilution of the Holder's interest in the
new entity), (b) following such merger, consolidation, amalgamation,
replacement,

                                      70
<PAGE>
 
conveyance, transfer or lease neither the Trust nor such successor entity will
be required to register as an investment company under the 1940 Act, and (c)
following such merger, consolidation, amalgamation or replacement, the Trust or
such successor entity will be treated as a grantor trust for United States
Federal income tax purposes and (viii) the Depositor or any permitted successor
or assignee owns, directly or indirectly, all of the common securities of such
successor entity and guarantees the obligations of such successor entity under
the Successor Securities at least to the extent provided by the Guarantee.
Notwithstanding the foregoing, the Trust shall not, except with the consent of
Holders of 100% in aggregate Liquidation Amount of the Preferred Securities,
consolidate, amalgamate, merge with or into, be replaced by or convey, transfer
or lease its properties and assets substantially as an entirety to any other
entity or permit any other entity to consolidate, amalgamate, merge with or
into, or replace it if such consolidation, amalgamation, merger, replacement,
conveyance, transfer or lease would cause the Trust or the successor entity to
be classified as other than a grantor trust for United States Federal income tax
purposes.


                                  ARTICLE 10
                           MISCELLANEOUS PROVISIONS

          SECTION 10.1.  Limitation of Rights of Securityholders. Other than as
                         ----------------------------------------              
set forth in Section 9.1, the death, incapacity, dissolution, bankruptcy or
termination of any Person having an interest, beneficial or otherwise, in Trust
Securities shall not operate to dissolve the Trust or terminate this Trust
Agreement, nor entitle the legal representatives or heirs of such Person or any
Securityholder for such Person to claim an accounting, take any action or bring
any proceeding in any court for a partition or winding-up of the arrangements
contemplated hereby, nor otherwise affect the rights, obligations and
liabilities of the parties hereto or any of them.

          SECTION 10.2.  Amendment.  (a)  This Trust Agreement may be amended
                         ----------                                          
from time to time by the Trustees and the Depositor, without the consent of any
Securityholders, (i) to cure any ambiguity, correct or supplement any provision
herein which may be inconsistent with any other provision herein, or to make any
other provisions with respect to matters or questions arising under this Trust
Agreement, which shall not be inconsistent with the other provisions of this
Trust Agreement, (ii) to modify, eliminate or add to any provisions of this
Trust Agreement to such extent as shall be necessary to ensure

                                      71
<PAGE>
 
that the Trust will be classified for United States Federal income tax purposes
as a grantor trust at all times that any Trust Securities are Outstanding or to
ensure that the Trust will not be required to register as an "investment
company" under the 1940 Act, or be classified as other than a grantor trust for
United States Federal income tax purposes, or (iii) to comply with the
requirements of the Commission in order to effect or maintain the qualification
of this Trust Agreement under the Trust Indenture Act; provided, however, that
                                                       --------  -------      
in the case of clause (i), such action shall not adversely affect in any
material respect the interests of any Securityholder, and any such amendments of
this Trust Agreement shall become effective when notice thereof is given to the
Securityholders.

          (b)  Except as provided in Section 10.2(c) hereof, any provision of
this Trust Agreement may be amended by the Trustees and the Depositor with (i)
the consent of Holders representing not less than a majority (based upon
Liquidation Amounts) of the Trust Securities then Outstanding, acting as a
single class, and (ii) receipt by the Trustees of an Opinion of Counsel to the
effect that such amendment or the exercise of any power granted to the Trustees
in accordance with such amendment will not affect the Trust's status as a
grantor trust for United States Federal income tax purposes or the Trust's
exemption from the status of an "investment company" under the 1940 Act,
provided, however, if any amendment or proposal that would adversely affect the
- --------  -------                                                              
powers, preferences or special rights of the Trust Securities, whether by way of
amendment or otherwise, would adversely affect only the Preferred Securities or
only the Common Securities, then only the affected class will be entitled to
vote on such amendment or proposal and such amendment or proposal shall not be
effective except with the approval of a majority in Liquidation Amount of such
class of Trust Securities.

          (c)  In addition to and notwithstanding any other provision in this
Trust Agreement, without the consent of each affected Securityholder (such
consent being obtained in accordance with Section 6.3 or 6.6 hereof), this Trust
Agreement may not be amended to (i) change the amount or timing of any
Distribution on the Trust Securities or otherwise adversely affect the amount of
any Distribution required to be made in respect of the Trust Securities as of a
specified date or (ii) restrict the right of a Securityholder to institute suit
for the enforcement of any such payment on or after such date; notwithstanding
any other provision herein, without the unanimous consent of the Securityholders
(such consent being obtained in accordance

                                      72
<PAGE>
 
with Section 6.3 or 6.6 hereof), this paragraph (c) of this Section 10.2 may not
be amended.

          (d)  Notwithstanding any other provisions of this Trust Agreement, no
Trustee shall enter into or consent to any amendment to this Trust Agreement
which would cause the Trust to fail or cease to qualify for the exemption from
the status of an "investment company" under the 1940 Act or be classified as
other than a grantor trust for United States Federal income tax purposes.

          (e)  Notwithstanding anything in this Trust Agreement to the contrary,
without the consent of the Depositor, this Trust Agreement may not be amended in
a manner which imposes any additional obligation on the Depositor.

          (f)  In the event that any amendment to this Trust Agreement is made,
the Administrative Trustees shall promptly provide to the Depositor a copy of
such amendment.

          (g)  Neither the Property Trustee nor the Delaware Trustee shall be
required to enter into any amendment to this Trust Agreement which affects its
own rights, duties or immunities under this Trust Agreement. The Property
Trustee shall be entitled to receive an Opinion of Counsel and an Officers'
Certificate stating that any amendment to this Trust Agreement is in compliance
with this Trust Agreement and that all conditions precedent, if any, in this
Trust Agreement to the execution and delivery of such amendment have been
satisfied.

          SECTION 10.3.  Separability.  In case any provision in this Trust
                         -------------                                     
Agreement or in the Trust Securities Certificates shall be invalid, illegal or
unenforceable, the validity, legality and enforceability of the remaining
provisions shall not in any way be affected or impaired thereby.

          SECTION 10.4.  Governing Law.  THIS TRUST AGREEMENT AND THE RIGHTS AND
                         --------------                                         
OBLIGATIONS OF EACH OF THE SECURITYHOLDERS, THE TRUST AND TRUSTEES WITH RESPECT
TO THIS TRUST AGREEMENT AND  THE TRUST SECURITIES SHALL BE CONSTRUED IN
ACCORDANCE WITH AND GOVERNED BY THE LAWS OF THE STATE OF DELAWARE WITHOUT REGARD
TO ITS CONFLICT OF LAWS PRINCIPLES AND EXCLUDING SECTIONS 3540 AND 3561 OF TITLE
12 THEREOF.

          SECTION 10.5.  Payments Due on Non-Business Day. If the date fixed for
                         ---------------------------------                      
any payment on any Trust Security shall be a day which is not a Business Day,
then such payment need not be made on such date but may be made on the

                                      73
<PAGE>
 
next succeeding day which is a Business Day except as otherwise provided in
Section 4.1 (a) and Section 4.2(d), with the same force and effect as though
made on the date fixed for such payment, and no interest shall accrue thereon
for the period after such date.

          SECTION 10.6.  Successors.  This Trust Agreement shall be binding upon
                         -----------                                            
and shall inure to the benefit of any successor to the Depositor, the Trust or
the Relevant Trustee, including any successor by operation of law. Except in
connection with a transaction that is permitted under Article 8 of the Indenture
and pursuant to which the assignee agrees in writing to perform the Depositor's
obligations hereunder, the Depositor shall not assign its obligations hereunder.

          SECTION 10.7.  Headings.  The Article and Section headings are for
                         ---------                                          
convenience only and shall not affect the construction of this Trust Agreement.

          SECTION 10.8.  Reports, Notices and Demands.  Any report, notice,
                         -----------------------------                     
demand or other communication which by any provision of this Trust Agreement is
required or permitted to be given or served to or upon any Securityholder or the
Depositor may be given or served in writing by deposit thereof, first-class
postage prepaid, in the United States mail, hand delivery or facsimile
transmission, in each case, addressed, (a) in the case of a Holder of Preferred
Securities, to such Holder as such Holder's name and address may appear on the
Securities Register; and (b) in the case of the Holder of the Common Securities,
to Aluminum Company of America, 201 Isabella Street, Pittsburgh, PA 15212-5858.

          Any notice, demand or other communication which by any provision of
this Trust Agreement is required or permitted to be given or served to or upon
the Trust, the Property Trustee, the Delaware Trustee or the Administrative
Trustees shall be given in writing addressed (until another address is published
by the Trust) as follows:  (a) with respect to the Property Trustee, to [The
Chase Manhattan Bank], [                         ], Attention:                ],
(b) with respect to the Delaware Trustee, to Chase Manhattan Bank Delaware, 
[           ], Delaware [     ], with a copy of any such notice to the Property
Trustee at its address above, and (c) with respect to the Administrative
Trustees, to them at the address for notices to the Depositor, marked
"Attention: [     ]. Such notice, demand or other communication to or upon the
Trust or the Property Trustee shall be deemed to have been sufficiently given or
made only

                                      74
<PAGE>
 
upon actual receipt of the writing by the Trust or the Property Trustee.

          SECTION 10.9.   Agreement Not to Petition.  Each of the Trustees and
                          --------------------------                          
the Depositor agrees for the benefit of the Securityholders that, until at least
one year and one day after the Trust has been dissolved in accordance with
Article 9, it shall not file, or join in the filing of, a petition against the
Trust under any bankruptcy, insolvency, reorganization or other similar law
(including, without limitation, the United States Bankruptcy Code)
(collectively, "Bankruptcy Laws") or otherwise join in the commencement of any
proceeding against the Trust under any Bankruptcy Law. In the event the
Depositor takes action in violation of this Section 10.9, the Property Trustee
agrees, for the benefit of Securityholders, that, at the expense of the
Depositor, it shall file an answer with the bankruptcy court or otherwise
properly contest the filing of such petition by the Depositor against the Trust
or the commencement of such action and raise the defense that the Depositor has
agreed in writing not to take such action and should be stopped and precluded
therefrom and such other defenses, if any, as counsel for the Trustee or the
Trust may assert. The provisions of this Section 10.9 shall survive the
dissolution of this Trust Agreement.

          SECTION 10.10.  Trust Indenture Act; Conflict with Trust Indenture
                          --------------------------------------------------
Act.  (a)  This Trust Agreement is subject to the provisions of the Trust
- ----                                                                     
Indenture Act that are required to be part of this Trust Agreement and shall, to
the extent applicable, be governed by such provisions.

          (b)  The Property Trustee shall be the only Trustee which is the
trustee for the purposes of the Trust Indenture Act.

          (c)  If any provision hereof limits, qualifies or conflicts with
another provision hereof which is required to be included in this Trust
Agreement by any of the provisions of the Trust Indenture Act, such required
provision shall control. If any provision of this Trust Agreement modifies or
excludes any provision of the Trust Indenture Act which may be so modified or
excluded, the latter provision shall be deemed to apply to this Trust Agreement
as so modified or to be excluded, as the case may be.

          (d)  The application of the Trust Indenture Act to this Trust
Agreement shall not affect the nature of the Trust Securities as equity
securities representing undivided beneficial interests in the assets of the
Trust.

                                      75
<PAGE>
 
          SECTION 10.11.  Acceptance of Terms of Trust Agreement, Guarantee and
                          -----------------------------------------------------
Indenture.  THE RECEIPT AND ACCEPTANCE OF A TRUST SECURITY OR ANY INTEREST
- ----------                                                                
THEREIN BY OR ON BEHALF OF A SECURITYHOLDER OR BENEFICIAL OWNER, WITHOUT ANY
SIGNATURE OR FURTHER MANIFESTATION OF ASSENT, SHALL CONSTITUTE THE UNCONDITIONAL
ACCEPTANCE BY THE SECURITYHOLDER AND ALL OTHERS HAVING A BENEFICIAL INTEREST IN
SUCH TRUST SECURITY OF ALL THE TERMS AND PROVISIONS OF THIS TRUST AGREEMENT AND
AGREEMENT TO SUBORDINATION PROVISIONS AND OTHER TERMS OF THE GUARANTEE AND THE
INDENTURE, AND SHALL CONSTITUTE THE AGREEMENT OF THE TRUST, SUCH SECURITYHOLDER
AND SUCH OTHERS THAT THE TERMS AND PROVISIONS OF THIS TRUST AGREEMENT SHALL BE
BINDING, OPERATIVE AND EFFECTIVE AS THE AGREEMENT OF THE TRUST AND SUCH
SECURITYHOLDER AND SUCH OTHERS.

          SECTION 10. 12.  Counterparts.  This Trust Agreement may contain more
                           -------------                                       
than one counterpart of the signature page and this Trust Agreement may be
executed by the affixing of the signature of each of the Trustees to one of such
counterpart signature pages.  All of such counterpart signature pages shall be
read as though one, and they shall have the same force and effect as though all
of the signers had signed a single signature page.

                                      76
<PAGE>
 
          IN WITNESS WHEREOF, the parties hereto have caused this Trust
Agreement to be duly executed as of the day and year first above written.

                                   ALUMINUM COMPANY OF AMERICA,
                                   as Depositor

                                   By: ____________________________________
                                   Name: __________________________________
                                   Title: _________________________________


                                   THE CHASE MANHATTAN BANK,
                                   as Property Trustee

                                   By:_____________________________________
                                   Name: __________________________________
                                   Title: _________________________________


                                   CHASE MANHATTAN BANK DELAWARE,
                                   as Delaware Trustee

                                   By: ____________________________________
                                   Name: __________________________________
                                   Title: _________________________________


                                   ________________________________________
                                   [                  ],
                                   as Administrative Trustee

                                   ________________________________________
                                   [                 ],
                                   as Administrative Trustee

                                   ________________________________________
                                   [               ],
                                   as Administrative Trustee

                                      77
<PAGE>
 
                                             EXHIBIT A - Certificate of Trust of
                                                                   Alcoa Trust I


                              CERTIFICATE OF TRUST

                                       OF

                                 ALCOA TRUST I


          THIS Certificate of Trust of Alcoa Trust I (the "Trust"), dated as of
[                 ], is being duly executed and filed by the undersigned, as
trustees, to form a business trust under the Delaware Business Trust Act (12
Del. C. (S)3801 et seq.).
- ---- --         -------  

          1.  Name. The name of the business trust formed hereby is Alcoa Trust
              -----  
[ ].

          2.  Delaware Trustee.  The name and business address of the trustee of
              -----------------                                                 
the Trust with a principal place of business in the State of Delaware are [
], Delaware [     ].

          3.  Effective Date. This Certificate of Trust shall be effective upon
              ---------------
filing.     

     IN WITNESS WHEREOF, the undersigned, being the trustees of the Trust, have
executed this Certificate of Trust as of the date first-above written.


                                        [                         ], not in
                                        its individual capacity but solely as
                                        trustee of the Trust
 
 
                                        By: ____________________________________
                                        Name:
                                        Title:


                                        [                   ], not in his
                                        individual capacity but solely as
                                        trustee of the Trust
                                         
                                        ________________________________________

                                      A-1
<PAGE>
 
                                                 EXHIBIT B - Form of Certificate
                                                            Depositary Agreement

                                                             [Attach DTC Letter]

                                      B-1
<PAGE>
 
                                        EXHIBIT C - Form of Common Securities of
                                                                   Alcoa Trust I


                     THIS CERTIFICATE IS NOT TRANSFERABLE 
                     EXCEPT TO AN ENTITY WHOLLY OWNED BY 
                     ALUMINUM COMPANY OF AMERICA OR TO 
                     CERTAIN SUCCESSORS OF ALUMINUM COMPANY 
                     OF AMERICA

          Certificate Number _____   Number of Common Securities ___

                   Certificate Evidencing Common Securities
                                      of
                                 Alcoa Trust I

                               Common Securities
                 (Liquidation Amount $50 per Common Security)

           Alcoa Trust I, a statutory business trust created under the laws of
the State of Delaware (the "Trust"), hereby certifies that Aluminum Company of
America (the "Holder") is the registered owner of ________ common securities of
the Trust representing undivided beneficial interests in the assets of the Trust
(the "Common Securities"). Except as set forth in Section 5.10 of the Trust
Agreement (as defined below), the Common Securities are not transferable and any
attempted transfer hereof shall be void. The designations, rights, privileges,
restrictions, preferences and other terms and provisions of the Common
Securities are set forth in, and this certificate and the Common Securities
represented hereby are issued and shall in all respects be subject to the terms
and provisions of, the Amended and Restated Trust Agreement of the Trust dated
as of [         ,    ], as the same may be amended from time to time (the "Trust
Agreement") including the designation of the terms of the Common Securities as
set forth therein. [The Holder is entitled to the benefits of the Common
Securities Guarantee Agreement entered into by Aluminum Company of America, a
Pennsylvania corporation, and The Chase Manhattan Bank, as Guarantee Trustee,
dated as of [          ,    ] (the "Guarantee"), to the extent provided
therein.] The Trust will furnish a copy of the Trust Agreement and the Guarantee
to the Holder without charge upon written request to the Trust at its principal
place of business or registered office.

