UNION TANK CAR CO
S-3, 1996-12-02
RAILROAD EQUIPMENT
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<PAGE>   1

   AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON DECEMBER 2, 1996

                                                   Registration No. 333-________
     
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                                WASHINGTON, D.C. 

                             -----------------------
                                    FORM S-3
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933

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

                             UNION TANK CAR COMPANY
             (Exact name of registrant as specified in its charter)

            DELAWARE                                             36-3104688
 (State or other jurisdiction of                              (I.R.S. Employer
 incorporation or organization)                              Identification No.)

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

                           225 WEST WASHINGTON STREET
                            CHICAGO, ILLINOIS  60606
                                 (312) 372-9500
          (Address, including zip code and telephone number, including
            area code, of registrant's principal executive offices)

                                 PROCOR LIMITED
             (Exact name of registrant as specified in its charter)

             CANADA                                                 NONE
 (State or other jurisdiction of                              (I.R.S. Employer
 incorporation or organization)                              Identification No.)

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

                                2001 SPEERS ROAD
                       OAKVILLE, ONTARIO, CANADA L6J 5E1
                                 (905) 827-4111
          (Address, including zip code and telephone number, including
            area code, of registrant's principal executive offices)

                            WILLIAM M. HOLZMAN, ESQ.
                            NEAL, GERBER & EISENBERG
                            TWO NORTH LASALLE STREET
                            CHICAGO, ILLINOIS  60602
                                 (312) 269-8000
            (Name, address, including zip code, and telephone number
                   including area code, of agent for service)
                                   Copies to:
                             BARRY P. BIGGAR, ESQ.
                              MAYER, BROWN & PLATT
                                 1675 BROADWAY
                            NEW YORK, NEW YORK 10019
                                 (212) 506-2500  

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

         Approximate date of commencement of proposed sale to the public:  From
time to time after the effective date of this Registration Statement.
<PAGE>   2
         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 [ ].



                        CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
===================================================================================================================
                                                          Proposed
                                                           Maximum                     Amount of
         Title of Each Class of                           Aggregate                  Registration
       Securities to be Registered                  Offering Price(1)(2)                  Fee                      
- -------------------------------------------------------------------------------------------------------------------
<S>                                                     <C>                            <C>
Debt Securities and Pass Through Certificates           $400,000,000                   $121,213
===================================================================================================================
</TABLE>

(1)      Estimated in accordance with Rule 457 solely for the purpose of
         determining the registration fee.
(2)      Any offering of Debt Securities denominated in any foreign currency
         will be treated as the equivalent in U.S. dollars based on the
         exchange rate applicable to the purchase of such Debt Securities from
         the registrant.
                           -----------------------

         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 OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(a),
MAY DETERMINE.

================================================================================
<PAGE>   3
                                EXPLANATORY NOTE

         This Registration Statement contains a Prospectus (the "Pass Through
Certificate Prospectus") relating to up to $400,000,000 aggregate principal
amount of pass through certificates of Union Tank Car Company (the "Company")
and Procor Limited, a wholly-owned subsidiary of the Company ("Procor"), and a
Prospectus (the "Debt Security Prospectus") relating to up to $400,000,000
aggregate principal amount of debt securities of the Company.  The aggregate
principal amount of pass through certificates to be offered and sold pursuant
to this Registration Statement is subject to reduction by the aggregate
principal amount of debt securities sold pursuant to this Registration
Statement and vice versa.

         Upon the public offering or sale of the pass through certificates or
debt securities registered under this Registration Statement, a Prospectus
Supplement describing the particular terms of such offer or sale will be filed
in accordance with the rules of the Securities and Exchange Commission together
with either the Pass Through Certificate Prospectus or the Debt Security
Prospectus, as applicable.

         No offers or sales of pass through certificates or debt securities may
be made unless accompanied by a Prospectus Supplement applicable to the
securities offered thereby.
<PAGE>   4
[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 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 DECEMBER 2, 1996

PROSPECTUS

$400,000,000

UNION TANK CAR COMPANY

PASS THROUGH CERTIFICATES

Up to $400,000,000 aggregate principal amount of Pass   Through
Certificates may be offered for sale from time to time pursuant to this
Prospectus and related Prospectus Supplements.  Pass Through Certificates may
be issued in one or more series in amounts, at prices and on terms to be
determined at the time of the offering. In respect of each offering of Pass
Through Certificates, a separate Union Tank Car Company Pass Through Trust for
each series of Pass Through Certificates being offered (each, a "Trust") will
be formed pursuant to the Pass Through Trust Agreement (the "Basic Agreement")
and a supplement thereto (a "Trust Supplement") relating to such Trust among
Union Tank Car Company (the "Company"), if specified in the Prospectus
Supplement, Procor Limited, a wholly-owned subsidiary of the Company
("Procor"), and, unless otherwise specified in the Prospectus Supplement,
__________________________________ (the "Pass Through Trustee"), as pass
through trustee under each Trust.  Each Pass Through Certificate in a series
will represent a fractional undivided interest in the related Trust and will
have no rights, benefits or interest in respect of any other Trust.  The
property of each Trust will consist of (i) equipment notes (the "Equipment
Notes") issued on a nonrecourse basis by one or more owner trustees pursuant to
one of more leveraged lease transactions to finance or refinance a portion of
the equipment cost of certain railcars ("Equipment Units") which have been or
will be leased to the Company or (ii) equipment trust certificates (the
"Company ETCs") issued pursuant to one or more equipment trust agreements
between the Company and ________________________________, as trustee, or
equipment trust certificates (the "Procor ETCs" and, together with the Company
ETCs, the "ETCs") issued pursuant to one or more equipment trust agreements
between Procor Limited, an indirect wholly-owned subsidiary of the Company
("Procor"), and ____________________________________________, as trustee.  Each
such equipment trust agreement is hereinafter referred to as an "Equipment
Trust Agreement", and ____________________________________________________, as
trustee under each Equipment Trust Agreement, is hereinafter referred to as the
"Equipment Trust Trustee". Amounts payable pursuant to the Company ETCs and the
Procor ETCs will be fully and unconditionally guaranteed by the Company.  The
Prospectus Supplement relating to each offering of Pass Through Certificates
will describe certain terms of the Pass Through Certificates being offered, the
Trust or Trusts relating thereto, the Equipment Notes or ETCs to be purchased
by such Trust or Trusts, the Equipment Units relating to such Equipment Notes
and the leveraged lease transactions, if any, relating thereto.

The Equipment Notes will not be direct obligations of, or guaranteed by,
the Company, but the amounts unconditionally payable by the Company for the
lease of the Equipment Units will be sufficient to pay in full when due all
payments required to be made on such Equipment Notes.

Equipment Notes may be issued in respect of Equipment Units in one or more
series, each series having a different interest rate and final maturity date. 
A separate Trust may purchase one or more series of the Equipment Notes issued
with respect to each group of Equipment Units (an "Equipment Group").  All of
the Equipment Notes held in such Trust will have an interest rate equal to the
interest rate applicable to the Pass Through Certificates issued by such Trust
and maturity dates occurring on or before the final distribution date
applicable to such Pass Through Certificates.  The Equipment Notes issued with
respect to each Equipment Group will be secured by a security interest in such
Equipment Group and by the lease relating thereto (each, a "Lease"), including
the right to receive rent payable by the Company in respect of such Equipment
Group.

Interest paid on the Equipment Notes or ETCs held in each Trust will be passed
through to the holders of the Pass Through Certificates relating to such
Trust on the dates and at the rate per annum set forth in the Prospectus
Supplement relating to such Pass Through Certificates until the final
distribution date for such Trust.  Principal paid on the Equipment Notes or
ETCs held in each Trust will be passed through to the holders of the Pass
Through Certificates relating to such Trust in scheduled amounts on the dates
set forth in the Prospectus Supplement relating to such Pass Through
Certificates until the final distribution date for such Trust.

The Pass Through Certificates may be offered for sale directly to purchasers
and may also be offered through underwriters, dealers or agents.  See "Plan of  
Distribution."  The Prospectus Supplement will set forth the names of any
underwriters, dealers or agents involved in the sale of the Pass Through
Certificates in respect of which this Prospectus is being delivered and any
applicable fee, commission or discount arrangements with them. 

<PAGE>   5
                            ---------------------

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.

This Prospectus may not be used to consummate a sale of Pass Through
Certificates unless accompanied by a Prospectus Supplement.

The date of this Prospectus is                 , 1997.
<PAGE>   6
                            AVAILABLE INFORMATION

         The Company has filed with the Securities and Exchange Commission (the
"Commission") a Registration Statement on Form S-3 (the "Registration
Statement") under the Securities Act of 1933, as amended (the "Securities
Act"), with respect to the Debt Securities.  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 pertaining to the Debt Securities and the Company, reference is
made to the Registration Statement.  Any statement contained herein concerning
the provisions of any document is 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.

         The Company 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 Commission.
Information concerning the Company can be inspected and copied at the public
reference facilities maintained by the Commission at 450 Fifth Street, N.W.,
Washington, D.C. 20549, and at the following Regional Offices of the
Commission:  Chicago Regional Office, Citicorp Center, 500 West Madison Street,
Suite 1400, Chicago, Illinois 60661 and New York Regional Office, 7 World Trade
Center, Suite 1300, New York, New York 10048.  Copies of such material can be
obtained from the Public Reference Section of the Commission at 450 Fifth
Street, N.W., Washington, D.C. 20549 at prescribed rates.  Such materials also
may be accessed electronically by means of the Commission's home page on the
Internet at http://www.sec.gov.


                      DOCUMENTS INCORPORATED BY REFERENCE

         The Company's Annual Report on Form 10-K/A for the fiscal year ended
December 31, 1995 and its Quarterly Reports on Form 10-Q for the quarters ended
March 31, 1996, June 30, 1996 and September 30, 1996, as filed with the
Commission pursuant to the Exchange Act, are incorporated herein by reference.

         All documents filed by the Company pursuant to Section 13(a), 13(c),
14 or 15(d) of the Exchange Act after the date of this Prospectus and prior to
the termination of the offering of the Debt 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 that a statement contained herein or in any other
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, except as so modified or
superseded, to constitute a part of this Prospectus.

         The Company will provide without charge to each person to whom this
Prospectus is delivered, upon written request of such person, a copy (without
exhibits) of any or all documents incorporated by reference in this Prospectus.
Requests for such copies should be directed to the General Counsel and
Secretary, Union Tank Car Company, 225 West Washington Street, Chicago,
Illinois 60606, telephone (312) 372-9500.


                                  THE COMPANY

         Union Tank Car Company (with its wholly-owned subsidiaries herein
collectively referred to, except as the context otherwise requires, as the
"Company") is principally engaged in the leasing of railway tank cars and other
rail cars to United States, Canadian and Mexican manufacturers and other
shippers of chemical products, including liquid fertilizers, petroleum
products, including liquid petroleum gas, food products and bulk plastics.  The
Company owns and operates one of the largest fleets of privately-owned railway
tank cars in the world.





                                      -2-
<PAGE>   7
         The Company, which was incorporated in Delaware in 1980 and is the
successor to a business which was incorporated in New Jersey in 1891 and
reincorporated in Delaware in 1968, is a wholly-owned subsidiary of Marmon
Industrial Corporation, a wholly-owned subsidiary of Marmon Holdings,
Inc.  Substantially all the stock of Marmon Holdings, Inc. is owned, directly
or indirectly, by trusts for the benefit of certain members of the Pritzker
family.  As used herein, "Pritzker family" refers to the lineal descendants of
Nicholas J. Pritzker, deceased.

         The Company's principal executive offices are located at 225 West
Washington Street, Chicago, Illinois 60606, and its telephone number is (312)
372-9500.


                            FORMATION OF THE TRUSTS

         In respect of each offering of Pass Through Certificates, one or more
Trusts will be formed, and the related Pass Through Certificates will be
issued, pursuant to separate Trust Supplements to be entered into between the
Pass Through Trustee and the Company in accordance with the terms of the Basic
Agreement.  All Pass Through Certificates with respect to each Trust will
represent fractional undivided interests in such Trust and the property held in
such Trust and will have no rights, benefits or interest in respect of any
other Trust or the property held therein.  Concurrently with the execution and
delivery of each Trust Supplement relating to one or more leveraged lease
transactions, the Pass Through Trustee, on behalf of the Trust formed thereby,
will enter into one or more financing, refinancing, purchase or participation
agreements (each such agreement being herein referred to as a "Participation
Agreement") relating to one or more Equipment Groups described in the
applicable Prospectus Supplement.  Concurrently with the execution and delivery
of each Trust Supplement relating to ETCs, the Pass Through Trustee, on behalf
of such Trust, will purchase such ETCs from the Equipment Trust Trustee.
Pursuant to the applicable Participation Agreement or Equipment Trust
Agreement, the Pass Through Trustee, on behalf of the Trust formed in
connection with the offering of Pass Through Certificates, will purchase the
Equipment Notes issued with respect to each such Equipment Group or ETCs so
that all of the Equipment Notes or ETCs held in such Trust will have an
interest rate equal to the interest rate applicable to the Pass Through
Certificates issued by such Trust.  Unless otherwise indicated in the
Prospectus Supplement, the maturity dates of the Equipment Notes
or ETCs acquired by each Trust will occur on or before the final distribution
date applicable to the Pass Through Certificates issued with respect to such
Trust.  The Pass Through Trustee will distribute the amount of payments of
principal, premium, if any, and interest received by it as holder of the
Equipment Notes or ETCs to the Certificateholders of the Pass Through
Certificates with respect to the Trust in which such Equipment Notes or ETCs
are held.  See "Description of the Pass Through Certificates", "Description of
the Equipment Notes" and "Description of the ETCs".


                                USE OF PROCEEDS

         The Pass Through Certificates offered pursuant to any Prospectus
Supplement will be issued (i) to facilitate the financing or refinancing of the
debt component of one or more separate leveraged lease transactions entered
into by the Company, as lessee, with respect to the Equipment Units described
therein or (ii) to purchase Company ETCs or Procor ETCs.  The proceeds from the
sale of Pass Through Certificates relating to one or more leveraged lease
transactions will be used by the Pass Through Trustee on behalf of the
applicable Trust or Trusts to purchase, at par, the Equipment Notes to be
issued by the respective Owner Trustee or Owner Trustees to finance or
refinance all or a portion of the equipment cost of such Equipment Units.
Simultaneously with the acquisition of such Equipment Units, the respective
Owner Trustee will lease such Equipment Units to the Company.  In the case of
ETCs, the proceeds from the sale of Pass Through Certificates will be used by
the Pass Through Trustee on behalf of the applicable Trust or Trusts to
purchase, at par, Company ETCs or Procor ETCs.  The Company will use the net
proceeds from each separate leveraged lease transaction and the Company or
Procor, as the case





                                      -3-
<PAGE>   8
may be, will use the net proceeds from the issuance of ETCs to finance the
addition of railcars to the Company's fleet, for general corporate purposes or
as otherwise specified in the applicable Prospectus Supplement.

         The Equipment Notes with respect to each Equipment Group will be
issued under a separate Trust Indenture and Security Agreement (each, an
"Indenture") between a bank or trust company as trustee thereunder (each, an
"Indenture Trustee") and an owner trustee, not in its individual capacity
(except as expressly set forth therein) but solely as trustee (each, an "Owner
Trustee"), of a separate trust for the benefit of one or more institutional or
corporate investors (each, an "Owner Participant").  Each Owner Participant
will provide, from sources other than the Equipment Notes, the balance of the
equipment cost of the related Equipment Group.  No Owner Participant, however,
will be personally liable for any amount payable under the related Indenture or
the Equipment Notes issued thereunder.  Subject to certain restrictions, each
Owner Participant may transfer its interest in the related Equipment Group.

         Because the Company's obligation to make payments (i) under the Leases
relating to the Equipment Notes and (ii) in respect of the Company ETCs and the
Procor ETCs will be unconditional, and not affected by the financial
performance of the railcars within the related Equipment Groups or subject to
the related Equipment Trust Agreements, the Company believes that historical
financial information with respect to such railcars will not be relevant to
purchasers of the Pass Through Certificates.


                  DESCRIPTION OF THE PASS THROUGH CERTIFICATES

         In connection with each offering of Pass Through Certificates, one or
more separate Trusts will be formed and one or more series of Pass Through
Certificates will be issued pursuant to the Basic Agreement and one or more
Trust Supplements to be entered into between the Company and the Pass Through
Trustee.  The following summary relates to the Basic Agreement and each of the
Trust Supplements, the Trusts to be formed thereby and the Pass Through
Certificates to be issued by each Trust except to the extent, if any, described
in the applicable Prospectus Supplement.  Citations to the relevant sections of
the Basic Agreement appear below in parentheses.  The statements under this
caption are a summary and do not purport to be complete.  This summary makes
use of terms defined in and is qualified in its entirety by reference to all of
the provisions of the Basic Agreement, the form of which has been filed as an
exhibit to the Registration Statement of which this Prospectus is a part.  The
form of the Trust Supplement relating to each series of Pass Through
Certificates and the forms of the Leases, Participation Agreements, Indentures,
Equipment Notes and Equipment Trust Agreements, if any, relating thereto will
be filed as exhibits to a report by the Company on Form 8-K, 10-Q, or 10-K, as
applicable, to be filed with the Commission following the offering of such
series of Pass Through Certificates.

GENERAL

         The Pass Through Certificates of each Trust will be issued in fully
registered form only.  Each Pass Through Certificate will represent a
fractional undivided interest in the separate Trust created by the Trust
Supplement pursuant to which such Pass Through Certificate is issued.  The
property of each Trust will include the Equipment Notes or ETCs held in such
Trust, all monies at any time paid thereon and all monies due and to become due
thereunder and funds from time to time deposited with the Pass Through Trustee
in accounts relating to such Trust.  Each Pass Through Certificate will
correspond to a pro rata share of the outstanding principal amount of the
Equipment Notes or ETCs and other property held in the related Trust and will
be issued in denominations of $1,000 or any integral multiple of $1,000.
(Sections 2.1 and 3.1)

         Except as otherwise provided in the applicable Trust Supplement, Pass
Through Certificates will be registered in the name of Cede & Co. ("Cede") as
the nominee of The Depository Trust Company ("DTC") and no person acquiring an
interest in Pass Through Certificates (a "Certificate Owner") will be entitled
to receive a certificate representing such person's interest in the related
Trust unless "Definitive Certificates" are issued as





                                      -4-
<PAGE>   9
described below.  Unless Definitive Certificates are issued, all references to
actions by Certificateholders shall refer to actions taken by DTC upon
instructions from DTC Participants (as defined below), and all references
herein to distributions, notices, reports and statements to Certificateholders
shall refer, as the case may be, to distributions, notices, reports and
statements to DTC or Cede, as the registered holder of the Pass Through
Certificates, or to DTC Participants for distribution to Certificate Owners in
accordance with DTC procedures.  See "-Book-Entry Registration." (Section 3.9)

         Interest will be passed through to Certificateholders of each Trust at
the rate per annum set forth on the cover page of the applicable Prospectus
Supplement and will be calculated on the basis of a 360-day year of twelve 30-
day months.

         The Pass Through Certificates of each series represent interests only
in the related Trust and all payments and distributions shall be made only from
the related Trust Property.  (Section 3.8)  The Pass Through Certificates do
not represent an interest in or obligation of the Company, the Pass Through
Trustee, the Owner Trustee, if any, in its individual capacity, the Owner
Participant, if any, or any affiliate of any thereof.

         The Basic Agreement does not and, except as otherwise described in the
applicable Prospectus Supplement, the Indentures will not, include financial
covenants or "event risk" provisions specifically designed to afford
Certificateholders protection in the event of a highly leveraged transaction
affecting the Company.  However, the Certificateholders of each series will
have the benefit of (i) a lien on the specific Equipment Group securing the
related Equipment Notes held in the related Trust or, (ii) in the case of the
ETCs held in the related Trust, the indirect benefit of the Equipment Trust
Trustee under the relevant Equipment Trust Agreement holding title to the
equipment securing the ETCs, as well as the Company's full and unconditional
guarantee of the ETCs.  See "- Guarantee," "Description of the Equipment
Notes-Security" and "Description of the ETCs-Guaranties" and "-Security".

BOOK-ENTRY REGISTRATION

         Except as otherwise described in the applicable Prospectus Supplement,
Pass Through Certificates will be subject to the provisions described under
this caption for book-entry registration with DTC.

         DTC.  DTC has advised the Company that it is a limited purpose trust
company organized under the laws of the State of New York, a member of the
Federal Reserve System, a "clearing corporation" within the meaning of the New
York Uniform Commercial Code and a "clearing agency" registered pursuant to
Section 17A of the Exchange Act.  DTC was created to hold securities for its
participants ("DTC Participants") and to facilitate the clearance and
settlement of securities transactions between DTC Participants through
electronic book-entries, thereby eliminating the need for physical movement of
certificates.  DTC Participants include securities brokers and dealers, banks,
trust companies and clearing corporations.  Indirect access to the DTC system
also is available to others such as banks, brokers, dealers and trust companies
that clear through or maintain a custodial relationship with a DTC Participant
either directly or indirectly ("Indirect Participants").

         Certificate Owners that are not DTC Participants or Indirect
Participants but desire to purchase, sell or otherwise transfer ownership of,
or other interests in, Pass Through Certificates may do so only through DTC
Participants and Indirect Participants.  In addition, Certificate Owners will
receive all distributions of principal, premium, if any, and interest from the
Pass Through Trustee through DTC Participants or Indirect Participants, as the
case may be.  Under a book-entry format, Certificate Owners may experience some
delay in their receipt of payments, because such payments will be forwarded by
the Pass Through Trustee to Cede, as nominee for DTC.  DTC will forward such
payments to DTC Participants, which thereafter will forward them to Indirect
Participants or Certificate Owners, as the case may be, in accordance with
customary industry practices.  The forwarding of such distributions to the
Certificate Owners will be the responsibility of such DTC Participants.  The
only "Certificateholder" will be Cede, as nominee of DTC.  Certificate Owners
will not be recognized by the Pass





                                      -5-
<PAGE>   10
Through Trustee as Certificateholders, as such term is used in the Basic
Agreement, and Certificate Owners will be permitted to exercise the rights of
Certificateholders only indirectly through DTC and DTC Participants.

         Under the rules, regulations and procedures creating and affecting DTC
and its operations (the "Rules"), DTC is required to make book-entry transfers
of Pass Through Certificates among DTC Participants on whose behalf it acts
with respect to the Pass Through Certificates and to receive and transmit
distributions of principal of, premium, if any, and interest on the Pass
Through Certificates.  DTC Participants and Indirect Participants with which
Certificate Owners have accounts with respect to the Pass Through Certificates
similarly are required to make book-entry transfers and receive and transmit
such payments on behalf of their respective Certificate Owners.  Accordingly,
although Certificate Owners will not possess Pass Through Certificates, the
Rules provide a mechanism by which Certificate Owners will receive payments and
will be able to transfer their interests.

         Because DTC can only act on behalf of DTC Participants, who in turn
act on behalf of Indirect Participants, the ability of a Certificate Owner to
pledge Pass Through Certificates to persons or entities that do not participate
in the MC system, or to otherwise act with respect to such Pass Through
Certificates, may be limited due to the lack of a physical certificate for such
Pass Through Certificates.

         The Company understands that DTC will take any action permitted to be
taken by Certificateholders only at the direction of one or more DTC
Participants to whose accounts with DTC the Pass Through Certificates are
credited.  Additionally, the Company understands that DTC will take such
actions with respect to any specified percentage of the beneficial interest of
Certificateholders held in each Trust only at the direction of and on behalf of
DTC Participants whose holders include undivided interests that satisfy any
such percentage.  DTC may take conflicting actions with respect to other
undivided interests to the extent that such actions are taken on behalf of DTC
Participants whose holders include such undivided interests.

         Neither the Company nor the Pass Through Trustee will have any
liability for any aspect of the records relating to or payments made on account
of beneficial ownership interests of the Pass Through Certificates held by
Cede, as nominee for DTC, or for maintaining, supervising or reviewing any
records relating to such beneficial ownership interests.

         The information contained in this section concerning DTC and DTC's
book-entry system has been obtained from sources that the Company believes to
be reliable, but the Company takes no responsibility for the accuracy thereof.

         DEFINITIVE CERTIFICATES.  With respect to each Trust, the related Pass
Through Certificates will be issued in fully registered, certificated form
("Definitive Certificates") to Certificate Owners or their nominees, rather
than to DTC or its nominee, only if (i) the Company advises the Pass Through
Trustee in writing that DTC is no longer willing or able to properly discharge
its responsibilities as depository with respect to such Pass Through
Certificates and the Pass Through Trustee or the Company is unable to locate a
qualified successor, (ii) the Company, at its option, elects to terminate the
book-entry system through DTC or (iii) after the occurrence of an Event of
Default (as defined below), Certificate Owners representing an aggregate
percentage interest in such Trust of not less than a majority advise the Pass
Through Trustee through DTC in writing that the continuation of a book-entry
system through DTC (or a successor thereto) is no longer in the Certificate
Owners' best interest.  (Section 3.9)

         Upon the occurrence of any event described in the immediately
preceding paragraph, the Pass Through Trustee will be required to notify all
affected Certificate Owners through DTC Participants of the availability of
Definitive Certificates.  Upon surrender by DTC of the certificates
representing the Pass Through Certificates and receipt of instructions for
re-registration, the Pass Through Trustee will reissue the Pass Through
Certificates as Definitive Certificates to Certificate Owners.  (Section 3.9)





                                      -6-
<PAGE>   11
         Distributions of principal of, premium, if any, and interest on the
Pass Through Certificates will thereafter be made by the Pass Through Trustee
in accordance with the procedures set forth in the Basic Agreement and the
applicable Trust Supplements, directly to holders of Definitive Certificates in
whose names such Definitive Certificates were registered at the close of
business on the applicable record date.  Such distributions will be made by
check mailed to the address of each such holder as it appears on the register
maintained with respect to the applicable Trust.  The final payment on any Pass
Through Certificate, however, will be made only upon presentation and surrender
of such Pass Through Certificate at the office or agency specified in the
notice of final distribution to Certificateholders. (Section 4.2 and 11.1)

         Definitive Certificates will be freely transferable and exchangeable
at the office of the Pass Through Trustee upon compliance with the requirements
set forth in the Basic Agreement and the applicable Trust Supplements.  No
service charge will be imposed for any registration of transfer or exchange,
but payment of a sum sufficient to cover any tax or other governmental charge
shall be required. (Section 3.4 and 11.1)

         SAME-DAY SETTLEMENT AND PAYMENT.  Settlement for the Pass Through
Certificates will be required to be made in immediately available funds.  So
long as the Pass Through Certificates are registered in the name of Cede, all
payments made by the Company to the Indenture Trustees, as assignees of the
Owner Trustees' rights under the Leases, in the case of Equipment Notes, or by
the Company or Procor in respect of Company ETCs or Procor ETCs, in the case of
ETCs, will be in immediately available funds and will be passed through by the
Pass Through Trustee to DTC in immediately available funds.

         Secondary trading in long-term notes and debentures of corporate
issuers is generally settled in clearinghouse or next-day funds.  In contrast,
the Pass Through Certificates will trade in DTC's Same Day Funds Settlement
System until maturity, and secondary market trading activity in the Pass
Through Certificates will therefore be required by DTC to settle in immediately
available funds.  No assurance can be given as to the effect, if any, of
settlement in immediately available funds on trading activity in the Pass
Through Certificates.

PAYMENTS AND DISTRIBUTIONS

         Payments received by the Pass Through Trustee of principal of,
premium, if any, and interest on the Equipment Notes or ETCs held in each Trust
will be distributed by the Pass Through Trustee to the Certificateholders of
such Trust on the date such receipt is confirmed, except in certain cases when
some or all of such Equipment Notes or ETCs are in default.  See "-Events of
Default and Certain Rights Upon an Event of Default."

        Payments of principal of, and interest on the unpaid principal amount
of, the Equipment Notes or ETCs held in each Trust will be scheduled to be
received by the Pass Through Trustee on the dates specified in the applicable
Prospectus Supplement (such scheduled payments of principal of, and interest
on, the Equipment Notes or ETCs are herein referred to as "Scheduled Payments,"
and the dates specified therefor in the applicable Prospectus Supplement are
herein referred to as "Regular Distribution Dates").  The Pass Through Trustee
of each Trust will distribute on each Regular Distribution Date to the
Certificateholders of such Trust all Scheduled Payments, the receipt of which
is confirmed by the Pass Through Trustee on such Regular Distribution Date.
Each such distribution of Scheduled Payments will be made by the Pass Through
Trustee to the holders of record of the Pass Through Certificates of such Trust
on the fifteenth day immediately preceding such Regular Distribution Date,
subject to certain exceptions. (Sections 4.1 and 4.2)  If a Scheduled Payment
is not received by the Pass Through Trustee on a Regular Distribution Date, it
will be distributed on the date received to such holders of record.  

         Each Certificateholder of each Trust will be entitled to receive a pro
rata share of any distribution in respect of Scheduled Payments of principal
and interest made on the Equipment Notes or ETCs held in such Trust.  Scheduled
Payments of principal on the Equipment Notes or ETCs held in each Trust will be
set forth in the





                                      -7-
<PAGE>   12
applicable Prospectus Supplement.  After a partial or full prepayment or
default in respect of some or all of such Equipment Notes or ETCs, a
Certificateholder should refer to the information with respect to the Pool
Balance and the Pool Factor for such Trust reported periodically by the Pass
Through Trustee.  See "-Pool Factors" and "-Statements to Certificateholders."

        Payments of principal, premium, if any, and interest received by the
Pass Through Trustee on account of a partial or full prepayment, if any, of the
Equipment Notes or ETCs held in a Trust, and payments received by the Pass
Through Trustee following a default in respect of the Equipment Notes or ETCs
held in a Trust (including, in the case of Equipment Notes, payments received
by the Pass Through Trustee on account of their purchase by the related Owner
Trustee or payments received on account of the sale of Equipment Notes or ETCs
by the Pass Through Trustee) ("Special Payments") will be distributed on the
dates specified therefor in the applicable Prospectus Supplement (a "Special
Distribution Date").  In general, the Pass Through Trustee will mail notice to
the Certificateholders of record of any Trust not less than 15 days prior to
the Special Distribution Date on which any Special Payment is scheduled to be
distributed by the Pass Through Trustee stating such anticipated Special
Distribution Date. (Section 4.2)  Each distribution of a Special Payment, other
than a final distribution, on a Special Distribution Date for any Trust will be
made by the Pass Through Trustee to the holders of record of the Pass Through
Certificates of such Trust as of the Record Date preceding such Special
Distribution Date.  See "-Events of Default and Certain Rights Upon an Event of
Default" and "Description of the Equipment Notes-Prepayments".

         The Basic Agreement requires that the Pass Through Trustee establish
and maintain, for each Trust and for the benefit of the Certificateholders of
such Trust, one or more non-interest bearing accounts (the "Certificate
Account") for the deposit of payments representing Scheduled Payments on the
Equipment Notes or ETCs held in such Trust. (Section 4.1)  The Basic Agreement
also requires that the Pass Through Trustee establish and maintain, for each
Trust and for the benefit of the Certificateholders of such Trust, one or more
accounts (the "Special Payments Account") for the deposit of payments
representing Special Payments.

         Pursuant to the terms of the Basic Agreement, the Pass Through Trustee
is required to deposit any Scheduled Payments relating to the applicable Trust
received by it in the Certificate Account of such Trust and to deposit any
Special Payments so received by it in the Special Payments Account of such
Trust. (Section 4.1)  All amounts so deposited will be distributed by the Pass
Through Trustee on a Regular Distribution Date or a Special Distribution Date
as appropriate. (Section 4.2)

         At such time, if any, as the Pass Through Certificates of any Trust
are issued in the form of Definitive Certificates and not to Cede, as nominee
for DTC, distributions by the Pass Through Trustee from the Certificate Account
or the Special Payments Account of such Trust on a Regular Distribution Date or
a Special Distribution Date, as appropriate, will be made by check mailed to
each Certificateholder of such Trust of record on the applicable record date at
its address appearing on the register maintained with respect to such Trust.
(Section 4.2)  The final distribution for each Trust, however, will be made
only upon presentation and surrender of the Pass Through Certificates for such
Trust at the office or agency of the Pass Through Trustee specified in the
notice given by the Pass Through Trustee of such final distribution.  The Pass
Through Trustee will mail such notice of the final distribution to the
Certificate-holders of such Trust, specifying the date set for such final
distribution and the amount of such distribution. (Section 11.1)  See
"-Termination of the Trusts."

         If any Regular Distribution Date or Special Distribution Date is not a
Business Day, distributions scheduled to be made on such Regular Distribution
Date or Special Distribution Date may be made on the next succeeding Business
Day without additional interest. (Section 13.11)

GUARANTEE

        The Company will fully and unconditionally guarantee the due and
punctual distribution to Certificateholders of principal and interest payable
in respect of each Procor ETC purchased by a Trust.  In addition, the Company
will fully and  unconditionally guarantee the due and punctual performance by
Procor of its obligations under each Procor Equipment Trust Agreement.

POOL FACTORS

         Unless there has been a prepayment, or a default in respect of one or
more issues of the Equipment Notes or ETCs held in a Trust, as described in the
applicable Prospectus Supplement or below in "-Events of Default and Certain
Rights Upon an Event of Default," the Pool Factor for such Trust will decline
in proportion to the scheduled





                                      -8-
<PAGE>   13
repayments of principal on the Equipment Notes or ETCs held in such Trust as
described in the applicable Prospectus Supplement.  In the event of a partial
or full prepayment or default, the Pool Factor and the Pool Balance of each
Trust so affected will be recomputed after giving effect thereto and notice
thereof will be mailed to Certificateholders of such Trust.  Each Trust will
have a separate Pool Factor and Pool Balance.

         Unless otherwise described in the applicable Prospectus Supplement, the
"Pool Balance" for each Trust indicates, as of any Regular Distribution Date or
Special Distribution Date, the aggregate unpaid principal amount of the
Equipment Notes or ETCs held in such Trust on such date plus any amounts in
respect of principal on such Equipment Notes or ETCs held by the Pass Through
Trustee and not yet distributed plus the amount of any moneys held in the
related escrow account (other than earnings thereon). The Pool Balance for each
Trust as of any Regular Distribution Date or Special Distribution Date shall be
computed after giving effect to the payment of principal, if any, on the
Equipment Notes or ETCs held in such Trust and distribution thereof to be made
on that date.

         Unless otherwise described in the applicable Prospectus Supplement, the
"Pool Factor" for each Trust, as of any Regular Distribution Date or Special
Distribution Date, is the quotient (rounded to the seventh decimal place)
computed by dividing (i) the Pool Balance of such Trust, by (ii) the aggregate
original principal amount of the Pass Through Certificates issued by such
Trust.  The Pool Factor for each Trust as of any Regular Distribution Date or
Special Distribution Date shall be computed after giving effect to the payment
of principal, if any, on the Equipment Notes or ETCs held in such Trust and
distribution thereof to be made on that date. (Section 1.1)  The Pool Factor
for each Trust will initially be 1.0000000; thereafter, the Pool Factor for
each Trust will decline as described above to reflect reductions in the Pool
Balance of such Trust.  The amount of a Certificateholder's pro rata share of
the Pool Balance of a Trust can be determined by multiplying the original
denomination of the Certificateholder's Pass Through Certificate of such Trust
by the Pool Factor for such Trust as of the applicable Regular Distribution
Date or Special Distribution Date.  The Pool Factor and the Pool Balance for
each Trust will be mailed to Certificateholders of record of such Trust on each
Regular Distribution Date and Special Distribution Date.

STATEMENTS TO CERTIFICATEHOLDERS

         On each Regular Distribution Date and Special Distribution Date, if
any, the Pass Through Trustee will include with each distribution of a
Scheduled Payment or Special Payment to Certificateholders of record of the
related Trust a statement, giving effect to such distribution to be made on
such Regular Distribution Date or Special Distribution Date, if any, setting
forth the following information (per $1,000 in aggregate principal amount of
Pass Through Certificates for such Trust, as to (i) and (ii) below):

              (i)         the amount of such distribution allocable to
                          principal and the amount allocable to premium, if
                          any;

              (ii)        the amount of such distribution allocable to 
                          interest; and

              (iii)       the Pool Balance and the Pool Factor for such Trust.
                          (Section 4.3)

         So long as the Pass Through Certificates of any Trust are registered
in the name of Cede, as nominee for DTC, on the applicable record date prior to
each Regular Distribution Date and Special Distribution Date, the Pass Through
Trustee will request from DTC a securities position listing setting forth the
names of all DTC Participants reflected on DTC's books as holding interests in
the Pass Through Certificates of such Trust on such record date.  On each
Regular Distribution Date and Special Distribution Date, the Pass Through
Trustee will mail to each such DTC Participant the statement described above,
and will make available additional copies as requested by such DTC Participant,
to be available for forwarding to Certificate Owners. (Section 3.9)

         In addition, after the end of each calendar year, the Pass Through
Trustee will prepare for each Certificateholder of record of each Trust at any
time during the preceding calendar year a report containing the sum of the
amounts determined pursuant to clauses (i) and (ii) above with respect to the
Trust for such calendar year





                                      -9-
<PAGE>   14
or, in the event such person was a Certificateholder of record during a portion
of such calendar year, for the applicable portion of such calendar year, and
such other items as are readily available to the Pass Through Trustee and which
a Certificateholder shall reasonably request as necessary for the purpose of
such Certificateholder's preparation of its federal income tax returns (Section
4.3)  Such report and such other items shall be prepared on the basis of
information supplied to the Pass Through Trustee by the DTC Participants, and
shall be delivered by the Pass Through Trustee to such DTC Participants to be
available for forwarding by such DTC Participants to Certificate Owners in the
manner described above.