           Upon receipt of this certificate, the Holder is bound by the Trust
Agreement and is entitled to the benefits thereunder.

                                      C-1
<PAGE>
 
          IN WITNESS WHEREOF, one of the Administrative Trustees of the Trust
has executed this certificate.

Dated:                             ALCOA TRUST I



                                   By: ______________________________________
                                   Name:   __________________________________
                                           As Administrative Trustee


                PROPERTY TRUSTEE'S CERTIFICATE OF AUTHENTICATION

          This is one of the Common Securities referred to in the within-
mentioned Trust Agreement.



                                   THE CHASE MANHATTAN BANK,
                                   as Property Trustee


                                      _____________________________________  
                                              Authorized Signatory

                                      C-2
<PAGE>
 
                                     EXHIBIT D - Form of Preferred Securities of
                                                                   Alcoa Trust I


          [IF THE PREFERRED SECURITY IS TO BE A GLOBAL CERTIFICATE, INSERT -
This Preferred Security is a Book-Entry Preferred Securities Certificate within
the meaning of the Trust Agreement hereinafter referred to and is registered in
the name of The Depository Trust Company ("DTC") or a nominee of DTC.  This
Preferred Security is exchangeable for Preferred Securities registered in the
name of a person other than DTC or its nominee only in the limited circumstances
described in the Trust Agreement and no transfer of this Preferred Security
(other than a transfer of this Preferred Security as a whole by DTC to a nominee
of DTC or by a nominee of DTC to DTC or another nominee of DTC) may be
registered except in limited circumstances.

          Unless this certificate is presented by an authorized representative
of The Depository Trust Company, a New York corporation ("DTC"), to 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 is
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.]

                                      D-1
<PAGE>
 
       Certificate Number ____      Number of Preferred Securities ____

                             CUSIP NO. ___________

                  CERTIFICATE EVIDENCING PREFERRED SECURITIES
                                       OF
                                ALCOA TRUST [  ]

                     ___% Convertible Preferred Securities
                (Liquidation Amount $50 per Preferred Security)

          Alcoa Trust [  ], a statutory business trust created under the laws of
the State of Delaware (the "Trust"), hereby certifies that ______________ (the
"Holder") is the registered owner of __________ preferred securities of the
Trust representing an undivided beneficial interest in the assets of the Trust
and designated the Alcoa Trust [  ] ___% Convertible Preferred Securities
(Liquidation Amount $50 per Preferred Security) (the "Preferred Securities").
Except to the extent set forth in the Trust Agreement (as defined below), the
Preferred Securities are transferable on the books and records of the Trust, in
person or by a duly authorized attorney, upon surrender of this certificate duly
endorsed and in proper form for transfer as provided in Section 5.4 of the Trust
Agreement (as defined below).  The designations, rights, privileges,
restrictions, preferences and other terms and provisions of the Preferred
Securities are set forth in, and this certificate and the Preferred Securities
represented hereby are issued and shall in all respects be subject to the terms
and provisions of, the Amended and Restated Trust Agreement of the Trust dated
as of [                     ] as the same may be amended from time to time (the
"Trust Agreement") including the designation of the terms of Preferred
Securities as set forth therein.  The Holder is entitled to the benefits of the
Guarantee Agreement entered into by Aluminum Company of America, a Pennsylvania
corporation, and The Chase Manhattan Bank, as Guarantee Trustee, dated as of [
] (the "Guarantee"), to the extent provided therein.  The Trust will furnish a
copy of the Trust Agreement and the Guarantee to the Holder without charge upon
written request to the Trust at its principal place of business or registered
office.

          Upon receipt of this certificate, the Holder is bound by the Trust
Agreement and is entitled to the benefits thereunder.

                                      D-2
<PAGE>
 
          IN WITNESS WHEREOF, one of the Administrative Trustees of the Trust
has executed this certificate.


Dated:                                       ALCOA TRUST I
 
                                             By: ______________________________
                                             Name:_____________________________
                                                  An Administrative Trustee


                PROPERTY TRUSTEE'S CERTIFICATE OF AUTHENTICATION

          This is one of the Preferred Securities referred to in the within-
mentioned Trust Agreement.



                                             THE CHASE MANHATTAN BANK,
                                             as Property Trustee
 
                                             By:  ______________________________
                                                       Authorized Signatory

                                      D-3
<PAGE>
 
                                   ASSIGNMENT

     FOR VALUE RECEIVED, the undersigned assigns and transfers this Preferred
Security to:

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________
(Insert assignee's social security or tax identification number)

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________
(Insert address and zip code of assignee)

and irrevocably appoints

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

agent to transfer this Preferred Securities Certificate on the books of the
Trust.  The agent may substitute another to act for him or her.

Date:       ______________________

Signature:  ______________________

(Sign exactly as your name appears on the other side of this Preferred
Securities Certificate)

                                      D-4
<PAGE>
 
                    [TO BE ATTACHED TO GLOBAL CERTIFICATE]

                                  SCHEDULE A

          The initial Liquidation Amount of this Global Certificate shall be
$_________.  The following increases or decreases in the Liquidation Amount of
this Global Certificate have been made:

<TABLE>
<CAPTION>
======================================================================
         Amount of                                           
         increase in                                          
         Liquidation                                          
         Amount of                                           
         this Global                      Liquidation               
         Certificate                      Amount of       Signature  
         including       Amount of        this Global     of      
         upon            decrease in      Certificate     authorized  
         exercise of     Liquidation      following       officer of  
         over-           Amount of        such            Trustee or  
Date     allotment       this Global      decrease or     Securities  
Made     option          Certificate      increase        Custodian  
- ----------------------------------------------------------------------
<S>      <C>             <C>              <C>             <C>
- ----------------------------------------------------------------------
 
- ----------------------------------------------------------------------
 
- ----------------------------------------------------------------------
 
- ----------------------------------------------------------------------
 
- ----------------------------------------------------------------------
 
- ----------------------------------------------------------------------
 
- ----------------------------------------------------------------------
 
- ----------------------------------------------------------------------
 
- ----------------------------------------------------------------------
 
- ----------------------------------------------------------------------
 
- ----------------------------------------------------------------------
 
- ----------------------------------------------------------------------
 
- ----------------------------------------------------------------------
 
- ----------------------------------------------------------------------

======================================================================
</TABLE>

                                      D-5
<PAGE>
 
                                                EXHIBIT E - Notice of Conversion

                             NOTICE OF CONVERSION

To:  The Chase Manhattan Bank,
     as Property Trustee of
     Alcoa Trust I

          The undersigned owner of these Preferred Securities hereby irrevocably
exercises the option to convert these Preferred Securities, or the portion below
designated, into Common Stock of Aluminum Company of America (the "Alcoa Common
Stock") in accordance with the terms of the Amended and Restated Trust Agreement
(as amended from time to time, the "Trust Agreement"), dated as of [ ], by
____________, ____________ and ____________, as Administrative Trustees, Chase
Manhattan Bank Delaware, as Delaware Trustee, The Chase Manhattan Bank, as
Property Trustee, Aluminum Company of America, as Depositor, and by the Holders,
from time to time, of undivided beneficial interests in the assets of the Trust
to be issued pursuant to the Trust Agreement. Pursuant to the aforementioned
exercise of the option to convert these Preferred Securities, the undersigned
hereby directs the Conversion Agent (as that term is defined in the Trust
Agreement) to (i) exchange such Preferred Securities for a portion of the
Debentures (as that term is defined in the Trust Agreement) held by the Trust
(at the rate of exchange specified in the terms of the Preferred Securities set
forth in the Trust Agreement) and (ii) promptly convert such Debentures on
behalf of the undersigned, into Alcoa Common Stock (at the conversion rate
specified in the terms of the Preferred Securities set forth in the Trust
Agreement).

          The undersigned does also hereby direct the Conversion Agent that the
shares issuable and deliverable upon conversion, together with any check in
payment for fractional shares, be issued in the name of and delivered to the
undersigned, unless a different name has been indicated in the assignment below.
If shares are to be issued in the name of a person other than the undersigned,
the undersigned will pay all transfer taxes payable with respect thereto.

                                      E-1
<PAGE>
 
Date: ____________
 
      in whole ___                      in part ______
 
                                        Number of Preferred Securities to be
                                        converted:
 
                                        ______________________________________
 
                                        If a name or names other than the
                                        undersigned, please indicate in the
                                        spaces below the name or names in
                                        which the shares of Alcoa Common
                                        Stock are to be issued, along with
                                        the address or addresses of such
                                        person or persons
 
                                        ______________________________________
                                        ______________________________________
                                        ______________________________________
                                        ______________________________________
                                        ______________________________________
                                        ______________________________________
 
                                        ______________________________________
                                        Signature (for conversion only)
 
                                        Please Print or Typewrite Name and
                                        Address, Including Zip Code, and
                                        Social Security or Other Identifying
                                        Number
 
                                        ______________________________________
                                        ______________________________________
                                        ______________________________________
Signature Guarantee:*
                                        ______________________________________


____________________
*    (Signature must be guaranteed by an institution which is a member of the
     following recognized Signature Guaranty Programs: (i) The Securities
     Transfer Agent Medallion Program (STAMP); (ii) The New York Stock Exchange
     Medallion Program (MSP); (iii) The Stock Exchange Medallion Program (SEMP);
     or (iv) in such other guarantee programs acceptable to the Trustee.

                                      E-2

<PAGE>
 
                                                                    EXHIBIT 4(N)
 
            ------------------------------------------------------------



                               GUARANTEE AGREEMENT

                                     between

                           ALUMINUM COMPANY OF AMERICA

                                       and

                          THE CHASE MANHATTAN BANK


                     Relating to the Preferred Securities of

                                  ALCOA TRUST I


                             Dated as of ____,19__


             ------------------------------------------------------------
<PAGE>
 
                             CROSS REFERENCE TABLE*
<TABLE> 
<CAPTION> 
Section of Trust                                                                           Section of
Indenture Act of                                                                            Guarantee
1939, as amended                                                                            Agreement
<S>                                                                                   <C>  
310(a).........................................................................................4.1(a)
310(b)....................................................................................4.1(c), 2.8
310(c)...................................................................................Inapplicable
311(a).........................................................................................2.2(b)
311(b).........................................................................................2.2(b)
311(c)...................................................................................Inapplicable
312(a).........................................................................................2.2(a)
312(b).........................................................................................2.2(b)
313...............................................................................................2.3
314(a)............................................................................................2.4
314(b)...................................................................................Inapplicable
314(c)............................................................................................2.5
314(d)...................................................................................Inapplicable
314(e)..................................................................................1.1, 2.5, 3.2
314(f)............................................................................................3.2
315(a).........................................................................................3.1(d)
315(b)............................................................................................2.7
315(c)............................................................................................3.1
315(d).........................................................................................3.1(d)
316(a)..................................................................................1.1, 2.6, 5.4
316(b)............................................................................................5.3
317(a)...................................................................................Inapplicable
317(b)...................................................................................Inapplicable
318(a).........................................................................................2.1(b)
318(b).........................................................................................2.1(b)
318(c).........................................................................................2.1(a)
</TABLE> 

________
*        This Cross-Reference Table does not constitute part of the Guarantee
         Agreement and shall not affect the interpretation of any of its terms
         or provisions.
<PAGE>
 
                                TABLE OF CONTENTS
                                -----------------
<TABLE> 
<S>                                                                                                <C>                       
ARTICLE I
         DEFINITIONS............................................................................    2
                           SECTION 1.1  Definitions.............................................    2

ARTICLE II
         TRUST INDENTURE ACT....................................................................    5
                           SECTION 2.1  Trust Indenture Act; Application........................    6
                           SECTION 2.2  List of Holders.........................................    6
                           SECTION 2.3  Reports by the Guarantee Trustee........................    6
                           SECTION 2.4  Periodic Reports to Guarantee Trustee...................    6
                           SECTION 2.5  Evidence of Compliance with Conditions
                  Precedent.....................................................................    7
                           SECTION 2.6  Events of Default; Waiver...............................    7
                           SECTION 2.7  Event of Default; Notice................................    7
                           SECTION 2.8  Conflicting Interests...................................    7

ARTICLE III
         POWERS, DUTIES AND RIGHTS OF THE GUARANTEE TRUSTEE....................................     8
                           SECTION 3.1  Powers and Duties of the Guarantee Trustee
                   .............................................................................    8
                           SECTION 3.2  Certain Rights of Guarantee Trustee.....................    9
                           SECTION 3.3  Indemnity...............................................   11

ARTICLE IV
         GUARANTEE TRUSTEE.....................................................................    12
                           SECTION 4.1  Guarantee Trustee; Eligibility.........................    12
                           SECTION 4.2  Appointment, Removal and Resignation of the
                  Guarantee Trustee............................................................    12

ARTICLE V
         GUARANTEE.............................................................................    13
                           SECTION 5.1  Guarantee..............................................    13
                           SECTION 5.2  Waiver of Notice and Demand............................    13
                           SECTION 5.3  Obligations Not Affected...............................    14
</TABLE> 

                                        i
<PAGE>
 
<TABLE> 
<S>                                                                                                <C>  

                           SECTION 5.4  Rights of Holders......................................    15
                           SECTION 5.5  Guarantee of Payment...................................    15
                           SECTION 5.6  Subrogation............................................    15
                           SECTION 5.7  Independent Obligations................................    16
                           SECTION 5.8  Subordination..........................................    16

ARTICLE VI
         COVENANTS.............................................................................    16
                           SECTION 6.1  Certain Covenants of the Guarantor.....................    16

ARTICLE VII
         TERMINATION...........................................................................    18
                           SECTION 7.1  Termination............................................    18

ARTICLE VIII
         SUBORDINATION OF GUARANTEE............................................................    18
                           SECTION 8.1  Guarantee Subordinate to Guarantor Senior
                  Debt.........................................................................    18
                           SECTION 8.2  Payment Over of Proceeds Upon Dissolution,
                  Etc..........................................................................    18
                           SECTION 8.3  No Payment When Guarantor Senior Debt in
                  Default......................................................................    19
                           SECTION 8.4  Guarantee Trustee to Effectuate Subordination
                   ............................................................................    20
                           SECTION 8.5  No Waiver of Subordination Provisions..................    20
                           SECTION 8.6  Notice to Guarantee Trustee............................    20
                           SECTION 8.7  Reliance on Judicial Order or Certificate of
                  Liquidating Agent............................................................    21
                           SECTION 8.8  Guarantee Trustee Not Fiduciary for Holders
                  of Guarantor Senior Debt.....................................................    21
                           SECTION 8.9  Rights of Guarantee Trustee as Holder of
                  Guarantor Senior Debt; Preservation of Guarantee Trustee's Rights
                   ............................................................................    21
                           SECTION 8.10  Certain Conversions or Exchanges Deemed
                  Payment......................................................................    21
</TABLE> 

                                       ii
<PAGE>
 
<TABLE>
<S>                                                                                              <C> 
ARTICLE IX                                                            
         MISCELLANEOUS.........................................................................  22
                           SECTION 9.1  Successors and Assigns.................................  22
                           SECTION 9.2  Amendments.............................................  22
                           SECTION 9.3  Notices................................................  22
                           SECTION 9.4  Benefit................................................  23
                           SECTION 9.5  Interpretation.........................................  23
                           SECTION 9.6  Governing Law..........................................  24
</TABLE> 

                                       iii
<PAGE>
 
                              GUARANTEE AGREEMENT


          This GUARANTEE AGREEMENT, dated as of _______, 19__, is executed and
delivered by ALUMINUM COMPANY OF AMERICA, a Pennsylvania corporation (the
"Guarantor") and THE CHASE MANHATTAN BANK, a corporation organized and existing
under the laws of the State of New York, as trustee (the "Guarantee Trustee"),
for the benefit of the Holders (as defined herein) from time to time of the
Preferred Securities (as defined herein) of Alcoa Trust I, a Delaware statutory
business trust (the "Issuer").

          WHEREAS, pursuant to an Amended and Restated Trust Agreement (the
"Trust Agreement"), dated as of _______, 19__, among the Trustees named therein,
the Guarantor, as Depositor, and the Holders from time to time of undivided
beneficial interests in the assets of the Issuer, the Issuer is issuing
_____________ of its _% [Convertible] Quarterly Income Preferred Securities
(liquidation amount $50 per preferred security) (the "Preferred Securities")
representing preferred undivided beneficial interests in the assets of the
Issuer and having the terms set forth in the Trust Agreement;

          WHEREAS, the Preferred Securities will be issued by the Issuer and the
proceeds thereof, together with the proceeds from the issuance of the Issuer's
Common Securities (as defined below), will be used to purchase the Debentures
(as defined in the Trust Agreement) of the Guarantor which will be deposited
with The Chase Manhattan Bank, as Property Trustee under the Trust Agreement, as
trust assets;

          WHEREAS, as incentive for the Holders to purchase Preferred
Securities, the Guarantor desires irrevocably and unconditionally to agree, to
the extent set forth herein, to pay to the Holders of the Preferred Securities
the Guarantee Payments (as defined herein) and to make certain other payments on
the terms and conditions set forth herein; and

          NOW, THEREFORE, in consideration of the purchase by each Holder of
Preferred Securities, which purchase the Guarantor hereby agrees shall benefit
the Guarantor, the Guarantor executes and delivers this Guarantee Agreement for
the benefit of the Holders from time to time of the Preferred Securities.
<PAGE>
 
                                   ARTICLE I
                                  DEFINITIONS

          SECTION 1.1  Definitions.  As used in this Guarantee Agreement, the
terms set forth below shall, unless the context otherwise requires, have the
following meanings.  Capitalized or otherwise defined terms used but not
otherwise defined herein shall have the meanings assigned to such terms in the
Trust Agreement as in effect on the date hereof.

          "Affiliate" of any specified Person means any other Person directly or
indirectly controlling or controlled by or under direct common control with such
specified Person, provided, however, that an Affiliate of the Guarantor shall
not be deemed to include the Issuer.  For the purposes of this definition,
"control" when used with respect to any specified Person means the power to
direct the management and policies of such Person, directly or indirectly,
whether through the ownership of voting securities, by contract or otherwise;
and the terms "controlling" and "controlled" have meanings correlative to the
foregoing.

          "Common Securities" means the securities representing common
beneficial interests in the assets of the Issuer.

          "Common Stock" shall mean the common stock, par value $1.00 per share,
of the Guarantor.

          "Debt" means, with respect to any Person, whether recourse is to all
or a portion of the assets of such Person and whether or not contingent, (i)
every obligation of such Person for money borrowed; (ii) every obligation of
such Person evidenced by bonds, debentures, notes or other similar instruments,
including obligations incurred in connection with the acquisition of property,
assets or businesses; (iii) every reimbursement obligation of such Person with
respect to letters of credit, bankers' acceptances or similar facilities issued
for the account of such Person; (iv) every obligation of such Person issued or
assumed as the deferred purchase price of property or services (but excluding
trade accounts payable or accrued liabilities arising in the ordinary course of
business); (v) every capital lease obligation of such Person; and (vi) every
obligation of the type referred to in clauses (i) through (v) of another Person
and all dividends of another person the payment of which, in either case, such
Person has guaranteed or for which such Person is responsible or liable,
directly or indirectly, as obligor or otherwise.

                                       2
<PAGE>
 
          "Event of Default" means a default by the Guarantor on any of its
payment or other obligations under this Guarantee Agreement; provided, however,
that, except with respect to a default in payment of any Guarantee Payments, no
Event of Default shall be deemed to have occurred under this Guarantee Agreement
unless and until the Guarantor shall have received written notice of default and
shall not have cured such default within 60 days after receipt of such notice.

          "Guarantee Payments" means the following payments or distributions,
without duplication, with respect to the Preferred Securities, to the extent not
paid or made by or on behalf of the Issuer:  (i) any accumulated and unpaid
Distributions (as defined in the Trust Agreement) required to be paid on the
Preferred Securities, to the extent the Issuer shall have funds on hand legally
available therefor at such time, (ii) the redemption price set forth in the
Trust Agreement, including premium, if any, all accrued and unpaid Distributions
to the date of redemption (the "Redemption Price"), with respect to the
Preferred Securities called for redemption by the Issuer to the extent the
Issuer shall have funds on hand legally available therefor, and (iii) upon a
voluntary or involuntary dissolution, winding-up or liquidation of the Issuer,
other than in connection with the distribution of Debentures to the Holders or
the redemption tion of all Preferred Securities issued by the Issuer, the lesser
of (a) the aggregate of the liquidation amount of $50 per Preferred Security
plus accrued and unpaid Distributions on the Preferred Securities to the date of
payment to the extent the Issuer shall have funds on hand legally available to
make such payment and (b) the amount of assets of the Issuer remaining available
for distribution to Holders in liquidation of the Issuer (in either case, the
"Liquidation Distribution").

          "Guarantee Trustee" means The Chase Manhattan Bank, until a Successor
Guarantee Trustee has been appointed and has accepted such appointment pursuant
to the terms of this Guarantee Agreement and thereafter means each such
Successor Guarantee Trustee.

          "Guarantor Senior Debt" means the principal of (and premium, if any)
and interest, if any (including interest accruing on or after the filing of any
petition in bankruptcy or for reorganization relating to the Guarantor whether
or not such claim for post-petition interest is allowed in such proceeding), on
Debt of the Guarantor, whether incurred on or prior to the date of the Indenture
or thereafter incurred, unless, in the instrument creating or evidencing the
same or pursuant to which the same is outstanding, it is provided that such
obligations are not superior in right of payment to the Debentures.

                                       3
<PAGE>
 
          "Holder" means any holder, as registered on the books and records of
the Issuer, of any Preferred Securities; provided, however, that in determining
whether the holders of the requisite percentage of Preferred Securities have
given any request, notice, consent or waiver hereunder, "Holder" shall not
include the Guarantor, the Guarantee Trustee or any Affiliate of the Guarantor
or the Guarantee Trustee.

          "Indenture" means the Indenture dated as of ____,19__ with
respect to the Debentures, between the Guarantor and The Chase Manhattan Bank,
as trustee, as the same may be supplemented and amended from time to time.

          "List of Holders" has the meaning specified in Section 2.2 (a).

          "Majority in Liquidation Amount of the Securities" means, except as
provided by the Trust Indenture Act, a vote by the Holder(s), voting separately
as a class, of more than 50% of the aggregate liquidation amount of all the
outstanding Preferred Securities issued by the Issuer.

          "Officers' Certificate" means, with respect to any Person, a
certificate signed by (i) the Chairman, Chief Executive Officer, President or a
Vice President, and by (ii) the Treasurer, an Assistant Treasurer, the
Controller, the Secretary or an Assistant Secretary of such Person, and
delivered to the Guarantee Trustee.  Any Officers' Certificate delivered with
respect to compliance with a condition or covenant provided for in this
Guarantee Agreement shall include:

              (a) a statement that each officer signing the Officers' Certifi-
cate has read the covenant or condition and the definitions relating thereto;

              (b) a brief statement of the nature and scope of the examination
or investigation undertaken by each officer in rendering the Officers'
Certificate;

                                       4
<PAGE>
 
              (c) a statement that each such officer has made such examination
or investigation as, in such officer's opinion, is necessary to enable such
officer to express an informed opinion as to whether or not such covenant or
condition has been complied with; and

              (d) a statement as to whether, in the opinion of each such
officer, such condition or covenant has been complied with.

          "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.

          "Responsible Officer" means, with respect to the Guarantee Trustee,
any officer of the Guarantee Trustee with direct responsibility for the
administration of this Guarantee Agreement, which may be an Executive Vice
President, Senior Vice President, any First Vice President, any Vice President,
any Assistant Vice President, the Secretary, any Assistant Secretary, the
Treasurer, any Assistant Treasurer, any Trust Officer or Assistant Trust Officer
or any other officer of the Corporate Trust Services Division of the Guarantee
Trustee customarily performing functions similar to those performed by any of
the above designated officers, and also means, with respect to a particular
corporate trust matter, any other officer to whom such matter is referred
because of that officer's knowledge of and familiarity with the particular
subject.

          "Successor Guarantee Trustee" means a successor Guarantee Trustee
possessing the qualifications to act as Guarantee Trustee under Section 4.1.

          "Trust Indenture Act" means the Trust Indenture Act of 1939, as
amended.


                                  ARTICLE II
                              TRUST INDENTURE ACT

          SECTION 2.1  Trust Indenture Act; Application.  (a)  This Guarantee
Agreement is subject to the provisions of the Trust Indenture Act that are
required to be part of this Guarantee Agreement and shall, to the extent
applicable, be governed by such provisions.

                                       5
<PAGE>
 
          (b) If and to the extent that any provision of this Guarantee
Agreement limits, qualifies or conflicts with the duties imposed by Sections 310
to 317, inclusive, of the Trust Indenture Act, such imposed duties shall
control.

          SECTION 2.2  List of Holders. (a)  The Guarantor shall furnish or
cause to be furnished to the Guarantee Trustee (unless the Guarantee Trustee is
acting as Securities Registrar with respect to the Debentures under the
Indenture) (i) semi-annually, on or before __________ and _______ of each year,
a list, in such form as the Guarantee Trustee may reasonably require, of the
names and addresses of the Holders ("List of Holders") as of a date not more
than 15 days prior to the delivery thereof, and (ii) at such other times as the
Guarantee Trustee may request in writing, within 30 days after the receipt by
the Guarantor of any such request, a List of Holders as of a date not more than
15 days prior to the time such list is furnished, in each case to the extent
such information is in the possession or control of the Guarantor and is not
identical to a previously supplied list of Holders or has not otherwise been
received by the Guarantee Trustee.  Notwithstanding the foregoing, the Guarantor
shall not be obligated to provide such List of Holders at any time the Preferred
Securities are represented by one or more Global Securities (as defined in the
Indenture). The Guarantee Trustee may destroy any List of Holders previously
given to it on receipt of a new List of Holders.

          (b) The Guarantee Trustee shall comply with its obligations under
Section 311(a), Section 311(b) and Section 312(b) of the Trust Indenture Act.

          SECTION 2.3  Reports by the Guarantee Trustee. Within 60 days of May
15 of each calendar year, the Guarantee Trustee shall provide to the Holders
such reports as are required by Section 313 of the Trust Indenture Act, if any,
in the form and in the manner provided by Section 313 of the Trust Indenture
Act. The Guarantee Trustee shall also comply with the requirements of Section
313(d) of the Trust Indenture Act.

          SECTION 2.4  Periodic Reports to Guarantee Trustee.  The Guarantor
shall provide to the Guarantee Trustee, the Securities and Exchange Commission
and the Holders such documents, reports and information, if any, as required by
Section 314 of the Trust Indenture Act and the compliance certificate required
by Section 314 of the Trust Indenture Act in the form, in the manner and at the
times required by Section 314 of the Trust Indenture Act.

                                       6
<PAGE>
 
          SECTION 2.5  Evidence of Compliance with Conditions Precedent. The
Guarantor shall provide to the Guarantee Trustee such evidence of compliance
with such conditions precedent, if any, provided for in this Guarantee Agreement
that relate to any of the matters set forth in Section 314(c) of the Trust
Indenture Act. Any certificate or opinion required to be given by an officer
pursuant to Section 314(c)(1) may be given in the form of an Officers'
Certificate.

          SECTION 2.6  Events of Default; Waiver.  The Holders of a Majority in
Liquidation Amount of the Securities may, by vote, on behalf of the Holders,
waive any past default or Event of Default and its consequences. Upon such
waiver, any such default or Event of Default shall cease to exist, and any
default or Event of Default arising therefrom shall be deemed to have been
cured, for every purpose of this Guarantee Agreement, but no such waiver shall
extend to any subsequent or other default or Event of Default or impair any
right consequent therefrom.

          SECTION 2.7  Event of Default; Notice. (a)  The Guarantee Trustee
shall, within 90 days after the occurrence of an Event of Default, transmit by
mail, first class postage prepaid, to the Holders, notices of all Events of
Default known to the Guarantee Trustee, unless such defaults have been cured
before the giving of such notice, provided, that, except in the case of a
default in the payment of a Guarantee Payment, the Guarantee Trustee shall be
protected in withholding such notice if and so long as the Board of Directors,
the executive committee or a trust committee of directors and/or Responsible
Officers of the Guarantee Trustee in good faith deter  mines that the
withholding of such notice is in the interests of the Holders.

          (b) The Guarantee Trustee shall not be deemed to have knowledge of any
Event of Default unless the Guarantee Trustee shall have received written
notice, or a Responsible Officer charged with the administration of the Trust
Agreement shall have obtained written notice, of such Event of Default.

          SECTION 2.8  Conflicting Interests.  The Trust Agreement and the
Indenture shall be deemed to be specifically described in this Guarantee
Agreement for the purposes of clause (i) of the first proviso contained in
Section 310(b) of the Trust Indenture Act.

                                       7
<PAGE>
 
                                  ARTICLE III
              POWERS, DUTIES AND RIGHTS OF THE GUARANTEE TRUSTEE

          SECTION 3.1  Powers and Duties of the Guarantee Trustee. (a) This
Guarantee Agreement shall be held by the Guarantee Trustee for the benefit of
the Holders, and the Guarantee Trustee shall not transfer this Guarantee
Agreement to any Person except a Holder exercising his or her rights pursuant to
Section 5.4(iv) or to a Successor Guarantee Trustee on acceptance by such
Successor Guarantee Trustee of its appointment to act as Successor Guarantee
Trustee.  The right, title and interest of the Guarantee Trustee shall
automatically vest in any Successor Guarantee Trustee, upon acceptance by such
Successor Guarantee Trustee of its appointment hereunder, and such vesting and
cessation of title shall be effective whether or not conveyancing documents have
been executed and delivered pursuant to the appointment of such Successor
Guarantee Trustee.

          (b) If an Event of Default actually known to the Responsible Officer
of the Guarantee Trustee has occurred and is continuing, the Guarantee Trustee
shall enforce this Guarantee Agreement for the benefit of the Holders.

          (c) The Guarantee Trustee, before the occurrence of any Event of
Default and after the curing of all Events of Default that may have occurred,
shall undertake to perform only such duties as are specifically set forth in
this Guarantee Agreement, and no implied covenants shall be read into this
Guarantee Agreement against the Guarantee Trustee.  In case an Event of Default
has occurred (that has not been cured or waived pursuant to Section 2.6) and is
actually known to the Responsible Officer of the Guarantee Trustee, the
Guarantee Trustee shall exercise such of the rights and powers vested in it by
this Guarantee Agreement, and use the same degree of care and skill in its
exercise thereof, as a prudent person would exercise or use under the
circumstances in the conduct of his or her own affairs.

          (d) No provision of this Guarantee Agreement shall be construed to
relieve the Guarantee Trustee from liability for its own negligent action, its
own negligent failure to act or its own willful misconduct, except that:

              (i) prior to the occurrence of any Event of Default and after
     the curing or waiving of all such Events of Default that may have occurred;

                                       8
<PAGE>
 
                (A) the duties and obligations of the Guarantee Trustee shall be
     determined solely by the express provisions of this Guarantee Agreement,
     and the Guarantee Trustee shall not be liable except for the performance of
     such duties and obligations as are specifically set forth in this Guarantee
     Agreement; and

                (B) in the absence of bad faith on the part of the Guarantee
     Trustee, the Guarantee Trustee may conclusively rely, as to the truth of
     the statements and the correctness of the opinions expressed therein, upon
     any certificates or opinions furnished to the Guarantee Trustee and
     conforming to the requirements of this Guarantee Agreement; but in the case
     of any such certificates or opinions that by any provision hereof or of the
     Trust Indenture Act are specifically required to be furnished to the
     Guarantee Trustee, the Guarantee Trustee shall be under a duty to examine
     the same to determine whether or not they conform to the requirements of
     this Guarantee Agreement;

          (ii)  the Guarantee Trustee shall not be liable for any error of
     judgment made in good faith by a Responsible Officer of the Guarantee
     Trustee, unless it shall be proved that the Guarantee Trustee was negligent
     in ascertaining the pertinent facts upon which such judgment was made;

          (iii) the Guarantee Trustee shall not be liable with respect to
     any action taken or omitted to be taken by it in good faith in accordance
     with the direction of the Holders of not less than a Majority in
     Liquidation Amount of the Securities relating to the time, method and place
     of conducting any proceeding for any remedy available to the Guarantee
     Trustee, or exercising any trust or power conferred upon the Guarantee
     Trustee under this Guarantee Agreement; and

          (iv)  no provision of this Guarantee Agreement shall require the
     Guarantee Trustee to expend or risk its own funds or otherwise incur
     personal financial liability in the performance of any of its duties or in
     the exercise of any of its rights or powers, if the Guarantee Trustee shall
     have reasonable grounds for believing that the repayment of such funds or
     liability is not reasonably assured to it under the terms of this Guarantee
     Agreement or adequate indemnity against such risk or liability is not
     reasonably assured to it.

                                       9
<PAGE>
 
          SECTION 3.2  Certain Rights of Guarantee Trustee. (a)  Subject to the
provisions of Section 3.1:

          (i)    The Guarantee Trustee may rely and shall be fully protected in
     acting or refraining from acting upon any resolution, certificate,
     statement, proxy, instrument, opinion, report, notice, request, direction,
     consent, order, bond, debenture, note, other evidence of indebtedness or
     other paper or document believed by it to be genuine and to have been
     signed, sent or presented by the proper party or parties.

          (ii)   Any direction or act of the Guarantor contemplated by this
     Guarantee Agreement shall be sufficiently evidenced by an Officers'
     Certificate unless otherwise prescribed herein.

          (iii)  Whenever, in the administration of this Guarantee Agreement,
     the Guarantee Trustee shall deem it desirable that a matter be proved or
     established before taking, suffering or omitting to take any action
     hereunder, the Guarantee Trustee (unless other evidence is herein
     specifically prescribed) may, in the absence of bad faith on its part,
     request and rely upon an Officers' Certificate which, upon receipt of such
     request from the Guarantee Trustee, shall be promptly delivered by the
     Guarantor.

          (iv)   The Guarantee Trustee may consult with legal counsel, and the
     written advice or opinion of such legal counsel with respect to legal
     matters shall be full and complete authorization and protection in respect
     of any action taken, suffered or omitted to be taken by it hereunder in
     good faith and in accordance with such advice or opinion. Such legal
     counsel may be legal counsel to the Guarantor or any of its Affiliates and
     may be one of its employees. The Guarantee Trustee shall have the right at
     any time to seek instructions concerning the administration of this
     Guarantee Agreement from any court of competent jurisdiction.