         At such time, if any, as the Pass Through Certificates of a Trust are
issued in the form of Definitive Certificates, the Pass Through Trustee will
prepare and deliver the information described above to each Certificateholder
of record of such Trust as the name and period of record ownership of such
Certificateholder appears on the records of the Registrar of the Pass Through
Certificates.

VOTING OF EQUIPMENT NOTES AND ETCS

         The Pass Through Trustee, as holder of the Equipment Notes and ETCs
held in each Trust, has the right to vote and give consents and waivers in
respect of such Equipment Notes and ETCs under the applicable Indenture or
Equipment Trust Agreement.  The Basic Agreement sets forth the circumstances in
which the Pass Through Trustee shall direct any action or cast any vote as the
holder of the Equipment Notes and ETCs held in the applicable Trust at its own
discretion and the circumstances in which the Pass Through Trustee shall seek
instructions from the Certificateholders of such Trust.  Prior to an Event of
Default with respect to any Trust, the principal amount of the Equipment Notes
and ETCs held in such Trust directing any action or being voted for or against
any proposal shall be in proportion to the principal amount of Pass Through
Certificates held by the Certificateholders of such Trust taking the
corresponding position. (Sections 6.1 and 10.1) Whenever the Agreements
require or permit actions to be taken based upon instructions or directions of
Certificateholders of such Pass Through Trust holding a specified percentage
interest of a Pass Through Trust, DTC shall be deemed to represent such
percentage interest only to the extent that it has received instructions to
such effect from Certificate Owners and/or DTC Participants owning or
representing, respectively, such required percentage interest and has delivered
such instructions to the Pass Through Trustee.

EVENTS OF DEFAULT AND CERTAIN RIGHTS UPON AN EVENT OF DEFAULT

         The Basic Agreement defines an event of default with respect to a
Trust (an "Event of Default") as the occurrence and continuance of an event of
default under one or more of (i) the related Indentures (an "Indenture Event of
Default") or (ii) the related Equipment Trust Agreements (an "Equipment Trust
Event of Default").  The Indenture Events of Default or Equipment Trust Event
of Defaults will be described in the applicable Prospectus Supplement and, in
the case of Equipment Notes, will include events of default under the related
Lease.  Because the Equipment Notes issued under an Indenture may be held in
more than one Trust, a continuing Indenture Event of Default under such
Indenture would result in an Event of Default with respect to each such Trust.
There will be, however, no cross-default provisions in the Indentures and
events resulting in an Indenture Event of Default under any particular
Indenture (or a default under any other indebtedness of the Company) will not
necessarily result in an Indenture Event of Default occurring under any other
Indenture.  If an Indenture Event of Default occurs in fewer than all of the
Indentures related to a Trust, the Equipment Notes issued pursuant to the
related Indentures with respect to which an Indenture Event of Default has not
occurred will continue to be held in such Trust and payments of principal and
interest on such Equipment Notes will continue to be distributed to the holders
of the Pass Through Certificates of such Trust as originally scheduled.
Similarly, except as described in a Prospectus Supplement, an Equipment Trust
Event of Default under a Company Equipment Trust Agreement will not result in
an Equipment Trust Event of Default under a Procor Equipment Trust Agreement,
nor will an Equipment Trust Event of Default under any Procor Equipment Trust
Agreement result in an Equipment Trust Event of Default under a Company
Equipment Trust Agreement.  Accordingly, if an Equipment Trust Event of Default
occurs with respect to an Equipment Trust Agreement, but no Equipment Trust
Event of Default has occurred with respect to any other Equipment Trust
Agreement, the ETC under the non-defaulted Equipment Trust Agreement will
continue to be held in the applicable Trust, and payments of principal and
interest on such ETC will continue to be distributed to the holders of Pass
Through Certificates of such Trust as originally scheduled.

         In the case of Equipment Notes, the Owner Trustee and the Owner
Participant under each Indenture will each have the right under certain
circumstances to cure an Indenture Event of Default that results from the





                                      -10-
<PAGE>   15
occurrence of a Lease Event of Default under the related Lease.  If the Owner
Trustee or the Owner Participant chooses to exercise such cure right, the
Indenture Event of Default and consequently the Event of Default with respect
to the related Trust or Trusts will be deemed to be cured.

         The ability of the holders of the Pass Through Certificates issued
with respect to any one Trust to cause the Indenture Trustee with respect to
any Equipment Notes or the Equipment Trust Trustee with respect to any ETCs
held in such Trust to accelerate the payment on such Equipment Notes under the
related Indenture or Equipment Trust Agreement or to direct the exercise of
remedies by such Indenture Trustee under the related Indenture or Equipment
Trust Trustee under the related Equipment Trust Agreement will depend, in part,
upon the percentage of the aggregate principal amount of all Equipment Notes
outstanding under such Indenture or ETCs outstanding under such Equipment Trust
Agreement that are represented by the Equipment Notes outstanding under such
Indenture or ETCs outstanding under such Equipment Trust Agreement and held in
such Trust.  Each Trust will hold Equipment Notes with different terms from
those of the Equipment Notes held in the other Trusts and therefore the
Certificateholders of a Trust may have divergent or conflicting interests from
those of the Certificateholders of the other Trusts holding Equipment Notes
relating to the same Equipment Group.  In addition, so long as the same
institution acts as Pass Through Trustee of each Trust, in the absence of
instructions from the Certificateholders of any such Trust, the Pass Through
Trustee for such Trust could for the same reason be faced with a potential
conflict of interest upon an Indenture Event of Default or Equipment Trust
Event of Default.  In such event, the Pass Through Trustee has indicated that
it would resign as trustee of one or all such Trusts, and a successor trustee
for one or all of such Trusts would be appointed in accordance with the terms
of the Basic Agreement.

         The Basic Agreement provides that, as long as (i) an Indenture Event
of Default under any Indenture relating to Equipment Notes held in a Trust or
(ii) an Equipment Trust Event of Default under any Equipment Trust Agreement
relating to ETCs held in such Trust shall have occurred and be continuing, the
Pass Through Trustee of such Trust may vote all of the Equipment Notes issued
under such Indenture or all of the ETCs issued under such Equipment Trust
Agreement that are held in such Trust, and upon the direction of the holders of
Pass Through Certificates evidencing fractional undivided interests aggregating
not less than a majority in interest of such Trust, shall vote not less than a
corresponding majority of such Equipment Notes or ETCs in favor of directing
the related Indenture Trustee or Equipment Trust Trustee to declare the unpaid
principal amount of all Equipment Notes issued under such Indenture or ETCs
issued under such Equipment Trust Agreement and any accrued and unpaid interest
thereon to be due and payable.  The Basic Agreement also provides that, if (i)
an Indenture Event of Default under any Indenture relating to Equipment Notes
held in a Trust or (ii) an Equipment Trust Event of Default under any Equipment
Trust Agreement relating to ETCs held in such Trust shall have occurred and be
continuing, the Pass Through Trustee of such Trust may, and upon the direction
of the holders of Pass Through Certificates evidencing fractional undivided
interests aggregating not less than a majority in interest of such Trust shall,
subject to certain conditions, vote all of the Equipment Notes issued under
such Indenture or all the ETCs issued under such Equipment Trust Agreement that
are held in such Trust in favor of directing the related Indenture Trustee or
Equipment Trust Trustee as to the time, method and place of conducting any
proceeding for any remedy available to such Indenture Trustee or of exercising
any trust or power conferred on such Indenture Trustee or Equipment Trust
Trustee under such Indenture or Equipment Trust Agreement. (Sections 6.1 and
6.4)


         As an additional remedy, if an Indenture Event of Default or Equipment
Trust Event of Default shall have occurred and be continuing, the Basic
Agreement provides that the Pass Through Trustee of a Trust holding Equipment
Notes issued under such Indenture or ETCs issued under such Equipment Trust
Agreement may, and upon the direction of the holders of Pass Through
Certificates evidencing fractional undivided interests aggregating not less
than a majority in interest of such Trust shall, sell all or part of such
Equipment Notes or ETCs for cash to any person. (Sections 6.1 and 6.2)  Any
proceeds received by the Pass Through Trustee upon any such sale shall be
deposited in the Special Payments Account for such Trust and shall be
distributed to the Certificateholders of such Trust on a Special Distribution
Date. (Sections 4.1 and 4.2)  The market for Equipment Notes or ETCs in
default may be very limited and there can be no assurance that they could be
sold for a reasonable price. Furthermore, so long as the same institution acts
as Trustee of each Trust, it may be faced with a conflict in





                                      -11-
<PAGE>   16
deciding from which Trust to sell Equipment Notes or ETCs to available buyers.
If the Pass Through Trustee sells any such Equipment Notes with respect to
which an Indenture Event of Default exists or ETCs with respect to which an
Equipment Trust Event of Default exists for less than their outstanding
principal amount thereof, the Certificateholders of such Trust will receive a
smaller amount of principal distributions than anticipated and will not have
any claim for the shortfall against the Pass Through Trustee, the related Owner
Trustee, the related Owner Participant, or, except as provided in the next
sentence, Procor or the Company.  Inasmuch as Procor will fully and
unconditionally guarantee the payment of principal of and interest on the
Procor ETCs and the Company will fully and unconditionally guarantee the
payment of the principal of and interest on the Company ETCs and the Procor
ETCs, as well as the due and punctual distribution to Certificateholders of
principal and interest payable in respect of each Procor ETC held by a Trust,
the Certificateholders will have a claim against the Company for any shortfall
arising from the sale by the Pass Through Trustee of a Company ETC or Procor
ETC in default. (Sections 4.1 and 4.2) See "Description of the
ETCs-Guaranties".  Neither the Pass Through Trustee nor the Certificateholders
of such Trust could take any action with respect to any remaining Equipment
Notes or ETCs held in such Trust so long as no Indenture Event of Default or
Equipment Trust Event of Default existed with respect thereto.

         Any amount distributed to the Pass Through Trustee of any Trust by (i)
the Indenture Trustee under any Indenture on account of the Equipment Notes
held in such Trust following an Indenture Event of Default under such Indenture
or (ii) the Equipment Trust Trustee under any Equipment Trust Agreement on
account of the ETCs held in such Trust following an Equipment Trust Event of
Default shall be deposited in the Special Payments Account for such Trust and
shall be distributed to the Certificateholders of such Trust on a Special
Distribution Date.  In addition, if, following an Indenture Event of Default
under any Indenture, the related Owner Trustee exercises its option, if any, to
prepay or purchase the outstanding Equipment Notes issued under such Indenture
as described in the related Prospectus Supplement, the price paid by such Owner
Trustee to the Pass Through Trustee of any Trust for the Equipment Notes issued
under such Indenture and held in such Trust shall be deposited in the Special
Payments Account for such Trust and shall be distributed to the
Certificateholders of such Trust on a Special Distribution Date. (Sections 4.1
and 4.2)

         Any funds held by the Pass Through Trustee in the Special Payments
Account for a Trust representing either payments received with respect to (i)
any Equipment Notes held in such Trust following an Indenture Event of Default
or (ii) any ETCs held in such Trust following an Equipment Trust Event of
Default or proceeds from the sale by the Pass Through Trustee of any such
Equipment Notes or ETCs, shall, to the extent practicable, be invested and
reinvested by the Pass Through Trustee in Permitted Government Investments
pending the distribution of such funds on a Special Distribution Date.
(Sections 4.1 and 4.2)

         The Basic Agreement provides that the Pass Through Trustee of each
Trust shall, within 30 days after the occurrence of a default (as defined
below) in respect of such Trust, give to the Certificate holders of such Trust
notice, transmitted by mail, of all uncured or unwaived defaults with respect
to such Trust known to it; provided that, except in the case of default in the
payment of principal of, premium, if any, or interest on any of the Equipment
Notes or ETCs held in such Trust, the Pass Through Trustee shall be protected
in withholding such notice if it in good faith determines that the withholding
of such notice is in the interest of such Certificateholders.  The term
"default," for the purpose of the provision described in this paragraph only,
shall mean the occurrence of any Event of Default with respect to a Trust as
specified above, except that in determining whether any such Event of Default
has occurred any grace period or notice in connection therewith shall be
disregarded. (Section 7.2)

         The Basic Agreement contains a provision entitling the Pass Through
Trustee of each Trust, subject to the duty of the Pass Through Trustee during a
default to act with the required standard of care, to obtain security from or
be indemnified by





                                      -12-
<PAGE>   17
the holders of the Pass Through Certificates of such Trust before proceeding to
exercise any right or power under the Basic Agreement at the request of such
Certificateholders. (Section 7.3)

         In certain cases, the holders of Pass Through Certificates of a Trust
evidencing fractional undivided interests aggregating not less than a majority
in interest of such Trust may on behalf of the holders of all Pass Through
Certificates of such Trust waive any past default or Event of Default with
respect to such Trust and thereby annul any direction given by the Pass Through
Trustee on behalf of such holders to the related Indenture Trustee with respect
thereto, except (i) a default in payment of the principal of, premium, if any,
or interest on any of the Equipment Notes or ETCs held in such Trust, and (ii)
a default in respect of any covenant or provision of the Basic Agreement or the
related Trust Supplement that cannot be modified or amended without the consent
of each Certificateholder of such Trust affected thereby. (Section 6.5)  Each
Indenture and Equipment Trust Agreement will provide that, with certain
exceptions, the holders of a majority in aggregate unpaid principal amount of
the Equipment Notes or ETCs issued thereunder may on behalf of all such holders
waive any past default or Indenture Event of Default or Equipment Trust Event
of Default under such Equipment Trust Agreement thereunder.  In the event of a
waiver with respect to a Trust as described above, the principal amount of the
Equipment Notes issued under the related Indenture or ETCs issued under the
related Equipment Trust Agreement held in such Trust shall be counted as waived
in the determination of the majority in aggregate unpaid principal amount of
Equipment Notes or ETCs required to waive a default or an Indenture Event of
Default under such Indenture or Equipment Trust Event of Default under such
Equipment Trust Agreement.  Therefore, if the Certificateholders of a Trust
waive a past default or Event of Default such that the principal amount of the
Equipment Notes or ETCs held in such Trust constitutes the required majority in
aggregate unpaid principal amount under the applicable Indenture or Equipment
Trust Agreement, such past default, Indenture Event of Default under such
Indenture or Equipment Trust Event of Default under such Equipment Trust
Agreement shall be waived.  For a discussion of waivers of Indenture Events of
Default under the Indentures and Equipment Trust Events of Default under the
Equipment Trust Agreements, see "Description of the Equipment Notes-Indenture
Events of Default and Remedies" and "Description of the ETCs-Events of Default
and Provisions Relating Thereto".

MODIFICATIONS OF THE BASIC AGREEMENT

         The Basic Agreement contains provisions permitting the Company, Procor
and the Pass Through Trustee of each Trust to enter into supplemental trust
agreements, without the consent of the holders of any of the Pass Through
Certificates of such Trust, (i) to evidence the succession of another
corporation to the Company or Procor and the assumption by such corporation of
the Company's or Procor's obligations under the Basic Agreement and the
applicable Trust Supplement, (ii) to add to the covenants of the Company or
Procor for the benefit of the holders of such Pass Through Certificates, (iii)
to cure any ambiguity, to correct any manifest error or to correct or
supplement any defective or inconsistent provision of such Basic Agreement, the
applicable Trust Supplement or any supplemental trust agreement, or to make any
other provisions with respect to matters or questions arising thereunder,
provided such action shall not adversely affect the interest of the holders of
such Pass Through Certificates, (iv) to evidence and provide for a successor
Trustee for some or all of the Trusts, or (v) to make any other amendments or
modifications which shall only apply to Pass Through Certificates of one or
more series to be issued thereafter. (Section 9.1)

         The Basic Agreement also contains provisions permitting the Company,
Procor and the Pass Through Trustee of each Trust, with the consent of the
Certificateholders of such Trust evidencing fractional undivided interests
aggregating not less than a majority in interest of such Trust, to execute
supplemental trust agreements adding any provisions to or changing or
eliminating any of the provisions of the Basic Agreement, to the extent
relating to such Trust, and the applicable Trust Supplement, or modifying the
rights of such Certificateholders, except that no such supplemental trust
agreement may, without the consent of the holder of each such Pass Through
Certificate so affected, (a) reduce in any manner the amount of, or delay the
timing of, any receipt by the Pass Through Trustee of payments on the Equipment
Notes or ETCs held in such Trust, or distributions in respect of any Pass
Through Certificate of such Trust, or make distributions payable in coin or
currency other than that





                                      -13-
<PAGE>   18
provided for in such Pass Through Certificates, or impair the right of any
Certificateholder of such Trust to institute suit for the enforcement of any
such payment when due, (b) permit the disposition of any Equipment Note or ETC
held in such Trust, except as provided in the Basic Agreement or the applicable
Trust Supplement, or (c) reduce the percentage of the aggregate fractional
undivided interests of the Trust provided for in the Basic Agreement or the
applicable Trust Supplement, the consent of the holders of which is required
for any such supplemental trust agreement or for any waiver provided for in the
Basic Agreement or such Trust Supplement. (Section 9.2)

MODIFICATION AND CONSENTS AND WAIVERS UNDER THE INDENTURES, THE EQUIPMENT TRUST
AGREEMENTS AND RELATED AGREEMENTS

         In the event that the Pass Through Trustee, as the holder of any
Equipment Notes or ETCs held in a Trust, receives a request for its consent to
any amendment, modification or waiver under the Indenture, Lease, if any, or
other document relating to such Equipment Notes, or Equipment Trust Agreement
relating to such ETCs, which requires the consent of the Certificateholders of
such Trust, the Pass Through Trustee shall mail a notice of such proposed
amendment, modification or waiver to each Certificateholder of such Trust as of
the date of such notice.  The Pass Through Trustee shall request instructions
from the Certificateholders of such Trust as to whether or not to consent to
such amendment, modification or waiver.  The Pass Through Trustee shall vote or
consent with respect to such Equipment Notes or ETCs in such Trust in the same
proportion as the Pass Through Certificates of such Trust were actually voted
by the holders thereof by a certain date.  Notwithstanding the foregoing, if an
Event of Default in respect of such Trust shall have occurred and be
continuing, the Pass Through Trustee, subject to the voting instructions
referred to under "-Events of Default and Certain Rights Upon an Event of
Default," may in its own discretion consent to such amendment, modification or
waiver, and may so notify the Indenture Trustee or equipment trust trustee to
which such consent relates. (Section 10.1)

TERMINATION OF THE TRUSTS

         The obligations of the Company, Procor and the Pass Through Trustee
with respect to a Trust will terminate upon the distribution to
Certificateholders of such Trust of all amounts required to be distributed to
them pursuant to the Basic Agreement and the applicable Trust Supplement and
the disposition of all property held in such Trust.  The Pass Through Trustee
will mail to each Certificateholder of record of such Trust notice of the
termination of such Trust, the amount of the proposed final payment and the
proposed date for the distribution of such final payment for such Trust.  The
final distribution to any Certificateholder of such Trust will be made only
upon surrender of such Certificateholder's Pass Through Certificates at the
office or agency of the Pass Through Trustee specified in such notice of
termination. (Section 11.1)

DELAYED PURCHASE

         In the event that, on the date of issuance of any Pass Through
Certificates, all of the proceeds from the sale of such Pass Through
Certificates are not used to purchase the Equipment Notes or ETCs contemplated
to be held in the related Trust, such Equipment Notes or ETCs may be purchased
by the Pass Through Trustee at any time on or prior to the date specified in
the applicable Prospectus Supplement.  In such event, the Pass Through Trustee
will hold the proceeds from the sale of such Pass Through Certificates not used
to purchase Equipment Notes or ETCs in an escrow account pending the purchase
of the Equipment Notes or ETCs not so purchased.  Such proceeds will be
invested in Specified Investments at the direction and risk of, and for the
account of, the Company.  Earnings on Specified Investments in the escrow
account for each Trust will be paid to the Company periodically, and the
Company will be responsible for any losses realized on such Specified
Investments. (Section 2.2)

         On the Regular Distribution Date occurring after the issuance of such
Pass Through Certificates, the Company will pay to the Pass Through Trustee an
amount equal to the interest that would have accrued on any Equipment Notes or
ETCs which are purchased after the date of the issuance of such Pass Through
Certificates from the date of the issuance of such Pass Through Certificates
to, but excluding, the date of the purchase of such Equipment Notes or ETCs by
the Pass Through Trustee. (Section 2.2)





                                      -14-
<PAGE>   19
         To the extent that Equipment Notes or ETCs are not purchased by the
Pass Through Trustee on or prior to the date specified in the applicable
Prospectus Supplement, the unexpended proceeds from the sale of such Pass
Through Certificates, together with interest thereon at the rate applicable to
such Pass Through Certificates, will be distributed to the holders of such Pass
Through Certificates as a Special Payment.

THE PASS THROUGH TRUSTEE

         Unless otherwise specified in the applicable Prospectus Supplement,
________________________________________________________________ will be the
Pass Through Trustee for each of the Trusts.  The Pass Through Trustee and any
of its affiliates may hold Pass Through Certificates in their own names.
(Section 7.5)  With certain exceptions, the Pass Through Trustee makes no
representations as to the validity or sufficiency of the Basic Agreement, the
Trust Supplements, the Pass Through Certificates, the Equipment Notes, the
Indentures, the Leases, the ETCs, the Equipment Trust Agreements or other
related documents. (Section 7.4)  Unless otherwise specified in a Prospectus
Supplement, __________________________________ will also be the Indenture
Trustee of the Indentures under which the Equipment Notes are issued and the
equipment trust trustee under which the ETCs are issued.  [Prior relationships
between the Company and the trustee to be described.]

         The Pass Through Trustee may resign with respect to any or all of the
Trusts at any time, in which event the Company will be obligated to appoint a
successor trustee.  If the Pass Through Trustee ceases to be eligible to
continue as Trustee with respect to a Trust or becomes incapable of acting as
Trustee or becomes insolvent, the Company may remove such Trustee.  In
addition, any holder of Pass Through Certificates of such Trust for at least
six months may in such circumstances, on behalf of himself and all others
similarly situated, petition any court of competent jurisdiction for the
removal of such Trustee and the appointment of a successor trustee.  Any
resignation or removal of the Pass Through Trustee with respect to a Trust and
appointment of the successor trustee for such Trust does not become effective
until acceptance of the appointment by the successor trustee. (Section 7.9)
Pursuant to such resignation and successor trustee provisions, it is possible
that a different trustee could be appointed to act as the successor trustee
with respect to each Trust.  All references in this Prospectus to the Pass
Through Trustee are to the trustee acting in such capacity under each of the
Trusts and should be read to take into account the possibility that each of the
Trusts could have a different successor trustee in the event of such a
resignation or removal.

         The Basic Agreement provides that the Company will pay the Pass
Through Trustee's fees and expenses and will indemnify the Pass Through Trustee
in accordance with the Participation Agreement with respect to certain taxes.
To the extent not indemnified by the Company with respect to such taxes, the
Pass Through Trustee may be entitled to be reimbursed by the applicable Trust.
(Section 7.7)


                       DESCRIPTION OF THE EQUIPMENT NOTES

         The statements under this caption are summaries and do not purport to
be complete.  Except as otherwise indicated below or as described in the
applicable Prospectus Supplement, the following summaries will apply to the
Equipment Notes, the Indenture, the Lease and the Participation Agreement
relating to each Equipment Group.  Additional provisions with respect to the
Equipment Notes, the Indentures, the Leases and the Participation Agreements
relating to any particular Equipment Group will be described in the applicable
Prospectus Supplement.

GENERAL

         Each Equipment Note issued under the same Indenture will relate to a
single Equipment Group.  The Equipment Notes with respect to each Equipment
Group will be issued under a separate Indenture between the related Indenture
Trustee and the Owner Trustee of a trust for the benefit of the Owner
Participant which is the beneficial owner of such Equipment Group.





                                      -15-
<PAGE>   20
         The Equipment Notes will be nonrecourse obligations of the related
Owner Trustee.  Except in certain circumstances involving the Company's
purchase of Equipment Units and the assumption of the Equipment Notes related
thereto, the Equipment Notes will not be direct obligations of, or guaranteed
by, the Company; however, the Company will be obligated to make or cause to be
made rental and other payments to the related Owner Trustee under the Lease of
the related Equipment Group in amounts that will be at least sufficient to pay
when due all payments required to be made on the Equipment Notes issued with
respect to such Equipment Group.  The Company's rental obligations under each
Lease will be general obligations of the Company.

PRINCIPAL AND INTEREST PAYMENTS

         Interest paid on the Equipment Notes held in each Trust will be passed
through to the Certificateholders of such Trust on the dates and at the rate
per annum set forth in the applicable Prospectus Supplement until the final
distribution date for such Trust.  Principal paid on the Equipment Notes held
in each Trust will be passed through to the Certificateholders of such Trust in
scheduled amounts on the dates set forth in the applicable Prospectus
Supplement until the final distribution date for such Trust.

         If any date scheduled for any payment of principal of, premium, if
any, or interest on the Equipment Notes is not a Business Day, such payment may
be made on the next succeeding Business Day without any additional interest.

PREPAYMENTS

         The applicable Prospectus Supplement will describe the circumstances,
whether voluntary or involuntary, under which the related Equipment Notes may
be prepaid or purchased, the premium, if any, related to certain prepayments or
purchases and other terms applying to prepayments or purchases of such
Equipment Notes.

SECURITY

         The Equipment Notes issued with respect to an Equipment Group will be
secured by (i) an assignment by the related Owner Trustee to the related
indenture Trustee of such Owner Trustee's rights (except for certain limited
rights described in the Prospectus Supplement) under the Lease with respect to
such Equipment Group, including the right to receive payments of rent
thereunder and (ii) a perfected security interest to such Indenture Trustee in
such Equipment Group, subject to the rights of the Company under such Lease.
Unless and until an Indenture Event of Default with respect to an Equipment
Group has occurred and is continuing, the Indenture Trustee may not exercise
the rights of the Owner Trustee under the related Lease, except the right to
receive payments of rent due thereunder.

         The Equipment Notes issued under different Indentures will not be
cross-collateralized and consequently the Equipment Notes issued in respect of
any one Equipment Group will not be secured by any other Equipment Group or the
Lease related to any other Equipment Group.

         The Company will be required to file each Indenture, any indenture
supplement, each Lease and any lease supplement with respect to each Equipment
Group with the Surface Transportation Board and will be further required to
deposit such documents with the Registrar General of Canada under the Railway
Act of Canada and to publish notice of such deposit in accordance with such
Act.  The filing with the Surface Transportation Board will give the Indenture
Trustee a perfected security interest in each Equipment Unit in such Equipment
Group whenever it is located in the United States and in the Lease.  Such
deposit and publication in Canada will be done in order to protect the lien of
the Indenture Trustee in and to the Lease and the Equipment Units subject to
the Indenture in Canada or any province or territory thereof, to the extent
provided for in the Railway Act of Canada.

         Each Equipment Unit may be operated by the Company or, subject to
certain limitations, under sublease or interchange arrangements in the United
States, Canada or Mexico.  The extent to which the Indenture Trustee's





                                      -16-
<PAGE>   21
security interest would be recognized in an Equipment Unit located in countries
other than the United States is uncertain.

         Funds, if any, held from time to time by the Indenture Trustee with
respect to any Equipment Units, including funds held as the result of the loss
or destruction of such Equipment Units or termination of the Lease, if any,
relating thereto, will be invested and reinvested by such Indenture Trustee, at
the direction of the Company (except in the case of a Lease Event of Default
under the applicable Lease, if any), in Specified Investments.  The Company
will pay the amount of any loss resulting from any such investment directed by
it.

         The Company will be obligated, at its cost and expense, to maintain,
repair and keep each Equipment Unit in accordance with prudent industry
maintenance practices and in compliance in all material respects with all laws
and regulations.

LIMITATION OF LIABILITY

         Except in certain circumstances involving the Company's purchase of
Equipment Units and the assumption of the Equipment Notes related thereto, the
Equipment Notes will not be direct obligations of, or guaranteed by, the
Company or the Owner Trustees.  None of the Owner Trustees, the Owner
Participants or the Indenture Trustees, or any affiliates thereof, will be
personally liable to any holder of an Equipment Note or, in the case of the
Owner Trustees and the Owner Participants, to the Indenture Trustees for any
amounts payable under the Equipment Notes or, except as provided in each
Indenture, for any liability under such Indenture.  Except in the circumstances
described above, all payments of principal of, premium, if any, and interest on
Equipment Notes issued with respect to any Equipment Group (other than payments
made in connection with an optional prepayment or purchase by the related Owner
Trustee) will be made only from the assets subject to the lien of the Indenture
with respect to such Equipment Group or the income and proceeds received by the
related Indenture Trustee therefrom (including rent payable by the Company
under the Lease with respect to such Equipment Group).

         Except as otherwise provided in the Indentures, each Owner Trustee in
its individual capacity shall not be answerable or accountable under the
Indentures or under the Equipment Notes under any circumstances except for its
own wilful misconduct or gross negligence.  None of the Owner Participants will
have any duty or responsibility under any of the Indentures or the Equipment
Notes to the Indenture Trustees or to any holder of any Equipment Note.

INDENTURE EVENTS OF DEFAULT AND REMEDIES

         The applicable Prospectus Supplement will describe the Indenture
Events of Default under the related Indentures, the remedies that the Indenture
Trustee may exercise with respect to the related Equipment Group, either at its
own initiative or upon instruction from holders of the related Equipment Notes,
and other provisions relating to the occurrence of an indenture Event of
Default and the exercise of remedies.  There will be no cross-default
provisions in the Indentures and events resulting in an indenture Event of
Default under any particular Indenture (or a default under any other
indebtedness of the Company) will not necessarily result in an Indenture Event
of Default under any other Indenture.

         In the event of the bankruptcy of an Owner Participant, it is possible
that, notwithstanding that the related Equipment Group is owned by an Owner
Trustee in trust, such Equipment Group and its Lease and the Equipment Notes
related thereto might become part of the bankruptcy proceeding.  In such event,
payments on such Equipment Notes might be interrupted and the ability of the
Indenture Trustee to exercise its remedies under the applicable Indenture might
be restricted, although the Indenture Trustee would retain its status as a
secured creditor in respect of such Lease and the related Equipment Group.  In
addition, in the event of an Owner Participant bankruptcy, the estate might
seek court approval to reject the related Lease as an executory contract.  Such
a Lease rejection, if successful, would leave the Indenture Trustee as a
secured creditor in respect of the related Equipment Group with a claim for
damages against the estate.





                                      -17-
<PAGE>   22
THE LEASES

         The following provisions will be applicable unless otherwise disclosed
in the Prospectus Supplement.

         TERM AND RENTALS.  Each Equipment Group will be leased separately by
the related Owner Trustee to the Company for a term commencing on the delivery
date thereof to such Owner Trustee and expiring on a date not earlier than the
latest maturity date of the Equipment Notes issued with respect to such
Equipment Group unless previously terminated as permitted by the related Lease.
The basic rental payments by the Company under each Lease will be payable on
the dates specified in the applicable Prospectus Supplement, and will be
assigned by the Owner Trustee under the related Indenture to provide the funds
necessary to make payments of principal and interest due from such Owner
Trustee on the Equipment Notes issued under such Indenture.  Although in
certain cases the basic rental payments under the Leases may be adjusted, under
no circumstances will rental payments be less than the scheduled payments of
principal and interest on the Equipment Notes issued under the Indenture
relating to such Lease.  The balance of any basic rental payments under each
Lease, after payment of the scheduled principal and interest on the Equipment
Notes issued under the Indenture relating to such Lease, will be paid over to
the related Owner Trustee.  The Company's obligation to pay rent and to cause
other payments to be made under each Lease will be a general obligation of the
Company.

         NET LEASE.  The Company's obligations in respect of each Equipment
Group leased to the Company by an Owner Trustee will be those of a lessee under
a "net lease." Accordingly, the Company will be obligated, at its cost and
expense, to maintain, repair and keep each Equipment Unit in any such Equipment
Group in accordance with prudent industry maintenance practices and in
compliance in all material respects with all laws and regulations and
consistent with maintenance practices used by the Company in respect of
equipment owned or leased by the Company similar in type to such Equipment
Unit.  Subject to certain exceptions, the Company will, at its expense, make
all alterations, replacements or modifications required to be made by the
Association of American Railroads, the United States Department of
Transportation, or any other United States, state or local governmental agency.
The Company reserves the right to contest the validity or applicability of any
required alterations, replacements or modifications.  The Company shall have
the right to make alterations, modifications and improvements with respect to
each Equipment Unit in any such Equipment Group, provided that no such
alteration, modification or improvement shall materially diminish the fair
market value, utility or remaining economic useful life of such Unit.

         INSURANCE.  Unless waived or otherwise excused by the terms of any
Lease, the Company will be required, at its own expense, to cause to be carried
and maintained insurance in respect of the Equipment in amounts and against
such risks and with deductibles and terms and conditions not less than the
insurance, if any, maintained by the Company in respect of similar equipment
owned or leased by the Company, but in no event shall such coverage be for
amounts or against risks less than the prudent industry standard for companies
engaged in full service leasing of tank and hopper cars.  The Company does not
maintain casualty insurance with respect to the Equipment.

         LEASE EVENTS OF DEFAULT; REMEDIES.  The applicable Prospectus
Supplement will describe the Lease Events of Default under the related Lease,
the remedies that the Owner Trustee, or Indenture Trustee as assignee of the
Owner Trustee, may exercise with respect to an Equipment Group, and other
provisions relating to the occurrence of a Lease Event of Default and the
exercise of remedies.

         Lease Events of Default under each Lease will include, among other
things, (a) failure by the Company to make rental payments under the Lease, (b)
failure to maintain insurance as required by the Lease, (c) use of the
Equipment Group in contravention of the Lease, (d) breach of any representation
or warranty made by the Company in the Lease or in the related Participation
Agreement and (e) the occurrence of certain events of bankruptcy,
reorganization or insolvency of the Company.  Upon the occurrence of a Lease
Event of Default under any Lease, the related Indenture Trustee, as assignee of
the related Owner Trustee's rights under such Lease, will be entitled to
repossess the Equipment Units and use or sell such Equipment Units free and
clear of the Company's rights therein.





                                      -18-
<PAGE>   23
         If the Company were to become a debtor in a bankruptcy or
reorganization case under the Bankruptcy Code, the Company or its bankruptcy
trustee could reject any or all Leases to which it is a party.  In such event,
there could be no assurance that the amount of any claim for damages under such
Leases that would be allowed in such bankruptcy case would be in an amount
sufficient to provide for the repayment of the related Equipment Notes.  In any
case, rejection of a Lease by the Company or its bankruptcy trustee would not
deprive the related indenture Trustee of its security interest in the related
Equipment Group.

         The Company is not a railroad, and the protections against the
automatic stay in bankruptcy under Section 1168 of the Bankruptcy Code which
are granted to lessors, conditional vendors and purchase money financiers of
rolling stock to a common carrier by railroad will not be available to an
Indenture Trustee upon the occurrence of a Lease Event of Default.

THE PARTICIPATION AGREEMENTS

         The Company will be required to indemnify the Pass Through Trustee,
each Indenture Trustee, each Owner Participant and each Owner Trustee for
certain losses and claims and for certain other matters.  Each Owner
Participant will be required to discharge certain liens or claims on or against
the assets subject to the lien of the related Indenture that arise out of any
act of or failure to act by or claim against such Owner Participant.  Subject
to certain restrictions, each Owner Participant may transfer its interest in
the related Equipment Group.


                            DESCRIPTION OF THE ETCS

         The statements under this caption are summaries only of the ETCs and
the Equipment Trust Agreements under which they will be issued and do not
purport to be complete.  Additional provisions relating to any particular ETCs
will be described in the applicable Prospectus Supplement.

GENERAL

         The ETCs will be limited to the aggregate principal amount set forth
in the applicable Equipment Trust Agreement.  The ETCs will be issued against
the deposit with the Equipment Trust Trustee by the Pass Through Trustee of
like amounts of Deposited Cash.  Each ETC will represent an interest equal to
its principal amount in the trust created under the applicable Equipment Trust
Agreement.

PRINCIPAL AND INTEREST PAYMENTS

         Interest paid on the ETCs held in each Trust will be passed through to
the Certificateholders of such Trust on the dates and at the rate per annum set
forth in the applicable Prospectus Supplement until the final distribution date
for such Trust.  Principal paid on the ETCs held in each Trust will be passed
through to the Certificateholders of such Trust in scheduled amounts on the
dates set forth in the applicable Prospectus Supplement until the final
distribution date for such Trust.