          (v)    The Guarantee Trustee shall be under no obligation to
     exercise any of the rights or powers vested in it by this Guarantee
     Agreement at the request or direction of any Holder, unless such Holder
     shall have provided to the Guarantee Trustee such adequate security and
     indemnity as would satisfy a reasonable person in the position of the
     Guarantee Trustee, against the costs, expenses (including attorneys' fees
     and expenses) and liabilities that might be incurred by it in complying
     with such request or

                                      10
<PAGE>
 
     direction, including such reasonable advances as may be requested by the
     Guarantee Trustee; provided that nothing contained in this Section
     3.2(a)(v) shall be taken to relieve the Guarantee Trustee, upon the
     occurrence of an Event of Default, of its obligation to exercise the rights
     and powers vested in it by this Guarantee Agreement and use the same degree
     of care and skill in the exercise thereof as a prudent person would
     exercise or use under the circumstances in the conduct of his or her own
     affairs.

          (vi)   The Guarantee Trustee shall not be bound to make any
     investigation into the facts or matters stated in any resolution,
     certificate, statement, instrument, opinion, report, notice, request,
     direction, consent, order, bond, debenture, note, other evidence of
     indebtedness or other paper or document, but the Guarantee Trustee, in its
     discretion, may make such further inquiry or investigation into such facts
     or matters as it may see fit.

          (vii)  The Guarantee Trustee may execute any of the trusts or
     powers hereunder or perform any duties hereunder either directly or by or
     through its agents or attorneys or any Affiliate, and the Guarantee Trustee
     shall not be responsible for any misconduct or negligence on the part of
     any such agent or attorney appointed with due care by it hereunder.

          (viii) Whenever in the administration of this Guarantee Agreement
     the Guarantee Trustee shall deem it desirable to receive instructions
     with respect to enforcing any remedy or right or taking any other action
     hereunder, the Guarantee Trustee (A) may request instructions from the
     Holders of a Majority in Liquidation Amount of the Securities, (B) may
     refrain from enforcing such remedy or right or taking such other action
     until such instructions are received, and (C) shall be protected in acting
     in accordance with such instructions.

          (ix)   Any action taken by the Guarantee Trustee or its agents
     hereunder shall bind the Holders, and the signature of the Guarantee
     Trustee or its agents alone shall be sufficient and effective to perform
     any such action. No third party shall be required to inquire as to the
     authority of the Guarantee Trustee to so act or as to its compliance with
     any of the terms and provisions of this Guarantee Agreement both of which
     shall be conclusively evidenced by the Guarantee Trustee's or its agent's
     taking such action.

                                      11
<PAGE>
 
          (b) No provision of this Guarantee Agreement shall be deemed to impose
any duty or obligation on the Guarantee Trustee to perform any act or acts or
exercise any right, power, duty or obligation conferred or imposed on it in any
jurisdiction in which it shall be illegal, or in which the Guarantee Trustee
shall be unqualified or incompetent in accordance with applicable law, to
perform any such act or acts or to exercise any such right, power, duty or
obligation.  No permissive power or authority available to the Guarantee Trustee
shall be construed to be a duty to act in accordance with such power and
authority.

          SECTION 3.3  Indemnity.  The Guarantor agrees to indemnify the
Guarantee Trustee for, and to hold it harmless against, any loss, liability or
expense incurred without negligence or bad faith on the part of the Guarantee
Trustee, arising out of or in connection with the acceptance or administration
of this Guarantee Agreement, including the reasonable costs and expenses of
defending itself against any claim or liability in connection with the exercise
or performance of any of its powers or duties hereunder.  The Guarantee Trustee
will not claim or exact any lien or charge on any Guarantee Payment as a result
of any amount due to it under this Guarantee Agreement.


                                  ARTICLE IV
                               GUARANTEE TRUSTEE

          SECTION 4.1  Guarantee Trustee; Eligibility. (a)  There shall at all
times be a Guarantee Trustee which shall:

               (i)     not be an Affiliate of the Guarantor; and

               (ii)    be a Person that is eligible pursuant to the Trust
     Indenture Act to act as such and has a combined capital and surplus of at
     least $50,000,000, and shall be a corporation meeting the requirements of
     Section 310(a) of the Trust Indenture Act. If such corporation publishes
     reports of condition at least annually, pursuant to law or to the
     requirements of the supervising or examining authority, then, for the
     purposes of this Section and to the extent permitted by the Trust Indenture
     Act, the combined capital and surplus of such corporation shall be deemed
     to be its combined capital and surplus as set forth in its most recent
     report of condition so published.

                                      12
<PAGE>
 
          (b) If at any time the Guarantee Trustee shall cease to be eligible to
so act under Section 4.1(a), the Guarantee Trustee shall immediately resign in
the manner and with the effect set out in Section 4.2(c).

          (c) If the Guarantee Trustee has or shall acquire any "conflicting
interest" within the meaning of Section 310(b) of the Trust Indenture Act, the
Guarantee Trustee and Guarantor shall in all respects comply with the provisions
of Section 310(b) of the Trust Indenture Act.  The Trust Agreement and the
Indenture shall not be deemed to constitute conflicting interests of the
Guarantee Trustee.

          SECTION 4.2  Appointment, Removal and Resignation of the Guarantee
Trustee.  (a)  Subject to Section 4.2(b) the Guarantee Trustee may be appointed
or removed without cause at any time by the Guarantor.

          (b) The Guarantee Trustee shall not be removed in accordance with
Section 4.2(a) until a Successor Guarantee Trustee has been appointed and has
accepted such appointment by written instrument executed by such Successor
Guarantee Trustee and delivered to the Guarantor.

          (c) The Guarantee Trustee appointed to office hereunder shall hold
office until a Successor Guarantee Trustee shall have been appointed or until
its removal or resignation.  The Guarantee Trustee may resign from office
(without need for prior or subsequent accounting) by an instrument in writing
executed by the Guarantee Trustee and delivered to the Guarantor, which
resignation shall not take effect until a Successor Guarantee Trustee has been
appointed and has accepted such appointment by an instrument in writing executed
by such Successor Guarantee Trustee and delivered to the Guarantor and the
resigning Guarantee Trustee.

          (d) If no Successor Guarantee Trustee shall have been appointed and
accepted appointment as provided in this Section 4.2 within 60 days after
delivery to the Guarantor of an instrument of resignation, the resigning
Guarantee Trustee may petition, at the expense of the Guarantor, any court of
competent jurisdiction for appointment of a Successor Guarantee Trustee.  Such
court may thereupon, after prescribing such notice, if any, as it may deem
proper, appoint a Successor Guarantee Trustee.

                                      13
<PAGE>
 
                                   ARTICLE V
                                   GUARANTEE

          SECTION 5.1  Guarantee.  The Guarantor irrevocably and uncondi-
tionally agrees, subject to Section 5.8 and Article 8, to pay in full to the
Holders the Guarantee Payments (without duplication of amounts theretofore paid
by or on behalf of the Issuer), as and when due, regardless of any defense,
right of set-off or counter  claim which the Issuer may have or assert other
than the defense of payment.  The Guarantor's obligation to make a Guarantee
Payment may be satisfied by direct payment of the required amounts by the
Guarantor to the Holders or by causing the Issuer to pay such amounts to the
Holders.

          SECTION 5.2  Waiver of Notice and Demand.  The Guarantor hereby waives
notice of acceptance of the Guarantee Agreement and of any liability to which it
applies or may apply, presentment, demand for payment, any right to require a
proceeding first against the Guarantee Trustee, Issuer or any other Person
before proceeding against the Guarantor, protest, notice of nonpayment, notice
of dishonor, notice of redemption and all other notices and demands.

          SECTION 5.3  Obligations Not Affected.  The obligations, covenants,
agreements and duties of the Guarantor under this Guarantee Agreement shall in
no way be affected or impaired by reason of the happening from time to time of
any of the following:

          (a)   the release or waiver, by operation of law or otherwise, of the
performance or observance by the Issuer of any express or implied agreement,
covenant, term or condition relating to the Preferred Securities to be performed
or observed by the Issuer;

          (b)   the extension of time for the payment by the Issuer of all or
any portion of the Distributions, Redemption Price, Liquidation Distribution or
any other sums payable under the terms of the Preferred Securities or the
extension of time for the performance of any other obligation under, arising out
of, or in connection with, the Preferred Securities (other than an extension of
time for payment of Distributions that results from the extension of any
interest payment period on the Debentures as so provided in the Indenture);

                                      14
<PAGE>
 
          (c)   any failure, omission, delay or lack of diligence on the part of
the Holders to enforce, assert or exercise any right, privilege, power or remedy
conferred on the Holders pursuant to the terms of the Preferred Securities, or
any action on the part of the Issuer granting indulgence or extension of any
kind;

          (d)   the voluntary or involuntary liquidation, dissolution, sale of
any collateral, receivership, insolvency, bankruptcy, assignment for the benefit
of creditors, reorganization, arrangement, composition or readjustment of debt
of, or other similar proceedings affecting, the Issuer or any of the assets of
the Issuer;

          (e)   any invalidity of, or defect or deficiency in, the Preferred
Securities;

          (f)   the settlement or compromise of any obligation guaranteed hereby
or hereby incurred; or

          (g)   any other circumstance whatsoever that might otherwise
constitute a legal or equitable discharge or defense of a guarantor, it being
the intent of this Section 5.3 that the obligations of the Guarantor hereunder
shall be absolute and unconditional under any and all circumstances.

          There shall be no obligation of the Holders or the Guarantee Trustee
to give notice to, or obtain the consent of, the Guarantor with respect to the
happening of any of the foregoing.

          SECTION 5.4  Rights of Holders.  The Guarantor expressly acknowledges
that: (i) this Guarantee Agreement will be deposited with the Guarantee Trustee
to be held for the benefit of the Holders; (ii) the Guarantee Trustee has the
right to enforce this Guarantee Agreement on behalf of the Holders; (iii) the
Holders of a Majority in Liquidation Amount of the Securities have the right to
direct the time, method and place of conducting any proceeding for any remedy
available to the Guarantee Trustee in respect of this Guarantee Agreement or to
direct the exercise of any trust or power conferred upon the Guarantee Trustee
under this Guarantee Agreement;  (iv) any Holder may institute a legal
proceeding directly against the Guarantor to enforce its rights under this
Guarantee Agreement, without first instituting a legal proceeding against the
Guarantee Trustee, the Issuer or any other Person; and (v) if an Event of
Default with respect to the Debentures constituting the failure to pay interest
or principal on the Debentures on the date such interest or principal is
otherwise payable has occurred and is continuing, then any Holder shall

                                      15
<PAGE>
 
have the right, which is absolute and unconditional, to proceed directly against
the Guarantor to obtain Guarantee Payments without first waiting to determine if
the Guarantee Trustee has enforced this Guarantee Agreement or instituting a
legal proceeding against the Issuer, the Guarantee Trustee or any other Person.

          SECTION 5.5  Guarantee of Payment.  This Guarantee Agreement creates a
guarantee of payment and not of collection.  This Guarantee Agreement will not
be discharged except by payment of the Guarantee Payments in full (without
duplication of amounts theretofore paid by the Issuer) or upon distribution of
Debentures to Holders as provided in the Trust Agreement.

          SECTION 5.6  Subrogation.  The Guarantor shall be subrogated to all
(if any) rights of the Holders against the Issuer in respect of any amounts paid
to the Holders by the Guarantor under this Guarantee Agreement and shall have
the right to waive payment by the Issuer pursuant to Section 5.1; provided,
however, that the Guarantor shall not (except to the extent required by
mandatory provisions of law) be entitled to enforce or exercise any rights which
it may acquire by way of subrogation or any indemnity, reimbursement or other
agreement, in all cases as a result of payment under this Guarantee Agreement,
if, at the time of any such payment, any amounts are due and unpaid under this
Guarantee Agreement.  If any amount shall be paid to the Guarantor in violation
of the preceding sentence, the Guarantor agrees to hold such amount in trust for
the Holders and to pay over such amount to the Guarantor Trustee for the benefit
of the Holders.

          SECTION 5.7  Independent Obligations.  The Guarantor acknowledges
that its obligations hereunder are independent of the obligations of the Issuer
with respect to the Preferred Securities and that the Guarantor shall be liable
as principal and debtor hereunder to make Guarantee Payments pursuant to the
terms of this Guarantee Agreement notwithstanding the occurrence of any event
referred to in subsections (a) through (g), inclusive, of Section 5.3 hereof.

          SECTION 5.8  Subordination.  The Guarantee Agreement will constitute
an unsecured obligation of the Guarantor and will rank (i) subordinate and
junior in right of payment to all other liabilities of the Guarantor; (ii) pari
passu with the most senior preferred stock or preference stock, if any,
hereafter issued by the Guarantor and with any guarantee hereafter entered into
by the Guarantor in respect

                                      16
<PAGE>
 
of any preferred or preference stock or interests of any affiliate of the
Guarantor** and (iii) senior to the Guarantor's Common Stock. Each Holder of
Preferred Securities, by its acceptance thereof, agrees to the subordination
provisions and other terms of this Guarantee Agreement.

          If an "Event of Default" (as defined in the Indenture) has occurred
and is continuing, the rights of holders of Common Securities to receive
Guarantee Payments under the Common Securities Guarantee Agreement are
subordinate to the rights of the Holders of Preferred Securities to receive
Guarantee Payments under this Guarantee Agreement.


                                  ARTICLE VI
                                   COVENANTS

          SECTION 6.1  Certain Covenants of the Guarantor.  (a)  Guarantor
covenants and agrees that if and so long as (i) the Issuer is the holder of all
the Debentures, (ii) a Tax Event (as defined in the Trust Agreement) in respect
of the Issuer has occurred and is continuing and (iii) the Guarantor has
elected, and has not revoked such election, to pay Additional Sums (as defined
in the Trust Agreement) in respect of the Preferred Securities and Common
Securities, the Guarantor will pay to the Issuer such Additional Sums.

          (b)   The Guarantor covenants and agrees that so long as any Preferred
Securities remain outstanding, it will not (i) declare or pay any dividends on
make any distributions with respect to, or redeem, purchase or make a
liquidation payment with respect to, any of its Common Stock (other than (i)
purchases or acquisitions of shares of Common Stock in connection with the
satisfaction by the Guarantor of its obligations under any employee benefit
plan, (ii) as a result of a reclassification of the Guarantor's Common Stock or
the exchange or conversion of one class or series of the Guarantor's Common
Stock for another class or series of the Guarantor's Common Stock, (iii) the
purchase of fractional interests in shares of the Guarantor's Common Stock
pursuant to the conversion or exchange provisions of such Common Stock of the
Guarantor or the security being converted or exchanged or (iv) purchases or
acquisitions of shares of Common Stock to be used in connec-

_____________________

**   Should we differentiate between operating subsidiaries and financing 
     subsidiaries?

                                      17
<PAGE>
 
tion with acquisitions of Common Stock by shareholders pursuant to the
Guarantor's dividend reinvestment plan) or make any guarantee payments with
respect to the foregoing and (b) the Guarantor shall not make any payment of
principal or premium, if any, on or repurchase any debt securities (including
guarantees) other than at stated maturity issued by the Guarantor which rank
pari passu with or junior to the Debentures if at such time (x) there shall have
occurred any event of which the Guarantor has actual knowledge that (A) with the
giving of notice or the lapse of time, or both, would constitute an Event of
Default under this Guarantee Agreement or the Trust Agreement and (B) in respect
or which the Guarantor shall not have taken reasonable steps to cure or (y) the
Guarantor shall have given notice of its selection of an Extension Period (as
defined in the Indenture) with respect to the Debentures and shall not have
rescinded such notice, or such Extension Period, or any extension thereof, shall
be continuing.


          (c)   The Guarantor covenants and agrees (i) to maintain directly or
indirectly 100% ownership of the Common Securities, provided that certain 
successors which are permitted by the Indenture may succeed to the Guarantor's
ownership of the Common Securities, (ii) not to voluntarily terminate, wind-up
or liquidate the Issuer, except (a) in connection with a distribution of the
Debentures to the holders of the Preferred Securities in liquidation of the
Issuer or (b) in connection with certain mergers, consolidations or
amalgamations permitted by the Trust Agreement, (iii) to use its reasonable
efforts, consistent with the terms and provisions of the Trust Agreement, to
cause the Issuer to remain classified as a grantor trust for United States
Federal income tax purposes, (iv) for so long as Preferred Securities are
outstanding, not to convert Debentures except pursuant to a notice of conversion
delivered to the Conversion Agent (as defined in the Trust Agreement) by a
Holder, (v) to maintain the reservation for issuance of the number of shares of
Common Stock that would be required from time to time upon the conversion of all
the Debentures then outstanding, (vi) to deliver shares of Common Stock upon an
election by the Holders to convert such Preferred Securities into Common Stock
and (vii) to honor all obligations relating to the conversion or exchange of the
Preferred Securities into or for Common Stock or Debentures.


                                  ARTICLE VII
                                  TERMINATION

                                      18
<PAGE>
 
          SECTION 7.1  Termination.  This Guarantee Agreement shall terminate as
to each Holder with respect to the Preferred Securities of the Issuer and be of
no further force and effect upon the earliest of (i) full payment of the 
redemption price of all Preferred Securities, (ii) distribution of the
Debentures of the Guaran tor held by the Issuer to the Holders or (iii) full
payment of the amounts payable in accordance with the Trust Agreement upon
liquidation of the Issuer. Notwithstanding the foregoing, this Guarantee
Agreement will continue to be effective or will be reinstated, as the case may
be, if at any time any Holder must restore payment of any sums paid under such
Preferred Securities or this Guarantee Agreement.