         If any date scheduled for any payment of principal of, premium, if
any, or interest on the ETCs is not a Business Day, such payment may be made on
the next succeeding Business Day without any additional interest.

GUARANTIES

         The Company will fully and unconditionally guarantee (i) the payment
as and when due of the principal of and interest on each Company ETC and (ii)
the due and punctual distribution to Certificateholders of principal and
interest payable in respect of each Procor ETC and the performance by Procor of
its obligations under each





                                      -19-
<PAGE>   24
Procor Equipment Trust Agreement.  Procor will fully and unconditionally
guarantee the payment as and when due of the principal of and interest on each
Procor ETC.

PREPAYMENT

         The applicable Prospectus Supplement will describe the circumstances,
whether voluntary or involuntary, under which the related ETCs may be prepaid
or purchased, the premium (if any) related to certain prepayments or purchases
and other terms applying to prepayments or purchases of such ETCs.

SECURITY

         Except as otherwise set forth in the applicable Prospectus Supplement,
the applicable Equipment Trust Agreement will provide for the sale by the
Company or Procor to the Equipment Trust Trustee of railway tank cars and other
rail cars (the "Trust Equipment") of the types used in the Company's or
Procor's business having an estimated cost of not less than 125% of the
principal amount of the related ETC.  For the purpose of determining the cost
of any unit of Equipment built by the Company or Procor, so-called "car
builder's cost" (which includes direct cost of labor, material and overhead,
but excludes any manufacturing profit) will be used; otherwise the actual cost
to the Company or Procor will be used.

         When and as any of the Trust Equipment shall be delivered to the
Equipment Trust Trustee, the Equipment Trust Trustee will pay to the Company or
Procor, as applicable, out of Deposited Cash an amount which will not exceed
80% of the aggregate cost (without deduction for depreciation) of such Trust
Equipment (or such other percentage as may be set forth in the applicable
Prospectus Supplement), and the balance of the cost will be paid by the
Equipment Trust Trustee from advance rentals paid to the Equipment Trust
Trustee by the Company or Procor, as applicable.  Until so paid out, Deposited
Cash and other funds held by the Equipment Trust Trustee pending delivery to it
of Trust Equipment may be invested, at the risk of the Company or Procor, as
applicable, in direct obligations of the United States, in certain obligations
guaranteed by the United States, in certificates of deposit or time deposits or
in prime commercial paper.

         Each Equipment Trust Agreement will contain provisions requiring the
Company or Procor, as applicable, to cause such agreements and each supplement
thereto, promptly after the execution and delivery thereof, to be recorded with
the Surface Transportation Board and the Registrar General of Canada.  In
addition, the Company or Procor, as applicable, will be required to take
similar actions in all other jurisdictions required by law or reasonably
requested by the Equipment Trust Trustee for the purposes of proper protection
of the Equipment Trust Trustee's title to the Trust Equipment subject thereto
and the rights of the holders of the ETCs; provided, however, that neither the
Company nor Procor will be required to so record in any jurisdiction if (1) in
the opinion of the Company or Procor, as applicable, such recording would be
unduly burdensome, and (2) after giving effect to such failure to record, the
Company or Procor, as applicable, has taken all action required by law to
protect the title of the Equipment Trust Trustee to Trust Equipment having a
value (defined as the greater of (a) the actual value of such Trust Equipment
and (b) the cost thereof less 1/20th of such cost for each year the Trust
Equipment has been in use) of not less than 90% of the value of all such Trust
Equipment.

         Each Company Equipment Trust Agreement will provide for the lease to
the Company of all the Trust Equipment subject to such agreement for a period
specified in the applicable Prospectus Supplement.  The rent and other amounts
payable by the Company will be sufficient to enable the Equipment Trust Trustee
to pay when due the principal of and interest on the applicable Company ETC, as
well as all the expenses of the trust created under the Equipment Trust
Agreement and certain other charges.  At the termination of the lease and after
all payments due or to become due from the Company under the Equipment Trust
Agreement shall have been fully made, such payments shall be applied and
treated as purchase money as the full purchase price of the Trust Equipment,
and title to all Trust Equipment held in the trust shall vest in the Company.





                                      -20-
<PAGE>   25
         Each Procor Equipment Trust Agreement will provide for the conditional
sale to Procor of all the Trust Equipment subject to such agreement and will
obligate Procor to make payments to the Equipment Trust Trustee during the
period specified in the applicable Prospectus Supplement.  The payments in
respect of the purchase of the Trust Equipment and other amounts payable will
be sufficient to enable the Equipment Trust Trustee to pay when due the
principal of and interest on the applicable Procor ETC, as well as all the
expenses of the trust created under the Equipment Trust Agreement and certain
other charges.  After all payments due or to become due from Procor under the
Equipment Trust Agreement shall have been fully made, such payments shall be
deemed to represent payment of the full purchase price for Procor's purchase of
the Trust Equipment, and title to all Trust Equipment held in the trust shall
vest in Procor.

         Each Equipment Trust Agreement will permit the possession and use of
the Trust Equipment in the Company's or Procor's business, as applicable,
including the sublease thereof to others subject to the terms and conditions of
the applicable Equipment Trust Agreement.

         The Trust Equipment subject to any Company Equipment Trust Agreement
will not secure the payment of a Company ETC issued under any other Company
Equipment Trust Agreement or of any Procor ETC, nor will the Trust Equipment
subject to any Procor Equipment Trust Agreement secure the payment of a Procor
ETC issued under any other Procor Equipment Trust Agreement or of any Company
ETC.

MAINTENANCE, RELEASE AND SUBSTITUTION OF TRUST EQUIPMENT

         The Company and Procor will be required to maintain and keep the
relevant Trust Equipment in good order and proper repair unless and until it
becomes worn out, unsuitable for use, lost or destroyed (a "Casualty
Occurrence").  Each Equipment Trust Agreement will provide that, whenever Trust
Equipment having a value specified therein shall have suffered a Casualty
Occurrence, the Company or Procor, as applicable, shall either deposit with the
Equipment Trust Trustee an amount in cash equal to the value of such Trust
Equipment or convey to the Equipment Trust Trustee additional Equipment
having a value not less than the value of the Trust Equipment suffering the
Casualty Occurrence.

         Each Equipment Trust Agreement will provide that if the aggregate cost
of the Trust Equipment initially delivered to the Equipment Trust Trustee by
the Company or Procor, as applicable, shall exceed 125% of the aggregate
principal amount of the Company ETC or the Procor ETC (or such other percentage
as may be specified in the applicable Prospectus Supplement), the Equipment
Trust Trustee, upon request of the Company or Procor, as applicable, shall
release Trust Equipment from the relevant trust having an aggregate cost of not
more than the amount of such excess.

         Each Equipment Trust Agreement will provide for the release by the
Equipment Trust Trustee of any Trust Equipment upon request of the Company or
Procor, as applicable, and (a) the conveyance to the Equipment Trust Trustee of
other Equipment (irrespective of when first put into use) of value not less
than the value of the Trust Equipment to be released or (b) the payment to the
Equipment Trust Trustee of cash in an amount not less than the value of the
Trust Equipment to be released.  Any cash so deposited (and any cash deposited
as provided in the second preceding paragraph) will be paid over by the
Equipment Trust Trustee to the Company or Procor, as applicable, against the
conveyance to the Equipment Trust Trustee of additional Equipment having a
value not less than the amount of cash to be paid over.

INFORMATION CONCERNING THE EQUIPMENT TRUST TRUSTEE

         ______________________________________________________________will be
the Equipment Trust Trustee under each Equipment Trust Agreement.  [Prior
relationships between the Company, Procor and the trustee to be described.]





                                      -21-
<PAGE>   26
EQUIPMENT TRUST EVENTS OF DEFAULT AND PROVISIONS RELATING THERETO

         Equipment Trust Events of Default will be defined in each Equipment
Trust Agreement as being: default for more than 10 Business Days in the payment
of any rental payable under a Company Equipment Trust Agreement or any amount
payable under a Procor Equipment Trust Agreement; any unauthorized assignment
or transfer of the Company's or Procor's rights under the applicable Equipment
Trust Agreement, continuing as provided therein; any unauthorized transfer,
sublease or parting with the possession of any Trust Equipment, continuing as
provided therein; any failure or refusal to perform any other covenant in such
Equipment Trust Agreement for the shorter of (i) 60 days after the Equipment
Trust Trustee shall have demanded in writing such performance and (ii) 30 days
after the Company or Procor, as applicable, has knowledge of any such failure;
certain events of bankruptcy; or the termination of the lease provided for in a
Company Equipment Trust Agreement or the security interest provided for in a
Procor Equipment Trust Agreement by operation of law or by the Equipment Trust
Trustee in the event of any unauthorized assignment or transfer of the
Company's or Procor's rights under such Equipment Trust Agreement or any
unauthorized transfer or sublease of any of the Trust Equipment. (Section
5.01)  The appointment of a receiver or trustee in bankruptcy or reorganization
for the Company or Procor, as applicable, or for their respective property will
be deemed to be an unauthorized assignment if, prior to the exercise of the
remedies of the Equipment Trust Trustee under an Equipment Trust Agreement,
such receiver or trustee shall not be discharged or duly assume the Company's
or Procor's obligations under such agreement. (Section 4.09)  In addition, (i)
each Company Equipment Trust Agreement which relates to the issuance of a
Company ETC to the same Trust that is concurrently acquiring a Procor ETC will
provide that a failure by the Company to perform in respect of the Procor ETC
will constitute an Equipment Trust Event of Default under such Company
Equipment Trust Agreement and (ii) each Procor Equipment Trust Agreement will
provide that certain events of bankruptcy of the Company will constitute an
Equipment Trust Event of Default under such Procor Equipment Trust Agreement. 
Each Equipment Trust Agreement will provide that the Equipment Trust Trustee
shall, promptly  after the occurrence of any Equipment Trust Event of Default
thereunder known to it, give to the holders of the related Company ETC or the
Procor ETC, as applicable, notice of the occurrence thereof.  However, unless
such default is the failure to make payments in respect of the principal of or
interest on an ETC, the Equipment Trust Trustee shall be protected in
withholding such notice if and so long as it in good faith determines that the
withholding of such notice is in the interest of the holders of the defaulted
ETC. (Section 5.07)

         In the event of the bankruptcy or reorganization of the Company, the
right of the Equipment Trust Trustee to repossess or dispose of Trust Equipment
subject to a Company Equipment Trust Agreement would be subject to the
provisions of the Bankruptcy Code of 1978, as amended, applicable to industrial
companies generally, and not those provisions applicable to railroads,
particularly Section 1168 thereof.  In the event of the bankruptcy or
reorganization of Procor, the right of the Equipment Trust Trustee to repossess
or dispose of Trust Equipment subject to a Procor Equipment Trust Agreement
would be subject to the provisions of the Canadian federal Bankruptcy and
Insolvency Act and the Companies' Creditors Arrangement Act and applicable
provincial legislation which governs the manner in which creditors can enforce
interests in the assets of a debtor.

         Upon the happening of an Equipment Trust Event of Default, the
Equipment Trust Trustee or the holders of not less than a majority in aggregate
principal amount of the relevant Company ETC or Procor ETC, as applicable, may
declare the principal thereof and all accrued interest thereon to be due and
payable. (Section 5.04)  Subject to certain conditions, however, any such
declaration may be rescinded by the holders of 66 2/3% in principal amount of
such Company ETC or Procor ETC upon payment of all sums then due otherwise than
by acceleration. Prior to such declaration, the holders of a majority in
principal amount of the outstanding Company ETC or Procor ETC may waive any
past Equipment Trust Event of Default, except an Equipment Trust Event of
Default in the payment of rentals or conditional sale payments due in respect
of the principal of or interest on such Company ETC or Procor ETC. (Section
5.04)

         The right of any holder of a Company ETC or a Procor ETC to institute
action for any remedy under a Company Equipment Trust Agreement or a Procor
Equipment Trust Agreement (except such holder's right to





                                      -22-
<PAGE>   27
enforce payment of the principal of and interest on a Company ETC or a Procor
ETC when due if such enforcement will not impair the Equipment Trust Trustee's
title to the Trust Equipment) will be subject to certain conditions precedent,
including a written request by the holders of not less than a majority in
principal amount of such Company ETC or Procor ETC to the Equipment Trust
Trustee to take action, and an offer to the Equipment Trust Trustee of
reasonable indemnification against liabilities incurred by it in so doing. 
(Section 5.09)

         Each Company Equipment Trust Agreement and Procor Equipment Trust
Agreement will require the annual filing by the Company or Procor, as
applicable, with the Equipment Trust Trustee of a certificate as to the absence
of default and as to compliance with the terms of the relevant equipment trust
agreement. (Section 4.08)


                              ERISA CONSIDERATIONS

         Unless otherwise indicated in the applicable Prospectus Supplement,
Pass Through Certificates may be purchased by an employee benefit plan (a
"Plan") subject to the Employee Retirement Income Security Act of 1974, as
amended ("ERISA").  A fiduciary of a Plan must determine that the purchase of a
Pass Through Certificate is consistent with its fiduciary duties under ERISA
and does not result in a non-exempt prohibited transaction as defined in
Section 406 of ERISA or Section 4975 of the Code (as hereinafter defined).
Employee benefit plans which are governmental plans (as defined in Section
3(32) of ERISA) and certain church plans (as defined in Section 3(33) of ERISA)
are not subject to the fiduciary responsibility provisions of ERISA.  Any Plan
that purchases a Pass Through Certificate must be an "accredited investor" as
defined in Rule 501(a)(1) of Regulation D promulgated under the Securities Act.


                   CERTAIN FEDERAL INCOME TAX CONSEQUENCES

         The following is a general discussion by the Company of the
anticipated material federal income tax consequences of the purchase, ownership
and disposition of Pass Through Certificates.  This summary is based on laws,
regulations, rulings and court decisions now in effect, all of which are
subject to change by legislative, administrative or judicial action, which
change may be retroactive.  The statements of law and legal conclusions
contained herein are based on the opinion of Neal, Gerber & Eisenberg, counsel
to the Company.  The discussion below does not purport to address federal
income tax consequences applicable to particular categories of investors, some
of which (for example, banks, tax exempt organizations, insurance companies or
foreign investors) may be subject to special rules.  Investors should consult
their own tax advisors in determining the federal, state, local and foreign tax
consequences to them of the purchase, ownership and disposition of Pass Through
Certificates, including the advisability of making any election discussed
below.  Prospective investors should note that no rulings have been or will be
sought from the Internal Revenue Service (the "IRS") with respect to any of the
federal income tax consequences discussed below and no assurance can be given
that the IRS will not take contrary positions.  The Pass Through Trusts are not
indemnified for any federal income taxes that may be imposed upon them, the
imposition of which could significantly reduce the amounts available for
distribution to the Certificate Owners.  For purposes of this "Certain Federal
Income Tax Consequences" section, the terms "Pass Through Certificate" and
"Certificate" also refer to an indirect interest in a Pass Through Certificate
held by a Certificate Owner.

GENERAL

         Based upon an interpretation of analogous authorities under currently
applicable law, the Trusts should not be classified as associations taxable as
a corporation, but rather each should be classified as grantor trusts for
purposes of Sections 671 through 679 of the Internal Revenue Code of 1986, as
amended (the "Code"), and each Certificate Owner of a Trust should be treated
as the owner of a pro rata undivided interest in each of the Equipment Notes,
ETCs or any other property held in such Trust.





                                      -23-
<PAGE>   28
         The Company believes that each Certificate Owner of a Trust will be
required to report on its federal income tax return its pro rata share of the
entire income from the Equipment Notes, ETCs or any other property in such
Trust, in accordance with such Certificate Owner's method of accounting.  A
Certificate Owner using the cash method of accounting should take into account
its pro rata share of income as and when received by the Pass Through Trustee.
A Certificate Owner using the accrual method of accounting should take into
account its pro rata share of income as it accrues or is received by the Pass
Through Trustee, whichever is earlier.

         A purchaser of a Pass Through Certificate should be treated as
purchasing an interest in each Equipment Note, ETC and any other property in a
Trust at a price determined by allocating the purchase price paid for the Pass
Through Certificate among such Equipment Notes, ETCs and other property in
proportion to their fair market values at the time of purchase of the Pass
Through Certificate.  The Company believes that at the time of formation of a
particular Trust, the purchase price paid for a Pass Through Certificate by an
original purchaser of such certificate will be allocated among the Equipment
Notes and ETCs in such Trust in proportion to their respective principal
amounts.

SALES OF PASS THROUGH CERTIFICATES

         A Certificate Owner that sells or exchanges a Pass Through Certificate
will recognize gain or loss (in the aggregate) equal to the difference between
its adjusted tax basis in the Pass Through Certificate and the amount realized
(except to the extent attributable to accrued interest, which would be taxable
as interest income).  Subject to the market discount provisions of the Code
(described below), if the Certificate Owner held such Pass Through Certificate
as a capital asset, any such gain or loss should be capital gain or loss, which
will be long-term capital gain or loss if the Pass Through Certificate was held
for more than one year (but only to the extent the Trust also held the
underlying Equipment Notes or ETCs for more than one year).  Any long term
capital gains realized on a sale or exchange of Pass Through Certificates will
be taxable under current law to corporate taxpayers at the rates applicable to
ordinary income, and to individual taxpayers at their applicable marginal rate
for capital gains.  Any capital losses realized generally will be deductible by
a corporate taxpayer only to the extent of capital gains and by an individual
taxpayer only to the extent of capital gains plus $3,000 of other income.

ORIGINAL ISSUE DISCOUNT

         It is anticipated that neither the Equipment Notes nor the ETCs will
be issued with original issue discount.

MARKET DISCOUNT

         A subsequent purchaser of a Pass Through Certificate will be
considered to have acquired an interest in an Equipment Note or ETC held in a
Trust at a "market discount" to the extent the remaining aggregate principal
amount of such Equipment Note or ETC exceeds the Certificate Owner's tax basis
allocable to such Equipment Note or ETC, provided such excess exceeds a
prescribed de minimis amount.  If such excess exceeds the de minimis amount,
the Certificate Owner will be subject to the market discount rules of Section
1276 of the Code with regard to its interest in such Equipment Note or ETC.

         In the case of a sale or other disposition of indebtedness subject to
the market discount rules, Section 1276 of the Code requires that gain, if any,
from such sale or other disposition be treated as ordinary income to the extent
such gain represents market discount that has accrued during the period in
which the indebtedness was held.

         In the case of a partial principal payment on indebtedness subject to
the market discount rules, Section 1276 of the Code requires that such payment
be included in gross income as ordinary income to the extent such payment does
not exceed the market discount that has accrued during the period such
indebtedness was held.





                                      -24-
<PAGE>   29
The amount of any accrued market discount later required to be included in
income upon a disposition, or subsequent partial principal payment, will be
reduced by the amount of accrued market discount previously included in income.

         Market discount generally accrues under either a straight line method
or, at the election of the taxpayer, a constant interest rate method.  However,
in the case of installment obligations (such as certain of the Equipment
Notes), determination of the manner in which market discount is to be accrued
has been left to Treasury regulations not yet issued.  Until such Treasury
regulations are issued, the Conference Committee Report to the Tax Reform Act
of 1986 (the "Conference Report") indicates that holders of installment
obligations with market discount may elect to accrue market discount either (i)
on the basis of a constant interest rate or (ii) by treating as accrued market
discount an amount equal to total remaining market discount times a fraction,
the numerator of which is the amount of stated interest paid in the accrual
period and the denominator of which is the total amount of stated interest
remaining to be paid on the installment obligation as of the beginning of such
period.

         Under Section 1277 of the Code, if in any taxable year interest paid
or accrued on indebtedness incurred or continued to purchase or carry
indebtedness subject to the market discount rules exceeds the interest
currently includible in income with respect to such indebtedness, deduction of
the excess interest must be deferred to the extent of the market discount
allocable to the taxable year.  The deferred portion of any interest expense
will generally be deductible when such market discount is included in income
upon the sale or other disposition (including repayment) of the indebtedness.

         A taxpayer may elect to include market discount in gross income
currently.  If such election is made, the rules of Sections 1276 and 1277
(described above) will not apply to the taxpayer.

PREMIUM

         A Certificate Owner will generally be considered to have acquired an
interest in an Equipment Note or ETC held in a Trust at a premium to the extent
the purchaser's tax basis allocable to such interest exceeds the remaining
aggregate principal amount of the Equipment Note or ETC allocable to such
interest.  In that event, a Certificate Owner who holds a Pass Through
Certificate as a capital asset may elect to amortize that premium as an offset
to interest income under Section 171 of the Code, with corresponding reductions
in the Certificate Owner's tax basis in its interest in the Equipment Note or
ETC.  Generally, such amortization is on a constant yield basis.  However, in
the case of installment obligations, the Conference Report indicates a
Congressional intent that amortization will be in accordance with the same
rules that will apply to the accrual of market discount on installment
obligations (see the discussion above).

         In the case of obligations that may be called at a premium prior to
maturity, amortizable bond premium may be determined by reference to an early
call date.  Due to the complexities of the amortizable premium rules,
particularly where there is more than one possible call date and the amount of
any premium is uncertain, Certificate Owners are urged to consult their own tax
advisors as to the amount of any amortizable premium.

BACKUP WITHHOLDING

         Payments made on the Pass Through Certificates and proceeds from the
sale of the Pass Through Certificates to or through certain brokers may be
subject to a "backup" withholding tax of 31% unless the Certificate Owner
complies with certain reponing procedures or is an exempt recipient under
Section 6049(b) (4) of the Code.  Any such withheld amounts will be allowed as
a credit against the Certificate Owner's federal income tax.





                                      -25-
<PAGE>   30
                       CERTAIN CANADIAN TAX CONSEQUENCES

         In the opinion of Osler, Hoskin & Harcourt, Canadian counsel for the
Company and Procor, the following is, as of the date hereof, a fair and
accurate summary of the principal Canadian federal income tax consequences to a
Certificate Owner who is a non-resident of Canada and who purchased Pass
Through Certificates issued by a Trust that acquires a Procor ETC.  This
summary is based on the current provisions of the Income Tax Act (Canada) (the
"Tax Act") and the regulations thereunder, counsel's understanding of the
current administrative practices published by Revenue Canada and all specific
proposals to amend the Tax Act and the regulations announced by the Minister of
Finance prior to the date hereof.  This summary does not otherwise take into
account or anticipate changes in the law, whether by judicial, governmental or
legislative decision or action, nor does it take into account tax legislation
or considerations of any province or territory of Canada or any jurisdiction
other than Canada.

         This summary is of a general nature only and is not intended to be,
and should not be construed as, legal or tax advice to any particular
Certificate Owner.  Purchasers of Pass Through Certificates issued by a Trust
that acquires a Procor ETC should consult their own tax advisors with respect
to their particular circumstances.

         The payment by Procor of the interest on and principal of a Procor ETC
to the Pass Through Trustee of __________________ will be exempt from Canadian
withholding tax.  Also, the payment by such Pass Through Trustee of interest on
and principal of the Pass Through Certificates issued by a Trust that acquires
a Procor ETC to a Certificate Owner will be exempt from Canadian withholding
tax for a Certificate Owner who is, or is deemed to be, a non-resident of
Canada and with whom the Company and Procor deal at arm's length, within the
meaning of the Tax Act, at the time of making the payment.  For the purposes of
the Tax Act, related persons (as therein defined) are deemed not to deal at
arm's length, and it is a question of fact whether persons not related to each
other deal at arm's length.

         No other taxes on income (including taxable capital gains) will be
payable under the Tax Act in respect of the holding or disposition of a Procor
ETC, or the receipt of interest thereon, by the Pass Through Trustee.  No other
taxes on income (including taxable capital gains) will be payable under the Tax
Act in respect of the acquisition, holding or disposition of Pass Through
Certificates issued by a Trust that acquires a Procor ETC or the receipt of
interest thereon by Certificate Owners who are, or are deemed to be,
non-residents of Canada for purposes of the Tax Act at any time during which
they hold such Pass Through Certificates and who do not use or hold and are not
deemed by such laws to use or hold such Pass Through Certificates in carrying
on business in Canada for the purposes of the Tax Act, and, in the case of a
Certificate Owner who carries on an insurance business in Canada and elsewhere,
whose Pass Through Certificates are not effectively connected with its Canadian
insurance business.


                          CERTAIN _____________ TAXES

         The Pass Through Trustee is a ____________________________ with its
principal corporate trust office in _______________________________________.
________________________________, counsel to _________________, has advised the
Company that, in its opinion, under currently applicable law, [assuming that
the Trusts are taxable as a corporation, but, rather, are classified as grantor
trusts under subpart E, Part I of Subchapter J of the Code,] (i) the Trusts
will not be subject to any tax (including, without limitation, net or gross
income, tangible or intangible property, net worth, capital, franchise or doing
business tax), fee or other governmental charge under the laws of the State of
_____________ or any political subdivision thereof and (ii) Certificate Owners
who are not residents of or otherwise subject to tax in ____________ will not
be subject to any tax (including, without limitation, net or gross income,
tangible or intangible property, net worth, capital, franchise or doing
business tax), fee or other governmental charge under the laws of the State of
____________ or any political subdivision thereof solely as a result of
purchasing, holding (including receiving payments with respect to) or disposing
of a Pass Through Certificate, except to the extent (a) the Indenture Trustee
forecloses on the Equipment and any of the Equipment is located in





                                      -26-
<PAGE>   31
____________, (b) the Equipment Trust Trustee forecloses on the Trust Equipment
and any of the Trust Equipment is located in ___________ or (c) the Indenture
Trust, the trust created under a Company Equipment Trust Agreement or under the
Procor Equipment Trust Agreement, or the Pass Through Trust, as applicable,
engages in business in ____________ as a result of such foreclosure.  Neither
the Trusts nor the Certificate Owners will be indemnified for any state or
local taxes imposed on them, the imposition of which on a Trust could reduce
the amounts available for distribution to the Certificate Owners of such Trust.
In general, should a Certificate Owner or a Trust be subject to any state or
local tax which would not be imposed if the Pass Through Trustee were located
in a different jurisdiction in the United States, the Pass Through Trustee will
resign and a new Pass Through Trustee in such other jurisdiction will be
appointed.


                              PLAN OF DISTRIBUTION

         The Company may sell the Pass Through Certificates being offered
hereby: (i) through agents, (ii) to or through underwriters, (iii) through
dealers, (iv) directly to purchasers or (v) through a combination of any such
methods of sale.

         The distribution of the Pass Through Certificates may be effected from
time to time in one or more transactions either (i) at a fixed price or prices,
which may be changed, or (ii) at market prices prevailing at the time of sale,
or (iii) at prices related to such prevailing market prices, or (iv) at
negotiated prices.

         Offers to purchase the Pass Through Certificates may be solicited
directly by the Company or by agents designated by the Company from time to
time.  Any such agent, which may be deemed to be an underwriter as that term is
defined in the Securities Act, involved in the offer or sale of the Pass
Through Certificates in respect of which this Prospectus is delivered will be
named, and any commissions payable by the Company to such agent will be set
forth, in the applicable Prospectus Supplement.  Unless otherwise indicated in
the Prospectus Supplement, any such agent will be acting on a best efforts
basis for the period of its appointment.

         If an underwriter or underwriters are utilized in the sale, the
Company will execute an underwriting agreement with such underwriters at the
time of sale to them and the names of the underwriters and the terms of the
transaction, including commissions, discounts and other compensation of the
underwriters and dealers, if any, will be set forth in the Prospectus
Supplement, which will be used by the underwriters to make resales of the Pass
Through Certificates in respect of which this Prospectus is delivered to the
public.

         If a dealer is utilized in the sale of the Pass Through Certificates
in respect of which this Prospectus is delivered, the Company or the Pass
Through Trustee, as the case may be, will sell such Pass Through Certificates
to the dealer, as principal.  The dealer may then resell such Pass Through
Certificates to the public at varying prices to be determined by such dealer at
the time of resale.

         Underwriters, dealers, agents and other persons may be entitled, under
agreements which may be entered into with the Company, to indemnification
against certain civil liabilities, including liabilities under the Securities
Act.

         Underwriters, dealers and agents may be customers of, engage in
transactions with or perform services for the Company in the ordinary course of
business.


                                 LEGAL OPINIONS

         Unless otherwise indicated in the Prospectus Supplement to this
Prospectus, the validity of the Pass Through Certificates will be passed upon
for the Company by Neal, Gerber & Eisenberg, Chicago, Illinois, and for any
underwriters or agents, by Mayer, Brown & Platt, New York, New York.  Both
Neal, Gerber & Eisenberg





                                      -27-
<PAGE>   32
and Mayer, Brown & Platt will rely on the opinion of _________________________  
_________________________ as to matters relating to the authorization,
execution, authentication, issuance and delivery of the Pass Through
Certificates under the Basic Agreement.


                                    EXPERTS

         The consolidated financial statements and related schedules of Union
Tank Car Company appearing in Union Tank Car Company's Annual Report (Form
10-K/A) for the year ended December 31, 1995, have been audited by Ernst &
Young LLP, independent auditors, as set forth in their report thereon included
therein and incorporated herein by reference.  Such consolidated financial
statements are incorporated herein by reference in reliance upon such report
given upon the authority of such firm as experts in accounting and auditing.





                                      -28-
<PAGE>   33
                                                                      APPENDIX I

                           GLOSSARY OF CERTAIN TERMS

         The following is a glossary of certain terms used in this Prospectus
relating to the Pass Through Certificates.  The definitions of terms used in
this glossary that are also used in the Basic Agreement, Trust Supplements,
Indentures, Leases or Participation Agreements are qualified in their entirety
by reference to the definitions of such terms contained therein.  Additional
terms or changes in the terms defined below may appear in the applicable
Prospectus Supplement.

         "Basic Agreement" means the Pass Through Trust Agreement, dated as of
____________, 199_, between the Company and the Pass Through Trustee.

         "Business Day," when used with respect to the Pass Through
Certificates of any series, means any day other than a Saturday, a Sunday, or a
day on which commercial banking institutions in New York, New York, Chicago,
Illinois or a city and state in which the Pass Through Trustee or any related
Indenture Trustee maintains its Corporate Trust Office are authorized or
obligated by law, regulation or executive order to be closed.

         "Certificate Account" means the one or more non-interest-bearing
accounts established and maintained by the Pass Through Trustee pursuant to the
Basic Agreement on behalf of the Certificate holders of each Trust for the
deposit of payments representing Scheduled Payments on the Equipment Notes held
in such Trust.

         "Certificate Owner" means a person acquiring an interest in a Pass
Through Certificate registered in the name of Cede & Co. as the nominee of The
Depository Trust Company.

         "Certificateholder" means the Person in whose name a Pass Through
Certificate is registered.

         "Code" means the United States Internal Revenue Code of 1986, as
amended.

         "Commission" means the Securities and Exchange Commission.

         "Company ETC" means each of the equipment trust
certificates to be issued pursuant to an Equipment Trust Agreement between the
Company and the Equipment Trust Trustee.

         "ETCs" means the Company ETCs and the Procor ETCs.

         "Equipment Group" means all the railcars (which may include various
types or categories of standard gauge rolling stock) in respect of which a
particular series of Equipment Notes is issued.

         "Equipment Trust Agreement" means an equipment trust agreement between
the Company or Procor, as applicable, and the Equipment Trust Trustee.

         "Equipment Trust Event of Default" means each of the events designated
as an Event of Default in an Equipment Trust Agreement, as described in the
applicable Prospectus Supplement.

         "Equipment Trust Trustee" means _________________________,  in its 
capacity as trustee under an Equipment Trust Agreement, and each other
person which may from time to time act as successor trustee under such
agreement.
                                           
         "Equipment Unit" or "Unit" means an individual railcar.

         "Event of Default" means, with respect to the Equipment Notes held in
any Trust, the occurrence and continuance of an Indenture Event of Default
under one or more of the related Indentures.





                                      I-1
<PAGE>   34
         "Indenture" means each of the separate trust indenture and security
agreements entered into from time to time between an Owner Trustee and an
Indenture Trustee with respect to the issuance of Leased Equipment Notes, as
each such agreement may be amended or supplemented in accordance with its
respective terms.

         "Indenture Event of Default" means each of the events designated as an
event of default in an Indenture, as described in the applicable Prospectus
Supplement.

         "Indenture Trustee," when used with respect to any Equipment Note or
the Indenture applicable thereto, means the bank or trust company designated as
indenture trustee under such Indenture, and any successor to such Indenture
Trustee as such trustee.

         "Lease" means each of the lease agreements entered into with respect
to Equipment Units between an Owner Trustee and the Company, as each such lease
agreement may from time to time be amended or supplemented.

         "Lease Event of Default" means each of the events designated as an
event of default in a Lease, as described in the applicable Prospectus
Supplement.  "Leased Equipment" means each Equipment Group leased by an Owner
Trustee to the Company pursuant to a Lease.

         "Owner Participant" means each of the owner participants for whose
benefit an Owner Trustee owns an Equipment Group leased to the Company pursuant
to a Lease and its permitted successors and assigns.

         "Owner Trustee," when used with respect to any Equipment Note or the
Indenture applicable thereto or the Lease related thereto, means the "Owner
Trustee" referred to in the applicable Indenture, not in its individual
capacity but solely as trustee; and each other Person which may from time to
time be acting as Owner Trustee in accordance with the provisions of the
applicable Indenture, Lease or Participation Agreement.

         "Participation Agreement" when used with respect to any Equipment
Note, means the note purchase, participation, refinancing or similar agreement
or agreements referred to in the related Indenture, providing for, among other
things, the purchase of Equipment Notes by the Pass Through Trustee.

         "Pass Through Certificate" means each of the Pass Through Certificates
to be issued by each of the Trusts pursuant to the Basic Agreement and the
related Trust Supplement.

         "Pass Through Trustee" means, unless otherwise specified in a
Prospectus Supplement, __________________________________, in its capacity as
Pass Through Trustee under each Trust, and each other person which may from
time to time act as successor Pass Through Trustee under such Trust.

          "Pool Balance" means, for each Trust, as of any date, the aggregate
unpaid principal amount of the Equipment Notes held in such Trust on such date
plus any amounts in respect of principal on such Equipment Notes held by the
Pass Through Trustee and not yet distributed plus the amount of any moneys held
in the related escrow account (other than earnings thereon).  The Pool Balance
for each Trust as of any Regular Distribution Date or Special Distribution Date
shall be computed after giving effect to the payment of principal, if any, on
the Equipment Notes held in such Trust and distribution thereof to be made on
that date.

         "Pool Factor" means, for each Trust, as of any date, the quotient
(rounded to the seventh decimal place) computed by dividing (i) the Pool
Balance of such Trust by (ii) the aggregate original principal amount of the
Equipment Notes held in such Trust.  The Pool Factor for each Trust as of any
Regular Distribution Date or Special Distribution Date shall be computed after
giving effect to the payment of principal, if any, on the Equipment Notes held
in such Trust and distribution thereof to be made on that date.





                                      I-2
<PAGE>   35
         "Procor ETC" means each of the equipment trust certificates to be
issued pursuant to an Equipment Trust Agreement between Procor and the
Equipment Trust Trustee.

         "Regular Distribution Date" means each date on which a Scheduled
Payment will be distributed, as specified in the applicable Prospectus
Supplement.

         "Scheduled Payment" means each payment of interest or principal on an
Equipment Note scheduled to be received by the Pass Through Trustee on the
Regular Distribution Dates specified in the applicable Prospectus Supplement.

         "Special Distribution Date" means each date on which a Special Payment
will be distributed, as specified in the applicable Prospectus Supplement.

         "Special Payment" means (i) any payment of principal, premium, if any,
and interest resulting from the prepayment or purchase of an Equipment Note
held in a Trust, (ii) any payment of principal and interest (including any
interest accruing upon default) on or any other amount in respect of an
Equipment Note held in a Trust upon an Indenture Event of Default in respect
of, or upon acceleration relating to, such Equipment Note, (iii) any payment of
principal, premium, if any, and interest on an Equipment Note which is not in
fact paid within five days of a Regular Distribution Date, (iv) any proceeds
from the sale of any Equipment Note upon an Event of Default, or (v) the
amounts available for distribution from a Trust as a result of the failure to
apply such amounts to the purchase of Equipment Notes on or prior to the date
specified in the applicable Prospectus Supplement.

         "Special Payments Account" means the one or more accounts established
and maintained by the Pass Through Trustee pursuant to the Basic Agreement on
behalf of the Certificateholders of each Trust for the deposit of payments
representing Special Payments on the Equipment Notes held in such Trust.

         "Specified Investments" when used with respect to any Trust, means,
unless otherwise specified in the related Prospectus Supplement, (i) direct
obligations of the United States of America and agencies thereof for which the
full faith and credit of the United States of America is pledged, (ii)
obligations fully guaranteed by the United States of America, (iii)
certificates of deposit issued by, or bankers' acceptances of, or time deposits
with, any bank, trust company or national banking association incorporated or
doing business under the laws of the United States of America or one of the
states thereof having combined capital and surplus and retained earnings of at
least $500,000,000 (including any Indenture Trustee or Owner Trustee H such
conditions are met) and (iv) repurchase agreements with any financial
institution having a combined capital and surplus of at least $750,000,000
fully collateralized by obligations of the type described in clauses (i)
through (iii) above; provided that if all of the above investments are
unavailable, the entire amounts to be invested may be used to purchase Federal
funds from an entity described in clause (iii) above; and provided further that
no investment shall be eligible as a "Specified Investment" unless the final
maturity or date of return of such investment is 91 days or less from the date
of purchase thereof.

         "Trust" means each of the Union Tank Car Company Pass Through Trusts
to be formed pursuant to the Basic Agreement and a Trust Supplement.

         "Trust Property" means the Equipment Notes held as the property of a
Trust and all funds from time to time deposited in the related Certificate
Account, the related Special Payments Account and any other account maintained
as a part of such Trust, including any proceeds from the sale by the Pass
Through Trustee of any such Equipment Note in connection with an Event of
Default.

         "Trust Supplement" means each of the Pass Through Trust Supplements
between the Company and the Pass Through Trustee, pursuant to each of which a
Trust is formed and a series of Pass Through Certificates is issued to evidence
fractional undivided ownership interests in the Trust Property held in such
Trust.





                                      I-3
<PAGE>   36
[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 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 DECEMBER 2, 1996





PROSPECTUS


$400,000,000


UNION TANK CAR COMPANY


DEBT SECURITIES



Union Tank Car Company, a Delaware corporation (the "Company"), may offer from
time to time, in one or more series, up to $400,000,000 aggregate principal
amount (or the equivalent in foreign currencies or currency units) of its
debt securities ("Debt Securities"), on terms to be determined at the time the
Debt Securities are offered for sale.  Unless otherwise provided in a
Prospectus Supplement, the Debt Securities of any series may be represented by
a single global certificate registered in the name of a depository's nominee
and, if so represented, beneficial interests in the global certificate will be
shown on, and transfers thereof will be effected only through, records
maintained by the depository and its participants.  Debt Securities may be
offered for sale directly to purchasers and may also be offered through
underwriters, dealers or agents.  The names of any underwriters, dealers or
agents and any compensation to such underwriters, dealers or agents will be set
forth in the Prospectus Supplement.

The terms of the Debt Securities, including, where applicable, the specific
designation, aggregate principal amount, authorized denominations,
currencies in which such Debt Securities are issued or payable, maturity, rate
(or manner of calculation thereof) and time of payment of interest, if any,
whether the Debt Securities are issuable in registered form or bearer form or
both, whether any series of the Debt Securities will be represented by a single
global certificate, any terms for redemption or for sinking fund payments,
whether the Debt Securities are convertible into Debt Securities of a different
series, the initial public offering price, the net proceeds to the Company from
the sale of the Debt Securities and any other specific terms in connection with
the offering and sale of the Debt Securities in respect of which this
Prospectus is being delivered will be set forth in a 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.

This Prospectus may not be used to consummate a sale of Debt Securities unless
accompanied by a Prospectus Supplement.

The date of this Prospectus is             , 1997.
<PAGE>   37
                             AVAILABLE INFORMATION

         The Company has filed with the Securities and Exchange Commission (the
"Commission") a Registration Statement on Form S-3 (the "Registration
Statement") under the Securities Act of 1933, as amended (the "Securities
Act"), with respect to the Debt Securities.  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 pertaining to the Debt Securities and the Company, reference is
made to the Registration Statement.  Any statement contained herein concerning
the provisions of any document is 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.

         The Company 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 Commission.
Information concerning the Company can be inspected and copied at the public
reference facilities maintained by the Commission at 450 Fifth Street, N.W.,
Washington, D.C. 20549, and at the following Regional Offices of the
Commission:  Chicago Regional Office, Citicorp Center, 500 West Madison Street,
Suite 1400, Chicago, Illinois 60661 and New York Regional Office, 7 World Trade
Center, Suite 1300, New York, New York 10048.  Copies of such material can be
obtained from the Public Reference Section of the Commission at 450 Fifth
Street, N.W., Washington, D.C. 20549 at prescribed rates.  Such materials also
may be accessed electronically by means of the Commission's home page on the
Internet at http://www.sec.gov.


                      DOCUMENTS INCORPORATED BY REFERENCE

         The Company's Annual Report on Form 10-K/A for the fiscal year ended
December 31, 1995 and its Quarterly Reports on Form 10-Q for the quarters ended
March 31, 1996, June 30, 1996 and September 30, 1996, as filed with the
Commission pursuant to the Exchange Act, are incorporated herein by reference.

         All documents filed by the Company pursuant to Section 13(a), 13(c),
14 or 15(d) of the Exchange Act after the date of this Prospectus and prior to
the termination of the offering of the Debt 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 that a statement contained herein or in any other
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, except as so modified or
superseded, to constitute a part of this Prospectus.

         The Company will provide without charge to each person to whom this
Prospectus is delivered, upon written request of such person, a copy (without
exhibits) of any or all documents incorporated by reference in this Prospectus.
Requests for such copies should be directed to the General Counsel and
Secretary, Union Tank Car Company, 225 West Washington Street, Chicago,
Illinois 60606, telephone (312) 372-9500.


                                USE OF PROCEEDS

         The net proceeds to be received by the Company from the sale of Debt
Securities will be added to the general funds of the Company and may be used to
finance the addition of railcars to the Company's fleet and other capital
expenditures, to finance acquisitions, to repay outstanding indebtedness, or
for other corporate purposes or as may be described in a Prospectus Supplement.
The Company has not allocated a specific portion of the proceeds for any
particular use at this time. Pending such use, the net proceeds may be
temporarily invested in short-term securities.





                                      -2-
<PAGE>   38
                                  THE COMPANY

         Union Tank Car Company (with its wholly-owned subsidiaries herein
collectively referred to, except as the context otherwise requires, as the
"Company") is principally engaged in the leasing of railway tank cars and other
rail cars to United States, Canadian and Mexican manufacturers and other
shippers of chemical products, including liquid fertilizers, petroleum
products, including liquid petroleum gas, food products and bulk plastics.  The
Company owns and operates one of the largest fleets of privately-owned railway
tank cars in the world.

         The Company, which was incorporated in Delaware in 1980 and is the
successor to a business which was incorporated in New Jersey in 1891 and
reincorporated in Delaware in 1968, is a wholly-owned subsidiary of Marmon
Industrial Corporation, a wholly-owned subsidiary of Marmon Holdings, Inc. 
Substantially all the stock of Marmon Holdings, Inc. is owned, directly or
indirectly, by trusts for the benefit of certain members of the Pritzker
family.  As used herein, "Pritzker family" refers to the lineal descendants of
Nicholas J. Pritzker, deceased.

         The Company's principal executive offices are located at 225 West
Washington Street, Chicago, Illinois 60606, and its telephone number is (312)
372-9500.


                         DESCRIPTION OF DEBT SECURITIES

         The following description sets forth certain general terms and
provisions of the Debt Securities to which any Prospectus Supplement may
relate.  The particular terms and provisions of the series of Debt Securities
offered by a Prospectus Supplement, including any additional covenants or
changes to existing covenants relating to such series, and the extent to which
such general terms and provisions described below may apply thereto, will be
described in the Prospectus Supplement relating to such series of Debt
Securities.

         The Debt Securities are to be issued under an Indenture, dated as of
____________, 1996, as supplemented (the "Debt Indenture"), between the Company
and _______________________________________,  as Trustee (the "Debt Trustee").
The following summaries of certain provisions of the Debt Securities and the
Debt Indenture do not purport to be complete and are subject to, and are
qualified in their entirety by reference to, all provisions of the Debt
Securities and the Debt Indenture, including the definitions therein of certain
terms.  Particular sections of the Debt Indenture which are relevant to the
discussion are cited parenthetically.  Wherever particular sections or defined
terms of the Debt Indenture are referred to, it is intended that such sections
or defined terms shall be incorporated herein by reference.  Capitalized terms
not otherwise defined herein shall have the meaning ascribed to such terms in
the Debt Indenture.

GENERAL

         The Debt Indenture does not limit the amount of Debt Securities which
can be issued thereunder or the amount of debt which may otherwise be incurred
by the Company, and additional debt securities may be issued under the Debt
Indenture up to the aggregate principal amount which may be authorized from
time to time by, or pursuant to a resolution of, the Company's Board of
Directors or by a supplemental indenture.  Reference is made to the Prospectus
Supplement for the following terms, if applicable, of the particular series of
Debt Securities being offered thereby: (i) the title of the Debt Securities of
the series; (ii) any limit upon the aggregate principal amount of the Debt
Securities of the series; (iii) the date or dates on which the principal of the
Debt Securities of the series will be payable; (iv) the rate or rates (or
manner of calculation thereof), if any, at which the Debt Securities of the
series will bear interest, the date or dates from which any such interest will
accrue and on which such interest will be payable, and, with respect to Debt
Securities of the series in registered form, the record date for the interest
payable on any interest payment date; (v) the place or places where the
principal of and interest, if any, on the Debt Securities of the series will be
payable; (vi) any redemption or sinking fund provisions; (vii) the
denominations in which Debt Securities of the series shall be issuable; (viii)
if other than the principal amount thereof, the portion of the principal amount
of Debt Securities of the series which will be payable upon declaration of
acceleration of the maturity thereof; (ix) whether the Debt Securities of the
series will be issuable in registered or bearer form or





                                      -3-
<PAGE>   39
both, any restrictions applicable to the offer, sale or delivery of Debt
Securities in bearer form ("bearer Debt Securities") and whether and the terms
upon which bearer Debt Securities will be exchangeable for Debt Securities in
registered form ("registered Debt Securities") and vice versa; (x) any
provisions relating to the conversion of Debt Securities of the series into
Debt Securities of a different series; (xi) whether and under what
circumstances the Company will pay additional amounts on the Debt Securities of
the series held by a person who is not a U.S. person (as defined below) in
respect of taxes or similar charges withheld or deducted and, if so, whether
the Company will have the option to redeem such Debt Securities rather than pay
such additional amounts; (xii) the currencies in which payments of interest,
premium or principal are payable with respect to such Debt Securities; (xiii)
whether the Debt Securities of any series will be issued as one or more Global
Securities; (xiv) whether Debt Securities of the series will be issuable in
Tranches; and (xv) any additional provisions or other terms not inconsistent
with the provisions of the Debt Indenture, including any terms which may be
required by or advisable under United States laws or regulations or advisable
in connection with the marketing of Debt Securities of such series. (Section
2.1 and 2.2)  To the extent not described herein, principal and interest, if
any, will be payable, and the Debt Securities of a particular series will be
transferable, in the manner described in the Prospectus Supplement relating to
such series.  "Principal" when used herein includes, when appropriate, the
premium, if any, on the Debt Securities.

         Each series of Debt Securities will constitute unsecured and
unsubordinated indebtedness of the Company and will rank on a parity with the
Company's other unsecured and unsubordinated indebtedness.  There are no
covenants or "event risk" provisions contained in the Debt Indenture that may
afford holders of Debt Securities protection in the event of a highly leveraged
transaction involving the Company.

         Debt Securities of any series may be issued as registered Debt
Securities or bearer Debt Securities or both as specified in the terms of the
series.  Additionally, Debt Securities of any series may be represented by a
single global note registered in the name of a depository's nominee and, if so
represented, beneficial interests in such global note will be shown on, and
transfers thereof will be effected only through, records maintained by a
designated depository and its participants.  Unless otherwise indicated in the
Prospectus Supplement, Debt Securities will be issued in the denomination of
$1,000 and integral multiples thereof and bearer Debt Securities will not be
offered, sold, resold or delivered to U.S. persons in connection with their
original issuance.  Debt Securities of any series may be denominated in and
payments of principal and interest may be made in United States dollars or any
other currency, including composite currencies such as the European Currency
Unit.  For purposes of this Prospectus, "U.S. person" means a citizen or
resident of the United States, any corporation, partnership or other entity
created or organized in or under the laws of the United States or any political
subdivision thereof, or any estate or trust the income of which is subject to
United States federal income taxation regardless of its source.

         To the extent set forth in the Prospectus Supplement, except in
special circumstances set forth in the Debt Indenture, interest on bearer Debt
Securities will be payable only against presentation and surrender of the
coupons for the interest installments evidenced thereby as they mature at a
paying agency of the Company located outside of the United States and its
possessions. (Section 2.5(c)) The Company will maintain such an agency for a
period of two years after the principal of such bearer Debt Securities has
become due and payable.  During any period thereafter for which it is necessary
in order to conform to United States tax laws or regulations, the Company will
maintain a paying agent outside of the United States and its possessions to
which the bearer Debt Securities and coupons related thereto may be presented
for payment and will provide the necessary funds therefor to such paying agent
upon reasonable notice. (Section 2.4)

         Bearer Debt Securities and the coupons related thereto will be
transferable by delivery. (Section 2.8(f))

         If appropriate, United States federal income tax consequences
applicable to a series of Debt Securities will be described in the Prospectus
Supplement relating thereto.

BOOK-ENTRY REGISTRATION

         If the Prospectus Supplement so indicates, the Debt Securities will be
represented by one or more certificates (the "Global Securities").  The Global
Securities representing Debt Securities will be deposited with,





                                      -4-
<PAGE>   40
or on behalf of, The Depository Trust Company ("DTC") or other successor
depository appointed by the Company (DTC or such other depository is herein
referred to as the "Depository") and registered in the name of the Depository
or its nominee.  Debt Securities represented by a Global Security will not be
issuable in definitive form.

         DTC currently limits the maximum denomination of any single Global
Security to $200,000,000.  Therefore, for purposes hereof, "Global Security"
refers to the Global Security or Global Securities representing the entire
issue of Debt Securities of a particular series.

         DTC has advised the Company and any underwriters, dealers or agents
named in the Prospectus Supplement as follows: DTC is a limited-purpose trust
company organized under the laws of the State of New York, a member of the
Federal Reserve System, a "clearing corporation" within the meaning of the New
York Uniform Commercial Code and a "clearing agency" registered pursuant to the
provisions of Section 17A of the Exchange Act.  DTC was created to hold
securities for its participants ("DTC Participants") and to facilitate the
clearance and settlement of securities transactions between DTC Participants
through electronic book-entry changes in accounts of DTC Participants, thereby
eliminating the need for physical movement of securities certificates.  DTC
Participants include securities brokers and dealers, banks, trust companies and
clearing corporations.  Indirect access to the DTC book-entry system is also
available to others, such as banks, brokers, dealers and trust companies, that
clear through or maintain a custodial relationship with a DTC Participant,
either directly or indirectly ("Indirect Participants").

         Upon the issuance by the Company of Debt Securities represented by a
Global Security, DTC will credit, on its book-entry registration and transfer
system, the respective principal amounts of the Debt Securities represented by
such Global Security to the accounts of DTC Participants.  The accounts to be
credited shall be designated by the underwriters, dealers or agents.  Ownership
of beneficial interests in the Global Security will be limited to DTC
Participants and Indirect Participants.  Ownership of beneficial interests in
Debt Securities represented by the Global Security will be shown on, and the
transfer of that ownership will be effected only through, records maintained by
DTC (with respect to interests of DTC Participants), or by DTC Participants or
Indirect Participants (with respect to persons other than DTC Participants).
The laws of some states require that certain purchasers of securities take
physical delivery of such securities in definitive form.  Such limits and such
laws may impair the ability to transfer beneficial interests in the Global
Security.

         So long as the Depository for the Global Security, or its nominee, is
the registered owner of the Global Security, the Depository or its nominee, as
the case may be, will be considered the sole owner or holder of the Debt
Securities represented by such Global Security for all purposes under the Debt
Indenture.  Except as provided below, owners of beneficial interests in Debt
Securities represented by the Global Security will not be entitled to have Debt
Securities represented by such Global Security registered in their names, will
not receive or be entitled to receive physical delivery of Debt Securities in
definitive form and will not be considered the owners or holders thereof under
the Debt Indenture.

         Payments of principal of and interest, if any, on the Debt Securities
represented by the Global Security registered in the name of DTC or its nominee
will be made by the Company through the Debt Trustee under the Debt Indenture
or a paying agent (the "Paying Agent"), which may also be the Debt Trustee
under the Debt Indenture, to DTC or its nominee, as the case may be, as the
registered owner of the Global Security.  Neither the Company, the Debt
Trustee, nor the Paying Agent will have any responsibility or liability for any
aspect of the records relating to or payments made on account of beneficial
ownership interests of the Global Security or for maintaining, supervising or
reviewing any records relating to such beneficial ownership interests.

         The Company has been advised that DTC, upon receipt of any payment of
principal or interest in respect of a Global Security, will credit immediately
the accounts of DTC Participants with payment in amounts proportionate to their
respective holdings in principal amount of beneficial interest in such Global
Security as shown on the records of DTC.  The Company expects that payments by
DTC Participants to owners of beneficial interests in a Global Security will be
governed by standing customer instructions and customary practices, as is now
the case with securities held for the accounts of customers in bearer form or
registered in "street name" and will be the responsibility of such DTC
Participants.





                                      -5-
<PAGE>   41
         If the Depository with respect to a Global Security is at any time
unwilling or unable to continue as Depository and a successor Depository is not
appointed by the Company within 90 days, the Company will issue certificated
notes in exchange for the Debt Securities represented by such Global Security.

         The information contained in this section concerning DTC and DTC's
book-entry system has been obtained from sources that the Company believes to
be reliable but the Company takes no responsibility for the accuracy thereof.

SAME-DAY SETTLEMENT

         If the Prospectus Supplement so indicates, settlement for the Debt
Securities will be made by the underwriters, dealers or agents in immediately
available funds and all payments of principal and interest on the Debt
Securities will be made by the Company in immediately available funds.
Secondary trading in long-term notes and debentures of corporate issuers is
generally settled in clearinghouse or next-day funds.  In contrast, the Debt
Securities subject to settlement in immediately available funds will trade in
the Depository's Same-Day Funds Settlement System until maturity, and secondary
market trading activity in such Debt Securities will therefore be required by
the Depository to settle in immediately available funds.  No assurance can be
given as to the effect, if any, of settlement in immediately available funds on
trading activity in the Debt Securities.

EXCHANGE OF DEBT SECURITIES

         Registered Debt Securities may be exchanged, subject to certain
specified restrictions, for an equal aggregate principal amount of registered
Debt Securities of the same series and date of maturity in such authorized
denominations as may be requested upon surrender of the registered Debt
Securities at an agency of the Company maintained for such purpose and upon
fulfillment of all other requirements of such agent. (Section 2.8(a))

         To the extent permitted by the terms of a series of Debt Securities
authorized to be issued in registered form and bearer form, bearer Debt
Securities may be exchanged for an equal aggregate principal amount of
registered or bearer Debt Securities of the same series and date of maturity in
such authorized denominations as may be requested upon surrender of the bearer
Debt Securities with all unpaid coupons relating thereto at an agency of the
Company maintained for such purpose and upon fulfillment of all other
requirements of such agent. (Section 2.8(b))  As of the date of this
prospectus, temporary United States Treasury regulations essentially prohibit
exchanges of registered debt securities for bearer debt securities and, unless
such regulations are modified, the terms of a series of debt securities will
not permit registered debt securities to be exchanged for bearer debt
securities.

AMENDMENT AND WAIVER

         Subject to certain exceptions, the Debt Indenture and the Debt
Securities may be amended or supplemented by the Company and the Debt Trustee
with the written consent of the holders of a majority in principal amount of
the outstanding Debt Securities of each series affected by the amendment or
supplement (with each series voting as a class), or compliance with any
provision may be waived with the consent of the holders of a majority in
principal amount of the outstanding Debt Securities of each series affected by
such waiver (with each series voting as a class).  However, without the consent
of each Securityholder affected, an amendment or waiver may not (i) reduce the
amount of Debt Securities whose holders must consent to an amendment or waiver,
(ii) change the rate of or change the time for payment of interest on any Debt
Security; (iii) change the principal of or change the Stated Maturity of any
Debt Security; (iv) reduce any premium payable upon redemption of any Debt
Security; (v) waive a default in the payment of the principal of or interest on
any Debt Security; (vi) make any Debt Security payable in money other than that
stated in the Debt Security; or (vii) impair the right to institute suit for
the enforcement of any payment on or with respect to any Debt Security.
(Section 9.02) The Debt Indenture may be amended or





                                      -6-
<PAGE>   42
supplemented without the consent of any Securityholder (i) to cure any
ambiguity, defect or inconsistency in the Debt Indenture or in the Debt
Securities of any series; (ii) to provide for the assumption of all the
obligations of the Company under the Debt Securities and any coupons
appertaining thereto and under the Debt Indenture by any corporation in
connection with a merger, consolidation, or transfer or lease of the Company's
property and assets substantially as an entirety, as provided for in the Debt
Indenture; (iii) to secure the Debt Securities; (iv) to provide for
uncertificated Debt Securities in addition to or in place of certificated Debt
Securities; (v) to make any change that does not adversely affect the rights of
any Securityholder; (vi) to provide for the issuance of and establish the form
and terms and conditions of a series of Debt Securities or to establish the
form of any certifications required to be furnished pursuant to the terms of
the Debt Indenture or any series of Debt Securities; or (vii) to add to rights
of Securityholders. (Section 9.1)

SUCCESSOR ENTITY

         The Company may consolidate with, or merge into, or be merged into, or
transfer or lease its property and assets substantially as an entirety to,
another U.S. corporation which assumes all the obligations of the Company under
the Debt Securities and any coupons appertaining thereto and under the Debt
Indenture if, after giving effect thereto, no default under the Debt Indenture
shall have occurred and be continuing.  Thereafter, except in the case of a
lease, all such obligations of the Company shall terminate. (Section 5.1 and
Section 5.2)

DEFEASANCE, SATISFACTION AND DISCHARGE OF THE DEBT SECURITIES PRIOR TO MATURITY

         Defeasance.  Unless provided for otherwise in the Prospectus
Supplement, if the Company shall deposit with the Debt Trustee, in trust, at or
before maturity, lawful money or direct obligations of the United States of
America or obligations the principal of and interest on which are guaranteed by
the United States of America in such amounts and maturing at such times that
the proceeds of such obligations to be received upon the respective maturities
and interest payment dates of such obligations will provide funds sufficient,
in the opinion of a nationally recognized firm of independent public
accountants chosen by the Company, to pay when due the principal of and
interest on the Debt Securities to maturity (such money or direct obligations
of, or obligations guaranteed by, the United States of America, initially
deposited or equivalent cash or securities subsequently exchanged therefor, to
be held as security for the payment of such principal and interest), then the
Company may omit to comply with certain of the terms of the Debt Indenture as
they relate to the Debt Securities, [INCLUDING CERTAIN OF THE RESTRICTIVE
COVENANTS DESCRIBED HEREIN UNDER THE CAPTION "-- CERTAIN COVENANTS OF THE
COMPANY"] and the Event of Default described in clause (iv) under the caption
"Description of Debt Securities -- Events of Default," and such other
restrictive covenants or Events of Default as may be set forth in the
Prospectus Supplement. Defeasance of the Debt Securities would be subject to
the satisfaction of certain conditions, including, among others, (i) the
absence of an Event of Default at the date of the deposit, (ii) the perfection
of the holders' interest in such deposit and (iii) that such deposit would not
result in a breach of a material instrument by which the Company is bound.
(Section 8.2)

         Satisfaction and Discharge.  Upon the deposit of money or securities
contemplated above and the satisfaction of certain conditions, the Company may
omit to comply with its obligations duly and punctually to pay the principal of
and interest on the Debt Securities, or with any Events of Default with respect
thereto, and thereafter the holders of Debt Securities shall be entitled only
to payment out of the money or securities deposited with the Debt Trustee.
Such conditions may include, among others, (i) except in certain limited
circumstances involving a deposit made within one year of maturity, (A) the
absence of an Event of Default at the date of deposit or on the 91st day
thereafter, and (B) the delivery to the Debt Trustee by the Company of an
opinion of nationally recognized tax counsel to the effect that holders of Debt
Securities will not recognize income, gain or loss for Federal income tax
purposes as a result of such deposit and discharge and will be subject to
Federal income tax on the same amounts and in the same manner and at the same
times as would have been the case if such deposit and discharge had not
occurred, and (ii) the receipt by the Company of an opinion of counsel to the
effect that such satisfaction and discharge will not result in a violation of
the rules of any nationally recognized exchange on which the Debt Securities
are listed. (Section 8.1)





                                      -7-
<PAGE>   43
EVENTS OF DEFAULT

         The following events are defined in the Debt Indenture as "Events of
Default" with respect to a series of Debt Securities: (i) default in the
payment of interest on any Debt Security of such series for 30 days; (ii)
default in the payment of the principal of any Debt Security of such series;
(iii) default in the payment of any sinking fund installment required to be
made by the Company with respect to any series of Debt Securities; (iv) failure
by the Company for 90 days after notice to it to comply with any of its other
agreements in the Debt Securities of such series, in the Debt Indenture or in
any supplemental indenture under which the Debt Securities of that series may
have been issued; and (v) certain events of bankruptcy or insolvency. (Section
6.1) If an Event of Default occurs with respect to the Debt Securities of any
series and is continuing, the Debt Trustee or the holders of at least 25% in
principal amount of all of the outstanding Debt Securities of that series may
declare the principal (or, if the Debt Securities of that series are original
issue discount Debt Securities, such portion of the principal amount as may be
specified in the terms of that series) of, and any accrued interest on, all the
Debt Securities of that series to be due and payable.  Upon such declaration,
such principal (or, in the case of original issue discount Debt Securities,
such specified amount) and all accrued interest thereon shall be due and
payable immediately. (Section 6.2)

         Securityholders may not enforce the Debt Indenture or the Debt
Securities, except as provided in the Debt Indenture.  (Section 6.6)  The Debt
Trustee may require indemnity satisfactory to it before it enforces the Debt
Indenture or the Debt Securities. (Section 7.1(f))  Subject to certain
limitations, holders of a majority in principal amount of the Debt Securities
of each series affected (with each series voting as a class) may direct the
Debt Trustee in its exercise of any trust power. (Section 6.5)  The Debt
Trustee may withhold from Securityholders notice of any continuing default
(except a default in payment of principal or interest) if it determines in good
faith that withholding notice is in their interests. (Section 7.5)  The
Company is not required under the Debt Indenture to furnish any periodic
evidence as to the absence of default or as to compliance with the terms of the
Debt Indenture.

CONCERNING THE DEBT TRUSTEE

         The Company may maintain banking relationships in the ordinary course
of business with the Debt Trustee.  Prior relationships between the Company and
the trustee to be described.


                              PLAN OF DISTRIBUTION

         The Company may sell the Debt Securities being offered hereby: (i)
directly to purchasers, (ii) through agents, (iii) to or through underwriters,
(iv) through dealers or (v) through a combination of any such methods of sale.

         The distribution of the Debt Securities may be effected from time to
time in one or more transactions either (i) at a fixed price or prices, which
may be changed, or (ii) at market prices prevailing at the time of sale, or
(iii) at prices related to such prevailing market prices, or (iv) at negotiated
prices.

         Offers to purchase Debt Securities may be solicited directly by the
Company or by agents designated by the Company from time to time.  Any such
agent, which may be deemed to be an underwriter as that term is defined in the
Securities Act, involved in the offer or sale of the Debt Securities in respect
of which this Prospectus is delivered will be named, and any commissions
payable by the Company to such agent will be set forth, in the Prospectus
Supplement.  Unless otherwise indicated in the Prospectus Supplement, any such
agent will be acting on a best efforts basis for the period of its appointment.

         If an underwriter or underwriters are utilized in the sale, the
Company will execute an underwriting agreement with such underwriters at the
time of sale to them and the names of the underwriters and the terms of the
transaction, including commissions, discounts and other compensation of the
underwriters and dealers, if any, will be set forth in the Prospectus
Supplement, which will be used by the underwriters to make resales of the Debt
Securities in respect of which this Prospectus is delivered to the public.





                                      -8-
<PAGE>   44
         If a dealer is utilized in the sale of the Debt Securities in respect
of which this Prospectus is delivered, the Company will sell such Debt
Securities to the dealer, as principal.  The dealer may then resell such Debt
Securities to the public at varying prices to be determined by such dealer at
the time of resale.

         If so indicated in the Prospectus Supplement, the Company will
authorize agents, underwriters or dealers to solicit offers by certain
specified institutions to purchase Debt Securities from the Company at the
public offering price set forth in the Prospectus Supplement pursuant to
contracts providing for payment and delivery on a specified date in the future.
Such contracts will be subject only to those conditions set forth in the
Prospectus Supplement, and the Prospectus Supplement will set forth the
commission payable for solicitation of such contracts.

         Underwriters, dealers, agents and other persons may be entitled, under
agreements which may be entered into with the Company, to indemnification
against certain civil liabilities, including liabilities under the Securities
Act.

         Underwriters, dealers and agents may be customers of, engage in
transactions with or perform services for the Company in the ordinary course of
business.


                                 LEGAL OPINIONS

         Unless otherwise indicated in the Prospectus Supplement to this
Prospectus, certain legal matters in connection with the Debt Securities
offered hereby will be passed upon for the Company by Neal, Gerber & Eisenberg,
Chicago, Illinois, and for any underwriters or agents, by Mayer, Brown & Platt,
New York, New York.


                                    EXPERTS

         The consolidated financial statements of Union Tank Car Company
appearing in Union Tank Car Company's Annual Report (Form 10-K/A) for the year
ended December 31, 1995, have been audited by Ernst & Young LLP, independent
auditors, as set forth in their report thereon included therein and
incorporated herein by reference.  Such consolidated financial statements are
incorporated herein by reference in reliance upon such report given upon the
authority of such firm as experts in accounting and auditing.





                                      -9-
<PAGE>   45

                                    PART II

                     INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 14.  OTHER EXPENSES OF ISSUANCE AND DISTRIBUTION

         The following table sets forth the estimated expenses (other than
underwriting discounts and commissions) to be incurred by the registrant in
connection with the offering described in this Registration Statement:

<TABLE>
          <S>                                                                       <C>
          Securities and Exchange Commission registration fee   . . . . . .         $121,213*
          Blue Sky filing and counsel fees  . . . . . . . . . . . . . . . .            8,000
          Trustees' fees and expenses   . . . . . . . . . . . . . . . . . .             **
          Printing expenses   . . . . . . . . . . . . . . . . . . . . . . .           65,000
          Auditors' fees and expenses   . . . . . . . . . . . . . . . . . .             **
          Attorneys' fees and expenses  . . . . . . . . . . . . . . . . . .          125,000
          Rating agency fees  . . . . . . . . . . . . . . . . . . . . . . .          200,000
          Miscellaneous   . . . . . . . . . . . . . . . . . . . . . . . . .             **
                 Total  . . . . . . . . . . . . . . . . . . . . . . . . . .         $   **   
                                                                                     ========
                          
- --------------------------
</TABLE>

*    Actual.  All other amounts are estimated.
**   To be provided by amendment.

ITEM 15.  INDEMNIFICATION OF DIRECTORS AND OFFICERS

         Section 145 of the Delaware General Corporation Law, Article Sixth of
the Company's Restated Certificate of Incorporation and Article VIII of the
Company's By-Laws authorize and empower the Company to indemnify its directors,
officers, employees and agents against liabilities incurred in connection with,
and related expenses resulting from, any claim, action or suit brought against
any such person as a result of such person's relationship with the Company,
provided that such persons acted in accordance with a stated standard of
conduct in connection with the acts or events on which such claim, action or
suit is based.  The finding of either civil or criminal liability on the part of
such persons in connection with such acts or events is not necessarily
determinative of the question of whether such persons have met the required
standard of conduct and are, accordingly, entitled to be indemnified.

         Section 124 of the Canada Business Corporations Act and Section 33 of
By-law 15 of Procor authorize and empower Procor to indemnify its directors and
officers against all costs, charges and expenses including an amount paid to
settle an action or satisfy a judgment, reasonably incurred by him in respect
of any civil, criminal or administrative action or proceeding to which he is
made a party by reason of being or having been a director or officer of Procor,
if he acted honestly and in good faith with a view to the best interests of
Procor and, in the case of a criminal or administrative action or proceeding
that is enforced by a monetary penalty, if he had reasonable grounds for
believing that his conduct was lawful.

         Reference is made to Section 8 of the form of Underwriting Agreement
filed as Exhibit I hereto for provisions regarding indemnification of the
Company and Procor and their respective officers, directors and controlling
persons against certain liabilities.

ITEM 16.  EXHIBITS

<TABLE>
<CAPTION>
EXHIBIT
NUMBER   DESCRIPTION OF DOCUMENTS
- ------   ------------------------
<S>      <C>       <C>
1(a)     --        Form of Underwriting Agreement (Pass Through Certificates).

1(b)     --        Form of Underwriting Agreement (Debt Securities).
</TABLE>





                                      II-1
<PAGE>   46
<TABLE>
<CAPTION>
EXHIBIT
NUMBER   DESCRIPTION OF DOCUMENTS
- ------   ------------------------
<S>      <C>       <C>
4(a)(1)  --        Form of Pass Through Trust Agreement among the Company, Procor and the Pass Through Trustee.

4(a)(2)  --        Form of Pass Through Certificate (included in Exhibit 4(a)(1)).

4(b)     --        Form of Indenture between the Company and the Debt Trustee.

4(c)(1)  --        Form of Equipment Trust Agreement between the Company and the Equipment Trust Trustee relating to the
                   Company ETCs.*

4(c)(2)  --        Form of the Company ETC (included in Exhibit 4(c)(1)).*

4(c)(3)  --        Form of Equipment Trust Agreement between Procor and the Equipment Trust Trustee relating to the
                   Procor ETCs.*

4(c)(4)  --        Form of the Procor ETC (included in Exhibit 4(c)(3)).*

5(a)     --        Opinion of Neal, Gerber & Eisenberg, counsel for the Company.*

5(b)     --        Opinion of                                          , counsel for the Pass Through Trustee.*
                              -----------------------------------------                                        

8(a)     --        Tax Opinion of Neal, Gerber & Eisenberg, counsel for the Company.*

8(b)     --        Tax Opinion of Osler, Hoskin & Harcourt, counsel for Procor.*

8(c)     --        Tax Opinion of                             , counsel for the Pass Through Trustee.*
                                  ----------------------------                                        

12       --        Computation of Ratios of Earnings to Fixed Charges.**

23(a)    --        Consent of Ernst & Young LLP, Independent Auditors.

23(b)    --        Consent of Neal, Gerber & Eisenberg (included in Exhibits 5(a) and 8(a)).*

23(c)    --        Consent of                                            (included in Exhibit 5(b) and 8(c)).*
                              ------------------------------------------                                      

23(d)    --        Consent of Osler, Hoskin & Harcourt (included in Exhibit 8(b)).*

24       --        Powers of Attorney (included on the signature pages to this Registration Statement).

25(a)    --        Statement of Eligibility of Pass Through Trustee on Form T-1.*

25(b)    -         Statement of Eligibility of Indenture Trustee on Form T-1.*
</TABLE>

__________________________

*        To be filed by amendment.

**       The computation for each of the five fiscal years ended December 31,
         1995, 1994, 1993, 1992 and 1991 is incorporated herein by reference to
         Exhibit 12 to the Company's Annual Report on Form 10-K/A for the year
         ended December 31, 1995.





                                      II-2
<PAGE>   47
ITEM 17.  UNDERTAKINGS

         A.        Undertakings Regarding Rule 415 Offering.

         (a)       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;

                          (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, represent
                   a fundamental change in the information set forth in the
                   Registration Statement.  Notwithstanding the foregoing, any
                   increase or decrease in volume of securities offered (if the
                   total dollar value of securities offered would not exceed
                   that which was registered) and any deviation from the low or
                   high and of the estimated maximum offering range may be
                   reflected in the form of prospectus filed with the
                   Commission pursuant to Rule 424(b) if, in the aggregate, the
                   changes in volume and price represent no more than 20
                   percent change in the maximum aggregate offering price set
                   forth in the "Calculation of Registration Fee" table in the
                   effective registration statement;

                          (iii)   To include any material information with
                   respect to the plan of distribution not previously disclosed
                   in the Registration Statement or any material change to such
                   information in the Registration Statement.

                   (2)    That, for the purpose of determining any liability
         under the Securities Act, each such post-effective amendment 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.

                   (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.

         B.        Undertaking Regarding Documents Subsequently Filed Under the
Exchange Act.

         The Company and Procor hereby undertake 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
Exchange Act that is incorporated by reference in this Registration Statement
shall be deemed to be a new Registration Statement relating to the securities
offered herein, and the offering of such securities at that time shall be
deemed to be the initial bona fide offering thereof.

         C.        Undertaking in Respect of Indemnification.

         Insofar as indemnification for liabilities arising under the
Securities Act of 1933 may be permitted to directors, officers and controlling
persons of the Company pursuant to the provisions described under Item 15
above, or otherwise, the Company has been advised that in the opinion of the
Commission such indemnification is





                                      II-3
<PAGE>   48
against public policy as expressed in the Securities Act of 1933 and is,
therefore, unenforceable.  In the event that a claim for indemnification
against such liabilities (other than the payment by the Company of expenses
incurred or paid by a director, officer or controlling person of the Company 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 Company 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 Securities Act of 1933 and will be governed by the
final adjudication of such issue.