                                  ARTICLE VII
                           SUBORDINATION OF GUARANTEE

          SECTION 8.1  Guarantee Subordinate to Guarantor Senior Debt. The
Guarantor covenants and agrees, and each Holder, by its acceptance thereof,
likewise covenants and agrees, that the payment of the Guarantee Payments
pursuant to this Guarantee Agreement is hereby expressly made subordinate and
subject in right of payment to the prior payment in full in cash of all amounts
then due and payable in respect of all Guarantor Senior Debt (whether
outstanding on the date hereof or hereafter created, incurred, assumed or
guaranteed), and that the subordination is for the benefit of the holders of
Guarantor Senior Debt and that no payment of the Guarantee Payments pursuant to
this Guarantee Agreement may be made unless full payment of all amounts then due
for principal, premium, if any, and interest then due on all Guarantor Senior
Debt (by lapse of time, acceleration or otherwise) has been made or duly
provided for in cash or in a manner satisfactory to the holders of such
Guarantor Senior Debt.

          SECTION 8.2  Payment Over of Proceeds Upon Dissolution, Etc. Upon any
distribution of the Guarantor's assets in connection with any dissolution,
winding-up, liquidation or reorganization of the Guarantor, whether voluntary or
involuntary, in bankruptcy, insolvency or receivership proceedings (each such
event, if any, herein sometimes referred to as a "Proceeding"), or upon an
assignment for the benefit of creditors or otherwise:  (i) all Guarantor Senior
Debt (including without limitation all interest accruing on or after the filing
of any petition in bankruptcy relating to the Guarantor at the relevant
contractual rate, whether or not such claim for post-petition interest is
allowed in such Proceeding) must be paid in

                                      19
<PAGE>
 
full in cash before the Holders are entitled to any payments or distributions of
any kind or character on account of any Guarantee Payments pursuant to this
Guarantee Agreement, and (ii) any payment or distribution of the Guarantor's
assets of any kind or character, whether in cash, securities or other property,
which would otherwise (but for these subordination provisions) be payable or
deliverable in respect of the Guarantee Payments shall be paid or delivered
directly to the holders of such Guarantor Senior Debt (or their representative
or trustee) in accordance with the priorities then existing among such holders
until all Guarantor Senior Debt shall have been paid in full in cash before any
payment or distribution is made to the Holders.

          In the event that, notwithstanding the subordination provisions set
forth herein, any payment or distribution of assets of any kind or character is
made at a time when the respective payment is not permitted to be made as a
result of the subordination provisions described above and before all Guarantor
Senior Debt is paid in full in cash, the Guarantee Trustee or the Holders
receiving such payment will be required to pay over such payment or distribution
to the holders of such Guarantor Senior Debt.

          The consolidation of the Guarantor with, or the merger of the
Guarantor into, another Person or the liquidation or dissolution of the
Guarantor following the sale of all or substantially all of its properties and
assets as an entirety to another Person upon the terms and conditions set forth
in Article VIII of the Indenture shall not be deemed a Proceeding for the
purposes of this Section if the Person formed by such consolidation or into
which the Guarantor is merged or the Person which acquires by sale such
properties and assets as an entirety, as the case may be, shall, as a part of
such consolidation, merger, or sale comply with the conditions set forth in
Article 8.

          SECTION 8.3  No Payment When Guarantor Senior Debt in Default. In the
event and during the continuation of any default in the payment of principal of
(or premium, if any) or interest on, or any other amounts owing with respect to,
any Guarantor Senior Debt when the same becomes due and payable or in the event
any judicial proceeding shall be pending with respect to any such default, then,
unless and until such default shall have been cured or waived or shall have
ceased to exist, no payment or distribution of any kind or character, whether in
cash or properties shall be made by the Guarantor on account of any Guarantee
Payment.

          The Guarantor shall give prompt written notice to the Guarantee
Trustee of any default in payment of principal of or interest on any Guarantor
Senior

                                      20
<PAGE>
 
Debt; provided that no failure to give such a notice shall have any effect
whatsoever on the subordination provisions described herein.

          In the event that, notwithstanding the foregoing, the Guarantor shall
make any payment to the Guarantee Trustee or any Holder prohibited by the
foregoing provisions of this Section, and if such fact shall, at or prior to the
time of such payment, have been made known as set forth in Section 8.6, to the
Guarantee Trustee or, as the case may be, such Holder, then and in such event
such payment shall be paid over and delivered forthwith to the Guarantor.

          The provisions of this Section shall not apply to any payment with
respect to which Section 8.2 would be applicable.

          SECTION 8.4  Guarantee Trustee to Effectuate Subordination.  Each
Holder by his or her acceptance thereof authorizes and directs the Guarantee
Trustee on his or her behalf to take such action as may be necessary or
appropriate to acknowledge or effectuate the subordination provided in this
Article and appoints the Guarantee Trustee as his or her attorney-in-fact for
any and all such purposes.

          SECTION 8.5  No Waiver of Subordination Provisions.  No right of any
present or future holder of any Guarantor Senior Debt to enforce subordination
as herein provided shall at any time in any way be prejudiced or impaired by any
act or failure to act on the part of the Guarantor or by any act or failure to
act, in good faith, by any such holder, or by any noncompliance by the Guarantor
with the terms, provisions and covenants of this Guarantee Agreement, regardless
of any knowledge thereof that any such holder may have or be otherwise charged
with.

          SECTION 8.6  Notice to Guarantee Trustee.  The Guarantor shall give
written notice as soon as commercially practicable to the Guarantee Trustee of
any fact actually known to the Guarantor which would prohibit the making of any
payment to or by the Guarantee Trustee in respect of the Guarantee Payments.
Notwithstanding the provisions of this Article or any other provision of this
Guarantee Agreement, the Guarantee Trustee shall not be charged with knowledge
of the existence of any facts which would prohibit the making of any payment to
or by the Guarantee Trustee in respect of the Guarantee Payments, unless and
until the Guarantee Trustee shall have received written notice thereof from
the Guarantor or a Person representing itself as a holder of Guarantor Senior
Debt or from any trustee, agent or representative therefor (whether or not the
facts contained in such notice are true).

                                      21
<PAGE>
 
          SECTION 8.7  Reliance on Judicial Order or Certificate of Liquidating
Agent.  Upon any payment or distribution of assets of the Guarantor referred to
in this Article, the Guarantee Trustee, subject to the provisions of Article 3,
and the Holders shall be entitled to rely upon any order or decree entered by
any court of competent jurisdiction in which a Proceeding is pending, or a
certificate of the trustee in bankruptcy, receiver, liquidating trustee,
custodian, assignee for the benefit of creditors, agent or other Person making
such payment or distribution, delivered to the Guarantee Trustee or to the
Holders, for the purpose of ascertaining the Persons entitled to participate in
such payment or distribution, the holders of the Guarantor Senior Debt and other
indebtedness of the Guarantor, the amount thereof or payable thereon, the amount
or amounts paid or distributed thereon and all other facts pertinent thereto or
to this Article.

          SECTION 8.8 Guarantee Trustee Not Fiduciary for Holders of Guarantor
Senior Debt. With respect to the holders of the Guarantor Senior Debt, the
Guarantee Trustee undertakes to perform or observe only such of its obligations
and covenants as are set forth in this Article 8, and no implied covenants or
obligations with respect to the holders of such Guarantor Senior Debt shall be
read into this Guarantee Agreement against The Chase Manhattan Bank and/or the
Guarantee Trustee. The Chase Manhattan Bank and/or the Guarantee Trustee shall
not be deemed to owe any fiduciary duty to the holders of such Guarantor Senior
Debt and, subject to the provisions of Section 3.2, neither the Guarantee
Trustee nor The Chase Manhattan Bank shall be liable to the holder of any
Guarantor Senior Debt if it shall pay over or deliver to Holders, the Guarantor,
or any other person, money or assets to which any holder of such Guarantor
Senior Debt shall be entitled by virtue of this Article 8 or otherwise.

          SECTION 8.9  Rights of Guarantee Trustee as Holder of Guarantor Senior
Debt; Preservation of Guarantee Trustee's Rights.  The Guarantee Trustee in its
individual capacity shall be entitled to all the rights set forth in this
Article with respect to any Guarantor Senior Debt which may at any time be held
by it, to the same extent as any other holder of Guarantor Senior Debt, and,
subject to the requirements of the Trust Indenture Act, nothing in this
Guaranty Agreement shall deprive the Guarantee Trustee of any of its rights as
such holder.

          SECTION 8.10  Certain Conversions or Exchanges Deemed Payment.  For
the purpose of this Article only, (a) the issuance and delivery of junior
securities upon conversion or exchange of Debentures shall not be deemed to

                                      22
<PAGE>
 
constitute a payment or distribution on account of the principal of (or premium,
if any) or interest (including any Additional Interest) on the Debentures or on
account of the purchase or other acquisition of Debentures, and (b) the payment,
issuance or delivery of cash (including any payments for fractional shares),
property or securities (other than junior securities) upon conversion or
exchange of a Debenture shall be deemed to constitute payment on account of the
principal of such security.  For the purpose of this Section, the term "junior
securities" means (i) shares of any stock of any class of the Guarantor and (ii)
securities of the Guarantor which are subordinated in right of payment to all
Guarantor Senior Debt which may be outstanding at the time of issuance or
delivery of such securities to substantially the same extent as, or to a greater
extent than, the Debentures which are so subordinated as provided in this
Article.


                                  ARTICLE IX
                                 MISCELLANEOUS

          SECTION 9.1  Successors and Assigns.  All guarantees and agreements
contained in this Guarantee Agreement shall bind the successors, assigns,
receivers, trustees and representatives of the Guarantor and shall inure to the
benefit of the Holders of the Preferred Securities then outstanding.  Except in
connection with a consolidation, merger or sale involving the Guarantor that is
permitted under Article 8 of the Indenture and pursuant to which the assignee
agrees in writing to perform the Guarantor's obligations hereunder, the
Guarantor shall not assign its obligations hereunder.

          SECTION 9.2  Amendments.  Except with respect to any changes which do
not adversely affect the rights of the Holders in any material respect (in which
case no consent of the Holders will be required), this Guarantee Agreement may
only be amended with the prior approval of the Holders of not less than a
Majority in Liquidation Amount of the Securities.  The provisions of Article 6
of the Trust Agreement concerning meetings of the Holders shall apply to the
giving of such approval.  The Guarantor shall furnish the Guarantee Trustee with
an Officers' Certificate and an Opinion of Counsel to the effect that any
amendment of this Agreement is authorized and permitted and that all conditions 
precedent, if any, in this Guarantee Agreement, to the execution and delivery of
such amendment have been satisfied.

          SECTION 9.3  Notices.  Any notice, request or other communication
required or permitted to be given hereunder shall be in writing, duly signed by
the party giving such notice, and delivered, telecopied or mailed by first class
mail as

                                      23
<PAGE>
 
follows:  (a)  if given to the Guarantor, to the address set forth below
or such other address as the Guarantor may give notice of to the Holders:

       Aluminum Company of America
       201 Isabella Street
       Pittsburgh, Pennsylvania 15212-5858
       Attention: Treasurer

          (b)   if given to the Issuer, in care of the Guarantee Trustee, at the
Issuer's (and the Guarantee Trustee's) address set forth below or such other
address as the Guarantee Trustee on behalf of the Issuer may give notice of to
the Holders:

       Alcoa Trust I
       c/o Aluminum Company of America
       201 Isabella Street
       Pittsburgh, Pennsylvania 15212-5858
       Attention: Treasurer

       with a copy to:

       The Chase Manhattan Bank
       450 West 33/rd/ Street, 15th Floor
       New York, New York 10001
       Attention: Global Trust Services

          (c)   if given to any Holder, at the address set forth on the books
and records of the Issuer.

          All notices hereunder shall be deemed to have been given when received
in person, telecopied with receipt confirmed, or mailed by first class mail,
postage prepaid, except that if a notice or other document is refused delivery
or cannot be delivered because of a changed address of which no notice was
given, such notice or other document shall be deemed to have been delivered on
the date of such refusal or inability to deliver.

          SECTION 9.4  Benefit.  This Guarantee Agreement is solely for the
benefit of the Holders and is not separately transferable from the Preferred
Securities.

                                      24
<PAGE>
 
          SECTION 9.5  Interpretation.  In this Guarantee Agreement, unless the
context otherwise requires:

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

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

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

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

          (e)   a term defined in the Trust Indenture Act has the same meaning
when used in this Guarantee Agreement unless otherwise defined in this Guarantee
Agreement or unless the context otherwise requires;

          (f)   a reference to the singular includes the plural and vice versa;
and

          (g)   the masculine, feminine or neuter genders used herein shall
include the masculine, feminine and neuter genders.

          SECTION 9.6  Governing Law.  THIS GUARANTEE AGREEMENT SHALL BE
GOVERNED BY AND CONSTRUED AND INTERPRETED IN ACCORDANCE WITH THE LAWS OF THE
STATE OF NEW YORK WITH  OUT REGARD TO THE CONFLICTS OF LAW PRINCIPLES THEREOF.

          This instrument may be executed in any number of counterparts, each of
which so executed shall be deemed to be an original, but all such counterparts
shall together constitute but one and the same instrument.

                                      25
<PAGE>
 
          THIS GUARANTEE AGREEMENT is executed as of the day and year first
above written.


                              ALUMINUM COMPANY
                              OF AMERICA


                              By: ____________________________
                                  Name:
                                  Title:


                              THE CHASE MANHATTAN BANK
                              as Guarantee Trustee


                              By: ____________________________
                                  Name:
                                  Title:

                                      26

<PAGE>
 
                                                                      Exhibit 21

              SUBSIDIARIES AND EQUITY ENTITIES OF THE REGISTRANT
                             (As of June 30,1998)


<TABLE> 
<CAPTION> 
                                                   State or Country of
               Name                                Organization
               ----                                ------------
<S>                                                <C> 
Alcoa Alumina & Chemicals, L.L.C.*                 Delaware
     Alcoa ACC Industrial Chemicals Ltd.           India
     Alcoa Kasei Limited                           Japan
     Alcoa Minerals of Jamaica, Inc., L.L.C.       Delaware
     Alcoa Steamship Company, Inc.                 New York
     Halco (Mining) Inc.                           Delaware
          Compagnie des Bauxites de Guinee         Delaware
     Lib-Ore Steamship                             Liberia
     Moralco Limited                               Japan
     St. Croix Alumia, L.L.C.                      Delaware
     Suriname Aluminum Company, L.L.C.             Delaware
Alcoa Brazil Holdings Company                      Delaware
     Alcoa Aluminio S.A.                           Brazil
Alcoa Building Products, Inc.**                    Ohio
Alcoa Closure Systems International, Inc.          Delaware
Alcoa Generating Corporation                       Indiana
Alcoa International Holdings Company               Delaware
     Alcoa Inter-America, Inc.                     Delaware
     Alcoa Japan Limited                           Japan
     Alcoa-Kofem Kft                               Hungary
     Alcoa Nederland Holding B.V.                  Netherlands
          Alcoa Inespal S.A.                       Spain
               Aluminio Espanol S.A.               Spain
               Alumina Espanola S.A.               Spain
               Inespal Metal S.A.                  Spain
          Alcoa International, S.A.                Switzerland
          Alcoa Italia S.p.A.                      Italy
          Alcoa Nederland B.V.                     Netherlands
          Norsk Alcoa A/S                          Norway
     Alcoa of Australia Limited                    Australia
          A.F.P. Pty. Limited                      Australia
               Hedges Gold Pty. Ltd.               Australia
          Alcoa of Australia (Asia) Limited.       Hong Kong
     Alcoa Russia, Inc.                            Delaware
     Asian-American Packaging Systems Co., Ltd.    China
     Kobe Alcoa Transportation Products, Ltd.      Japan
     Unified Accord SDN. BHD.                      Malaysia
</TABLE> 

*    Registered to do business in California, Florida, Georgia, Louisiana, North
     Carolina, Pennsylvania and Texas under the name of Alcoa Industrial
     Chemicals.
**   Registered to do business in Ohio under the name of Mastic.

<TABLE> 
<CAPTION> 

               Name                               State or Country of
               ----                               Organization                  
                                                  ------------
 <S>                                              <C> 
Alcoa Laudel, Inc.                                Delaware
Alcoa Manufacturing (G.B.) Limited                England
Alcoa Properties, Inc.                            Delaware
     Alcoa South Carolina, Inc.                   Delaware
Alcoa Recycling Company, Inc.                     Delaware
Alcoa Securities Corporation                      Delaware
     Alcoa Automotive Structures, Inc.            Delaware
     Alcoa Brite Products, Inc.                   Delaware
     Alcoa Fujikura Ltd.                          Delaware
          Stribel GmbH                            Germany
          Michels GmbH                            Germany
     Alcoa Kobe Transportation Products, Inc.     Delaware
     Alcoa Nederland Finance B.V.                 Netherlands
          Alcoa Automotive Structures GmbH        Germany
               Alcoa Chemie GmbH                  Germany
               Alcoa Deutschland GmbH             Germany
               Alcoa Extrusions Hannover
               GmbH & Co., KG                     Germany
               Alcoa Chemie Nederland B.V.        Netherlands
               Alcoa Moerdijk B.V.                Netherlands
     Alcoa Packaging Machinery, Inc.              Delaware
     ASC Alumina, Inc.                            Delaware
     B & C Research, Inc.                         Ohio
     Halethorpe Extrusions, Inc.                  Delaware
     H-C Industries de Mexico, S.A. de C.V.       Mexico
     Northwest Alloys, Inc.                       Delaware
     Pimalco, Inc.                                Arizona
     Three Rivers Insurance Company               Vermont
     Tifton Aluminum Company, Inc.                Delaware
Alcoa (Shanghai) Aluminum Products
     Company Limited                              China
Alumax Inc.                                       Delaware
AMX Acquisition Corp.                             Delaware
Capsulas Metalicas, S.A.                          Spain
Gulf Closures W.L.L.                              Bahrain
Shibazaki Seisakusho Limited                      Japan
Tapoco, Inc.                                      Tennessee
Yadkin, Inc.                                      North Carolina
</TABLE>
 
The names of certain subsidiaries and equity entities which, considered in the
aggregate, would not constitute a significant subsidiary, have been omitted from
the above list.



<PAGE>
 
<TABLE> 
<CAPTION> 
                                                            State or Country of
               Name                                         Organization      
               ----                                         ------------      
<S>                                                         <C> 
Alcoa Laudel, Inc.                                          Delaware          
Alcoa Manufacturing (G.B.) Limited                          England           
Alcoa Properties, Inc.                                      Delaware         
     Alcoa South Carolina, Inc.                             Delaware          
Alcoa Recycling Company, Inc.                               Delaware          
Alcoa Securities Corporation                                Delaware          
     Alcoa Automotive Structures, Inc.                      Delaware          
     Alcoa Brite Products, Inc.                             Delaware          
     Alcoa Fujikura Ltd.                                    Delaware          
          Stribel GmbH                                      Germany           
          Michels GmbH                                      Germany           
     Alcoa Kobe Transportation Products, Inc.               Delaware          
     Alcoa Nederland Finance B.V.                           Netherlands       
          Alcoa Automotive Structures GmbH                  Germany           
               Alcoa Chemie GmbH                            Germany           
               Alcoa Deutschland GmbH                       Germany           
               Alcoa Extrusions Hannover GmbH & Co., KG     Germany
          Alcoa Chemie Nederland B.V.                       Netherlands  
          Alcoa Moerdijk B.V.                               Netherlands  
     Alcoa Packaging Machinery, Inc.                        Delaware     
     ASC Alumina, Inc.                                      Delaware     
     B & C Research, Inc.                                   Ohio         
     Halethorpe Extrusions, Inc.                            Delaware     
     H-C Industries de Mexico, S.A. de C.V.                 Mexico       
     Northwest Alloys, Inc.                                 Delaware     
     Pimalco, Inc.                                          Arizona     
     Three Rivers Insurance Company                         Vermont      
     Tifton Aluminum Company, Inc.                          Delaware      
Alcoa (Shanghai) Aluminum Products Company Limited          China
Alumax Inc.                                                 Delaware       
AMX Acquisition Corp.                                       Delaware        
Capsulas Metalicas, S.A.                                    Spain           
Gulf Closures W.L.L.                                        Bahrain        
Shibazaki Seisakusho Limited                                Japan           
Tapoco, Inc.                                                Tennessee      
Yadkin, Inc.                                                North Carolina  
</TABLE> 

The names of certain subsidiaries and equity entities which, considered in the
aggregate, would not constitute a significant subsidiary, have been omitted from
the above list.

<PAGE>
 
                                                                  EXHIBIT 23(a)
 
                                 July 16, 1998

 
Securities and Exchange Commission
450 Fifth Street, N.W.
Washington, D.C. 20549
 
                        RE: ALUMINUM COMPANY OF AMERICA
 
  We are aware that our report, dated April 6, 1998, of our review of interim
financial information of Aluminum Company of America (the "Company") and
subsidiaries for the three-month period ended March 31, 1998, and included in
the Company's quarterly report on Form 10-Q for the quarter then ended, is
incorporated by reference in this Registration Statement on Form S-3 for the
registration of Debt Securities, Warrants to purchase Senior Debt Securities,
Preferred Stock and Common Stock of the Company and Trust Preferred Securities
of Alcoa Trust I. Pursuant to Rule 436(e) under the Securities Act of 1933,
this report should not be considered as part of a registration statement
prepared or certified by us within the meaning of Sections 7 and 11 of that
Act.

 
                                          PricewaterhouseCoopers LLP


<PAGE>
 
                                                                  EXHIBIT 23(b)
 
                      CONSENT OF INDEPENDENT ACCOUNTANTS
 
  We consent to the incorporation by reference in this Registration Statement
on Form S-3 of Aluminum Company of America (the "Company") and Alcoa Trust I
under the Securities Act of 1933, of our report dated January 8, 1998, except
Note V, for which the date is February 6, 1998, on our audits of the
consolidated financial statements and financial statement schedules of
Aluminum Company of America and consolidated subsidiaries as of December 31,
1997 and 1996, and for each of the three years in the period ended December
31, 1997, which reports are incorporated by reference or included in the
Company's Annual Report on Form 10-K for the fiscal year ended December 31,
1997. We also consent to the reference to our firm under the caption
"Experts."

 
                                          PricewaterhouseCoopers LLP
Pittsburgh, Pennsylvania
July 16, 1998


<PAGE>
 
                                                                      EXHIBIT 24





                               POWER OF ATTORNEY

     KNOWN ALL PERSONS BY THESE PRESENTS, that each of the under  signed
Directors of Aluminum Company of America (the "Company") hereby constitutes and
appoints RICHARD B. KELSON, EARNEST J. EDWARDS and DENIS A. DEMBLOWSKI, or any
of them, his true and lawful attorneys and agents to do any and all acts and
things and to execute any and all instruments which said attorneys and agents,
or any of them, may deem necessary or advisable or may be required to enable the
Company to comply with the Securities Act of 1933, as amended, and any rules,
regulations or requirements of the Securities and Exchange Commission in respect
thereof, in connection with the registration under said Act of up to $750
million of convertible debt securities of the Company, up to $750 million of
convertible preferred securities of a Delaware business trust or other entity
affiliated with the Company (the "Issuer"), a guaranty by the Company of such
convertible preferred securities of the Issuer, and such number of shares of
common stock, par value $1.00 per share, of the Company as are issuable upon
conversion from time to time of any of the foregoing securities, and including
specifically, but without limiting the generality of the foregoing, power and
authority to sign the name of each of the undersigned Directors of the Company
in the capacity of Director thereof to any registration statement to be filed
with the Securities and Exchange Commission in respect of said securities, to
any and all pre-effective amendments, post-effective amendments and supplements
to any such registration statement, and to any instruments or documents filed as
part of or in connection with any such registration statement or pre-effective
amendments or post-effective amendments or supplements thereto; and the
undersigned hereby ratifies and confirms all that said attorneys and agents, or
any of them, shall do or cause to be done by virtue hereof.

     IN WITNESS WHEREOF, the undersigned have subscribed these presents on the
date set opposite the names below.


 
/s/ Kenneth W. Dam
- --------------------------
Kenneth W. Dam                                    March 13, 1998
                                      
                                      
 /s/ Joseph T. Gorman                 
- --------------------------            
Joseph T. Gorman                                  March 13, 1998

                                      
 /s/ Judith M. Gueron                 
- --------------------------            
Judith M. Gueron                                  March  13, 1998
<PAGE>
 
 /s/ Sir Ronald Hampel
- --------------------------
Sir Ronald Hampel                              March 13, 1998
 

 /s/ John P. Mulroney
- --------------------------
John P. Mulroney                               March 13, 1998

 
 /s/ Sir Arvi Parbo
- --------------------------
Sir Arvi Parbo                                 March 13, 1998

 
 /s/ Henry B. Schacht
- --------------------------
Henry B. Schacht                               March 13, 1998
                                     
                                     
 /s/ Forrest N. Shumway              
- --------------------------           
Forrest N. Shumway                             March 13, 1998
                                     
                                     
 /s/ Franklin A. Thomas              
- --------------------------           
Franklin A. Thomas                             March 13, 1998
                                     
                                     
 /s/ Marina v.N. Whitman             
- --------------------------           
Marina v.N. Whitman                            March 13, 1998

                                       2
<PAGE>
 
                               POWER OF ATTORNEY


     KNOWN ALL PERSONS BY THESE PRESENTS, that the undersigned Executive Vice
President and Chief Financial Officer of Aluminum Company of America (the
"Company") hereby constitutes and appoints EARNEST J. EDWARDS and DENIS A.
DEMBLOWSKI, or any of them, his true and lawful attorneys and agents to do any
and all acts and things and to execute any and all instruments which said
attorneys and agents, or any of them, may deem necessary or advisable or may be
required to enable the Company to comply with the Securities Act of 1933, as
amended, and any rules, regulations or requirements of the Securities and
Exchange Commission in respect thereof, in connection with the registration
under said Act of up to $750 million of convertible debt securities of the
Company, up to $750 million of convertible preferred securities of a Delaware
business trust or other entity affiliated with the Company (the "Issuer"), a
guaranty by the Company of such convertible preferred securities of the Issuer,
and such number of shares of common stock, par value $1.00 per share, of the
Company as are issuable upon conversion from time to time of any of the
foregoing securities, and including specifically, but without limiting the
generality of the foregoing, power and authority to sign the name of the
undersigned Executive Vice President and Chief Financial Officer of the Company
in the capacity of Principal Financial Officer thereof to any registration
statement to be filed with the Securities and Exchange Commission in respect of
said securities, to any and all pre-effective amendments, post-effective
amendments and supplements to any such registration statement, and to any
instruments or documents filed as part of or in connection with any such
registration statement or pre-effective amendments or post-effective amendments
or supplements thereto; and the under  signed hereby ratifies and confirms all
that said attorneys and agents, or any of them, shall do or cause to be done by
virtue hereof.

     IN WITNESS WHEREOF, the undersigned has subscribed these presents on the
date set opposite the name below.


  /s/ Richard B. Kelson
 ---------------------------------
Richard B. Kelson                           March 13, 1998
Executive Vice President and
Chief Financial Officer
<PAGE>
 
                               POWER OF ATTORNEY


     KNOWN ALL PERSONS BY THESE PRESENTS, that the undersigned Senior Vice
President and Controller of Aluminum Company of America (the "Company") hereby
constitutes and appoints RICHARD B. KELSON and DENIS A. DEMBLOWSKI, or any of
them, his true and lawful attorneys and agents to do any and all acts and things
and to execute any and all instruments which said attorneys and agents, or any
of them, may deem necessary or advisable or may be required to enable the
Company to comply with the Securities Act of 1933, as amended, and any rules,
regulations or requirements of the Securities and Exchange Commission in respect
thereof, in connection with the registration under said Act of up to $750
million of convertible debt securities of the Company, up to $750 million of
convertible preferred securities of a Delaware business trust or other entity
affiliated with the Company (the "Issuer"), a guaranty by the Company of such
convertible preferred securities of the Issuer, and such number of shares of
common stock, par value $1.00 per share, of the Company as are issuable upon
conversion from time to time of any of the foregoing securities, and including
specifically, but without limiting the generality of the foregoing, power and
authority to sign the name of the undersigned Senior Vice President and
Controller of the Company in the capacity of Principal Accounting Officer
thereof to any registration statement to be filed with the Securi ties and
Exchange Commission in respect of said securities, to any and all pre-effective
amendments, post-effective amendments and supplements to any such registration
statement, and to any instruments or documents filed as part of or in connection
with any such registration statement or pre-effective amendments or post-
effective amendments or supplements thereto; and the undersigned hereby ratifies
and confirms all that said attorneys and agents, or any of them, shall do or
cause to be done by virtue hereof.

     IN WITNESS WHEREOF, the undersigned has subscribed these presents on the
date set opposite the name below.


    /s/ Earnest J. Edwards
- ---------------------------------
Earnest J. Edwards                          March 13, 1998
Vice President and Controller
<PAGE>
 
                               POWER OF ATTORNEY


     KNOWN ALL PERSONS BY THESE PRESENTS, that the undersigned Chairman of the
Board and Chief Executive Officer of Aluminum Company of America (the "Company")
hereby constitutes and appoints RICHARD B. KELSON, EARNEST J. EDWARDS and DENIS
A. DEMBLOWSKI, or any of them, his true and lawful attorneys and agents to do
any and all acts and things and to execute any and all instruments which said
attorneys and agents, or any of them, may deem necessary or advisable or may be
required to enable the Company to comply with the Securities Act of 1933, as
amended, and any rules, regulations or requirements of the Securities and
Exchange Commission in respect thereof, in connection with the registration
under said Act of up to $750 million of convertible debt securities of the
Company, up to $750 million of convertible preferred securities of a Delaware
business trust or other entity affiliated with the Company (the "Issuer"), a
guaranty by the Company of such convertible preferred securities of the Issuer,
and such number of shares of common stock, par value $1.00 per share, of the
Company as are issuable upon conversion from time to time of any of the
foregoing securities, and including specifically, but without limiting the
generality of the foregoing, power and authority to sign the name of the
undersigned Chairman of the Board and Chief Executive Officer of the Company in
the capacity of Principal Executive Officer thereof to any registration
statement to be filed with the Securities and Exchange Commission in respect of
said securities, to any and all pre-effective amendments, post-effective
amendments and supplements to any such registration statement, and to any
instruments or documents filed as part of or in connection with any such
registration statement or pre-effective amendments or post-effective amendments
or supplements thereto; and the undersigned hereby ratifies and confirms all
that said attorneys and agents, or any of them, shall do or cause to be done by
virtue hereof.

     IN WITNESS WHEREOF, the undersigned has subscribed these presents on the
date set opposite the name below.


  /s/ Paul H. O'Neill
 ------------------------------
Paul H. O'Neill                             March 13, 1998
Chairman of the Board and
Chief Executive Officer
<PAGE>
 
                               POWER OF ATTORNEY

     KNOWN ALL PERSONS BY THESE PRESENTS, that the undersigned Director of
Aluminum Company of America (the "Company") hereby constitutes and appoints
RICHARD B. KELSON, EARNEST J. EDWARDS and DENIS A. DEMBLOWSKI, or any of them,
his true and lawful attorneys and agents to do any and all acts and things and
to execute any and all instruments which said attorneys and agents, or any of
them, may deem necessary or advisable or may be required to enable the Company
to comply with the Securities Act of 1933, as amended, and any rules,
regulations or requirements of the Securities and Exchange Commission in respect
thereof, in connection with the registration under said Act of up to $750
million of convertible preferred securities of the Company, up to $750 million
of convertible preferred securities of a Delaware business trust or other entity
affiliated with the Company (the "Issuer"), a guaranty by the Company of such
convertible preferred securities of the Issuer, and such number of shares of
common stock, par value $1.00 per share, of the Company as are issuable upon
conversion from time to time of any of the foregoing securities, and including
specifically, but without limiting the generality of the foregoing, power and
authority to sign the name of the undersigned Director of the Company in the
capacity of Director thereof to any registration statement to be filed with the
Securities and Exchange Commission in respect of said securities, to any and all
pre-effective amendments, post-effective amendments and supplements to any such
registration statement, and to any instruments or documents filed as part of
or in connection with any such registration statement or pre-effective
amendments or post-effective amendments or supplements thereto; and the
undersigned hereby ratifies and confirms all that said attorneys and agents, or
any of them, shall do or cause to be done by virtue hereof.

     IN WITNESS WHEREOF, the undersigned has subscribed these presents on the
date set opposite the name below.

/s/ Hugh M. Morgan
- ------------------------------------
Hugh M. Morgan                                May 22, 1998
<PAGE>
 
                               POWER OF ATTORNEY

     KNOWN ALL PERSONS BY THESE PRESENTS, that each of the under  signed
Directors of Aluminum Company of America (the "Company") hereby constitutes and
appoints RICHARD B. KELSON, EARNEST J. EDWARDS and DENIS A. DEMBLOWSKI, or any
of them, his true and lawful attorneys and agents to do any and all acts and
things and to execute any and all instruments which said attorneys and agents,
or any of them, may deem necessary or advisable or may be required to enable the
Company to comply with the Securities Act of 1933, as amended, and any rules,
regulations or requirements of the Securities and Exchange Commission in respect
thereof, in connection with the registration under said Act of up to $1 billion
of securities, including but not limited to, debt, convertible, common,
preferred or hybrid securities of the Company, including specifically, but
without limiting the generality of the foregoing, power and authority to sign
the name of each of the undersigned Directors of the Company in the capacity of
Director thereof to any registration statement to be filed with the Securities
and Exchange Commission in respect of said securities, to any and all pre-
effective amendments, post-effective amendments and supplements to any such
registration statement, and to any instruments or documents filed as part of or
in connection with any such registration statement or pre-effective amendments
or post-effective amendments or supplements thereto; and the undersigned hereby
ratifies and confirms all that said attorneys and agents, or any of them, shall
do or cause to be done by virtue hereof.

     IN WITNESS WHEREOF, the undersigned have subscribed these presents on the
date set opposite the names below.