         D.        Undertakings Pursuant to Rule 430A.

         (1)       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 Company pursuant to Rule
424(b)(1) or (4) or 497(h) under the Securities Act of 1933 shall be deemed to
be part of this Registration Statement as of the time it was declared
effective.

         (2)       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.

         E.        Undertakings Under the Trust Indenture Act of 1939.

         The Company hereby undertakes to file an application for the purpose
of determining the eligibility of the trustee to act under subsection (a) of
Section 310 of the Trust Indenture Act in accordance with the rules and
regulations prescribed by the Commission under Section 305(b)(2) of the
Securities Act of 1933.





                                      II-4
<PAGE>   49
                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, Union Tank
Car Company 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 Chicago, State of Illinois on the 27th day of
November, 1996.

                                                   UNION TANK CAR COMPANY


                                                   /s/ R.C. Gluth
                                                   -----------------------------
                                                       Robert C. Gluth,
                                                       Executive Vice President,
                                                       Treasurer and Director

         Each person whose signature appears below hereby constitutes and
appoints Robert C. Gluth, Robert W. Webb and Kenneth P. Fischl, and each of
them, the true and lawful attorneys-in-fact and agents of the undersigned, with
full power of substitution and resubstitution, for and in the name, place and
stead of the undersigned and to file the same, with all exhibits thereto, in
any and all capabilities, to sign any and all amendments and any registration
statement filed pursuant to Rule 462(b) of the Securities Act of 1933, as
amended (including post-effective amendments thereto and other documents in
connection therewith), with the Securities and Exchange Commission, and hereby
grants to such attorneys-in-fact and agents, and each of them, full power and
authority to do and perform each and every act and thing requisite and
necessary to be done, as fully to all intents and purposes as the undersigned
might or could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or any of them, or their or his substitutes, may
lawfully do or cause to be done by virtue hereof.

         Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities indicated on the 27th day of November, 1996.

<TABLE>
<CAPTION>
                   Signature                                        Title
                   ---------                                        -----
         <S>                                                <C>
         /s/ Jay A. Pritzker                                 Chairman of the Board
- ----------------------------------------------------         and Director
                            
              Jay A. Pritzker                               


         /s/ Robert A. Pritzker                              President and Director
- ---------------------------------------------------          (principal executive officer)                             
              Robert A. Pritzker                            



         /s/ R.C. Gluth                                      Executive Vice President,
- -----------------------------------------------------        Treasurer and Director                                             
              Robert C. Gluth                                (principal financial and accounting
                                                             officer)                           
                                                                                               
                                                            
         /s/ K.P. Fischl                                     Director
- -----------------------------------------------------                        
                K.P. Fischl
</TABLE>





                                      II-5
<PAGE>   50
                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, Procor
Limited 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 Chicago, State of Illinois on the 27th day of
November, 1996.

                                                   PROCOR LIMITED


                                                   /s/ R.C. Gluth       
                                                   -----------------------------
                                                      Robert C. Gluth,
                                                      Vice President,
                                                      Treasurer and Director

         Each person whose signature appears below hereby constitutes and
appoints Robert C. Gluth, Robert W. Webb and Kenneth P. Fischl, and each of
them, the true and lawful attorneys-in-fact and agents of the undersigned, with
full power of substitution and resubstitution, for and in the name, place and
stead of the undersigned and to file the same, with all exhibits thereto, in
any and all capabilities, to sign any and all amendments and any registration
statement filed pursuant to Rule 462(b) of the Securities Act of 1933, as
amended (including post-effective amendments thereto and other documents in
connection therewith), with the Securities and Exchange Commission, and hereby
grants to such attorneys-in-fact and agents, and each of them, full power and
authority to do and perform each and every act and thing requisite and
necessary to be done, as fully to all intents and purposes as the undersigned
might or could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or any of them, or their or his substitutes, may
lawfully do or cause to be done by virtue hereof.

         Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed by the following persons in the
capacities indicated on the 27th day of November, 1996.

<TABLE>
<CAPTION>
              Signature                                     Title
              ---------                                     -----
         <S>                                                <C>
         /s/ Frank D. Lester                                President
- ---------------------------------------------------         (principal executive officer)           
              Frank D. Lester                      


         /s/ R.C. Gluth                                     Vice President, Treasurer and Director
- ----------------------------------------------------        (principal financial and accounting     
              Robert C. Gluth                               officer) 
                                                   

         /s/ David H. Patterson                             Director
- --------------------------------------------------         
              David H. Patterson


         /s/ K.P. Fischl                                    Director
- -----------------------------------------------------               
              K.P. Fischl


         /s/ Peter E. Lawford                               Director
- ---------------------------------------------------                 
              Peter E. Lawford


         /s/ S. Donald Hamilton                             Director
- -------------------------------------------------          
              S. Donald Hamilton

</TABLE>




                                      II-6

<PAGE>   1



                             Union Tank Car Company
                                      and
                                 Procor Limited

                                   $
                                    ---------

                    Pass Through Certificates, Series
                                                      -----

                             Underwriting Agreement


                                                              New York, New York

                                                                       ---------

Salomon Brothers Inc
7 World Trade Center
New York, New York  10048

Morgan Stanley & Co. Incorporated
1585 Broadway
New York, New York  10036

Dear Ladies and Gentlemen:

     Union Tank Car Company, a Delaware corporation ("Union"), and Procor
Limited, a Canadian corporation and an indirect wholly-owned subsidiary of
Union ("Procor" and, together with Union, the "Companies") propose to cause to
be sold to you the underwriters (the "Underwriters") $______ aggregate
principal amount of Pass Through Certificates, Series ____ and Pass Through
Certificates, Series _____ [(together with the guarantee of Union of the due
and punctual distribution to holders of such certificates of principal and
interest payable in respect of the Procor ETC (as hereinafter defined) to be
endorsed on Pass Through Certificates, _____, the "Union Guarantee")], with the
interest rates and final distribution dates as set forth in Schedule A hereto
(the "Pass Through Certificates"), in the respective aggregate principal
amounts set forth on Schedule B hereto, to be issued under (i) the Pass Through
Trust Agreement ______, dated _______ (the "Pass Through Trust Agreement #1"),
between Union and _______, as Past Through Trustee (the "Pass Through Trustee")
and (ii) the Pass Through Trust Agreement _____, dated ______ (the "Pass
Through Trust Agreement

<PAGE>   2

#2", and together with the Pass Through Trust Agreement #1, the "Pass Through
Trust Agreements") among Union, Procor and the Pass Through Trustee,
respectively.

     The property to be purchased by the Pass Through Trustee under Pass
Through Agreement #1 and contained in such trust shall consist of $______
principal amount Equipment Notes, Series A to be issued under the Indenture.
The property to be purchased by the Pass Through Trustee under Pass Through
Trust Agreement #2 and contained in such trust shall consist of (i) $______
principal amount Equipment Notes, Series B, (ii) an aggregate of $______
principal amount Equipment Trust Certificates, Series ___ of Union (together
with the guarantee of Union to be endorsed thereon, the "Union ETCs") to be
issued by Union pursuant to an Equipment Trust Agreement, dated ________, as
may be amended or supplemented from time to time (the "Union Equipment Trust
Agreement"), between Union and _____________, as trustee (the "Union Equipment
Trust Trustee"), and (iii) a $_________ principal amount Equipment Trust
Certificate, Series ____ of Procor (together with the guarantee of Procor
endorsed thereon, the "Procor ETC") to be issued by Procor pursuant to an
Equipment Trust Agreement, dated ________, as may be amended or supplemented
from time to time (the "Procor Equipment Trust Agreement", and together with
the Union Equipment Trust Agreement, the "Equipment Trust Agreements"), between
Procor and __________, as trustee (the "Procor Equipment Trust Trustee", and
together with the Union Equipment Trust Trustee, the "Equipment Trust
Trustees").

     All capitalized terms used, but not defined herein, shall have the
meanings attributed to them in the Pass Through Trust Agreements.  As used in
this Agreement, the term "Operative Agreements" shall have the meaning set
forth in the Participation Agreement.  All other capitalized terms used herein
shall, for the purposes hereof, have the meanings attributed to them in this
Agreement.

     1. Representations and Warranties.  The Companies represent and warrant
to, and agree with you, that:

          (a) The Companies meet the requirements for use of Form S-3 under the
     Securities Act of 1933, as amended (the "Act"), and have filed with the    
     Securities and Exchange Commission (the "Commission") a registration
     statement (file number 333-_______) on such Form, including a related
     Preliminary Prospectus (as hereinafter defined), for the registration
     under the Act of the offering and sale of the Pass Through Certificates. 
     The Companies may have filed one or more amendments thereto, including the
     related Preliminary Prospectus, each of which has previously been
     furnished to you.  The Companies will next file with the Commission one of
     the following:  (i) prior to effectiveness of such registration statement,
     a further amendment to such registration statement, including the form of
     final prospectus or (ii) a final prospectus in accordance with Rules 430A
     and 424(b)(1) or (4) under the Act. In the case of clause (ii), the
     Companies have included in such registration statement,

                                     - 2 -


<PAGE>   3

     as amended at the Effective Date (as hereinafter defined) all information
     (other than Rule 430A Information (as hereinafter defined)) required
     by the Act and the rules thereunder to be included in the Prospectus (as
     hereinafter defined) with respect to the Pass Through Certificates and the
     offering thereof.  As filed, such amendment and form of final prospectus,
     or such final prospectus, shall contain all Rule 430A Information,
     together with all other such required information, with respect to the
     Pass Through Certificates and the offering thereof and, except to the
     extent you shall agree in writing to a modification, shall be in all
     substantive respects in the form furnished to you prior to the Execution
     Time (as hereinafter defined) or, to the extent not completed at the
     Execution Time, shall contain only such specific additional information
     and other changes (beyond that contained in the latest Preliminary
     Prospectus) as the Companies have advised you, prior to the Execution
     Time, will be included or made therein.

          (b) On the Effective Date (as hereinafter defined), the Registration
     Statement did or will, and when the Prospectus is first filed (if
     required) in accordance with Rule 424(b) and on the Closing Date (as
     hereinafter defined), the Prospectus (as hereinafter defined) (and any
     supplements thereto) will, comply in all material respects with the
     applicable requirements of the Act and the Securities Exchange Act of
     1934, as amended (the "Exchange Act"), and the respective rules and
     regulations thereunder; on the Effective Date, the Registration Statement
     (as hereinafter defined) did not or will not contain any untrue statement
     of a material fact or omit to state any material fact required to be
     stated therein or necessary in order to make the statements therein not
     misleading; on the Effective Date and on the Closing Date (as hereinafter
     defined), the Pass Through Trust Agreements did or will comply in all
     material respects with the requirements of the Trust Indenture Act of
     1939, as amended (the "Trust Indenture Act"), and the rules thereunder;
     and, on the Effective Date, the Prospectus, if not filed pursuant to Rule
     424(b), did not or will not, and on the date of any filing pursuant to
     Rule 424(b) and on the Closing Date, the Prospectus (together with any
     supplement thereto) will not, include any untrue statement of a material
     fact or omit to state a material fact necessary in order to make the
     statements therein, in the light of the circumstances under which they
     were made, not misleading; provided, however, that the Companies make no
     representations or warranties as to (i) that part of the Registration
     Statement which shall constitute the Statement of Eligibility and
     Qualification (Form T-1) under the Trust Indenture Act of the Pass Through
     Trustee and (ii) the information contained in or omitted from the
     Registration Statement or the Prospectus (or any supplement thereto) in
     reliance upon and in conformity with information furnished in writing to
     the Company by you specifically for use in connection with the preparation
     of the Registration Statement or the Prospectus (or any supplement
     thereto).

          (c) The terms which follow, when used in this Agreement, shall have 
     the meanings indicated.  The term "Effective Date" shall mean each date 
     that the

                                     - 3 -

<PAGE>   4

     Registration Statement and any post-effective amendment or amendments
     thereto became or becomes effective.  "Execution Time" shall mean the
     date and time that this Agreement is executed and delivered by the parties
     hereto. "Preliminary Prospectus" shall mean any preliminary prospectus
     referred to in paragraph (a) above, and any preliminary prospectus
     included in the Registration Statement at the Effective Date that omits
     Rule 430A Information. "Prospectus" shall mean the prospectus relating to
     the Pass Through Certificates that is first filed pursuant to Rule 424(b)
     after the Execution Time or, if no filing pursuant to Rule 424(b) is
     required, shall mean the form of final prospectus relating to the Pass
     Through Certificates included in the Registration Statement at the
     Effective Date.  "Registration Statement" shall mean the registration
     statement referred to in paragraph (a) above, including incorporated
     documents, exhibits and financial statements, as amended at the Execution
     Time (or, if not effective at the Execution Time, in the form in which it
     shall become effective) and, in the event any post-effective amendment
     thereto becomes effective prior to the Closing Date, shall also mean such
     registration statement as so amended.  Such term shall include any Rule
     430A Information deemed to be included therein at the Effective Date as
     provided by Rule 430A.  "Rule 424", "Rule 430A" and "Regulation S-K" refer
     to such rules or regulation under the Act.  "Rule 430A Information" means
     information with respect to the Pass Through Certificates and the offering
     thereof permitted to be omitted from the Registration Statement when it
     becomes effective pursuant to Rule 430A.  Any reference herein to the
     Registration Statement, a Preliminary Prospectus or the Prospectus shall
     be deemed to refer to and include the documents incorporated by reference
     therein pursuant to Item 12 of Form S-3 which were filed under the
     Exchange Act on or before the Effective Date or the issue date of such
     Preliminary Prospectus or the Prospectus, as the case may be; and any
     reference herein to the terms "amend", "amendment" or "supplement" with
     respect to the Registration Statement, any Preliminary Prospectus or the
     Prospectus shall be deemed to refer to and include the filing of any
     document under the Exchange Act after the Effective Date of the
     Registration Statement, or, the issue date of any Preliminary Prospectus
     or the Prospectus, as the case may be, deemed to be incorporated therein
     by reference.
        
          (d) The consolidated financial statements incorporated by reference 
     in the Registration Statement and Prospectus present fairly the 
     consolidated financial position of Union and its subsidiaries as at the 
     dates indicated and the consolidated results of their operations and
     cash flows for the periods specified and have been prepared in conformity
     with generally accepted accounting principles applied on a consistent
     basis during the periods involved, except as indicated therein, and the
     supporting schedules incorporated by reference in the Registration
     Statement present fairly the information required to be stated therein.

          (e) The documents incorporated by reference in the Prospectus, at 
     the time they were or hereafter are filed with the Commission, complied 
     and will comply in all

                                     - 4 -

<PAGE>   5
     material respects with the requirements of the Exchange Act, and the       
     rules and regulations thereunder.

          (f) Since the respective dates as of which information is given in the
     Registration Statement and the Prospectus, except as otherwise stated
     therein or contemplated thereby, there has been no material adverse
     change in the condition, financial or otherwise, results of operations or
     general affairs of Union and its subsidiaries, taken as a whole.

          (g) Union and each Significant Subsidiary (with such term having the  
     meaning attributed to it under Rule 405 under the Act) of Union (including
     Procor) has been duly incorporated and is validly existing as a
     corporation in good standing under the laws of the jurisdiction in which
     it is chartered or organized, with full corporate power and authority to
     own its properties and conduct its business as described in the
     Prospectus, and is duly qualified to do business as a foreign corporation
     and is in good standing under the laws of each jurisdiction which requires
     such qualification wherein it owns or leases material properties or
     conducts material business, except in such jurisdictions in which the
     failure to so qualify would not have a material adverse effect on Union
     and its subsidiaries, taken as a whole.  Union owns either directly, or
     through wholly-owned subsidiaries, all of the issued and outstanding
     capital stock of Procor.

          (h) The execution and delivery by Union or Procor, as the case may 
     be, of this Agreement, the Participation Agreement, the Pass Through Trust
     Agreements, the Lease, the Equipment Trust Agreements and the other
     Operative Agreements to which Union or Procor, as the case may be, is, or
     is to be, a party, the consummation by the Companies of the transactions
     herein and therein contemplated, and the compliance by the Companies with
     the terms hereof and thereof do not and will not conflict with, or result
     in a breach of any of the terms or provisions of, or constitute a default
     under, the Certificate of Incorporation or by-laws, as amended, of Union,
     or the corporate charter or by-laws, as amended, of Procor, or any of
     their respective subsidiaries or any material indenture, mortgage, or
     other agreement or instrument to which the Companies or any of their
     respective subsidiaries is a party or by which any of their respective
     properties are bound, or any applicable law, rule, regulation, judgment,
     order or decree of any government, governmental instrumentality or court,
     domestic or foreign, having jurisdiction over the Companies or any of
     their respective subsidiaries or any of their respective properties; and,
     assuming due authorization, execution and delivery by all parties thereto
     other than the Companies, no consent, approval, authorization, order or
     license of, or filing with or notice to any government, governmental
     instrumentality, regulatory body or authority or court, domestic or
     foreign, is required for the valid authorization, issuance and delivery of
     the Pass Through Certificates, the ETCs and the Equipment Notes, the valid
     authorization,

                                     - 5 -

<PAGE>   6
     execution, delivery and performance by Union and Procor, as the case may
     be, of     this Agreement, the Participation Agreement, the Pass Through
     Trust Agreements, the Equipment Trust Agreements and the Lease and other
     Operative Agreements to which Union or Procor, as the case may be, is, or
     is to be, a party, or the consummation by the Companies of the
     transactions contemplated by this Agreement, the Participation Agreement,
     the Pass Through Trust Agreements, the Equipment Trust Agreements and the
     Lease and other Operative Agreements to which Union or Procor, as the case
     may be, is, or is to be, a party, except (w) such as are required under
     the Act, the Trust Indenture Act and the securities or Blue Sky laws of
     the various states, (x) such filings, recordings or registrations with the
     Surface Transportation Board of the Department of Transportation (the
     "STB") and under Section 90 of the Railway Act (Canada) as may be
     required, (y) the filing of Uniform Commercial Code financing statements
     in various jurisdictions and the filing of continuation statements with
     respect thereto required to be filed at periodic intervals under the
     Uniform Commercial Code and (z) such other filings, recordings or
     registrations as may be required under the Operative Agreements.
        
          (i) This Agreement, the Participation Agreement, the Pass Through 
     Trust Agreements, the Equipment Trust Agreements and the Lease and the 
     other Operative Agreements to which Union or Procor, as the case may
     be, is, or is to be, a party, have each been duly authorized by Union or
     Procor, as the case may be, and, when executed and delivered by Union or
     Procor, as the case may be, will constitute valid and binding obligations
     of Union or Procor, as the case may be, and the Pass Through Trust
     Agreements will have been duly qualified under the Trust Indenture Act. 
     On the Closing Date, the Equipment Trust Agreements, the Lease and other
     Operative Agreements to which Union or Procor, as the case may be, is, or
     is to be, a party will constitute the valid and binding obligations of
     Union or Procor, as the case may be.  The Pass Through Certificates, the
     ETCs, the Equipment Notes, the Indenture, the Participation Agreement, the
     Pass Through Trust Agreements, the Equipment Trust Agreements and the
     Lease and the other Operative Agreements to which Union or Procor, as the
     case may be, is, or is to be, a party will conform in all material
     respects to the descriptions thereof in the Prospectus.

          (j) Ernst & Young LLP ("Ernst & Young"), who reported on the 
     consolidated financial statements of Union as of __________ and for the 
     year then ended, which statements are incorporated by reference in the
     Registration Statement and Prospectus, were, as of the date of its report 
     on such consolidated financial statements, independent auditors as 
     required by the Act and the rules and regulations thereunder.

          (k) The Pass Through Certificates, when duly executed, authenticated
     and delivered by the Pass Through Trustee in accordance with the terms of 
     the Pass Through Trust Agreements and this Agreement, will be duly issued 
     under the Pass

                                     - 6 -

<PAGE>   7
     Through Trust Agreements and will constitute valid and binding obligations
     of the Pass Through Trustee; and the holders thereof will be entitled to
     the benefits of the Pass Through Trust Agreements.

          (l) Assuming due authorization, execution and delivery of the 
     Equipment Notes to be issued under the Indenture by the Owner Trustee and 
     due authentication of such Equipment Notes by the Indenture Trustee in
     accordance with the terms of the Indenture, the Equipment Notes will be
     duly issued under the Indenture and will constitute valid and binding
     obligations of such Owner Trustee; and the holders thereof will be
     entitled to the benefits of the Indenture.

     2. Purchase and Sale.  Subject to the terms and conditions and in reliance
upon the representations and warranties herein set forth, the Companies agree
to request the Pass Through Trustee to sell to each of you, in the respective
aggregate principal amounts set forth on Schedule B hereto, and each of you
severally, not jointly, agrees to purchase from the Pass Through Trustee, at a
purchase price of 100% of the principal amount thereof, the
respective aggregate principal amounts of Pass Through Certificates set forth
on such Schedule B.

     As compensation to each of you for its commitment and obligations
hereunder in respect of the Pass Through Certificates, including its
undertaking to distribute the Pass Through Certificates, the Owner Trustee has,
pursuant to Section 2.5 of the Participation Agreement, undertaken to pay, or
if the Owner Trustee does not pay when due, Union will pay when due, to you an
amount equal to the product of .____% times a fraction, the numerator of which
is the aggregate principal amount of Equipment Notes to be purchased by the
Pass Through Trusts and the denominator of which is the original principal
amount of the Pass Through Certificates purchased by you.  Union will pay to
you when due an amount equal to .___% of the original aggregate principal
amount of the Union ETCs and Procor will pay to you when due an amount equal to
 .____% of the original aggregate principal amount of the Procor ETC.  Subject
to the terms hereof, Procor's obligation to make such payment is hereby
unconditionally guaranteed by Union.  Such payments shall be made
simultaneously with the payment by you to the Pass Through Trustee of the
purchase price of the Pass Through Certificates as specified in Section 3
hereof.  Payment of such compensation shall be made by Federal funds check or
other immediately available funds to the order of Salomon Brothers Inc.

     3. Delivery and Payment.  Delivery of and payment for the Pass Through
Certificates shall be made at the offices of Neal, Gerber & Eisenberg, Two
North LaSalle Street, Chicago, Illinois, at 10:00 a.m., Chicago time, on _____
or such later date and time (not later than ____) as the Companies and you
shall determine (such date and time of delivery and payment for the Pass
Through Certificates being herein called the "Closing Date").  Delivery of the
Pass Through Certificates shall be made to your account at The Depository Trust
Company against payment by you of the purchase price thereof to or upon the
order of

                                     - 7 -
<PAGE>   8
the Pass Through Trustee by Federal funds check or other immediately
available funds.  The Pass Through Certificates shall be registered in such
names and in such denominations as you may request not less than three full
business days in advance of the Closing Date or such other date as may be
agreed upon.

     The Companies agree to have the Pass Through Certificates available for
inspection, checking and packaging by you in New York City, not later than 1:00
p.m. (New York City time) on the business day prior to the Closing Date.

     4. Offering by Salomon Brothers Inc and Morgan Stanley & Co. Incorporated.
It is understood that, after the Registration Statement becomes effective, each
of you propose to offer the Pass Through Certificates for sale to the public as
set forth in the Prospectus.

     5. Agreements.  The Companies agree with you that:
                                                    
          (a) The Companies will each use their reasonable best efforts to cause
     the Registration Statement, if not effective at the Execution Time, and
     any amendment thereof, to become effective and the Pass Through Trust
     Agreement to be qualified under the Trust Indenture Act.  The Companies
     will not file any amendment to the Registration Statement or supplement to
     the Prospectus unless the Companies have furnished you a copy for your
     review prior to filing and will not file any such proposed amendment or
     supplement to which you reasonably object.  Subject to the foregoing
     sentence, if filing of the Prospectus is required under Rule 424(b), the
     Companies will cause the Prospectus, properly completed, and any
     supplement thereto to be filed with the Commission pursuant to the
     applicable paragraph of Rule 424(b) within the time period prescribed and
     will provide evidence satisfactory to you of such timely filing.  The
     Companies will promptly advise you (i) when the Registration Statement, if
     not effective at the Execution Time, and any amendment thereto, shall have
     become effective, (ii) when the Prospectus, and any supplement thereto,
     shall have been filed (if required) with the Commission pursuant to Rule
     424(b), (iii) when, prior to termination of the offering of the Pass
     Through Certificates, any amendment to the Registration Statement shall
     have been filed or become effective, (iv) of any request by the Commission
     for any amendment of the Registration Statement or supplement to the
     Prospectus or for any additional information, (v) of the issuance by the
     Commission of any stop order suspending the effectiveness of the
     Registration Statement or the institution or threatening of any proceeding
     for that purpose (and each of the Companies agree that it will each use
     its reasonable best efforts to prevent the issuance of any such stop order
     and, if issued, to obtain as soon as possible the withdrawal thereof),
     (vi) of the receipt by the Companies of any notification with respect to
     the suspension of the qualification of the Pass Through Certificates for
     sale in any jurisdiction or the initiation or threatening of any
     proceeding for such purpose and (vii) during the period when a prospectus
     relating to the Pass Through Certificates is

                                     - 8 -


<PAGE>   9
     required to be delivered under the Act, of the mailing or the delivery to
     the Commission for filing of any document to be filed pursuant to
     the Exchange Act.  (b) If, at any time when a prospectus relating to the
     Pass Through Certificates is required to be delivered under the Act, any
     event occurs as a result of which the Prospectus as then supplemented
     would include any untrue statement of a material fact or omit to state any
     material fact necessary to make the statements therein, in the light of
     the circumstances under which they were made, not misleading, or if it
     shall be necessary to amend the Registration Statement or supplement the
     Prospectus to comply with the Act or the Exchange Act or the respective
     rules and regulations thereunder, the Companies promptly will prepare and
     file with the Commission, subject to paragraph (a) of this Section 5, an
     amendment or supplement which will correct such statement or omission or
     an amendment which will effect such compliance.
        
          (c) As soon as practicable, Union will make generally available to 
     its security holders and to the Underwriters an earnings statement or
     statements of Union and its subsidiaries which will satisfy the provisions
     of Section 11(a) of the Act and the applicable rules and regulations
     thereunder.

          (d) The Companies will furnish to you and your counsel, without 
     charge, signed copies of the Registration Statement (including exhibits 
     thereto) and, so long as delivery of a prospectus by you or a dealer may
     be required by the Act, as many copies of each Preliminary Prospectus and
     the Prospectus and any amendments thereof and supplements thereto as you
     may reasonably request.  Subject to the provisions of Section 2.5 of the
     Participation Agreement, the Companies will pay the expenses of printing
     all documents relating to the offering.
        
          (e) The Companies will cooperate with you and your special counsel to 
     arrange for the qualification of the Pass Through Certificates for sale
     under the laws of such jurisdictions as you may reasonably designate, will
     maintain such qualifications in effect so long as required for the
     distribution of the Pass Through Certificates and will arrange for the
     determination of the legality of the Pass Through Certificates for
     purchase by institutional investors; provided, however, that the Companies
     will not be required to qualify to do business in any jurisdiction in
     order to effect such qualification.

          (f) Between the date of this Agreement and the Closing Date, the
     Companies will not without your prior written consent offer, sell, or
     enter into any agreement to sell, any public debt securities registered
     under the Act (other than the Pass Through Certificates).

                                     - 9 -

<PAGE>   10
          (g) The Companies confirm as of the date hereof that each is in
     compliance with all provisions of Section 1 of Laws of Florida, Chapter
     92-198, An Act Relating to Disclosure of Doing Business with Cuba, and the
     Companies further agree that if either Union or Procor commences engaging
     in business with the government of Cuba or with any person or affiliate
     located in Cuba after the date the Registration Statement becomes or has
     become effective with the Commission or with the Florida Department of
     Banking and Finance (the "Department"), whichever date is later, or if the
     information reported in the Prospectus, if any, concerning Union's or
     Procor's business with Cuba or with any person or affiliate located in
     Cuba changes in any material way, the Companies will provide the
     Department notice of such business or change, as appropriate, in a form
     acceptable to the Department.

     6. Conditions to the Obligations of Salomon Brothers Inc and Morgan
Stanley & Co. Incorporated.  Your obligations to purchase the Pass Through
Certificates shall be subject to the accuracy of the representations and
warranties on the part of the Companies contained herein as of the Execution
Time and the Closing Date, to the accuracy of the statements of the Companies
made in any certificates delivered pursuant to the provisions hereof, to the
performance by the Companies of their obligations hereunder and to the
following additional conditions:

          (a) The Registration Statement shall have become effective not later
     than (i) 5:00 p.m., New York City time, on the date of determination of
     the public offering price, if such determination occurred at or prior to
     3:00 p.m., New York City time, on such date or (ii) 12:00 noon, New York
     City time, on the business day following the day on which the public
     offering price was determined, if such determination occurred after 3:00
     p.m., New York City time, on such date; if filing of the Prospectus, or
     any supplement thereto, is required pursuant to Rule 424(b), the
     Prospectus, and any such supplement, will be filed in the manner and
     within the time period required by Rule 424(b); and no stop order
     suspending the effectiveness of the Registration Statement shall have
     issued and no proceedings for that purpose shall have been instituted or
     threatened.

          (b) The Companies shall have furnished to you and to Moody's 
     Investors Service, Inc. and Standard and Poor's Corporation (together, 
     the "Rating Agencies"), if requested by you, the opinion of Neal,  Gerber
     & Eisenberg, special counsel to Union (incorporating and relying upon the 
     opinions of ______, Esquire, General Counsel of Procor, and _______, 
     special Canadian counsel to Procor, as to Canadian law matters,
     and _______, special STB counsel to Union, as to STB matters), dated the
     Closing Date, in form reasonably satisfactory to you and to Mayer, Brown &
     Platt, special counsel of the Underwriters, to the effect that:

                                     - 10 -

<PAGE>   11
          (i)  Each of Union and its Significant Subsidiaries (including
     Procor) has been duly incorporated and is validly existing as a
     corporation in good standing under the laws of the jurisdiction in which
     it is chartered or organized, with full corporate power and authority to
     own its properties and conduct its business as described in the
     Prospectus, and is duly qualified to do business as a foreign corporation
     and is in good standing under the laws of each jurisdiction which requires
     such qualification wherein it owns or leases material properties or
     conducts material business, except in such jurisdictions in which the
     failure to so qualify would not have a material adverse effect on Union
     and its subsidiaries, taken as a whole.

          (ii)  all the outstanding shares of capital stock of Procor have been
     duly and validly authorized and issued and are fully paid and
     nonassessable, and, all such capital stock of Procor is owned by Union,
     either directly or through wholly owned subsidiaries, free and clear of
     any perfected security interest and, to the knowledge of such counsel,
     after due inquiry, any other security interest, claims, liens or
     encumbrances.

          (iii) each of Union and Procor has the corporate power and authority
     under the laws of the jurisdiction in which it is chartered or organized
     to perform its obligations hereunder and under the Participation
     Agreement, the Pass Through Trust Agreements, the Equipment Trust
     Agreements, the Lease and the other Operative Agreements to which Union or
     Procor, as the case may be, is, or is to be, a party;

          (iv)  subject to the limitations and qualifications set forth in
     clause (xvi) of this Section 6(b), assuming that the Pass Through
     Certificates have been duly authorized and validly executed,
     authenticated, issued and delivered by the Pass Through Trustee pursuant
     to the Pass Through Trust Agreements, the holders of
     such Pass Through Certificates are entitled to the benefits of the Pass
     Through Trust Agreements;

          (v)  the Pass Through Certificates conform in all material respects
     to the description thereof contained in the Prospectus, and such
     description conforms in all material respects to the rights set forth in
     the instruments defining the same;

          (vi)  no authorization, approval, consent, order or license of or
     filing with or notice to any government, governmental instrumentality,
     regulatory body or authority or court is required for the valid
     authorization, execution, delivery and performance by the Companies of
     this Agreement, the Participation Agreement, the Pass Through Trust
     Agreements, the Equipment

                                     - 11 -

<PAGE>   12
     Trust Agreements, the Lease and the other Operative Agreements to which
     Union or Procor, as the case may be, is, or is to be, a party, or the
     consummation by Union or Procor, as the case may be, of the transactions
     contemplated by this Agreement, the Participation Agreement, the Pass
     Through Trust Agreements, the Equipment Trust Agreements, the Lease and the
     other Operative Agreements to which Union or Procor, as the case may be,
     is, or is to be, a party, except (w)such as are required under the Act,
     the Trust Indenture Act and the securities or Blue Sky laws of the various
     states, (x)such filings, recordings or registrations with the STB and
     under Section 90 of the Railway Act (Canada) as may be required, (y)the
     filing of Uniform Commercial Code financing statements in various
     jurisdictions and the filing of continuation statements with respect
     thereto required to be filed at periodic intervals under the Uniform
     Commercial Code and (z)such other filings, recordings or registrations     
     as may be required under the Operative Agreements;
        
          (vii)  to the best knowledge of such counsel, there is no pending or
     threatened action, suit or proceeding before any court or governmental
     agency, authority or body or any arbitrator involving the Companies or any
     of their respective subsidiaries, of a character required to be disclosed
     in the Registration Statement or the Prospectus which is not adequately
     disclosed, and there is no franchise, contract or other document of a
     character required to be described in the Registration Statement or
     Prospectus, or to be filed as an exhibit, which is not described or filed
     as required;

          (viii)  the Registration Statement has become effective under the Act;
     any required filing of the Prospectus, and any supplements thereto,
     pursuant to Rule 424(b) has been made in the manner and within the time
     period required by Rule 424(b); the Pass Through Trust Agreements have
     become qualified under the Trust Indenture Act; to the knowledge of such
     counsel, no stop order suspending the effectiveness of the Registration
     Statement has been issued, no proceedings for that purpose have been
     instituted or threatened, and the Registration Statement, the Prospectus
     and each amendment thereof or supplement thereto (other than the financial
     statements and related schedules and other financial and statistical
     information, including the notes thereto, included or incorporated by
     reference therein as to which such counsel need express no opinion) comply
     as to form in all material respects with the applicable requirements of the
     Act and the Exchange Act and the respective rules and regulations
     thereunder; the Pass Through Trust Agreements and the Statement of
     Eligibility and Qualification of the Pass Through Trustee on Form T-1
     comply as to form in all material respects with the requirements of the
     Trust Indenture Act and the rules and regulations thereunder; and each
     document filed pursuant to the Exchange Act and incorporated by reference
     in the Prospectus

                                     - 12 -

<PAGE>   13
     (except for the financial statements, including the notes thereto, and
     related schedules and other financial and statistical information included
     or incorporated by reference therein, as to which such counsel need express
     no opinion) appeared on its face, as of its respective filing date, to
     comply as to form in all material respects with the requirements of the
     Exchange Act and the rules and regulations thereunder;
        
          (ix)  title to the equipment to be subjected to the Lease will, when
     such equipment shall have been transferred to the Owner Trustee as
     provided in the Participation Agreement, be validly vested in the Owner
     Trustee, subject to no liens or encumbrances of record at the STB;

          (x)   other than rights of the Companies under the respective
     Equipment Trust Agreements, title to the equipment to be subjected to the
     Equipment Trust Agreements will, when such equipment shall have been
     transferred to the Equipment Trust Trustees as provided in the Equipment
     Trust Agreements, be validly vested in the respective Equipment Trust
     Trustee; the Equipment Trust Agreements have been duly filed and recorded
     with the STB and the Registrar General of Canada and such equipment is
     subject to no liens or encumbrances of record at the STB and the Registrar
     General of Canada;

          (xi)  this Agreement, the Pass Through Trust Agreements, the
     Participation Agreement, the Equipment Trust Agreements, the Lease, and
     all the other Operative Agreements to which Union or Procor is, or is to
     be, a party have been duly authorized and, on the Closing Date, assuming
     due authorization, execution and delivery by the parties thereto other than
     Union or Procor, as the case may be, upon execution and delivery by Union
     or Procor, as the case may be, will be valid and binding obligations of
     Union or Procor, as the case may be, enforceable against Union or Procor,
     as the case may be, in accordance with their respective terms, except (i)as
     may be limited by bankruptcy, insolvency, reorganization, moratorium or
     other similar laws affecting enforcement of creditors' rights generally and
     by general principles of equity (regardless of whether enforcement is
     considered in a proceeding in equity or at law), (ii)in the case of the
     Lease, as limited by applicable laws which may affect the remedies provided
     in the Lease, which laws, however, do not in such counsel's opinion make
     the remedies provided in the Lease inadequate for the practical realization
     of the rights and benefits provided thereby and (iii)in the case of this
     Agreement, as to provisions relating to indemnification or contribution for
     liabilities arising under the Act, as to which such counsel need express no
     opinion;

                                     - 13 -

<PAGE>   14
          (xii)  the Pass Through Trust Agreements, the Equipment Notes, the
     ETCs, the Indenture, the Participation Agreement, the Equipment Trust
     Agreements, the Lease and the other Operative Agreements (to the extent
     described therein) conform in all material respects to the descriptions
     thereof contained in the Prospectus;