 
/s/  Kenneth W. Dam
- --------------------------
Kenneth W. Dam
March 13, 1998

 
/s/  Joseph T. Gorman
- --------------------------
Joseph T. Gorman          
March 13, 1998
 

/s/  Judith M. Gueron
- --------------------------
Judith M. Gueron    
March 13, 1998

 
/s/  Sir Ronald Hampel
- --------------------------
Sir Ronald Hampel           
March 13, 1998
<PAGE>
 
/s/  John P. Mulroney
- --------------------------
John P. Mulroney     
March 13, 1998
 

/s/  Sir Arvi Parbo
- --------------------------
Sir Arvi Parbo            
March 13, 1998
 

/s/  Henry B. Schacht
- --------------------------
Henry B. Schacht     
March 13, 1998
 

/s/  Forrest N. Shumway
- --------------------------
Forrest N. Shumway          
March 13, 1998
 

/s/  Franklin A. Thomas
- --------------------------
Franklin A. Thomas          
March 13, 1998
 

/s/  Marina v.N. Whitman
- --------------------------
Marina v.N. Whitman         
March 13, 1998

                                       2
<PAGE>
 
                               POWER OF ATTORNEY

     KNOWN ALL PERSONS BY THESE PRESENTS, that the undersigned Executive Vice
President and Chief Financial Officer of Aluminum Company of America (the
"Company") hereby constitutes and appoints EARNEST J. EDWARDS and DENIS A.
DEMBLOWSKI, or either of them, his true and lawful attorneys and agents to do
any and all acts and things and to execute any and all instruments which said
attorneys and agents, or either of them, may deem necessary or advisable or may
be required to enable the Company to comply with the Securities Act of 1933, as
amended, and any rules, regulations or requirements of the Securities and
Exchange Commission in respect thereof, in connection with the registration
under said Act of up to $1 billion of securities, including but not limited to,
debt, convertible, common, preferred or hybrid securities of the Company,
including specifically, but without limiting the generality of the foregoing,
power and authority to sign the name of the undersigned Executive Vice President
and Chief Financial Officer of the Company in the capacity of Principal
Financial Officer thereof to any registration statement to be filed with the
Securities and Exchange Commission in respect of said securities, to any and all
pre-effective amendments, post-effective amendments and supplements to any such
registration statement, and to any instruments or documents filed as part of or
in connection with any such registration statement or pre-effective amendments
or post-effective amendments or supplements thereto; and the undersigned hereby
ratifies and confirms all that said attorneys and agents, or either of them,
shall do or cause to be done by virtue hereof.

     IN WITNESS WHEREOF, the undersigned have subscribed these presents on the
date set opposite the name below.

                                                
/s/  B. Kelson
- ----------------------------
Richard B. Kelson                               March 13, 1998
Executive Vice President and
Chief Financial Officer
<PAGE>
 
                               POWER OF ATTORNEY

     KNOWN ALL PERSONS BY THESE PRESENTS, that the undersigned Senior Vice
President and Controller of Aluminum Company of America (the "Company") hereby
constitutes and appoints RICHARD B. KELSON and DENIS A. DEMBLOWSKI, or either of
them, his true and lawful attorneys and agents to do any and all acts and things
and to execute any and all instruments which said attorneys and agents, or any
of them, may deem necessary or advisable or may be required to enable the
Company to comply with the Securities Act of 1933, as amended, and any rules,
regulations or requirements of the Securities and Exchange Commission in respect
thereof, in connection with the registration under said Act of up to $1 billion
of securities, including but not limited to, debt, convertible, common,
preferred or hybrid securities of the Company, including specifically, but
without limiting the generality of the foregoing, power and authority to sign
the name of the undersigned Senior Vice President and Controller of the Company
in the capacity of Principal Accounting Officer thereof to any registration
statement to be filed with the Securities and Exchange Commission in respect of
said securities, to any and all pre-effective amendments, post-effective
amendments and supplements to any such registration statement, and to any
instruments or documents filed as part of or in connection with any such
registration statement or pre-effective amendments or post-effective amendments
or supplements thereto; and the undersigned hereby ratifies and confirms all
that said attorneys and agents, or either of them, shall do or cause to be done
by virtue hereof.

     IN WITNESS WHEREOF, the undersigned have subscribed these presents on the
date set opposite the name below.

                                                
/s/  Earnest J. Edwards
- ------------------------------
Earnest J. Edwards                              March 13, 1998
Senior Vice President and Controller
<PAGE>
 
                               POWER OF ATTORNEY

     KNOWN ALL PERSONS BY THESE PRESENTS, that the undersigned Chairman of the
Board and Chief Executive Officer of Aluminum Company of America (the "Company")
hereby constitutes and appoints RICHARD B. KELSON, EARNEST J. EDWARDS and DENIS
A. DEMBLOWSKI, or any of them, his true and lawful attorneys and agents to do
any and all acts and things and to execute any and all instruments which said
attorneys and agents, or any of them, may deem necessary or advisable or may be
required to enable the Company to comply with the Securities Act of 1933, as
amended, and any rules, regulations or requirements of the Securities and
Exchange Commission in respect thereof, in connection with the registration
under said Act of up to $1 billion of securities, including but not limited to,
debt, convertible, common, preferred or hybrid securities of the Company,
including specifically, but without limiting the generality of the foregoing,
power and authority to sign the name of the undersigned Chairman of the Board
and Principal Executive Officer and/or Director thereof to any registration
statement to be filed with the Securities and Exchange Commission in respect of
said securities, to any and all pre-effective amendments, post-effective
amendments and supplements to any such registration statement, and to any
instruments or documents filed as part of or in connection with any such
registration statement or pre-effective amendments or post-effective amendments
or supplements thereto; and the under signed hereby ratifies and confirms all
that said attorneys and agents, or any of them, shall do or cause to be done by
virtue hereof.

     IN WITNESS WHEREOF, the undersigned have subscribed these presents on the
date set opposite the name below.

                                                
/s/ Paul H. O'Neill
- --------------------------
Paul H. O'Neill                                 March 13, 1998
Chairman of the Board and
Chief Executive Officer
<PAGE>
 
                               POWER OF ATTORNEY

     KNOWN ALL PERSONS BY THESE PRESENTS, that the undersigned Director of
Aluminum Company of America (the "Company") hereby constitutes and appoints
RICHARD B. KELSON, EARNEST J. EDWARDS and DENIS A. DEMBLOWSKI, or any of them,
his true and lawful attorneys and agents to do any and all acts and things and
to execute any and all instruments which said attorneys and agents, or any of
them, may deem necessary or advisable or may be required to enable the Company
to comply with the Securities Act of 1933, as amended, and any rules,
regulations or requirements of the Securities and Exchange Commission in respect
thereof, in connection with the registration under said Act of up to $1 billion
of securities, including but not limited to, debt, convertible, common,
preferred or hybrid securities of the Company, including specifically, but
without limiting the generality of the foregoing, power and authority to sign
the name of  the undersigned Director of the Company in the capacity of Director
thereof to any registration statement to be filed with the Securities and
Exchange Commission in respect of said securities, to any and all pre-effective
amendments, post-effective amendments and supplements to any such registration
statement, and to any instruments or documents filed as part of or in connection
with any such registration statement or pre-effective amendments or post-
effective amendments or supplements thereto; and the undersigned hereby ratifies
and confirms all that said attorneys and agents, or any of them, shall do or
cause to be done by virtue hereof.

     IN WITNESS WHEREOF, the undersigned has subscribed these presents on the
date set opposite the name below.

                                                
/s/  Hugh M. Morgan
- --------------------------
Hugh M. Morgan                                  May 22, 1998


<PAGE>
 
                                                                   EXHIBIT 25(B)
 
      ___________________________________________________________________

                      SECURITIES AND EXCHANGE COMMISSION
                           Washington, D. C.  20549
                           _________________________

                                   FORM  T-1

                           STATEMENT OF ELIGIBILITY
                   UNDER THE TRUST INDENTURE ACT OF 1939 OF
                  A CORPORATION DESIGNATED TO ACT AS TRUSTEE
                  ___________________________________________
              CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF
               A TRUSTEE PURSUANT TO SECTION 305(b)(2) ________
                   ________________________________________

                           THE CHASE MANHATTAN BANK
              (Exact name of trustee as specified in its charter)


NEW YORK                                                              13-4994650
(State of incorporation                                         (I.R.S. employer
if not a national bank)                                      identification No.)

270 PARK AVENUE
NEW YORK, NEW YORK                                                         10017
(Address of principal executive offices)                              (Zip Code)

                              William H. McDavid
                                General Counsel
                                270 Park Avenue
                           New York, New York 10017
                             Tel:  (212) 270-2611
           (Name, address and telephone number of agent for service)
                 ____________________________________________
                          ALUMINUM COMPANY OF AMERICA
              (Exact name of obligor as specified in its charter)

PENNSYLVANIA                                                          25-0317820
(State or other jurisdiction of                                 (I.R.S. employer
incorporation or organization)                               identification No.)

425 SIXTH AVENUE
PITTSBURGH, PENNSYLVANIA                                              15219-1850
(Address of principal executive offices)                              (Zip Code)

               _________________________________________________
                DEBT SECURITIES OF ALUMINUM COMPANY OF AMERICA
                      (Title of the indenture securities)
              ___________________________________________________
<PAGE>
 
                                    GENERAL

Item 1.   General Information.

          Furnish the following information as to the trustee:

          (a)  Name and address of each examining or supervising authority to
which it is subject.
 
               New York State Banking Department, State House, Albany, New York
               12110.

               Board of Governors of the Federal Reserve System, Washington,
               D.C., 20551

               Federal Reserve Bank of New York, District No. 2, 33 Liberty
               Street, New York, N.Y.

               Federal Deposit Insurance Corporation, Washington, D.C., 20429.


          (b)  Whether it is authorized to exercise corporate trust powers.

               Yes.


Item 2.   Affiliations with the Obligor.

     If the obligor is an affiliate of the trustee, describe each such
affiliation.

     None.
<PAGE>
 
Item 16.  List of Exhibits
 
     List below all exhibits filed as a part of this Statement of Eligibility.

     1.   A copy of the Articles of Association of the Trustee as now in effect,
including the  Organization Certificate and the Certificates of Amendment dated
February 17, 1969, August 31, 1977, December 31, 1980, September 9, 1982,
February 28, 1985, December 2, 1991 and July 10, 1996 (see Exhibit 1 to Form T-1
filed in connection with Registration Statement  No. 333-06249, which is
incorporated by reference).

     2.   A copy of the Certificate of Authority of the Trustee to Commence
Business (see Exhibit 2 to Form T-1 filed in connection with Registration
Statement No. 33-50010, which is incorporated by reference.  On July 14, 1996,
in connection with the merger of Chemical Bank and The Chase Manhattan Bank
(National Association), Chemical Bank, the surviving corporation, was renamed
The Chase Manhattan Bank).

     3.   None, authorization to exercise corporate trust powers being contained
in the documents identified above as Exhibits 1 and 2.

     4.   A copy of the existing By-Laws of the Trustee (see Exhibit 4 to Form
T-1 filed in connection with Registration Statement No. 333-06249, which is
incorporated by reference).

     5.   Not applicable.

     6.   The consent of the Trustee required by Section 321(b) of the Act (see
Exhibit 6 to Form T-1 filed in connection with Registration Statement No. 33-
50010, which is incorporated by reference. On July 14, 1996, in connection with
the merger of Chemical Bank and The Chase Manhattan Bank (National Association),
Chemical Bank, the surviving corporation, was renamed The Chase Manhattan Bank).

     7.   A copy of the latest report of condition of the Trustee, published
pursuant to law or the requirements of its supervising or examining authority.

     8.   Not applicable.

     9.   Not applicable.

                                   SIGNATURE

     Pursuant to the requirements of the Trust Indenture Act of 1939 the
Trustee, The Chase Manhattan Bank, a corporation organized and existing under
the laws of the State of New York, has duly caused this statement of eligibility
to be signed on its behalf by the undersigned, thereunto duly authorized, all in
the City of New York and State of New York, on the 10TH day of  JULY, 1998.

                              THE CHASE MANHATTAN BANK
 
                                   By /s/ Joanne Adamis
                                     ------------------------------
                                      Joanne Adamis
                                      Second Vice President

                                      -3-
<PAGE>
 
                             Exhibit 7 to Form T-1


                               Bank Call Notice

                            RESERVE DISTRICT NO. 2
                      CONSOLIDATED REPORT OF CONDITION OF

                           The Chase Manhattan Bank
                 of 270 Park Avenue, New York, New York 10017
                    and Foreign and Domestic Subsidiaries,
                    a member of the Federal Reserve System,

            at the close of business March 31, 1998, in accordance
         with a call made by the Federal Reserve Bank of this District
            pursuant to the provisions of the Federal Reserve Act.

<TABLE> 
<CAPTION> 
                                                                                        DOLLAR AMOUNTS
                     ASSETS                                                               IN MILLIONS
<S>                                                                                     <C>   
Cash and balances due from depository institutions:
     Noninterest-bearing balances and
     currency and coin ..............................................................       $ 12,037
     Interest-bearing balances ......................................................          4,054
Securities: .........................................................................               
Held to maturity securities .........................................................          2,340
Available for sale securities .......................................................         50,134
Federal funds sold and securities purchased under agreements to resell ..............         24,982
Loans and lease financing receivables:                                                              
     Loans and leases, net of unearned income                                $127,958
     Less: Allowance for loan and lease losses                                  2,797
     Less: Allocated transfer risk reserve ............................             0
                                                                             --------
     Loans and leases, net of unearned income, allowance, and reserve ...............        125,161
Trading Assets ......................................................................         61,820
Premises and fixed assets (including capitalized leases).............................          2,961
Other real estate owned .............................................................            347
Investments in unconsolidated subsidiaries and associated companies .................            242
Customers' liability to this bank on acceptances outstanding ........................          1,380
Intangible assets ...................................................................          1,549
Other assets ........................................................................         11,727
                                                                                              ------
                                                                                                    
TOTAL ASSETS ........................................................................       $298,734
                                                                                             ======= 
</TABLE> 

                                      -4-
<PAGE>
 
<TABLE> 
<CAPTION> 
                                  LIABILITIES

Deposits
<S>                                                                                           <C> 
     In domestic offices ................................................................   $  96,682
     Noninterest-bearing ...................................................    $  38,074
     Interest-bearing ......................................................       58,608
                                                                                   ------
     In foreign offices, Edge and Agreement, subsidiaries and IBF's .....................      72,630
     Noninterest-bearing ...................................................    $   3,289
     Interest-bearing ......................................................       69,341

Federal funds purchased and securities sold under agreements to repurchase ..............      42,735
Demand notes issued to the U.S. Treasury ................................................         872
Trading liabilities .....................................................................      45,545

Other borrowed money (includes mortgage indebtedness and obligations under 
     capitalized leases):
     With a remaining maturity of one year or less ......................................       4,454
     With a remaining maturity of more than one year 
            through three years .........................................................         231
     With a remaining maturity of more than three years..................................         106
Bank's liability on acceptances executed and outstanding                                        1,380
Subordinated notes and debentures .......................................................       5,708
Other liabilities .......................................................................      11,295

TOTAL LIABILITIES .......................................................................     281,638
                                                                                              -------

                                EQUITY CAPITAL

Perpetual preferred stock and related surplus                                                       0
Common stock ............................................................................       1,211
Surplus  (exclude all surplus related to preferred stock) ...............................      10,291
Undivided profits and capital reserves ..................................................       5,579
Net unrealized holding gains (losses)
on available-for-sale securities ........................................................          (1)
Cumulative foreign currency translation adjustments .....................................          16

TOTAL EQUITY CAPITAL ....................................................................      17,096
                                                                                            ---------
TOTAL LIABILITIES AND EQUITY CAPITAL ....................................................   $ 298,734
                                                                                            =========
</TABLE> 

I, Joseph L. Sclafani, E.V.P. & Controller of the above-named bank, do
hereby declare that this Report of Condition has been prepared in
conformance with the instructions issued by the appropriate Federal
regulatory authority and is true to the best of my knowledge and
belief.

                              JOSEPH L. SCLAFANI

We, the undersigned directors, attest to the correctness of this
Report of Condition and declare that it has been examined by us, and
to the best of our knowledge and belief has been prepared in
conformance with the instructions issued by the appropriate Federal
regulatory authority and is true and correct.

                                    WALTER V. SHIPLEY       )
                                    THOMAS G. LABRECQUE     ) DIRECTORS
                                    WILLIAM B. HARRISON, JR.)

                                      -5-

<PAGE>
 
                                                                   EXHIBIT 25(C)
 
       _________________________________________________________________

                      SECURITIES AND EXCHANGE COMMISSION
                           Washington, D. C.  20549
                           _________________________

                                   FORM  T-1

                           STATEMENT OF ELIGIBILITY
                   UNDER THE TRUST INDENTURE ACT OF 1939 OF
                  A CORPORATION DESIGNATED TO ACT AS TRUSTEE
                  ___________________________________________
              CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF
               A TRUSTEE PURSUANT TO SECTION 305(b)(2) ________
                   ________________________________________

                           THE CHASE MANHATTAN BANK
              (Exact name of trustee as specified in its charter)


NEW YORK                                                             13-4994650
(State of incorporation                                        (I.R.S. employer
if not a national bank)                                     identification No.)