          (xiii)  the execution and delivery by the Companies of this
     Agreement, the Participation Agreement, the Pass Through Trust Agreements,
     the Equipment Trust Agreements, the Lease and the other Operative
     Agreements to which Union or Procor, as the case may be, is, or is to be,
     a party, the consummation by the Companies of the transactions herein and
     therein contemplated and in the manner herein and therein contemplated and
     compliance by the Companies with the terms hereof and thereof, do not and
     will not conflict with, or result in a breach by the Companies of, any of
     the terms or provisions of, or constitute a default under, any material
     indenture or other agreement or instrument known to such counsel to which
     the Companies are a party or by which the Companies are bound, or any law,
     rule, regulation, judgment or order known to such counsel to be applicable
     to the Companies of any court, regulatory body, administrative agency,
     government or governmental body having jurisdiction over the Companies,
     except that such counsel need express no opinion or belief as to the
     accuracy or completeness of the Registration Statement or Prospectus
     except for the opinions expressed in clauses (v), (xii), and (xiv) (except
     that such counsel need not express any opinion as to any violation of any
     such law, rule or regulation, judgment or order (a)which does not
     materially affect the validity of the Equipment Notes, the ETCs or the
     Pass Through Certificates or (b)which reflects conclusions based on
     misrepresentations to, concealment of information from or other fraudulent
     acts perpetrated on such counsel);

          (xiv)  the statements in the Registration Statement and Prospectus
     under the headings "Certain Federal Income Tax Consequences", "Certain
     Illinois Taxes", "ERISA Considerations" and "_____", to the extent that
     they constitute matters of law or legal conclusions with respect thereto,
     have been prepared or reviewed by such counsel and are correct in all
     material respects;

          (xv)  neither Union nor Procor is an "investment company" or a
     company "controlled" by an "investment company" within the meaning of the
     Investment Company Act of 1940, as amended;

          (xvi)  on the Closing Date, assuming due authorization, execution,
     issuance and delivery of the ETCs by their respective Equipment Trust
     Trustee as contemplated by the related Equipment Trust Agreement, and
     assuming due

                                     - 14 -

<PAGE>   15
     authorization, execution, issuance and delivery of the Equipment Notes by
     the Owner Trustee as contemplated by the Indenture, and due authentication
     of such ETCs by the respective Equipment Trust Trustee and of such
     Equipment Notes by the Indenture Trustee, each of the ETCs and the
     Equipment Notes when issued will constitute valid and binding obligations
     of such Equipment Trust Trustee and the Owner Trustee, respectively,
     enforceable against such Equipment Trust Trustee and the Owner Trustee,
     respectively, in accordance with their terms, except as may be limited by
     bankruptcy, insolvency, reorganization, moratorium or other similar laws
     affecting enforcement of creditors' rights generally and by general
     principles of equity (regardless of whether enforcement is considered in a
     proceeding in equity or at law); and the holders of the ETCs will be
     entitled to the benefits of the respective Equipment Trust Agreement, and
     the holders of the Equipment Notes will be entitled to the benefits of the
     Indenture;
        
          (xvii)  assuming due authorization, execution and delivery of the
     Pass Through Trust Agreements by the Pass Through Trustee, each of the
     Pass Through Trust Agreements constitutes the valid and binding obligation
     of each of the Companies party to such Pass Through Agreement enforceable
     in accordance with its terms, except as may be limited by bankruptcy,
     insolvency, reorganization, moratorium or other similar laws affecting
     enforcement of creditors' rights generally and by general principles of
     equity (regardless of whether enforcement is considered in a proceeding in
     equity or at law);

          (xviii)  neither trust created by the Pass Through Trust Agreements
     will be classified as an association taxable as a corporation for federal
     income tax purposes, but rather, each will be classified as a grantor
     trust under subpart E, Part I of Subchapter J of the Internal Revenue Code
     of 1986, as amended (the "Code"), and each Certificate Owner will be
     treated as the owner of a pro rata undivided interest in each of the ETCs
     and Equipment Notes, as the case may be, and any other property held in
     such Pass Through Trusts;

          (xix)  although counsel is not aware of any judicial authority, the
     Pass Through Trusts are not required to be registered under the Investment
     Company Act of 1940, as amended;

          (xx)  assuming due authorization, execution and delivery of the
     Indenture by the parties thereto, the Indenture will subject the Indenture
     Estate covered by the Indenture to the security interests created thereby;

          (xxi)  there are no taxes, fees or other governmental charges payable
     under the laws of the State of Illinois or any political subdivision
     thereof in

                                     - 15 -

<PAGE>   16
     connection with the execution and delivery by the Pass Through Trustee, in
     its individual capacity or as Pass Through Trustee, the Equipment Trust
     Trustee or Indenture Trustee, as the case may be, of the Participation
     Agreement, the Pass Through Trust Agreements, the Equipment Trust
     Agreements and the Operative Agreements, as the case may be, or in
     connection with the issuance, execution, authentication and delivery of the
     Pass Through Certificates by the Pass Through Trustee pursuant to the Pass
     Through Trust Agreements or the issuance, authentication or delivery of the
     ETCs and the Equipment Notes;
        
          (xxii)  Except to the extent the Indenture Trustee forecloses on the
     Equipment and any of the Equipment is located in Illinois or the Equipment
     Trust Trustee forecloses on the Trust Equipment and any of the Trust
     Equipment is located in the State of Illinois or to the extent the
     Indenture Estate, the trust created by the Union Equipment Trust
     Agreement, the trust created by the Procor Equipment Trust Agreement or
     the trusts created by the Pass Through Trust Agreements, as applicable,
     engages in business in Illinois as a result of such foreclosure:

          (I) neither the trusts created by the Pass Through Trust Agreements,
     the Equipment Trust Agreements, the Indenture Estate nor the Pass Through
     Trustee (either in its individual capacity or as Pass Through Trustee),
     nor their respective affiliates, successors or assigns, will be subject to
     any tax (including, without limitation, net or gross income, tangible or
     intangible property, net worth, capital, franchise or doing business tax),
     fee or other governmental charge under the laws of the State of Illinois
     or any political subdivision thereof (other than taxes imposed on the fees
     received by the Pass Through Trustee for acting as Pass Through Trustee
     under the Pass Through Trust Agreements).

          (II) Certificate Owners who are not residents of or otherwise subject
     to tax in the State of Illinois will not be subject to any tax (including,
     without limitation, net or gross income, tangible or intangible property,
     net worth, capital, franchise or doing business tax), fee or other
     governmental charge under the laws of the State of Illinois or any
     political subdivision thereof as a result of purchasing, holding
     (including receiving payments with respect to) or selling a Certificate.

          (III) There are no applicable taxes under the laws of the State of
     Illinois or any political subdivision thereof upon or with respect to
     (a)the construction, mortgaging, financing, refinancing, purchase,
     acquisition, acceptance, rejection, delivery, nondelivery, transport,
     location, ownership, insurance, control, assembly, possession,
     repossession, operation, use,

                                     - 16 -

<PAGE>   17
     condition, maintenance, repair, sale, return, abandonment, replacement,
     preparation, installation, storage, redelivery, manufacture, leasing,
     subleasing, modification, rebuilding, importation, transfer of title,
     transfer of registration, exportation or other application or disposition
     of the Equipment or any interest in any thereof, (b)payments of Rent or the
     receipts, income or earnings arising therefrom or received with respect to
     the Equipment or any interest in any thereof or payable pursuant to the
     Lease, (c)any amount paid or payable pursuant to any Operative Agreement,
     (d)the Equipment or any interest therein or the applicability of the Lease
     to the Equipment or any interest thereof, (e)any or all of the Operative
     Agreements, any or all of the ETCs or the Equipment Notes or any interest
     in any or all thereof or the offering, registration, reregistration,
     issuance, acquisition, modification, assumption, reissuance, refinancing or
     refunding or any or all thereof, and any other documents contemplated
     hereby or thereby and amendments and supplements hereto and thereto, (f)the
     payment of the principal of, or interest or premium on, or other amounts
     payable with respect to, any or all of the ETCs or the Equipment Notes,
     whether as originally issued or pursuant to any refinancing, refunding,
     assumption, modification, or reissuance, or any other obligation evidencing
     any loan in replacement of the loan evidenced by any or all of the ETCs or
     the Equipment Notes, (g)the property, or the income, earnings, receipts or
     other proceeds received with respect to the property, held by the Indenture
     Trustee under the Indenture or held by the Equipment Trust Trustees under
     the respective Equipment Trust Agreements or (h)otherwise with respect to
     or in connection with the transactions contemplated by the Operative
     Agreements, which would not have been imposed if the Indenture Trustee or
     the Equipment Trust Trustees had not had their principal place of business
     in, had not performed (either in its individual capacity or as Indenture
     Trustee) any or all of their administrative duties under the Operative
     Agreements in, and had not engaged in any activities unrelated to the
     transactions contemplated by the Operative Agreements in, the State of
     Illinois;
        
          [(xxiii)  the Union Guarantee contained in Pass Through Agreement #2
     and endorsed on the Pass Through Certificates issued under such agreement
     has been duly authorized, executed and delivered by Union and assuming the
     due authorization, execution and delivery of the Pass Through Trust
     Agreement #2 and the due authentication of such Pass Through Certificates
     by the Pass Through Trustee, constitutes a valid and binding obligation of
     Union, enforceable against Union in accordance with its terms, except as
     may be limited by bankruptcy, insolvency, reorganization, moratorium or
     other similar laws affecting enforcement of creditors' rights generally
     and by general principals of equity (regardless of whether enforcement is
     considered in a proceeding in equity or at law);] and

                                     - 17 -

<PAGE>   18
          (xxiv)  neither the Union Equipment Trust Agreement can be terminated
     by Union nor the Procor Equipment Trust Agreement can be terminated by
     Procor so long as the Union ETC and the Procor ETC, respectively, are
     outstanding.

In passing on the form of the Registration Statement and the Prospectus and
each amendment and supplement thereof, such counsel may state that it has not
independently verified the accuracy, completeness or fairness of the statements
made or included therein and takes no responsibility therefor and that such
opinion is based upon such counsel's examination of the Registration Statement,
the Prospectus as amended or supplemented, its activities in connection with
the preparation thereof and its participation in conferences with certain
officers and employees of Union, Procor and their respective subsidiaries and
with representatives of Ernst & Young and any others referred to in such
opinion, and subject to the same qualifications, such counsel may also state
that, although they are not passing upon, and do not assume any responsibility
for, the accuracy, completeness or fairness of the statements contained in the
Registration Statement and Prospectus and have not made any independent check
or verification thereof, nothing has come to their attention in their
examination of the Registration Statement, their participation in the
preparation thereof and participation in the above-referenced conferences that
has caused them to believe that the Registration Statement, at the time it
became effective, 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, or the Prospectus, as of its date and as of
the Closing Date, contained an untrue statement of a material fact or omitted
to state a material fact necessary to make the statements therein, in the light
of the circumstances under which they were made, not misleading.  In rendering
such opinion, such counsel may state that it expresses no opinion as to the
laws of any jurisdiction other than the State of Illinois, the General
Corporation Law of the State of Delaware and the Federal law of the United
States of America and may rely (A)as to matters involving the application of
(x)laws of Canada or its Provinces and (y)laws, rules and regulations with
respect to the STB to the extent deemed proper and specified in such opinion,
upon the opinion of other counsel of good standing whom such counsel believes
to be reliable and who are satisfactory to you and your counsel; and (B)as to
matters of fact, to the extent deemed proper, on certificates of responsible
officers of the Company and public officials, and may assume for purposes of
its opinion with respect to this Agreement set forth in Section 6(b)(xi) that
the laws of the State of New York are identical to the laws of the State of
Illinois.

     (c) The Companies shall have furnished to you and the Rating Agencies if
requested by you, the opinion of ________, special Canadian counsel to Procor,
as to Canadian law matters, to the effect that

                                     - 18 -


<PAGE>   19
                     (i)  the payment by Procor of interest and principal on 
                the Procor ETC to the Pass Through Trustee will be exempt from
                Canadian withholding tax; the payment by the Pass Through
                Trustee of interest and principal on    the Pass Through
                Certificate, Series ____ to a holder thereof will be exempt
                from Canadian withholding tax for a holder who is, or is deemed
                to be, a non-resident of Canada and with whom Union and Procor
                deals at arm's length, within the meaning of the Income Tax Act
                (Canada) (the "Tax Act"), at the time of making the payment;
                and

                     (ii)  no other taxes on income (including taxable capital
                gains) will be payable under the Tax Act in respect of the 
     holding or disposition of the Procor ETC, or the receipt of interest
     thereon, by the Pass Through Trustee; no other taxes on income (including
     taxable capital gains) will be payable under the Tax Act in respect of
     the acquisition, holding or disposition of the Pass Through Certificates,
     Series ____, or the receipt of interest thereon by holders who are, or are
     deemed to be, non-residents of Canada for the purposes of the Tax Act at
     any time during which they hold Pass Through Certificates, Series ____ and
     who do not use or hold and are not deemed by such laws to use or hold the
     Pass Through Certificates, Series ____ in carrying on business in Canada
     for the purposes of the Tax Act, and, in the case of a Certificate Owner
     who carries on an insurance business in Canada and elsewhere whose Pass
     Through Certificates are not effectively connected with its Canadian
     insurance business.  In rendering such opinion, such counsel may state
     that it expresses no opinion as to     the laws of any jurisdiction other
     than Canada or its Provinces.

                (d)  You shall have received from ___________, counsel for ____,
         individually, as Pass Through Trustee, Equipment Trust Trustee and
         Indenture Trustee, an opinion, dated the Closing Date, in form and
         substance reasonably satisfactory to you and Mayer, Brown & Platt,
         your special counsel to the effect that:

                     (i)  The ________ is a national banking association validly
                existing and holding a valid certificate to do business as a
                national banking association with trust powers, and, in its
                individual capacity or as Pass Through Trustee, Equipment Trust
                Trustee or Indenture Trustee, as the case may be, has full 
                corporate power and authority to execute, deliver and
                carry out the terms of the Indenture, the Equipment Trust
                Agreements, the Participation Agreement, the Pass Through Trust
                Agreements and the other Operative Agreements to which it is a
                party;

                     (ii)  The ___________ (in its individual capacity, to the
                extent provided therein), the Pass Through Trustee, the 
                Equipment Trust Trustee or the Indenture Trustee, as the case 
                may be, has duly authorized, executed and delivered the 
                Indenture, the Participation Agreement, the Equipment Trust 
                Agreements, the Pass Through Trust Agreements and the other 
                Operative Agreements

                                     - 19 -

<PAGE>   20
     to which it is a party and each of such agreements constitutes the 
     valid and binding obligations of ____________ (in its individual capacity,
     to the extent provided therein), the Pass Through Trustee, the
     Equipment Trust Trustee or the Indenture Trustee, as the case may be,
     enforceable against __________ (in its individual capacity, to the extent
     provided therein), the Pass Through Trustee, the Equipment Trust Trustee
     or the Indenture Trustee, as the case may be, in accordance with their
     respective terms, except as limited by bankruptcy, insolvency, moratorium
     reorganization, receivership, fraudulent conveyance or other similar laws
     affecting enforcement of creditors' rights generally, and except as
     enforcement thereof is subject to general principles of equity (regardless
     of whether enforcement is considered in a proceeding in equity or at law);
        
          (iii)  the Pass Through Certificates have been duly authorized and
     validly executed, authenticated, issued and delivered by the Pass Through
     Trustee pursuant to the Pass Through Trust Agreements; and the holders of
     the Pass Through Certificates are entitled to the benefits of the Pass
     Through Trust Agreements;

          (iv)  the authorization, execution, delivery and performance by
     ________ (in its individual capacity, to the extent provided therein), the
     Pass Through Trustee, the Equipment Trust Trustee or the Indenture
     Trustee, as the case may be, of the Indenture, the Participation
     Agreement, the Equipment Trust Agreements, the Pass Through Trust
     Agreements and the other Operative Agreements to which it is or will be
     party and the consummation of the transactions therein contemplated and
     compliance with the terms thereof and issuance of the Pass Through
     Certificates thereunder do not and will not result in the violation of the
     provisions of the Articles of Association or By-Laws of _____________, and
     do not and will not conflict with, or result in a breach of any terms or
     provisions of, or constitute a default under, or result in the creation or
     the imposition of any lien, charge or encumbrance upon any property or
     assets of ____________, the Pass Through Trustee, the Equipment Trust
     Trustee or the Indenture Trustee, as the case may be, under any indenture,
     mortgage or other agreement or instrument known to such counsel to which
     the Pass Through Trustee, the Equipment Trust Trustee or the Indenture
     Trustee, as the case may be, is a party or by which it or any of its
     property is bound, or any Illinois or Federal law, rule or regulation
     governing ______________, the Pass Through Trustee's, the Equipment Trust
     Trustee's or the Indenture Trustee's banking or trust powers, or of any
     judgment, order of decree known to such counsel to be applicable to
     ____________, the Pass Through Trustee, the Equipment Trust Trustee or the
     Indenture Trustee, as the case may be, of any court, regulatory body,
     administrative agency, government or governmental body having jurisdiction
     over ______________, the Pass

                                     - 20 -


<PAGE>   21
          Through Trustee, the Equipment Trust Trustee or the Indenture Trustee
          or its respective properties;
        
                (v)  no authorization, approval, consent, license or order of,
         giving of notice to, registration with, or taking of any other action
         in respect of, any Federal or state governmental authority or agency
         pursuant to any Federal or Illinois law governing the banking or trust
         powers of __________, the Pass Through Trustee, the Equipment Trust
         Trustee or the Indenture Trustee is required for the authorization,
         execution, delivery and performance by _____________, (in its
         individual capacity, to the extent provided therein), the Pass Through
         Trustee, the Equipment Trust Trustee or the Indenture Trustee of the
         Indenture, the Participation Agreement, the Equipment Trust
         Agreements, the Pass Through Trust Agreement and the other Operative
         Agreements to which it is or will be a party or the consummation of
         any of the transactions by the Pass Through Trustee, the Equipment
         Trust Trustee or Indenture Trustee contemplated thereby or the
         issuance of the Pass Through Certificates under the Pass Through Trust
         Agreements (except as shall have been duly obtained, given or taken);
         and such authorization, execution, delivery, performance, consummation
         and issuance do not conflict with or result in a breach of the
         provisions of any such law.
        
In giving such opinion, __________, counsel for ________ (A) may state that no
opinion is expressed as to laws other than the laws of the State of Illinois
and the Federal law of the United States of America, (B)may assume as to the
opinions expressed in clause (ii) relating to any of the Operative Agreements,
insofar as they involve matters relating to the laws of any jurisdiction other
than Illinois, that such Operative Agreements constitute legal, valid and
binding instruments under such laws and (C)may include such other reasonable
assumptions as are customary in legal opinions delivered in connection with
transactions of this type.

         (e) You shall have received from Mayer, Brown & Platt, your special
     counsel, such opinion or opinions, dated the Closing Date, with respect to
     the issuance and sale of the Pass Through Certificates, the Pass
     Through Trust Agreements, the Registration Statement, the Prospectus and
     other related matters as you may reasonably require, and the Companies
     shall have furnished to such counsel such documents as they reasonably
     request for the purpose of enabling them to pass upon such matters.

         (f) You shall have been furnished with a certificate of each of the
     Companies, signed by the President or any Vice President and the principal 
     financial officer of each of the Companies, respectively, each dated the
     Closing Date, to the effect that the signers of such certificates have
     carefully examined the Registration Statement, the Prospectus and this
     Agreement and that:



                                     - 21 -

<PAGE>   22
          (i)  the representations and warranties of the Companies in this
     Agreement are true and correct in all material respects on and as of the
     Closing Date with the same effect as if made on the Closing Date and the
     Companies have complied with all the agreements and satisfied all the
     conditions on its part to be performed or satisfied at or prior to the
     Closing Date;

          (ii)  no stop order suspending the effectiveness of the Registration
     Statement has been issued and, to the Companies' knowledge, no proceedings
     for that purpose have been instituted or threatened; and

          (iii)  since the date of the most recent financial statements
     incorporated by reference in the Prospectus, there has been no material
     adverse change in the condition (financial or other), earnings, business
     or properties of the Companies and their respective subsidiaries, whether
     or not arising from transactions in the ordinary course of business, except
     as set forth in or contemplated in the Prospectus.
        
     (g) The representations and warranties of each of the Companies contained
in the Equipment Trust Agreements, the Participation Agreement, the Lease and
the other Operative Agreements to which it is a party shall be true and correct
in all material respects on and as of the Closing Date with the same effect as
though such representations and warranties had been made on and as of such
date, and each of the Companies shall have delivered to you a certificate, each
dated the Closing Date, signed in each case by its President or any Vice
President and its principal financial or accounting officer to the effect that
the signers of such certificate have carefully examined the Equipment Trust
Agreements, the Participation Agreement, the Lease and the other Operative
Agreements to which it is a party, the Registration Statement, the Preliminary
Prospectus and the Prospectus and that:

          (i) the representations and warranties of such Company in the
     Equipment Trust Agreements, Participation Agreement, the Lease and the
     other Operative Agreements to which it is a party are true and correct in
     all material respects on and as of the Closing Date as if made on and as
     of the Closing Date;

          (ii) such Company has complied with all the agreements and satisfied
     all the conditions on its part to be performed or satisfied on or prior to
     the Closing Date pursuant to the terms of the Equipment Trust Agreements,
     the Participation Agreement, the Lease and other Operative Agreements to
     which it is a party; and

          (iii) nothing has come to the attention of such person that would
     lead him or her to believe that the Registration Statement contains any
     untrue

                                     - 22 -

<PAGE>   23
     statement of material fact or omits to state any material fact
     necessary in order to make the statements therein, in the light of the
     circumstances under which they were made, not misleading.

     (h) At the Execution Time and at the Closing Date, Ernst & Young shall
have furnished to you a letter or letters, dated, respectively, as of the
Execution Time and as of the Closing Date, in form and substance satisfactory
to you, confirming that:

          (i)  they are independent auditors within the meaning of the Act and
     the applicable published rules and regulations thereunder and stating in
     effect that in their opinion the audited consolidated financial statements
     and schedules thereto incorporated by reference in the Registration
     Statement and the Prospectus and reported on by them comply as to form in
     all material respects with the applicable accounting requirements of the
     Act and the applicable published rules and regulations thereunder with
     respect to registration statements on Form S-3; and that nothing came to
     their attention which caused them to believe that the amounts under the
     caption "Selected Financial Information" for each of the five
     years ended ________ included in the Registration Statement and the
     Prospectus, do not agree with the corresponding amounts in the audited
     financial statements from which such amounts were derived; and as to the
     periods for which it served as Union's independent auditor, such financial
     statements were covered by unqualified reports issued by them; and

          (ii)  they have performed certain other specified procedures as a
     result of which they determined that certain information of an accounting,
     financial or statistical nature (which is limited to accounting, financial
     or statistical information derived from the general accounting records of
     Union) set forth in the Registration Statement and the Prospectus,
     including the information set forth under the captions "Selected Financial
     Information", and in [Exhibit 12] to the Registration Statement agrees
     with the accounting records and schedules of the Company and its
     subsidiaries, excluding any questions of legal interpretation.

     (i) In addition, Ernst & Young shall have furnished to you a letter or
letters, dated, respectively, as of the Execution Time and as of the Closing
Date, in form and substance satisfactory to you, to the effect that on the
basis of a reading of the unaudited condensed financial statements of Union
contained in Union's Quarterly Reports on Form 10-Q for the quarter ended
_______ incorporated by reference in the Registration Statement, the amounts
set forth under the captions "Selected Financial Information" and
"Capitalization" included in the Registration Statement and the Prospectus and
of the latest unaudited consolidated financial statements made available to
them by Union and its subsidiaries; carrying out certain specified procedures
(but

                                     - 23 -

<PAGE>   24
not an audit in accordance with generally accepted auditing standards)
which would not necessarily reveal matters of significance with respect to the
comments set forth in such letter; a reading of the minutes of the meetings of
the stockholders, directors and executive committees of Union and its
subsidiaries; and inquiries of certain officials of Union who have
responsibility for financial and accounting matters of Union and its
subsidiaries as to transactions and events subsequent to _______ nothing came
to their attention which caused them to believe that (A) the unaudited
consolidated financial statements of Union incorporated by reference in the
Registration Statement do not comply as to form in all material respects with
the applicable accounting requirements of the Act and the Exchange Act and the
rules and regulations thereunder as they apply to Form 10-Q or are not
presented in conformity with generally accepted accounting principles applied
on a basis substantially consistent with that of the audited consolidated
financial statements of Union incorporated by reference in the Registration
Statement, and (B)with respect to the period subsequent to __________, there
were any changes, at a specified date not more than five business days prior to
the date of the letter, in the borrowed debt of Union and its subsidiaries or
capital stock of Union or decreases in the stockholder's equity of Union and
its subsidiaries as compared with the amounts shown on the __________,
unaudited consolidated balance sheet data included in "Selected Financial
Information" in the Registration Statement and the Prospectus, or for the
period from _________ to such specified date, there were any
decreases, as compared with the corresponding period in the preceding year, in
total revenues from net sales and services, or in income before income taxes or
net income, of Union and its subsidiaries, except in all instances for changes
or decreases set forth in such letter, in which case the letter shall be
accompanied by an explanation by Union as to the significance thereof unless
said explanation is not deemed necessary by you.

References to the Prospectus in paragraphs (h) and (i) include any supplement
thereto at the date of the letter.

     (j) Subsequent to the Execution Time or, if earlier, the respective dates
as of which information is given in the Registration Statement and the
Prospectus, there shall not have been (i)any change or decrease specified in
the letters referred to in paragraphs (g) and (h) of this Section 6 or (ii)any
change, or any development involving a prospective change, in or affecting the
business or properties of Union and its subsidiaries taken as a whole the
effect of which, in any case referred to in clause (i) or (ii) above, is, in
your judgment, so material and adverse as to make it impractical or inadvisable
to proceed with the public offering or the delivery of the Pass Through
Certificates as contemplated by the Registration Statement and the Prospectus.

     (k) Subsequent to the Execution Time and prior to the Closing Date, there
shall not have occurred any downgrading, nor shall any notice have been given
of (i)any intended or potential downgrading or (ii)any review or possible
change in the

                                     - 24 -

<PAGE>   25
     rating accorded Union's debt securities by the Rating Agencies as of the
     Execution Time.
        
           (l) Prior to the Closing Date, the Companies shall have furnished to
     you and the Rating Agencies such further information, certificates and 
     documents as you and they may reasonably request.

           (m) The Pass Through Certificates shall have received ratings of "A2
     senior secured" by Moody's Investors Service, Inc. and "A+" by Standard &
     Poor's Corporation.

     If any of the conditions specified in this Section 6 shall not have been
fulfilled in all material respects when and as provided in this Agreement, or
if any of the opinions and certificates mentioned above or elsewhere in this
Agreement shall not be in all material respects reasonably satisfactory in form
and substance to you and your counsel, this Agreement and all your obligations
hereunder may be canceled at, or at any time prior to, the Closing Date by you.
Notice of such cancellation shall be given to the Companies in writing or by
telephone or telegraph confirmed in writing.

     7. Reimbursement of the Underwriters' Expenses.  If the sale of the Pass
Through Certificates provided for herein is not consummated because any
condition to your obligation set forth in Section 6 hereof is not satisfied,
because of any termination pursuant to Section 9 hereof or because of any
refusal, inability or failure on the part of the Companies to perform any
agreement herein or comply with any provision hereof other than by reason of a
default by you, the Companies will reimburse you upon demand for all
out-of-pocket expenses (including reasonable fees and disbursements of counsel)
that shall have been incurred by you in connection with the proposed purchase
and sale of the Pass Through Certificates.

     8. Indemnification and Contribution.  (a)  Union agrees to indemnify and
hold harmless you and each person who controls you within the meaning of either
the Act or the Exchange Act from and against any and all losses, claims,
damages or liabilities, joint or several, to which you or any of them may
become subject under the Act, the Exchange Act or other Federal or state
statutory law or regulation, at common law or otherwise, insofar as such
losses, claims, damages or liabilities (or actions in respect thereof) arise
out of or are based upon any untrue statement or alleged untrue statement of a
material fact contained in the registration statement for the registration of
the Pass Through Certificates as originally filed or in any amendment thereof,
or in any Preliminary Prospectus or the Prospectus, or in any amendment thereof
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, in the light of the circumstances
under which they were made, not misleading, and agrees to reimburse you and
each such controlling person for any legal or other expenses reasonably
incurred by you or such controlling person in connection with

                                     - 25 -

<PAGE>   26
investigating or defending any such loss, claim, damage, liability or action;
provided, however, that (i)Union will 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 any such untrue statement or alleged untrue statement or omission or
alleged omission made therein in reliance upon and in conformity with written
information furnished to the Companies by or on behalf of you specifically for
use in connection with the preparation thereof, and (ii)such indemnity with
respect to any Preliminary Prospectus shall not inure to your benefit (or to the
benefit of any person controlling you) if the person asserting any such loss,
claim, damage or liability purchased the Pass Through Certificates which are the
subject thereof did not receive a copy or the Prospectus (or the Prospectus as
amended or supplemented) excluding documents incorporated therein by reference
at or prior to the confirmation of the sale of such Pass Through Certificates to
such person in any case where such delivery is required by the Act and the
untrue statement or omission of a material fact contained in such Preliminary
Prospectus was corrected in the Prospectus (or the Prospectus as amended or
supplemented).  This indemnity agreement will be in addition to any liability
which Union may otherwise have.
        
     (b) You severally (and not jointly) agree to indemnify and hold harmless
each of the Companies, each of their respective directors, each of their
respective officers who signs the Registration Statement, and each person who
controls the Companies within the meaning of either the Act or the Exchange
Act, to the same extent as the foregoing indemnity from Union to you, but only
with reference to written information relating to you furnished to the
Companies by or on behalf of you specifically for use in the preparation of the
documents referred to in clause (a) of this Section 8.  This indemnity
agreement will be in addition to any liability which you may otherwise have.
The Companies acknowledge that the statements set forth in the last paragraph
of the cover page and under the heading "Underwriting" in any Preliminary
Prospectus and the Prospectus and the stabilization language included on the
inside front cover of any Preliminary Prospectus and the Prospectus constitute
the only information furnished in writing by or on behalf of you for inclusion
in any Preliminary Prospectus or the Prospectus, and you confirm that such
statements are correct.
        
     (c) Promptly after receipt by an indemnified party under this Section 8 of
notice of the commencement of any action, such indemnified party will, if a
claim in respect thereof is to be made against the indemnifying party under
this Section 8, notify the indemnifying party in writing of the commencement
thereof; but the omission so to notify the indemnifying party will not relieve
it from any liability which it may have to any indemnified party otherwise than
under this Section 8.  In case any such action is brought against any
indemnified party, and the indemnified party notifies the indemnifying party of
the commencement thereof, the indemnifying party will be entitled to appoint
counsel satisfactory to such indemnified party to represent the indemnified
party in such action; provided, however, if the defendants in any such action
include both the indemnified party and the indemnifying party and the
indemnified party shall have reasonably concluded that there may be legal
defenses available to it and/or other indemnified parties which are different
from or additional to those available to the

                                     - 26 -

<PAGE>   27
indemnifying party, the indemnified party or parties shall have the right to
select separate counsel to assert such legal defenses and to otherwise
participate in the defense of such action on behalf of such indemnified party or
parties.  Upon receipt of notice from the indemnifying party to such indemnified
party of the indemnifying party's election so to assume the defense of such
action and approval by the indemnified party of counsel, the indemnifying party
will not be liable to such indemnified party under this Section 8 for any legal
or other expenses subsequently incurred by such indemnified party in connection
with the defense thereof unless (i) the indemnified party shall have employed
separate counsel in connection with the assertion of legal defenses in
accordance with the proviso to the next preceding sentence (it being understood,
however, that the indemnifying party shall not be liable for the expenses of
more than one separate counsel, approved by you in the case of subparagraph (a),
representing the indemnified parties under subparagraph (a) who are parties to
such action), (ii)the indemnifying party shall not have employed counsel
satisfactory to the indemnified party to represent the indemnified party within
a reasonable time after notice of commencement of the action or (iii)the
indemnifying party has authorized the employment of counsel for the indemnified
party at the expense of the indemnifying party; and except that, if clause (i)
or (iii) is applicable, such liability shall be only in respect of the  counsel
referred to in such clause (i) or (iii).
        
     (d) In order to provide for just and equitable contribution in
circumstances in which the indemnification provided for in paragraph (a) of
this Section 8 is due in accordance with its terms but is for any reason held
by a court to be unavailable from Union on grounds of policy or otherwise,
Union and you shall contribute to the aggregate losses, claims, damages and
liabilities (including legal or other expenses reasonably incurred in
connection with investigating or defending same) to which Union and you may be
subject in such proportion so that each of you are responsible only for that
portion represented by the percentage that the aggregate underwriting
commission in respect of the Pass Through Certificates appearing on the cover
page of the Prospectus attributable to Pass Through Certificates sold by you
bears to the aggregate public offering price in respect of such Pass Through
Certificates appearing thereon and Union is responsible for the balance;
provided, however, that (y)in no case shall you be responsible for any amount in
excess of such respective underwriting commissions and (z)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.  For purposes of this Section 8, each person who
controls you within the meaning of the Act shall have the same rights to
contribution as you, and each person who controls the Companies within the
meaning of the Act, each officer of the Companies who shall have signed the
Registration Statement and each director of the Companies shall have the same
rights to contribution as the Companies, subject in each case to clauses (y) and
(z) of this paragraph (d).  Any party entitled to contribution will, promptly
after receipt of notice of commencement of any action, suit or proceeding
against such party in respect of which a claim for contribution may be made
against another party or parties under this paragraph (d), notify such party or
parties from whom contribution may be sought, but the omission to so notify

                                     - 27 -

<PAGE>   28
such party or parties shall not relieve the party or parties from whom
contribution may be sought from any other obligation it or they may have
hereunder or otherwise than under this paragraph (d).
        
     9. Termination.  This Agreement shall be subject to termination in your
absolute discretion by notice given to the Companies prior to delivery of and
payment for the Pass Through Certificates, if prior to such time (i) trading in
securities generally on the New York Stock Exchange shall have been suspended
or limited or minimum prices shall have been established on such Exchange, (ii)
a banking moratorium shall have been declared either by Federal, New York State
or Illinois State authorities or (iii) there shall have occurred any outbreak
or material escalation of hostilities or other calamity or crisis the effect of
which on the financial markets of the United States is such as to make it, in
your judgment, impracticable to market the Pass Through Certificates.

     10. Representations and Indemnities to Survive.  The respective
agreements, representations, warranties, indemnities and other statements of
the Companies or their respective officers and of you set forth in or made
pursuant to this Agreement will remain in full force and effect, regardless of
any investigation made by or on behalf of you or the Companies or any of their
respective officers, directors or controlling persons referred to in Section 8
hereof, and will survive delivery of and payment for the Pass Through
Certificates.  The provisions of Sections 7 and 8 hereof shall survive the
termination or cancellation of this Agreement.

     11. Notices.  All communications hereunder will be in writing and
effective only on receipt, and, if sent to you, will be mailed, delivered or
telegraphed and confirmed in the case of Solomon Brothers Inc at 7 World Trade
Center, New York, New York 10048, Attention:  Legal Department; in the case of
Morgan Stanley & Co. Incorporated at 1585 Broadway, New York, New York  10036,
Attention:  Legal Department; or, if sent to the Companies, will be mailed,
delivered or telegraphed and confirmed to it at 225 West Washington Street,
Chicago, Illinois 60606, Attention:  Secretary and to Procor at 2001 Speers
Road, Oakville, Ontario, Canada L6J 5E1, Attention:  President.

     12. Successors.  This Agreement will inure to the benefit of and be
binding upon the parties hereto and their respective successors and the
officers and directors and controlling persons referred to in Section 8 hereof,
and no other person will have any right or obligation hereunder.

     13. Applicable Law.  This Agreement will be governed by and construed in
accordance with the laws of the State of New York.


<PAGE>   29


     If the foregoing is in accordance with your understanding of our
agreement, please sign and return to us the enclosed duplicate hereof,
whereupon this letter and your acceptance shall represent a binding agreement
among the Company, Procor and you.

                                             Very truly yours,
 
                                             UNION TANK CAR COMPANY



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

                                             PROCOR LIMITED



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


The foregoing Agreement is
hereby confirmed and accepted as of the
date first written above.