270 PARK AVENUE
NEW YORK, NEW YORK                                                        10017
(Address of principal executive offices)                             (Zip Code)

                              William H. McDavid
                                General Counsel
                                270 Park Avenue
                           New York, New York 10017
                             Tel:  (212) 270-2611
           (Name, address and telephone number of agent for service)
                 ____________________________________________
                                 ALCOA TRUST I
              (Exact name of obligor as specified in its charter)

DELAWARE                                                            APPLIED FOR
(State or other jurisdiction of                                (I.R.S. employer
incorporation or organization)                              identification No.)

425 SIXTH AVENUE, ALCOA BUILDING
PITTSBURGH, PENNSYLVANIA                                             15219-1850
(Address of principal executive offices)                             (Zip Code)

                _______________________________________________
                  TRUST PREFERRED SECURITIES OF ALCOA TRUST I
                      (Title of the indenture securities)
      ___________________________________________________________________

<PAGE>
 
                                    GENERAL

Item 1.   General Information.

          Furnish the following information as to the trustee:

          (a) Name and address of each examining or supervising authority to
which it is subject.
 
          New York State Banking Department, State House, Albany, New York
12110.

          Board of Governors of the Federal Reserve System, Washington, D.C.,
20551
 
          Federal Reserve Bank of New York, District No. 2, 33 Liberty Street,
New York, N.Y.

          Federal Deposit Insurance Corporation, Washington, D.C., 20429.


          (b) Whether it is authorized to exercise corporate trust powers.

          Yes.


Item 2.   Affiliations with the Obligor.

          If the obligor is an affiliate of the trustee, describe each such
affiliation.

          None.
<PAGE>
 
Item 16.  List of Exhibits
 
          List below all exhibits filed as a part of this Statement of
Eligibility.

          1.  A copy of the Articles of Association of the Trustee as now in
effect, including the Organization Certificate and the Certificates of Amendment
dated February 17, 1969, August 31, 1977, December 31, 1980, September 9, 1982,
February 28, 1985, December 2, 1991 and July 10, 1996 (see Exhibit 1 to Form T-1
filed in connection with Registration Statement No. 333-06249, which is
incorporated by reference).

          2.  A copy of the Certificate of Authority of the Trustee to Commence
Business (see Exhibit 2 to Form T-1 filed in connection with Registration
Statement No. 33-50010, which is incorporated by reference.  On July 14, 1996,
in connection with the merger of Chemical Bank and The Chase Manhattan Bank
(National Association), Chemical Bank, the surviving corporation, was renamed
The Chase Manhattan Bank).

          3.  None, authorization to exercise corporate trust powers being
contained in the documents identified above as Exhibits 1 and 2.

          4.  A copy of the existing By-Laws of the Trustee (see Exhibit 4 to
Form T-1 filed in connection with Registration Statement No. 333-06249, which is
incorporated by reference).

          5.  Not applicable.

          6.  The consent of the Trustee required by Section 321(b) of the Act
(see Exhibit 6 to Form T-1 filed in connection with Registration Statement No.
33-50010, which is incorporated by reference. On July 14, 1996, in connection
with the merger of Chemical Bank and The Chase Manhattan Bank (National
Association), Chemical Bank, the surviving corporation, was renamed The Chase
Manhattan Bank).

          7.  A copy of the latest report of condition of the Trustee, published
pursuant to law or the requirements of its supervising or examining authority.

          8.  Not applicable.

          9.  Not applicable.

                                   SIGNATURE

          Pursuant to the requirements of the Trust Indenture Act of 1939 the
Trustee, The Chase Manhattan Bank, a corporation organized and existing under
the laws of the State of New York, has duly caused this statement of eligibility
to be signed on its behalf by the undersigned, thereunto duly authorized, all in
the City of New York and State of New York, on the 10TH day of  JULY, 1998.

                           THE CHASE MANHATTAN BANK
 
                                   By /s/ Joanne Adamis
                                      ---------------------------
                                        Joanne Adamis
                                        Second Vice President

                                      -3-
<PAGE>
 
                             Exhibit 7 to Form T-1


                               Bank Call Notice

                            RESERVE DISTRICT NO. 2
                      CONSOLIDATED REPORT OF CONDITION OF

                           The Chase Manhattan Bank
                 of 270 Park Avenue, New York, New York 10017
                    and Foreign and Domestic Subsidiaries,
                    a member of the Federal Reserve System,

                 at the close of business March 31, 1998, in 
       accordance with a call made by the Federal Reserve Bank of this 
        District pursuant to the provisions of the Federal Reserve Act.

<TABLE> 
<CAPTION> 
                                                                        DOLLAR AMOUNTS
                     ASSETS                                              IN MILLIONS
<S>                                                                     <C> 
Cash and balances due from depository institutions:
     Noninterest-bearing balances and
     currency and coin ........................................            $  12,037
     Interest-bearing balances ................................                4,054
Securities:  ..................................................
Held to maturity securities....................................                2,340
Available for sale securities..................................               50,134
Federal funds sold and securities purchased under         
     agreements to resell .....................................               24,982
Loans and lease financing receivables:
     Loans and leases, net of unearned income        $ 127,958
     Less: Allowance for loan and lease losses           2,797
     Less: Allocated transfer risk reserve .........         0
                                                     ---------
     Loans and leases, net of unearned income,
     allowance, and reserve ...................................              125,161
Trading Assets ................................................               61,820
Premises and fixed assets (including capitalized
     leases)...................................................                2,961
Other real estate owned .......................................                  347
Investments in unconsolidated subsidiaries and
     associated companies......................................                  242
Customers' liability to this bank on acceptances
     outstanding ..............................................                1,380
Intangible assets .............................................                1,549
Other assets ..................................................               11,727
                                                                              ------
TOTAL ASSETS ..................................................             $298,734
                                                                           =========
</TABLE> 

                                          - 4 -
<PAGE>
 
                                  LIABILITIES

<TABLE> 
<S>                                                                         <C> 
Deposits
     In domestic offices .............................................        $96,682
     Noninterest-bearing .................................... $38,074
     Interest-bearing .......................................  58,608
                                                               ------
     In foreign offices, Edge and Agreement,
     subsidiaries and IBF'sd
 . ....................................................................         72,630
Noninterest-bearing ......................................... $ 3,289
     Interest-bearing .......................................  69,341

Federal funds purchased and securities sold under agree-
ments to repurchase ..................................................         42,735
Demand notes issued to the U.S. Treasury .............................            872
Trading liabilities ..................................................         45,545

Other borrowed money (includes mortgage indebtedness and obligations 
     under capitalized leases):
     With a remaining maturity of one year or less ...................          4,454
     With a remaining maturity of more than one year 
            through three years ......................................            231
     With a remaining maturity of more than three years ..............            106
Bank's liability on acceptances executed and outstanding .............          1,380
Subordinated notes and debentures ....................................          5,708
Other liabilities ....................................................         11,295

TOTAL LIABILITIES ....................................................        281,638
                                                                              -------
                                      EQUITY CAPITAL

Perpetual preferred stock and related surplus ........................              0
Common stock .........................................................          1,211
Surplus  (exclude all surplus related to preferred stock) ............         10,291
Undivided profits and capital reserves ...............................          5,579
Net unrealized holding gains (losses)
on available-for-sale securities .....................................            (1)
Cumulative foreign currency translation adjustments ..................             16

TOTAL EQUITY CAPITAL .................................................         17,096
                                                                               ------
TOTAL LIABILITIES AND EQUITY CAPITAL .................................      $ 298,734
                                                                            =========
</TABLE> 

I, Joseph L. Sclafani, E.V.P. & Controller of the above-named
bank, do hereby declare that this Report of Condition has
been prepared in conformance with the instructions issued by
the appropriate Federal regulatory authority and is true to
the best of my knowledge and belief.

                              JOSEPH L. SCLAFANI

We, the undersigned directors, attest to the correctness
of this Report of Condition and declare that it has been
examined by us, and to the best of our knowledge and
belief has been prepared in conformance with the
instructions issued by the appropriate Federal regulatory
authority and is true and correct.

                              WALTER V. SHIPLEY       )
                              THOMAS G. LABRECQUE     ) DIRECTORS
                              WILLIAM B. HARRISON, JR.)

                                      -5-

<PAGE>
 
                                                                   EXHIBIT 25(D)
 
               ---------------------------------------------

                      SECURITIES AND EXCHANGE COMMISSION
                           Washington, D. C.  20549

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

                                   FORM  T-1

                           STATEMENT OF ELIGIBILITY
                   UNDER THE TRUST INDENTURE ACT OF 1939 OF
                  A CORPORATION DESIGNATED TO ACT AS TRUSTEE

                   ----------------------------------------        
              CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF
               A TRUSTEE PURSUANT TO SECTION 305(b)(2) ________

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

                           THE CHASE MANHATTAN BANK
              (Exact name of trustee as specified in its charter)


NEW YORK                                                        13-4994650
(State of incorporation                                   (I.R.S. employer
if not a national bank)                                identification No.)

270 PARK AVENUE
NEW YORK, NEW YORK                                                   10017
(Address of principal executive offices)                        (Zip Code)

                              William H. McDavid
                                General Counsel
                                270 Park Avenue
                           New York, New York 10017
                             Tel:  (212) 270-2611
           (Name, address and telephone number of agent for service)

             ----------------------------------------------------- 
                          ALUMINUM COMPANY OF AMERICA
              (Exact name of obligor as specified in its charter)

PENNSYLVANIA                                                    25-0317820
(State or other jurisdiction of                           (I.R.S. employer
incorporation or organization)                         identification No.)

425 SIXTH AVENUE, ALOCA BUILDING
PITTSBURGH, PENNSYLVANIA                                        15219-1850
(Address of principal executive offices)                        (Zip Code)

                 ---------------------------------------------
                      GUARANTEE OF PREFERRED SECURITIES OF
                          ALCOA TRUST I BY THE COMPANY
                      (Title of the indenture securities)

                 ---------------------------------------------
<PAGE>
 
                                    GENERAL

Item 1.General Information.

       Furnish the following information as to the trustee:

       (a) Name and address of each examining or supervising authority to which
it is subject.
 
           New York State Banking Department, State House, Albany, New York
           12110.

           Board of Governors of the Federal Reserve System, Washington, D.C.,
           20551
 
           Federal Reserve Bank of New York, District No. 2, 33 Liberty Street,
           New York, N.Y.

           Federal Deposit Insurance Corporation, Washington, D.C., 20429.


       (b) Whether it is authorized to exercise corporate trust powers.

           Yes.


Item 2.Affiliations with the Obligor.

       If the obligor is an affiliate of the trustee, describe each such
       affiliation.

       None.
<PAGE>
 
Item 16.  List of Exhibits
 
          List below all exhibits filed as a part of this Statement of
Eligibility.

          1.  A copy of the Articles of Association of the Trustee as now in
effect, including the Organization Certificate and the Certificates of Amendment
dated February 17, 1969, August 31, 1977, December 31, 1980, September 9, 1982,
February 28, 1985, December 2, 1991 and July 10, 1996 (see Exhibit 1 to Form T-1
filed in connection with Registration Statement No. 333-06249, which is
incorporated by reference).

          2.  A copy of the Certificate of Authority of the Trustee to Commence
Business (see Exhibit 2 to Form T-1 filed in connection with Registration
Statement No. 33-50010, which is incorporated by reference. On July 14, 1996, in
connection with the merger of Chemical Bank and The Chase Manhattan Bank
(National Association), Chemical Bank, the surviving corporation, was renamed
The Chase Manhattan Bank).

          3.  None, authorization to exercise corporate trust powers being
contained in the documents identified above as Exhibits 1 and 2.

          4.  A copy of the existing By-Laws of the Trustee (see Exhibit 4 to
Form T-1 filed in connection with Registration Statement No. 333-06249, which is
incorporated by reference).

          5.  Not applicable.

          6.  The consent of the Trustee required by Section 321(b) of the Act
(see Exhibit 6 to Form T-1 filed in connection with Registration Statement No.
33-50010, which is incorporated by reference. On July 14, 1996, in connection
with the merger of Chemical Bank and The Chase Manhattan Bank (National
Association), Chemical Bank, the surviving corporation, was renamed The Chase
Manhattan Bank).

          7.  A copy of the latest report of condition of the Trustee, published
pursuant to law or the requirements of its supervising or examining authority.

          8.  Not applicable.

          9.  Not applicable.

                                   SIGNATURE

          Pursuant to the requirements of the Trust Indenture Act of 1939 the
Trustee, The Chase Manhattan Bank, a corporation organized and existing under
the laws of the State of New York, has duly caused this statement of eligibility
to be signed on its behalf by the undersigned, thereunto duly authorized, all in
the City of New York and State of New York, on the 10TH day of  JULY, 1998.

                                   THE CHASE MANHATTAN BANK
 
                                         By   /s/ Joanne Adamis
                                            ----------------------    
                                                  Joanne Adamis
                                                  Second Vice President

                                      -3-
<PAGE>
 
                             Exhibit 7 to Form T-1


                               Bank Call Notice

                            RESERVE DISTRICT NO. 2
                      CONSOLIDATED REPORT OF CONDITION OF

                           The Chase Manhattan Bank
                 of 270 Park Avenue, New York, New York 10017
                    and Foreign and Domestic Subsidiaries,
                    a member of the Federal Reserve System,

            at the close of business March 31, 1998, in accordance
         with a call made by the Federal Reserve Bank of this District
            pursuant to the provisions of the Federal Reserve Act.

<TABLE> 
<CAPTION> 
                                                                                      DOLLAR AMOUNTS
                     ASSETS                                                            IN MILLIONS
<S>                                                                                   <C>
Cash and balances due from depository institutions:
     Noninterest-bearing balances and
     currency and coin .......................................................          $ 12,037
     Interest-bearing balances ...............................................             4,054
Securities:
Held to maturity securities ..................................................             2,340
Available for sale securities ................................................            50,134
Federal funds sold and securities purchased under
     agreements to resell ....................................................            24,982
Loans and lease financing receivables:
     Loans and leases, net of unearned income ................$127,958
     Less: Allowance for loan and lease losses ...............   2,797
     Less: Allocated transfer risk reserve ...................       0
                                                              --------     
     Loans and leases, net of unearned income,
     allowance, and reserve ..................................................           125,161
Trading Assets................................................................            61,820
Premises and fixed assets (including capitalized leases)......................             2,961
Other real estate owned ......................................................               347
Investments in unconsolidated subsidiaries and
     associated companies ....................................................               242
Customers' liability to this bank on acceptances
     outstanding..............................................................             1,380
Intangible assets.............................................................             1,549
Other assets..................................................................            11,727
                                                                                        --------
TOTAL ASSETS..................................................................          $298,734
                                                                                        ========
</TABLE> 

                                      -4-
<PAGE>
 
<TABLE> 

                                  LIABILITIES
<S>                                                                          <C>   
Deposits
     In domestic offices .................................................   $ 96,682
     Noninterest-bearing ...................................  $38,074
     Interest-bearing ......................................   58,608
                                                              -------
     In foreign offices, Edge and Agreement,
     subsidiaries and IBF's ..............................................     72,630
Noninterest-bearing ........................................  $ 3,289
     Interest-bearing ......................................   69,341

Federal funds purchased and securities sold under agree-
ments to repurchase ......................................................     42,735
Demand notes issued to the U.S. Treasury .................................        872
Trading liabilities ......................................................     45,545

Other borrowed money (includes mortgage indebtedness and obligations under
     capitalized leases):
     With a remaining maturity of one year or less .......................      4,454
     With a remaining maturity of more than one year                                      
            through three years ..........................................        231
     With a remaining maturity of more than three years...................        106
Bank's liability on acceptances executed and outstanding .................      1,380
Subordinated notes and debentures ........................................      5,708
Other liabilities ........................................................     11,295

TOTAL LIABILITIES ........................................................    281,638
                                                                             ---------

                                EQUITY CAPITAL

Perpetual preferred stock and related surplus                                       0
Common stock .............................................................      1,211
Surplus  (exclude all surplus related to preferred stock) ................     10,291
Undivided profits and capital reserves ...................................      5,579
Net unrealized holding gains (losses)
on available-for-sale securities .........................................         (1)
Cumulative foreign currency translation adjustments ......................         16

TOTAL EQUITY CAPITAL .....................................................     17,096
                                                                             ---------
TOTAL LIABILITIES AND EQUITY CAPITAL .....................................   $298,734
                                                                             =========
</TABLE> 


I, Joseph L. Sclafani, E.V.P. & Controller of the above-named 
bank, do hereby declare that this Report of Condition has 
been prepared in conformance with the instructions issued
by the appropriate Federal regulatory authority and is true
to the best of my knowledge and belief.

                                    JOSEPH L. SCLAFANI

We, the undersigned directors, attest to the correctness 
of this Report of Condition and declare that it has been
examined by us, and to the best of our knowledge and
belief has been prepared in conformance with the in-
structions issued by the appropriate Federal regulatory 
authority and is true and correct.

                                    WALTER V. SHIPLEY       )
                                    THOMAS G. LABRECQUE     ) DIRECTORS
                                    WILLIAM B. HARRISON, JR.)

                                      -5-


© 2022 IncJournal is not affiliated with or endorsed by the U.S. Securities and Exchange Commission