SALOMON BROTHERS INC
MORGAN STANLEY & CO. INCORPORATED


By SALOMON BROTHERS INC
 Acting on behalf of itself and
 Morgan Stanley & Co. Incorporated



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


<PAGE>   30


                                                                      Schedule A





Pass Through       Principal                              Final Distribution
Certificate          Amount         Interest Rates              Dates 





<PAGE>   31

                                                                      Schedule B





                           Pass Through Certificate  Pass Through Certificate
                                 Series _____             Series ______
                            Aggregate Principal         Aggregate Principal
                                   Amount                     Amount
                           ------------------------  ------------------------

Salomon Brothers Inc

Morgan Stanley & Co.
Incorporated
Total



<PAGE>   1



                             Union Tank Car Company



                                   $_________

                               _____% ___________

                                 [(Series ___)]

                             Underwriting Agreement


                                                          New York, New York
                                                          __________


Salomon Brothers Inc
7 World Trade Center
New York, New York  10048

Morgan Stanley & Co. Incorporated
1585 Broadway
New York, New York  10036

Dear Ladies and Gentlemen:

     Union Tank Car Company, a Delaware corporation (the "Company"), proposes
to cause to be sold to you the underwriters (the "Underwriters") $_______
aggregate principal amount of _____% _________ [(Series ___)], due _______,
with the interest rate and principal installment payments as set forth in
Schedule A hereto (the certificates, [together with the guaranty to be endorsed
thereon by the Company,] being herein referred to as the "Securities"), to be
issued under the _________, dated as of _______ (the "______ Agreement"),
between the Company and ____________, as trustee (the "Trustee").

     1. Representations and Warranties.  The Company represents and warrants
to, and agrees with you, that:

<PAGE>   2


        (a) The Company meets the requirements for use of Form S-3 under the
     Securities Act of 1933, as amended (the "Act"), and has filed with the
     Securities and Exchange Commission (the "Commission") a registration
     statement  (file number 333-______) on such Form, including a related
     Preliminary Prospectus (as hereinafter defined), for the registration
     under the Act of the offering and sale of the Securities.  The Company may
     have filed one or more amendments thereto, including the related
     Preliminary Prospectus, each of which has previously been furnished to
     you.  The Company will next file with the Commission one of the following: 
     (i) prior to effectiveness of such registration statement, a further
     amendment to such registration statement, including the form of final
     prospectus or (ii) a final prospectus in accordance with Rules 430A and
     424(b)(1) or (4) under the Act.  In the case of clause (ii), the Company
     has included in such registration statement, as amended at the Effective
     Date (as hereinafter defined), all information (other than Rule 430A
     Information (as hereinafter defined)) required by the Act and the rules
     thereunder to be included in the Prospectus (as hereinafter defined) with
     respect to the Securities and the offering thereof.  As filed, such
     amendment and form of final prospectus, or such final prospectus, shall
     contain all Rule 430A Information, together with all other such required
     information, with respect to the Securities and the offering thereof and,
     except to the extent you shall agree in writing to a modification, shall
     be in all substantive respects in the form furnished to you prior to the
     Execution Time (as hereinafter defined) or, to the extent not completed at
     the Execution Time, shall contain only such specific additional
     information and other changes (beyond that contained in the latest
     Preliminary Prospectus) as the Company has advised you, prior to the
     Execution Time, will be included or made therein.

        (b) On the Effective Date, the Registration Statement (as hereinafter
     defined) did or will, and when the Prospectus is first filed in accordance
     with Rule 424(b) (if required) and on the Closing Date (as hereinafter
     defined), the Prospectus (and any supplements thereto) will, comply in all
     material respects with the applicable requirements of the Act and the
     Securities Exchange Act of 1934, as amended (the "Exchange Act"), and the
     respective rules and regulations thereunder; on the Effective Date, the
     Registration Statement did not or will not contain any untrue statement of
     a material fact or omit to state any material fact required to be stated
     therein or necessary in order to make the statements therein not
     misleading; on the Effective Date and on the Closing Date, the ______
     Agreement did or will comply in all material respects with the
     requirements of the Trust Indenture Act of 1939, as amended (the "Trust
     Indenture Act") and the rules thereunder; and, on the Effective Date, the  
     Prospectus, if not filed pursuant to Rule 424(b), did not or will not, and
     on the date of any filing pursuant to Rule 424(b) and on the Closing Date,
     the Prospectus (together with any supplement thereto) will not, include
     any untrue statement of a material fact or omit to state a material fact
     necessary in order to make the statements therein, in the light of the
     circumstances under which they were made, not misleading; provided,
     however, 

                                     -2-

<PAGE>   3


     that the Company makes no representations or warranties as to (i) that
     part of the Registration Statement which shall constitute the Statement
     of Eligibility and Qualification (Form T-1) under the Trust Indenture Act
     of the Trustee and (ii) the information contained in or omitted from the
     Registration Statement or the Prospectus (or any supplement thereto) in
     reliance upon and in conformity with information furnished in writing to
     the Company by you specifically for use in connection with the preparation
     of the Registration Statement or the Prospectus (or any supplement
     thereto).

        (c) The terms which follow, when used in this Agreement, shall have the
     meanings indicated.  The term "Effective Date" shall mean each date that
     the Registration Statement and any post-effective amendment or amendments
     thereto became or becomes effective.  "Execution Time" shall mean the date
     and time that this Agreement is executed and delivered by the parties
     hereto. "Preliminary Prospectus" shall mean any preliminary prospectus
     referred to in paragraph (a) above and any preliminary prospectus included
     in the Registration Statement at the Effective Date that omits Rule 430A
     Information.  "Prospectus" shall mean the prospectus relating to the
     Securities that is first filed pursuant to Rule 424(b) after the Execution
     Time or, if no filing pursuant to Rule 424(b) is required, shall mean the
     form of final prospectus relating to the Securities included in the
     Registration Statement at the Effective Date. "Registration Statement"
     shall mean the registration statement referred to in paragraph (a) above,
     including incorporated documents, exhibits and financial statements, as
     amended at the Execution Time (or, if not effective at the Execution Time,
     in the form in which it shall become effective) and, in the event any
     post-effective amendment thereto becomes effective prior to the Closing
     Date, shall also mean such registration statement as so amended.  Such
     term shall include any Rule 430A Information deemed to be included therein
     at the Effective Date as provided by Rule 430A.  "Rule 424", "Rule 430A"
     and "Regulation S-K" refer to such rules or regulation under the Act. 
     "Rule 430A Information" means information with respect to the Securities
     and the offering thereof permitted to be omitted from the Registration
     Statement when it becomes effective pursuant to Rule 430A.  Any reference
     herein to the Registration Statement, a Preliminary Prospectus or the
     Prospectus shall be deemed to refer to and include the documents
     incorporated by reference therein pursuant to Item 12 of Form S-3 which
     were filed under the Exchange Act on or before the Effective Date, or the
     issue date of such Preliminary Prospectus or the Prospectus, as the case
     may be; and any reference herein to the terms "amend", "amendment" or
     "supplement" with respect to the Registration Statement, any Preliminary
     Prospectus or the Prospectus shall be deemed to refer to and include the
     filing of any document under the Exchange Act after the Effective Date of
     the Registration Statement, or, the issue date of any Preliminary
     Prospectus or the Prospectus, as the case may be, deemed to be
     incorporated therein by reference.



                                     -3-

<PAGE>   4


        (d) The consolidated financial statements incorporated by reference in
     the Registration Statement and Prospectus present fairly the consolidated
     financial position of the Company and its subsidiaries as at the dates
     indicated and the consolidated results of their operations and cash flows
     for the periods specified and have been prepared in conformity with
     generally accepted accounting principles applied on a consistent basis
     during the periods involved, except as indicated therein, and the
     supporting schedules incorporated by reference in the Registration
     Statement present fairly the information required to be stated therein.

        (e) The documents incorporated by reference in the Prospectus, at the
     time they were or hereafter are filed with the Commission, complied and
     will comply in all material respects with the requirements of the Exchange
     Act, and the rules and regulations thereunder.

        (f) Since the respective dates as of which information is given in the
     Registration Statement and the Prospectus, except as otherwise stated
     therein or contemplated thereby, there has been no material adverse change
     in the condition, financial or otherwise, results of operations or general
     affairs of the Company and its subsidiaries, taken as a whole.

        (g) The Company and each Significant Subsidiary (with such term having
     the meaning attributed to it under Rule 405 under the Act) of the Company
     has been duly incorporated and is validly existing as a corporation in
     good standing under the laws of the jurisdiction in which it is chartered
     or organized, with full corporate power and authority to own its
     properties and conduct its business as described in the Prospectus, and is
     duly qualified to do business as a foreign corporation and is in good
     standing under the laws of each jurisdiction which requires such
     qualification wherein it owns or leases material properties or conducts
     material business, except in such jurisdictions in which the failure to so
     qualify would not have a material adverse effect on the Company and its
     subsidiaries taken as a whole.  Union owns either directly or indirectly,
     all of the issued and outstanding capital stock of its subsidiaries, free
     and clear of any lien, adverse claim, security interest or other
     encumbrance.

        (h) The execution and delivery by the Company of this Agreement, the
     ______ Agreement and the Securities, the consummation by the Company of
     the transactions herein and therein contemplated, and the compliance by
     the Company with the terms hereof and thereof do not and will not conflict
     with, or result in a breach of any of the terms or provisions of, or
     constitute a default under, the Certificate of Incorporation or By-Laws,
     as amended, of the Company, or any of its subsidiaries, or any material
     indenture, mortgage, or other agreement or instrument to which the Company
     or any of its subsidiaries is a party or by which any of its properties
     are bound, or any applicable law, rule, regulation, judgment, order or
     decree of any 




                                     -4-

<PAGE>   5

     government, governmental instrumentality or court, domestic or foreign,
     having jurisdiction over the Company or any of its subsidiaries or
     any of its properties; and, assuming due authorization, execution and
     delivery by all parties thereto other than the Company, no consent,
     approval, authorization, order or license of, or filing with or notice to
     any government, governmental instrumentality, regulatory body or authority
     or court, domestic or foreign, is required for the valid authorization,
     issuance and delivery of the Securities, the valid authorization,
     execution, delivery and performance by the Company of this Agreement and
     the ______ Agreement or the consummation by the Company of the
     transactions contemplated by this Agreement, the ______ Agreement and the
     Securities, except (w) such as are required under the Act, the Trust
     Indenture Act and the securities or Blue Sky laws of the various states,
     (x) such filings, recordings or registrations with the Interstate Commerce
     Commission and under Section 90 of the Railway Act of Canada as may be
     required and (y) such other filings, recordings or registrations as may be
     required under the ______ Agreement or the Securities.

        (i) This Agreement and the ______ Agreement, assuming due
     authorization, execution and delivery by the other parties thereto, have
     each been duly authorized by the Company and, when executed and delivered
     by the Company, will constitute valid and binding obligations of the
     Company.  The Securities and the ______ Agreement will conform in all
     material respects to the descriptions thereof in the Prospectus.

        (j) Ernst & Young, who reported on the consolidated financial
     statements of the Company as of __________ and for the year then ended,
     which statements are incorporated by reference in the Registration
     Statement and Prospectus, were, as of the date of its report on such
     consolidated financial statements, and are, as of the date hereof,
     independent auditors as required by the Act and the rules and regulations
     thereunder.

        (k) The Securities have been duly authorized by the Company and when
     duly executed and delivered by the Trustee and the Company in accordance
     with the terms of the ______ Agreement and this Agreement, will be duly
     issued under such _____ Agreement and will constitute valid and binding
     obligations of the Company, and the holders thereof will be entitled to
     the benefits of the _____ Agreement.

     2. Purchase and Sale.  Subject to the terms and conditions and in reliance
upon the representations and warranties herein set forth, the Company agrees to
cause to be sold to you, and you agree to purchase, from the Trustee at a
purchase price of 100% of the principal amount thereof, the Securities.

     As compensation to you, for your commitment and obligations hereunder in
respect of the Securities, the Company will pay to you when due an amount equal
to ____% of the 




                                     -5-

<PAGE>   6

original aggregate principal amount of the Securities.  The Company's
payments under this paragraph shall be made simultaneously with the payment by
you to the Trustee as specified in Section 3 hereof.  Payment of such
compensation shall be made by Federal funds check or other immediately
available funds to the order of Salomon Brothers Inc.

     3. Delivery and Payment.  Delivery of and payment for the Securities shall
be made at the office of Neal, Gerber & Eisenberg, Two North LaSalle Street,
Chicago, Illinois, at 9:00 a.m., Chicago time, on ________, or such later date
(not later than _______) as you shall designate, which date and time may be
postponed by agreement between you and the Company (such date and time of
delivery and payment for the Securities being herein called the "Closing
Date").  Delivery of the Securities shall be made to you against payment by you
of the purchase price thereof to or upon the order of the Trustee by Federal
funds check or other immediately available funds.  Certificates for the
Securities shall be registered in such names and in such denominations as you
may request not less than three full business days in advance of the Closing
Date.

     The Company agrees to have the Securities available for inspection,
checking and packaging by you in New York, New York, not later than 1:00 p.m.
on the business day prior to the Closing Date.

     4. Offering by Salomon Brothers Inc and Morgan Stanley & Co. Incorporated.
It is understood that, after the Registration Statement becomes effective,
each of you propose to offer the Securities for sale to the public as set forth
in the Prospectus.

     5. Agreements.  The Company agrees with you that:

        (a) The Company will use its reasonable best efforts to cause the
     Registration Statement, if not effective at the Execution Time, and any
     amendment thereof, to become effective and the _____ Agreement to be
     qualified under the Trust Indenture Act.  The Company will not file any
     amendment to the Registration Statement or supplement to the Prospectus
     unless the Company has furnished you a copy for your review prior to
     filing and will not file any such proposed amendment or supplement to
     which you reasonably object.  Subject to the foregoing sentence, if filing
     of the Prospectus is required under Rule 424(b), the Company will cause
     the Prospectus, properly completed, and any supplement thereto to be filed
     with the Commission pursuant to the applicable paragraph of Rule 424(b)
     within the time period prescribed and will provide evidence satisfactory
     to you of such timely filing.  The Company will promptly advise you (i)
     when the Registration Statement, if not effective at the Execution Time,
     and any amendment thereto, shall have become effective, (ii) when the
     Prospectus, and any supplement thereto, shall have been filed (if
     required) with the Commission pursuant to Rule 424(b), (iii) when, prior
     to termination of the offering of the Securities, any amendment to the
     Registration Statement shall have been 





                                     -6-
<PAGE>   7

     filed or become effective, (iv) of any request by the Commission for any
     amendment to the Registration Statement or supplement to the
     Prospectus or for any additional information, (v) of the issuance by the
     Commission of any stop order suspending the effectiveness of the
     Registration Statement or the institution or threatening of any proceeding
     for that purpose (and the Company agrees that it will use its reasonable
     best efforts to prevent the issuance of any such stop order and, if
     issued, to obtain as soon as possible the withdrawal thereof) and (vi) of
     the receipt by the Company of any notification with respect to the
     suspension of the qualification of the Securities for sale in any
     jurisdiction or the initiation or threatening of any proceeding for such
     purpose and (vii) during the period when a prospectus relating to the
     Securities is required to be delivered under the Act, of the mailing or
     the delivery to the Commission for filing of any document to be filed
     pursuant to the Exchange Act.

        (b) If, at any time when a prospectus relating to the Securities is
     required to be delivered under the Act, any event occurs as a result of
     which the Prospectus as then supplemented would include any untrue
     statement of a material fact or omit to state any material fact necessary
     to make the statements therein, in the light of the circumstances under
     which they were made, not misleading, or if it shall be necessary to amend
     the Registration Statement or supplement the Prospectus to comply with the
     Act or the Exchange Act or the respective rules and regulations
     thereunder, the Company promptly will prepare and file with the
     Commission, subject to paragraph (a) of this Section 5, an amendment or
     supplement which will correct such statement or omission or an amendment
     which will effect such compliance.

        (c) As soon as practicable, the Company will make generally available
     to its security holders and to the Underwriters an earnings statement or
     statements of the Company and its subsidiaries which will satisfy the
     provisions of Section 11(a) of the Act and the applicable rules and
     regulations thereunder.

        (d) The Company will furnish to you and your counsel, without charge,
     signed copies of the Registration Statement (including exhibits thereto)
     and, so long as delivery of a prospectus by you or a dealer may be
     required by the Act, as many copies of each Preliminary Prospectus and the
     Prospectus and any amendments thereof and supplements thereto as you may
     reasonably request.  The Company will pay the expenses of printing all
     documents relating to the offering.

        (e) The Company will cooperate with you and your special counsel to
     arrange for the qualification of the Securities for sale under the laws of
     such jurisdictions as you may reasonably designate, will maintain such
     qualifications in effect so long as required for the distribution of the
     Securities and will cooperate with you and your counsel to arrange for the
     determination of the legality of the Securities for purchase by
     institutional investors; provided, however, that the Company will not


                                     -7-

<PAGE>   8


     be required to qualify to do business in any jurisdiction in order to
     effect such qualification.

        (f) Between the date of this Agreement and the Closing Date, the
     Company will not, without your prior written consent, offer, sell, or
     enter into any agreement to sell, any public debt securities registered
     under the Act (other than the Securities).

        (g) The Company confirms as of the date hereof that it is in compliance
     with all provisions of Section 1 of Laws of Florida, Chapter 92-198, An
     Act Relating to Disclosure of Doing Business with Cuba, and the Company
     further agrees, if necessary, that if the Company commences engaging in
     business with the government of Cuba or with any person or affiliate
     located in Cuba after the date the Registration Statement becomes or has
     become effective with the Commission or with the Florida Department of
     Banking and Finance (the "Department"), whichever date is later, or if the
     information reported in the Prospectus, if any, concerning the Company's
     business with Cuba or with any person or affiliate located in Cuba changes
     in any material way, the Company will provide the Department notice of
     such business or change, as appropriate, in a form acceptable to the
     Department.

     6. Conditions to the Obligations of Salomon Brothers Inc and Morgan
Stanley & Co. Incorporated.  Your obligations to purchase the Securities shall
be subject to the accuracy of the representations and warranties on the part of
the Company contained herein as of the Execution Time and the Closing Date, to
the accuracy of the statements of the Company made in any certificates
delivered pursuant to the provisions hereof, to the performance by the Company
of its obligations hereunder and to the following additional conditions:

        (a) The Registration Statement shall have become effective not later
     than (i) 5:00 p.m., New York City time, on the date of determination of
     the public offering price, if such determination occurred at or prior to
     3:00 p.m., New York City time, on such date or (ii) 12:00 noon, New York
     City time, on the business day following the day on which the public
     offering price was determined, if such determination occurred after 3:00
     p.m., New York City time, on such date; if filing of the Prospectus, or
     any supplement thereto, is required pursuant to Rule 424(b), the
     Prospectus, and any such supplement, will be filed in the manner and
     within the time period required by Rule 424(b); and no stop order
     suspending the effectiveness of the Registration Statement shall
     have been issued and no proceedings for that purpose shall have been
     instituted or threatened.

        (b) The Company shall have furnished to you and to Moody's Investors,
     Inc. Service and Standard and Poor's Corporation (together, the "Rating
     Agencies") if requested by you, the opinion of Neal, Gerber & Eisenberg,
     special counsel to the Company (incorporating and relying upon the
     opinions of ___________, special 



                                     -8-

<PAGE>   9

Canadian counsel to the Company, as to  Canadian law matters, and ________,
special Interstate Commerce Commission counsel to the Company, as to Interstate
Commerce Commission matters), dated the Closing Date, to the effect that:

          (i)  the Company and each of its Significant Subsidiaries has been
     duly incorporated and is validly existing as a corporation in good
     standing under the laws of the jurisdiction in which it is chartered or
     organized, with full corporate power and authority to own its properties
     and conduct its business as described in the Prospectus, and is duly
     qualified to do business as a foreign corporation and is in good standing
     under the laws of each jurisdiction which requires such qualification
     wherein it owns or leases material properties or conducts material
     business, except in such jurisdictions in which the failure to so qualify
     would not have a material adverse effect on the Company and its
     subsidiaries taken as a whole;

          (ii)  all the outstanding shares of capital stock of each of the
     Company's subsidiaries have been duly and validly authorized and issued
     and are fully paid and nonassessable, and, all such capital stock is owned
     directly or indirectly by the Company, free and clear of any perferected
     security interest and, to the knowledge of such counsel, after due
     inquiry, any other security interest, claims, liens or encumbrances;

          (iii)  the _____ Agreement has been duly authorized, executed and
     delivered by the Company, has been duly qualified under the Trust
     Indenture Act, and assuming due authorization, execution and delivery
     thereof by the Trustee, the _____ Agreement constitutes a legal, valid and
     binding obligation of the Company enforceable against the Company in
     accordance with its terms, except as may be limited by bankruptcy,
     insolvency, reorganization, moratorium or other similar laws affecting
     enforcement of creditors' rights generally and by general principles of
     equity (regardless of whether enforcement is considered in a
     proceeding in equity or at law);

          (iv)  to the best knowledge of such counsel, there is no pending or
     threatened action, suit or proceeding before any court or governmental
     agency, authority or body or any arbitrator involving the Company or any
     of its subsidiaries, of a character required to be disclosed in the
     Registration Statement which is not adequately disclosed in the
     Prospectus, and there is no franchise, contract or other document of a
     character required to be described in the Registration Statement or
     Prospectus, or to be filed as an exhibit, which is not described or filed
     as required;


                                     -9-

<PAGE>   10


          (v)  the Registration Statement has become effective under the Act;
     any required filing of the Prospectus, and any supplements thereto,
     pursuant to RuleE424(b) has been made in the manner and within the time
     period required by RuleE424(b); to the best knowledge of such counsel, no
     stop order suspending the effectiveness of the Registration Statement has
     been issued, no proceedings for that purpose have been instituted or
     threatened, and the Registration Statement, the Prospectus and each
     amendment or supplement thereto (other than the financial statements and
     related schedules and other financial and statistical information
     contained therein as to which such counsel need express no opinion) comply
     as to form in all material respects with the applicable requirements of
     the Act and the Exchange Act and the respective rules and regulations
     thereunder;

          (vi)  other than the rights of the Company under the _____ Agreement,
     title to the equipment to be subjected to the _____ Agreement will, when
     such equipment shall have been transferred to the Trustee as provided in
     the _____ Agreement, be validly vested in the Trustee; the _____ Agreement
     has been duly filed and recorded with the Interstate Commerce Commission
     and the Registrar General of Canada and such equipment is subject to no
     liens or encumbrances of record at the Interstate Commerce Commission and
     the Registrar General of Canada;

          (vii)  this Agreement has been duly authorized, executed and
     delivered by the Company and, assuming due authorization, execution and
     delivery by you, constitutes a valid and binding obligation of the
     Company, enforceable against the Company in accordance with its terms,
     except (i) as may be limited by bankruptcy, insolvency, reorganization,
     moratorium or other similar laws affecting enforcement of creditors'
     rights generally and by general principles of equity (regardless of
     whether enforcement is considered in a proceeding in equity or at law) and
     (ii) as to provisions of this Agreement relating to indemnification or
     contribution for liabilities arising under the Act, as to which such
     counsel need express no opinion;

          (viii)  no authorization, approval, consent, order or license of or
     filing with or notice to any government, governmental instrumentality,
     regulatory body or authority or court is required for the valid
     authorization, execution, delivery and performance by the Company of the
     Securities, this Agreement and the ______ Agreement or the consummation by
     the Company of the transactions contemplated by this Agreement, the ______
     Agreement and the Securities Agreement, except such as have been obtained
     under the Act and the Trust Indenture Act and such as may be required
     under the blue sky laws of any 



                                    -10-

<PAGE>   11

     jurisdiction in connection with the purchase and distribution of
     the Securities by you and such other approvals (specified in such opinion)
     as have been obtained;

          (ix)  neither the issue and sale of the Securities, nor the
     consummation of any other of the transactions herein contemplated nor the
     fulfillment of the terms hereof will conflict with, result in a breach of,
     or constitute a default under the charter or by-laws of the Company or the
     terms of any indenture or other agreement or instrument known to such
     counsel and to which the Company or any of its subsidiaries is a party or
     bound, or any order or regulation known to such counsel to be applicable
     to the Company or any of its subsidiaries of any court, regulatory body,
     administrative agency, governmental body or arbitrator having jurisdiction
     over the Company or any of its subsidiaries;

          (x)  the Company is not an "investment company" or a company
     "controlled" by an "investment company" within the meaning of the
     Investment Company Act of 1940, as amended;

          (xi)  on the Closing Date, assuming due execution and delivery of the
     Securities by the Trustee and the Company, the Securities when issued
     against payment therefor as provided herein will constitute valid and
     binding obligations of the Company, enforceable against the Company, in
     accordance with their terms, except as may be limited by bankruptcy,
     insolvency, reorganization, moratorium or other similar laws affecting
     enforcement of creditors' rights generally and by general principles of
     equity (regardless of whether enforcement is considered in a proceeding in
     equity or at law), and the holders of the Securities will be entitled to
     the benefits of the _____ Agreement;

          (xii)  the _____ Agreement and the Securities conform in all material
     respects to the descriptions thereof contained in the Prospectus;

          (xiii)  the _____ Agreement cannot be terminated by the Company for
     so long as the Securities are outstanding; and

          (xiv)  the statements in the Registration Statement and Prospectus
     under the headings "Certain Federal Income Tax Consequences," and
     "________", to the extent that they constitute matters of law or legal
     conclusions with respect thereto, have been prepared to reviewed by such
     counsel and are correct in all material respects.

In passing on the form of the Registration Statement and the Prospectus and
each amendment and supplement thereto, such counsel may state that it has not



                                    -11-

<PAGE>   12

     independently verified the accuracy, completeness or fairness of the
     statements made or included therein and takes no responsibility therefor
     and that such opinion is based upon such counsel's examination of the
     Registration Statement, the Prospectus as amended or supplemented, its
     activities in connection with the preparation thereof and its
     participation in conferences with certain officers and employees of the
     Company, its subsidiaries and its affiliates and with representatives of
     Ernst & Young and any others referred to in such opinion, and subject to
     the same qualifications, such counsel may also state that, although they
     are not passing upon, and do not assume any responsibility for, the
     accuracy, completeness or fairness of the statements contained in the
     Registration Statement and Prospectus and have not made any independent
     check or verification thereof, nothing has come to their attention in
     their examination of the Registration Statement, their participation in
     the preparation thereof and participation in the above-referenced
     conferences that has caused them to believe that the Registration
     Statement, at the time it became effective, 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, or the Prospectus, as of its date and as of the Closing Date,
     contained an untrue statement of a material fact or omitted to state a
     material fact necessary to make the statements therein, in the light of
     the circumstances under which they were made, not misleading. 

     In rendering such opinion, such counsel may state that it expresses no
     opinion as to the laws of any jurisdiction other than the State of
     Illinois,  the General Corporation Law of the State of Delaware and the
     Federal law of the United States of America and may rely (A) as to matters
     involving the application of (x) laws of Canada or its Provinces and (y)
     laws, rules and regulations with respect to the Interstate Commerce
     Commission to the extent deemed proper and specified in such opinion, upon
     the opinion of other counsel of good standing whom such counsel believes
     to be reliable and who are satisfactory to you and your counsel and (B) as
     to matters of fact, to the extent deemed proper, on certificates of
     responsible officers of the Company and public officials, and may assume
     for purposes of its opinion set forth in Section 6(b)(vi) that the laws of
     the State of New York are identical to the laws of the State of Illinois.

        (c) You shall have received from Mayer, Brown & Platt, your special
     counsel, such opinion or opinions, dated the Closing Date, with respect to
     the issuance and sale of the Securities, the _____ Agreement, the
     Registration Statement, the Prospectus and other related matters as you
     may reasonably require, and the Company shall have furnished to such
     counsel such documents as they request for the purpose of enabling them to
     pass upon such matters.

        (d) The Company shall have furnished to you a certificate of the
     Company, signed by the President or any Vice President and the principal
     financial officer of the Company, dated the Closing Date, to the effect
     that the signers of such certificate have 




                                    -12-

<PAGE>   13

     carefully examined the Registration Statement, the Prospectus and this
     Agreement and that:

                 (i)  the representations and warranties of the Company in this
            Agreement are true and correct in all material respects on and as
            of the Closing Date with the same effect as if made on the Closing
            Date and the Company has complied with all the agreements and
            satisfied all the conditions on its part to be performed or
            satisfied at or prior to the Closing Date;

                 (ii)  no stop order suspending the effectiveness of the
            Registration Statement has been issued and, to the Company's
            knowledge, no proceedings for that purpose have been instituted or
            threatened; and

                 (iii)  since the date of the most recent financial statements
            included and/or incorporated by reference in the Prospectus, there
            has been no material adverse change in the condition (financial or
            other), earnings, business or properties of the Company and its
            subsidiaries, whether or not arising from transactions in the
            ordinary course of business, except as set forth in or contemplated
            in the Prospectus.

        (e) At the Execution Time and at the Closing Date, Ernst & Young shall
     have furnished to you a letter or letters, dated, respectively, as of the
     Execution Time and as of the Closing Date, in form and substance
     satisfactory to you, confirming that they are independent auditors within
     the meaning of the Act and the applicable published rules and regulations
     thereunder and stating in effect that in their opinion the audited
     consolidated financial statements and schedules thereto incorporated by
     reference in the Registration Statement and the Prospectus and reported on
     by them comply as to form in all material respects with the applicable
     accounting requirements of the Act and the applicable published rules and
     regulations thereunder with respect to registration statements on
     FormES-3; and that nothing came to their attention which caused them to
     believe that the amounts under the caption "Selected Financial
     Information" for each of the five years ended _______ included in the
     Registration Statement and the Prospectus, do not agree with the
     corresponding amounts in the audited financial statements from which such
     amounts were derived; and as to the periods for which it served as the
     Company's independent auditor, such financial statements were covered by
     unqualified reports issued by them; and that they have performed certain
     other specified procedures as a result of which they determined that
     certain information of an accounting, financial or statistical nature
     (which is limited to accounting, financial or statistical information
     derived from the general accounting records of the Company) set forth in
     the Registration Statement and the Prospectus, including the information
     set forth under the captions "Selected Financial Information", 




                                    -13-

<PAGE>   14

and in [Exhibit 12] to the Registration Statement agrees with the accounting    
records and schedules of the Company and its subsidiaries, excluding any
questions of legal interpretation. 


     References to the Prospectus in this paragraph (e) include any
     supplement thereto at the date of the letter.

     (f) In addition, Ernst & Young shall have furnished to you a letter or
letters, dated, respectively, as of the Execution Time and as of the Closing
Date, in form and substance satisfactory to you, to the effect that:

                 (i) on the basis of a reading of the unaudited condensed
            financial statements of the Company contained in the Company's
            Quarterly Reports on Form 10-Q for the quarters ended ________,
            ________ and ________ incorporated by reference in the Registration
            Statement, the amounts set forth under the captions "Selected
            Financial Information" and "Capitalization" included in the
            Registration Statement and the Prospectus and of the latest
            unaudited consolidated financial statements made available to them
            by the Company and its subsidiaries; carrying out certain specified
            procedures (but not an audit in accordance with generally accepted
            auditing standards) which would not necessarily reveal matters of
            significance with respect to the comments set forth in such letter;
            a reading of the minutes of the meetings of the stockholders,
            directors and executive committees of the Company and its
            subsidiaries; and inquiries of certain officials of the Company who
            have responsibility for financial and accounting matters of the
            Company and its subsidiaries as to transactions and events
            subsequent to _________, nothing came to their attention which
            caused them to believe that (A) the unaudited consolidated
            financial statements of the Company incorporated by reference in
            the Registration Statement do not comply as to form in all material
            respects with the applicable accounting requirements of the Act and
            the Exchange Act and the rules and regulations thereunder as they
            apply to Form 10-Q or are not presented in conformity with
            generally accepted accounting principles applied on a basis
            substantially consistent with that of the audited consolidated
            financial statements of the Company incorporated by reference in
            the Registration Statement, and (B) with respect to the period
            subsequent to _______, there were any changes, at a specified date
            not more than five business days prior to the date of the letter,
            in the borrowed debt of the Company and its subsidiaries or capital
            stock of the Company or decreases in the stockholder's equity of
            the Company and its subsidiaries as compared with the amounts shown
            on the _________, unaudited consolidated balance sheet data
            included in 



                                    -14-

<PAGE>   15

            "Selected Financial Information" in the Registration Statement and
            the Prospectus, or for the period from _________ to such specified
            date, there were any decreases, as compared with the corresponding
            period in the preceding year, in total revenues from net sales and
            services, or in income before income taxes or net income, of the
            Company and its subsidiaries, except in all instances for changes
            or decreases set forth in such letter, in which case the letter
            shall be accompanied by an explanation by the Company as to the
            significance thereof unless said explanation is not deemed
            necessary by you.

        (g) Subsequent to the Execution Time or, if earlier, the respective
     dates as of which information is given in the Registration Statement and
     the Prospectus, there shall not have been (i)Eany change or decrease
     specified in the letter or letters referred to in paragraphsE(e) and (f)
     of this SectionE6 or (ii)Eany change, or any development involving a
     prospective change, in or affecting the business or properties of the
     Company and its subsidiaries taken as a whole the effect of which, in any
     case referred to in clauseE(i) or (ii) above, is, in your judgment, so
     material and adverse as to make it impractical or inadvisable to proceed
     with the public offering or the delivery of the Securities as contemplated
     by the Registration Statement and the Prospectus.

        (h) Subsequent to the Execution Time and prior to the Closing Date,
     there shall not have occurred any downgrading nor shall any notice have
     been given of (i) any intended or potential downgrading or (ii) any review
     or possible change in the rating accorded the Company's debt securities by
     the Rating Agencies as of the Execution Time.

        (i) Prior to the Closing Date, the Company shall have furnished to you
     and the Rating Agencies such further information, certificates and
     documents as you and they may reasonably request.

     If any of the conditions specified in this SectionE6 shall not have been
fulfilled in all material respects when and as provided in this Agreement, or
if any of the opinions and certificates mentioned above or elsewhere in this
Agreement shall not be in all material respects reasonably satisfactory in
form and substance to you and your counsel, this Agreement and all your
obligations hereunder may be canceled at, or at any time prior to, the Closing
Date by you.  Notice of such cancellation shall be given to the Company in
writing or by telephone or telegraph confirmed in writing.

     7.  Reimbursement of the Underwriters' Expenses.  If the sale of the
Securities provided for herein is not consummated because any condition to your
obligation set forth in Section 6 hereof is not satisfied, because of any
termination pursuant to Section 9 hereof or because of any refusal, inability
or failure on the part of the Company to perform any 


                                    -15-

<PAGE>   16


agreement herein or comply with any provision hereof other than by reason
of a default by you, the Company will reimburse you upon demand for all
out-of-pocket expenses (including reasonable fees and disbursements of counsel)
that shall have been incurred by you in connection with the proposed purchase
and sale of the Securities.

     8.  Indemnification and Contribution.  (a)  The Company agrees to
indemnify and hold harmless you and each person who controls you within the
meaning of either the Act or the Exchange Act from and against any and all
losses, claims, damages or liabilities, joint or several, to which you or any
of them may become subject under the Act, the Exchange Act or other Federal or
state statutory law or regulation, at common law or otherwise, insofar as such
losses, claims, damages or liabilities (or actions in respect thereof) arise
out of or are based upon any untrue statement or alleged untrue statement of a
material fact contained in the registration statement for the registration of
the Securities as originally filed or in any amendment thereof, or in any
Preliminary Prospectus or the Prospectus, or in any amendment thereof 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, in light of the circumstances under
which they were made, not misleading, and agree to reimburse you and each such
controlling person for any legal or other expenses reasonably incurred by you
or such controlling person in connection with investigating or defending any
such loss, claim, damage, liability or action; provided, however, that (i)Ethe
Company will 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 any such untrue
statement or alleged untrue statement or omission or alleged omission made
therein in reliance upon and in conformity with written information furnished
to the Company by or on behalf of you specifically for use in connection with
the preparation thereof, and (ii)Esuch indemnity with respect to any
Preliminary Prospectus shall not inure to your benefit (or to the benefit of
any person controlling you) if the person asserting any such loss, claim,
damage or liability purchased the Securities which are the subject thereof did
not receive a copy of the Prospectus (or the Prospectus as amended or
supplemented), excluding documents incorporated therein by reference, at or
prior to the confirmation of the sale of such Securities to such person in any
case where such delivery is required by the Act and the untrue statement or
omission of a material fact contained in such Preliminary Prospectus was
corrected in the Prospectus (or the Prospectus as amended or supplemented).
This indemnity agreement will be in addition to any liability which the Company
may otherwise have.

     (b) You severally (and not jointly) agree to indemnify and hold harmless
the Company, each of its directors, each of its officers who signs the
Registration Statement, and each person who controls the Company within the
meaning of either the Act or the Exchange Act, to the same extent as the
foregoing indemnity from the Company to you, but only with reference to written
information relating to you furnished to the Company by or on behalf of you
specifically for use in the preparation of the documents referred to in clause
(a) of this 


                                    -16-

<PAGE>   17


Section 8.  This indemnity agreement will be in addition to any liability which
you may otherwise have.  The Company acknowledges that the statements set forth
in the last paragraph of the cover page and under the heading "Underwriting" in
any Preliminary Prospectus and the Prospectus and the stabilization language
included on the inside front cover of any Preliminary Prospectus and the
Prospectus constitute the only information furnished in writing by or on behalf
of you for inclusion in any Preliminary Prospectus or the Prospectus, and you
confirm that such statements are correct.

     (c) Promptly after receipt by an indemnified party under this Section 8 of
notice of the commencement of any action, such indemnified party will, if a
claim in respect thereof is to be made against the indemnifying party under
this Section 8, notify the indemnifying party in writing of the commencement
thereof; but the omission so to notify the indemnifying party will not relieve
it from any liability which it may have to any indemnified party otherwise than
under this Section 8.  In case any such action is brought against any
indemnified party, and the indemnified party notifies the indemnifying party of
the commencement thereof, the indemnifying party will be entitled to appoint
counsel satisfactory to such indemnified party to represent the indemnified
party in such action; provided, however, if the defendants in any such action
include both the indemnified party and the indemnifying party and the
indemnified party shall have reasonably concluded that there may be legal
defenses available to it and/or other indemnified parties which are different
from or additional to those available to the indemnifying party, the
indemnified party or parties shall have the right to select separate counsel to
assert such legal defenses and to otherwise participate in the defense of such
action on behalf of such indemnified party or parties.  Upon receipt of notice
from the indemnifying party to such indemnified party of the indemnifying
party's election so to assume the defense of such action and approval by the
indemnified party of counsel, the indemnifying party will not be liable to such
indemnified party under this Section 8 for any legal or other expenses
subsequently incurred by such indemnified party in connection with the defense
thereof unless (i) the indemnified party shall have employed separate counsel
in connection with the assertion of legal defenses in accordance with the
proviso to the next preceding sentence (it being understood, however, that the
indemnifying party shall not be liable for the expenses of more than one
separate counsel, approved by you in the case of subparagraph (a), representing
the indemnified parties under subparagraph (a) who are parties to such action),
(ii) the indemnifying party shall not have employed counsel satisfactory to the
indemnified party to represent the indemnified party within a reasonable time
after notice of commencement of the action or (iii) the indemnifying party has
authorized the employment of counsel for the indemnified party at the expense
of the indemnifying party; and except that, if clause (i) or (iii) is
applicable, such liability shall be only in respect of the counsel referred to
in such clause (i) or (iii).

     (d) In order to provide for just and equitable contribution in
circumstances in which the indemnification provided for in paragraph (a) of
this Section 8 is due in accordance with its terms but is for any reason held
by a court to be unavailable from the Company on grounds of 



                                    -17-

<PAGE>   18

policy or otherwise, the Company and you shall contribute to the aggregate
losses, claims, damages and liabilities (including legal or other expenses
reasonably incurred in connection with investigating or defending same) to
which the Company and you may be subject in such proportion so that each of you
are responsible only for that portion represented by the percentage that the
aggregate underwriting commission in respect of the Securities appearing on the
cover page of the Prospectus bears to the aggregate public offering price in
respect of such Securities appearing thereon and the Company is responsible for
the balance; provided, however, that (y) in no case shall you be responsible
for any amount in excess of such aggregate underwriting commission and (z) 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.  For purposes of this Section 8,
each person who controls you within the meaning of the Act shall have the same
rights to contribution as you, and each person who controls the Company within
the meaning of the Act, each officer of the Company who shall have signed the
Registration Statement and each director of the Company shall have the same
rights to contribution as the Company, subject in each case to clauses (y) and
(z) of this paragraph  (d).  Any party entitled to contribution will, promptly
after receipt of notice of commencement of any action, suit or proceeding
against such party in respect of which a claim for contribution may be made
against another party or parties under this paragraph (d), notify such party or
parties from whom contribution may be sought, but the omission to so notify
such party or parties shall not relieve the party or parties from whom
contribution may be sought from any other obligation it or they may have
hereunder or otherwise than under this paragraph (d).

     9.  Termination.  This Agreement shall be subject to termination in your
absolute discretion by notice given to the Company prior to delivery of and
payment for the Securities, if prior to such time (i) trading in securities
generally on the New York Stock Exchange shall have been suspended or limited
or minimum prices shall have been established on such Exchange, (ii) a banking
moratorium shall have been declared either by Federal, New York State or
Illinois State authorities or (iii) there shall have occurred any outbreak or
material escalation of hostilities or other calamity or crisis the effect of
which on the financial markets of the United States is such as to make it, in
your judgment, impracticable to market the Securities.

     10.  Representations and Indemnities to Survive.  The respective
agreements, representations, warranties, indemnities and other statements of
the Company or its officers and of you set forth in or made pursuant to this
Agreement will remain in full force and effect, regardless of any investigation
made by or on behalf of you or the Company or any of its officers, directors or
controlling persons referred to in Section 8 hereof, and will survive delivery
of and payment for the Securities.  The provisions of Sections 7 and 8 hereof
shall survive the termination or cancellation of this Agreement.



                                    -18-

<PAGE>   19

     11.  Notices.  All communications hereunder will be in writing and
effective only on receipt, and, if sent to you, will be mailed, delivered or
telegraphed and confirmed in the case of Solomon Brothers Inc at 7 World Trade
Center, New York, New York 10048, Attention:  Legal Department; in the case of
Morgan Stanley & Co. Incorporated at 1585 Broadway, New York, New York  10036,
Attention:  Legal Department; or, if sent to the Company, will be mailed,
delivered or telegraphed and confirmed to it at 225 West Washington Street,
Chicago, Illinois 60606, Attention:  Secretary.

     12.  Successors.  This Agreement will inure to the benefit of and be
binding upon the parties hereto and their respective successors and the
officers and directors and controlling persons referred to in Section 8 hereof,
and no other person will have any right or obligation hereunder.

     13.  Applicable Law.  This Agreement will be governed by and construed in
accordance with the laws of the State of New York.



                                    -19-

<PAGE>   20


     If the foregoing is in accordance with your understanding of our
agreement, please sign and return to us the enclosed duplicate hereof,
whereupon this letter and your acceptance shall represent a binding agreement
between the Company and you.

                                             Very truly yours,

                                             UNION TANK CAR COMPANY


                                             By:________________________________
                                                Name:
                                                Title:



The foregoing Agreement is
hereby confirmed and accepted
as of the date first written
above:

SALOMON BROTHERS INC
MORGAN STANLEY & CO. INCORPORATED

By SALOMON BROTHERS INC.
   Acting on behalf of itself and
   Morgan Stanley & Co. Incorporated


By:_______________________________
   Name:
   Title:




                                    -20-

<PAGE>   21

                                   Schedule A





                    Aggregate Principal  Interest      Principal Installment
[Name of Security]  Amount                Rate              Payments
- --------------------------------------------------------------------------------
                    $                     %                       $


















<PAGE>   1



                       PASS THROUGH TRUST AGREEMENT _____

                                Dated _________

                                     among

                            UNION TANK CAR COMPANY,


                                [PROCOR LIMITED]


                                      and


                               _________________,
                            as Pass Through Trustee







                                   $________



                                 ______________
                           _______ Pass Through Trust
                           Pass Through Certificates,
                                 Series _______



<PAGE>   2


            TABLE OF CONTENTS TO PASS THROUGH TRUST AGREEMENT _____


<TABLE>
<CAPTION>

Section                                                                          Page
- -------                                                                          ----

                                   ARTICLE I

                                  DEFINITIONS

<S>           <C>                                                                 <C>
SECTION 1.1.  Definitions ........................................................  3
SECTION 1.2.  Compliance Certificates and Opinions  .............................. 13
SECTION 1.3.  Form of Documents Delivered to Pass Through Trustee ................ 14
SECTION 1.4.  Acts of Certificateholders  ........................................ 14


                                   ARTICLE II

                    ACQUISITION OF EQUIPMENT NOTES AND ETCs;
                       ORIGINAL ISSUANCE OF CERTIFICATES


SECTION 2.1.  Issuance of Certificates; Acquisition of Equipment Notes and ETCs .. 16
SECTION 2.2.  Declaration of Trust; Acceptance By Pass Through Trustee ........... 19
SECTION 2.3.  Limitation of Powers ............................................... 19
SECTION 2.4.  Sale of Equipment Notes Under Certain Circumstances ................ 19


                                  ARTICLE III

                                THE CERTIFICATES


SECTION 3.1.  Form, Denomination and Execution of Certificates ................... 19
SECTION 3.2.  Authentication of Certificates  .................................... 20     
SECTION 3.3.  Temporary Certificates  ............................................ 20
SECTION 3.4.  Registration of Transfer and Exchange of Certificates  ............. 21
SECTION 3.5.  Mutilated, Destroyed, Lost or Stolen Certificates  ................. 22
SECTION 3.6.  Persons Deemed Owners  ............................................. 22
SECTION 3.7.  Cancellation  ...................................................... 22
SECTION 3.8.  Limitation of Liability for Payments ............................... 22
SECTION 3.9.  Book-Entry and Registered Certificates  ............................ 23
</TABLE>


                                   ARTICLE IV

                          DISTRIBUTIONS; STATEMENTS TO
                               CERTIFICATEHOLDERS
                                      

                                      -i-


<PAGE>   3

<TABLE>
<CAPTION>

Section                                                                                         Page
- -------                                                                                         ----
<S>           <C>                                                                                <C>
SECTION 4.1.  Certificate Account and Special Payments Account  ...............................  25
SECTION 4.2.  Distribution from Certificate Account and Special Payments Account ..............  26
SECTION 4.3.  Statements to Certificateholders ................................................  27
SECTION 4.4.  Investment of Special Payment Money  ............................................  28


                                   ARTICLE V

                                 THE COMPANIES


SECTION 5.1.  Maintenance of Corporate Existence  .............................................  28
SECTION 5.2.  Consolidation, Merger or Sale of Assets Permitted  ..............................  29


                                   ARTICLE VI

                                    DEFAULT


SECTION 6.1.  Events of Default  ..............................................................  30
SECTION 6.2.  Incidents of Sale of Equipment Notes and ETCs  ..................................  32
SECTION 6.3.  Judicial Proceedings Instituted by Pass Through Trustee .........................  32
SECTION 6.4.  Control by Certificateholders  ..................................................  33
SECTION 6.5.  Waiver of Past Defaults .........................................................  34
SECTION 6.6.  Undertaking to Pay Court Costs  .................................................  34
SECTION 6.7.  Right of Certificateholders to Receive Payments Not to Be
                 Impaired .....................................................................  34
SECTION 6.8.  Certificateholders May Not Bring Suit Except Under
                 Certain Conditions  ..........................................................  35
SECTION 6.9.  Remedies Cumulative .............................................................  35


                                  ARTICLE VII

                            THE PASS THROUGH TRUSTEE


SECTION 7.1.   Certain Duties and Responsibilities ............................................  36
SECTION 7.2.   Notice of Defaults  ............................................................  37
SECTION 7.3.   Certain Rights of Trustee  .....................................................  37
SECTION 7.4.   Not Responsible for Recitals or Issuance of Certificates .......................  38
SECTION 7.5.   May Hold Certificates  .........................................................  39
SECTION 7.6.   Money Held in Pass Through Trust  ..............................................  39
SECTION 7.7.   Compensation and Reimbursement  ................................................  39
SECTION 7.8.   Corporate Trustee Required; Eligibility  .......................................  40
SECTION 7.9.   Resignation and Removal; Appointment of Successor ..............................  41

</TABLE>

                                      -ii-
<PAGE>   4
<TABLE>
<CAPTION>

Section                                                                                Page
- -------                                                                                ----
<S>            <C>                                                                      <C>
SECTION 7.10.  Acceptance of Appointment by Successor...............................    43

SECTION 7.11.  Merger, Conversion, Consolidation or Succession to Business..........    43
SECTION 7.12.  Maintenance of Agencies..............................................    43
SECTION 7.13.  Money for Certificate Payments to Be Held in Pass Through Trust......    45
SECTION 7.14.  Registration of Equipment Notes and ETCs in Pass Through
                 Trustee's  Name....................................................    45
SECTION 7.15.  Representations and Warranties of Pass Through Trustee...............    46
SECTION 7.16.  Withholding Taxes; Information Reporting.............................    47
SECTION 7.17.  Trustee's Liens......................................................    47
SECTION 7.18.  Preferential Collection of Claims....................................    47

                                  ARTICLE VIII

         CERTIFICATEHOLDERS' LISTS AND REPORTS BY PASS THROUGH TRUSTEE


SECTION 8.1.  The Companies to Furnish Pass Through Trustee with Names
                 and Addresses of Certificateholders................................    48
SECTION 8.2.  Preservation of Information; Communications to Certificateholders.....    48
SECTION 8.3.  Reports by Pass Through Trustee.......................................    48
SECTION 8.4.  Reports by the Company................................................    48


                                   ARTICLE IX

                  SUPPLEMENTS TO PASS THROUGH TRUST AGREEMENT

 SECTION 9.1. Supplements to Pass Through Trust Agreement Without
                 Consent of Certificateholders......................................    49
 SECTION 9.2. Supplements to Pass Through Trust Agreement with
                 Consent of Certificateholders......................................    50

SECTION 9.3.  Documents Affecting Immunity or Indemnity.............................    51
SECTION 9.4.  Execution of Supplements to Pass Through Trust Agreements.............    51
SECTION 9.5.  Effect of Supplements to Pass Through Trust Agreement.................    51
SECTION 9.6.  Conformity with Trust Indenture Act...................................    52

SECTION 9.7.  Reference in Certificates to Supplements to Pass
              Through Trust Agreements..............................................    52

</TABLE>
                                   ARTICLE X

                    AMENDMENTS TO INDENTURE, NOTE DOCUMENTS,
                  EQUIPMENT TRUST AGREEMENTS AND ETC DOCUMENTS

                                    -iii-

                                                                
<PAGE>   5

Section                                                                 Page
- -------                                                                 ----

                                   ARTICLE XI
                       TERMINATION OF PASS THROUGH TRUST


                                  ARTICLE XII

                               GUARANTEE OF UNION
<TABLE>
<CAPTION>
<S>                     <C>                                                     <C>
SECTION 12.1.           Guarantee...........................................     54
SECTION 12.2.           Execution and Delivery of Guarantee.................     55
SECTION 12.3.           Limitation of Union's Liability.....................     55
SECTION 12.4.           Guarantee Unconditional.............................     55


                                           ARTICLE XIII

                                     MISCELLANEOUS PROVISIONS


SECTION 13.1.           Limitation on Rights of Certificateholders..........     57
SECTION 13.2.           Certificates Nonassessable and Fully Paid...........     57
SECTION 13.3.           Notices.............................................     57

SECTION 13.4.          Communication by Certificateholder with Other
                         Certificateholders.................................     59


SECTION 13.5.           Governing Law.......................................     59
SECTION 13.6.           Severability of Provisions..........................     59
SECTION 13.7.           Trust Indenture Act Controls........................     59
SECTION 13.8.           Effect of Headings and Table of Contents............     59
SECTION 13.9.           Successors and Assigns..............................     59
SECTION 13.10.          Benefits of Pass Through Trust Agreement............     60
SECTION 13.11.          Legal Holidays......................................     60
SECTION 13.12.          Counterparts........................................     60

Exhibit A     -  Form of Certificate
Exhibit B     -  Guarantee
Exhibit C     -  Form of DTC Letter of Representations
Schedule I    -  Description of Equipment Notes to be Issued under the Indenture
Schedule II   -  Description of ETCs to be Issued under Equipment Trust Agreements
</TABLE>
                                        

                                        
                                     -iv-

<PAGE>   6


            This PASS THROUGH TRUST AGREEMENT _______, dated __________,
       is made with respect to the formation of the Union Tank Car
       Company ______ Pass Through Trust, among UNION TANK CAR COMPANY,
       a Delaware corporation ("Union"), [PROCOR LIMITED, a Canadian
       corporation and an indirect wholly-owned subsidiary of Union
       ("Procor" and together with Union, the "Companies")] and
       __________, a national banking association solely as Pass Through
       Trustee and not in its individual capacity.


                                  WITNESSETH:


            [WHEREAS, a $_______ aggregate principal amount Equipment
       Trust Certificate, Series ___ (together with the guarantee of
       Union to be endorsed thereon, the "Union ETCs"), will be issued
       pursuant to an Equipment Trust Agreement, dated ______ as may be
       amended or supplemented from time to time (the "Union Equipment
       Trust Agreement"), between Union and ___________, as trustee (the
       "Union Equipment Trust Trustee");]

            [WHEREAS, a $________ aggregate principal amount Equipment
       Trust Certificate, Series _____ (together with the guarantee of
       Procor endorsed thereon, the "Procor ETC" and, together with the
       Union ETCs, the "ETCs"), will be issued pursuant to an Equipment
       Trust Agreement, dated ________, as may be amended or
       supplemented from time to time (the "Procor Equipment Trust
       Agreement") between Procor and ___________, as trustee (the
       "Procor Equipment Trust Trustee");]

            [WHEREAS, the Union Equipment Trust Trustee will issue the
       Union ETCs in connection with the financing of railway tank cars
       and other rail cars of the type used in Union's business (the
       "Union Trust Equipment") and the Procor Equipment Trust Trustee
       will issue the Procor ETC in connection with the financing of
       railway tank cars and other rail cars of the type used in
       Procor's business (the  "Procor Trust Equipment");]

            [WHEREAS, pursuant to the terms of this Pass Through Trust
       Agreement, the Union Equipment Trust Agreement and the Procor
       Equipment Trust Agreement, the Union ETCs and the Procor ETC are
       to be sold upon their issuance to the Pass Through Trustee, and
       the Pass Through Trustee shall purchase the ETCs upon their
       issuance and shall hold such ETCs in trust for the benefit of the
       Certificateholders;]

            WHEREAS, a certain Owner Trustee, on behalf of a certain
       Owner Participant, will purchase certain Equipment (as defined)
       from [Union] [Procor];

            WHEREAS, the Owner Trustee will lease the Equipment to
       [Union] [Procor] pursuant to the Lease;


 

<PAGE>   7



            WHEREAS, such Owner Trustee will issue on a nonrecourse
       basis Equipment Notes, under the Indenture, in order to finance
       not more than 80% of the purchase price to be paid to [Union]
       [Procor] for the Equipment subject to the Lease;

            WHEREAS, pursuant to the terms and conditions of this Pass
       Through Trust Agreement and the Participation Agreement, such
       agreements to be entered into by the Pass Through Trustee
       contemporaneously with the execution and delivery of this Pass
       Through Trust Agreement, certain Equipment Notes are to be sold,
       from time to time, to the Pass Through Trustee, and the Pass
       Through Trustee shall purchase, from time to time, such Equipment
       Notes and shall hold such Equipment Notes in trust for the
       benefit of the Certificateholders;

            WHEREAS, the Pass Through Trustee, upon execution and
       delivery of this Pass Through Trust Agreement, hereby declares
       the creation of this Pass Through Trust for the benefit of the
       Certificateholders, and the initial Certificateholders as the
       grantors of the Pass Through Trust, by their respective
       acceptances of the Certificates, join in the creation of this
       Pass Through Trust with the Pass Through Trustee;

            WHEREAS, to facilitate the sale of the [ETCs] [and] [certain
       Equipment Notes] to the Pass Through Trustee and the purchase of
       such [ETCs] [and] [Equipment Notes] by the Pass Through Trustee,
       [each of] [Union] [and] [Procor] has duly authorized the
       execution and delivery of this Pass Through Trust Agreement as an
       "issuer", as such term is defined in and solely for purposes of
       the Securities Act of 1933, as amended, of the Certificates being
       issued hereunder and as an "obligor", as such term is defined in
       and solely for purposes of the Trust Indenture Act of 1939, as
       amended, with respect to the Certificates and is undertaking to
       perform certain administrative and ministerial duties hereunder
       and is also undertaking to pay the fees and expenses of the Pass
       Through Trustee; and

            WHEREAS, this Pass Through Trust Agreement is subject to the
       provisions of the Trust Indenture Act of 1939, as amended, and
       shall, to the extent applicable, be governed by such provisions;

            NOW, THEREFORE, in consideration of the mutual agreements
       herein contained, and of other good and valuable consideration
       the receipt and adequacy of which are hereby acknowledged, the
       parties hereto agree as follows:


                                     -2-

<PAGE>   8




                                   ARTICLE I

                                  DEFINITIONS

            SECTION 1.1.  Definitions.

            (a)  For all purposes of this Pass Through Trust Agreement,
       except as otherwise expressly provided or unless the context
       otherwise requires:
                 (i)  the terms used herein that are defined in this
            Article have the meanings assigned to them in this Article,
            and include the plural as well as the singular;

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

                 (iii) all references in this Pass Through Trust
            Agreement to designated "Articles", "Sections" and other
            subdivisions are to the designated Articles, Sections and
            other subdivisions of this Pass Through Trust Agreement; and

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

            (b)  For all purposes of this Pass Through Trust Agreement,
       the following capitalized terms have the following respective
       meanings:

            "Act," with respect to any Certificateholder, has the
       meaning specified in Section 1.4.

            "Affiliate" of any Person shall mean any other Person which
       directly or indirectly controls, or is controlled by, or is under
       a common control with, such Person.  The term "control", as used
       with respect to any Person, means the possession, directly or
       indirectly, of the power to direct or cause the direction of the
       management policies of such Person, whether through the ownership
       of voting securities, by contract or otherwise; and the terms
       "controlling" and "controlled" have meanings correlative to the
       foregoing.

            "Authorized Agent" means any Paying Agent or Registrar.

            "Avoidable Tax" has the meaning specified in Section 7.9(e).

            "Book-Entry Certificates" means a beneficial interest in the
       Certificates, ownership and transfers of which shall be made
       through book entries by a Clearing Agency as described in Section
       3.9.


                                     -3-

<PAGE>   9



            "Business Day" means any day other than a Saturday or a
       Sunday or a day on which commercial banking institutions or trust
       companies are authorized or required by law, regulation or
       executive order to be closed in New York, New York, Chicago,
       Illinois [, or, solely with respect to payments under the Procor
       Equipment Trust Agreement, Toronto, Ontario, Canada], or, so long
       as any Certificate is outstanding, a city and state in which the
       respective Corporate Trust Office of the Owner Trustee, the Pass
       Through Trustee, the Indenture Trustee, any Equipment Trust
       Trustee or Paying Agent is located.

            "Certificate" means any one of the certificates executed and
       authenticated by the Pass Through Trustee, substantially in the
       form of Exhibit A hereto.

            "Certificate Account" means the account or accounts created
       and maintained pursuant to Section 4.1(a).

            "Certificateholder" means the Person in whose name a
       Certificate is registered in the Register.

            "Certificate Owner" means, when used in Section 3.9, the
       Person who owns a Book Entry Certificate.

            "Clearing Agency" means an organization registered as a
       "clearing agency" pursuant to Section 17A of the Securities
       Exchange Act of 1934, as amended.

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

            "Closing Date" means _______.

            "Commission" means the Securities and Exchange Commission,
       as from time to time constituted, created under the Securities
       Exchange Act of 1934, 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 on such date.

            "Companies" means Union Tank Car Company, a Delaware
       corporation, [and Procor Limited, a Canadian corporation,] or
       [its][their respective] successors in interest pursuant to
       Section 5.2, or any other obligor with respect to the
       Certificates (within the meaning of the Trust Indenture Act).

            "Corporate Trust Office" means, with respect to the Pass
       Through Trustee, any Equipment Trustee and the Indenture Trustee,
       the office of such trustee in the city at which at any particular
       time its corporate trust business shall be principally
       administered.


 
                                     -4-
<PAGE>   10



            "De Minimis Certificate" has the meaning specified in
       Section 3.1.

            "Direction" has the meaning specified in Section 1.4(c).

            "Equipment" means, with respect to the Union ETCs, all of
       the Union Trust Equipment, with respect to the Procor ETC, all of
       the Procor Trust Equipment, and with respect to the Equipment
       Notes, all of the Units covered by the Lease; or as the context
       may require, all of the Equipment covered by the ETCs and the
       Equipment Notes.

            "Equipment Note" means any one of the Equipment Notes (as
       defined in the Indenture) described on Schedule I attached
       hereto, including any Equipment Note (as so defined) issued under
       the Indenture as a replacement or substitution therefor, held by
       the Pass Through Trustee.

            "Equipment Trust Agreement" means [either of] the Union
       Equipment Trust Agreement [or the Procor Equipment Trust
       Agreement, each] dated ________, as [each] such Equipment Trust
       Agreement may be amended or supplemented from time to time in
       accordance with its [respective] terms[; and "Equipment Trust
       Agreements" means both of such agreements].

            "Equipment Trust Default" means, with respect to either
       Equipment Trust Agreement, any Event of Default (as such term is
       defined in such Equipment Trust Agreement).

            "Equipment Trust Trustee" means the Union Equipment Trust
       Trustee [and the Procor Equipment Trust Trustee].

            "ETC" means any one of the Equipment Trust Certificates
       described in Schedule II attached hereto, including any ETC (as
       so defined) issued under the applicable Equipment Trust Agreement
       as a replacement or substitution therefor, held by the Pass
       Through Trustee.

            "ETC Documents", with respect to an ETC, means the
       applicable Equipment Trust Agreement.

            "Guarantee" means the guarantee of Union set forth in
       Article XII hereof and on each of the Certificates.

            "Escrow Account" has the meaning specified in Section
       2.1(b).

            "Escrowed Funds" has the meaning specified in Section
       2.1(b).

            "Event of Default" means an event described in Section 6.1.

                                     -5-
 

<PAGE>   11



            "Fractional Undivided Interest" means the undivided interest
       in the Pass Through Trust that is evidenced by an Outstanding
       Certificate expressed as a fraction of the total undivided
       interests in the Pass Through Trust represented by all
       Outstanding Certificates.

            "Indenture" means the Trust Indenture and Security Agreement
       (UTC Trust No. _____) (___), dated _______, between the Owner
       Trustee and the Indenture Trustee, as the Indenture may be
       amended or supplemented from time to time in accordance with its
       terms.  The term "Indenture" includes each Indenture Supplement
       entered into pursuant to the terms of the Indenture.

            "Indenture Default" means, with respect to the Indenture,
       any Indenture Event of Default (as such term is defined in the
       Indenture).

            "Indenture Trustee" means ______________, in its capacity as
       indenture trustee under the Indenture, and any other Person which
       may from time to time be acting as Indenture Trustee in
       accordance with the provisions of the Indenture.

            "Initial Cut-off Date" means _________.

            "Issuance Date" means the date of the issuance of the
       Certificates.

            "Lease" means the Equipment Lease Agreement (UTC Trust No.
       ______) (____) with respect to the Equipment between the Owner
       Trustee, as the lessor, and Union, as the lessee, as the Lease
       may be amended or supplemented from time to time in accordance
       with its terms.  Such term shall include each Lease Supplement
       entered into pursuant to the terms of the Lease.

            "Lease Event of Default" means, with respect to the Lease,
       an Event of Default under the Lease as specified in Section 14
       thereof.

            "Lease Supplement" has the meaning assigned to that term in
       the Lease.

            "Letter of Representations" means the agreement among the
       Companies, the Pass Through Trustee and the initial Clearing
       Agency substantially in the form attached hereto as Exhibit C.

            "Make-Whole Amount" has the meaning assigned to that term in
       the Indenture.

            "Note Documents," with respect to any Equipment Note, means
       the Indenture, the Lease and the Participation Agreement.

            "Officer's Certificate" means a certificate signed, (a) in
       the case of either of the Companies, by (i) the Treasurer, any
       Assistant Treasurer, the Controller or any Assistant Controller
       of such Company, signing alone, or (ii) any Vice President
       signing together with the


                                     -6-

<PAGE>   12


       Secretary, any Assistant Secretary, the Treasurer or any
       Assistant Treasurer of such Company, or (b) in the case of the
       Owner Trustee, an Equipment Trust Trustee or the Indenture
       Trustee, a Responsible Officer of such Owner Trustee, Equipment
       Trust Trustee or Indenture Trustee.

            "Opinion of Counsel" means a written opinion of legal
       counsel, who (i) in the case of counsel for either of the
       Companies may be (A) a lawyer employed by such Company, (B) Neal,
       Gerber & Eisenberg, or (C) such other counsel designated by such
       Company and reasonably acceptable to the Pass Through Trustee and
       (ii) in the case of the Owner Trustee, any Equipment Trust
       Trustee or the Indenture Trustee, such counsel as may be
       designated by any of them whether or not such counsel is an
       employee of any of them, and who shall be acceptable to the Pass
       Through Trustee.

            "Outstanding," with respect to Certificates, means, as of
       the date of determination, all Certificates theretofore
       authenticated and delivered under this Pass Through Trust
       Agreement, except:

                 (i)  Certificates theretofore canceled by the Registrar
            or delivered to the Pass Through Trustee or the Registrar
            for cancellation;

                 (ii)  Certificates for which money in the full amount
            required to make the final distribution payment to be made
            pursuant to Section 11.1 hereof has been theretofore
            deposited with the Pass Through Trustee in trust for the
            Certificateholders as provided in Section 4.1 pending
            distribution of such money to the Certificateholders
            pursuant to such final distribution payment; and

                 (iii)  Certificates in exchange for or in lieu of which
            other Certificates have been authenticated and delivered
            pursuant to this Pass Through Trust Agreement.

            "Owner Participant" means the "Owner Participant" referred
       to in the Participation Agreement and any permitted successor or
       assign of any such Owner Participant.

            "Owner Trustee," with respect to any Equipment Note or the
       Indenture or the Lease, means _______________, not in its
       individual capacity but solely as owner trustee of an owner trust
       for the benefit of the Owner Participant, and each other Person
       which may from time to time be acting as Owner Trustee in
       accordance with the provisions of the Note Documents.

            "Participation Agreement" means the Participation Agreement
       (UTC Trust No. ______) (____), dated _________, and to which the
       Pass Through Trustee, the Owner Trustee, the Indenture Trustee,
       the Owner Participant, and Union are parties, as the
       Participation Agreement may be amended or supplemented from time
       to time in accordance with its respective terms.


                                     -7-

<PAGE>   13



            "Pass Through Trust" means the trust created by this Pass
       Through Trust Agreement, the estate of which consists of the
       Trust Property.

            "Pass Through Trust Agreement" means this Pass Through Trust
       Agreement, as it may be amended from time to time in accordance
       with the terms hereof.

            "Pass Through Trustee" means the institution executing this
       Pass Through Trust Agreement as Pass Through Trustee, or its
       successor in interest, and any successor trustee appointed as
       provided herein.

            "Paying Agent" means the paying agent maintained and
       appointed pursuant to Section 7.12.

            "Permitted Investments" means each of (i) direct obligations
       of the United States of America and agencies thereof; (ii)
       obligations fully guaranteed by the United States of America;
       (iii) certificates of deposit issued by, or bankers' acceptances
       of, or time deposits with, any bank, trust company or national
       banking association incorporated or doing business under the laws
       of the United States of America or one of the states thereof
       having combined capital and surplus and retained earnings of at
       least $100,000,000, having general obligations rated at least A1
       by Moody's Investors Service, Inc. or A+ by Standard & Poor's
       Corporation (but excluding any new investment as to which there
       is a public announcement by the rating agency providing a rating
       thereon that such rating is under consideration for a possible
       downgrade below A1 or A+, as the case may be), including the
       Owner Trustee in its individual capacity or the Indenture Trustee
       in its individual capacity if such conditions are met; (iv)
       commercial paper of any holding company of a bank, trust company
       or national banking association described in clause (iii); (v)
       bearer note deposits with, or certificates of deposit issued by,
       or promissory notes of, any subsidiary incorporated under the
       laws of Canada (or any province thereof) of any bank, trust
       company or national banking association described in clause
       (iii); (vi) commercial paper of companies having a rating of
       A-l/P-l or better assigned to such commercial paper by Standard &
       Poor's Corporation or Moody's Investors Service, Inc.  (or, if
       neither such organization shall rate such commercial paper at any
       time, by any nationally recognized rating organization in the
       United States of America); (vii) U.S. dollar-denominated
       certificates of deposit issued by, or time deposits with, the
       European subsidiaries of any bank, trust company or national
       banking association described in clause (iii); (viii) Canadian
       Treasury Bills fully hedged to U.S. dollars; (ix) bonds, notes or
       other obligations of any state of the United States of America,
       or any political subdivision of any such state, or any agencies
       or other instrumentalities of any such state, including, but not
       limited to, industrial development bonds, pollution control
       revenue bonds, public power bonds, housing bonds, other revenue
       bonds or any general obligation bonds; provided that, at the time
       of their purchase, such obligations are rated in the highest
       rating category by Standard & Poor's Corporation or Moody's
       Investors Service, Inc.  (or, if neither such organization shall
       rate such obligations at such time, by any nationally recognized
       rating organization in the United States of America); or (x)
       bonds or other debt instruments of any company, if such bonds or
       other debt


                                     -8-

<PAGE>   14


       instruments, at the time of their purchase, are rated in the
       highest rating category by Standard & Poor's Corporation or
       Moody's Investors Service, Inc. (or, if neither such organization
       shall rate such obligations at such time, by any nationally
       recognized rating organization in the United States of America);
       provided that no investment shall be eligible as and included
       within the definition of the term "Permitted Investment" unless
       either (x) the final maturity or date of return of such
       investment is equal to one year or less from the date of purchase
       thereof, or (y) in the case of any investment referred to in the
       foregoing clause (i) or (ii) only, such investment has a final
       maturity or date of return greater than one year from the date of
       purchase thereof and closing prices on a national securities
       exchange or bid and asked prices, closing prices or yields to
       maturity for such investment are reported in The Wall Street
       Journal (or if The Wall Street Journal is not at the time
       published or ceases to report such prices, such prices are
       reported by any other publication of nationally recognized
       standing of general circulation in New York City).

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

            "Pool Balance" means, as of any date, the aggregate unpaid
       principal amount of the ETCs and the Equipment Notes held in the
       Pass Through Trust on such date plus the amount of the principal
       payments on the ETCs and the Equipment Notes held by the Pass
       Through Trustee and not yet distributed plus the amount of any
       moneys held in the Escrow Account (other than earnings thereon).
       The Pool Balance as of any Regular Distribution Date or Special
       Distribution Date shall be computed after giving effect to the
       payment of principal, if any, on the Equipment Notes held in the
       Pass Through Trust and distribution thereof to be made on that
       date.

            "Pool Factor" means, as of any date, the quotient (rounded
       to the seventh decimal place) computed by dividing (i) the Pool
       Balance by (ii) the aggregate original principal amount of the
       Certificates issued under the Pass Through Trust.  The Pool
       Factor as of any Regular Distribution Date or Special
       Distribution Date shall be computed after giving effect to the
       payment of principal, if any, on the ETCs and the Equipment Notes
       held in the Pass Through Trust and distribution thereof to be
       made on that date.

            "Postponed Notes" means the Equipment Notes or ETCs as to
       which a Postponement Notice shall have been delivered pursuant to
       Section 2.1(b).

            "Postponement Notice" means a certificate of Union signed by
       an officer of Union (i) requesting that the Pass Through Trustee
       execute and deliver the Participation Agreement but temporarily
       postpone payment of the purchase price of the Equipment Notes or
       ETCs to a date later than the Issuance Date, (ii) identifying the
       amount of the purchase price of each Equipment Note or ETC and
       the aggregate purchase price of all such Equipment Notes or ETCs,
       (iii) setting forth the reasons for such postponement and (iv)
       with respect to the Participation Agreement referred to in clause
       (i), either (A) setting or resetting a new Closing Date (which
       shall be on or


                                     -9-

<PAGE>   15


       prior to the Initial Cut-off Date) for payment by the Pass
       Through Trustee of such purchase price and issuance of the
       Equipment Note or ETC, or (B) indicating that such new Closing
       Date (which shall be on or prior to the Initial Cut-Off Date)
       will be set by subsequent written notice not less than one
       Business Day prior to such new Closing Date.

            ["Procor Equipment Trust Trustee" means __________, in its
       capacity as the trustee under the Procor Equipment Trust
       Agreement, and any other Person which from time to time will be
       acting as Equipment Trust Trustee in accordance with the
       provisions of the Procor Equipment Trust Agreement.]

            "Record Date" means the Business Day preceding a Regular
       Distribution Date or a Special Distribution Date, as applicable.

            "Register" has the meaning specified in Section 3.4.

            "Registered Certificates" has the meaning specified in
       Section 3.1.

            "Registrar" has the meaning specified in Section 3.4.

            "Regular Distribution Date" means, with respect to
       distributions of Scheduled Payments, _______ and _______ of each
       year, commencing on __________, until payment of all the
       Scheduled Payments to be made under the Equipment Notes and the
       ETCs has been made.

            "Request" means a request by Union, on behalf of the
       Companies, setting forth the subject matter of the request
       accompanied by an Officer's Certificate and an Opinion of Counsel
       as provided in Section 1.2 of this Pass Through Trust Agreement.

            "Responsible Officer" means (i) with respect to the initial
       Pass Through Trustee, any initial Equipment Trust Trustee or the
       initial Indenture Trustee, any officer in the Corporate Trust
       Office or any other office at which the Pass Through Trustee, any
       Equipment Trust Trustee or the Indenture Trustee conducts
       corporate trust business; and (ii) with respect to any successor
       Pass Through Trustee, successor Equipment Trust Trustee,
       successor Indenture Trustee or the Owner Trustee, the chairman or
       vice-chairman of the board of directors or trustees, the chairman
       or vice-chairman of the executive or standing committee of the
       board of directors or trustees, the president, the chairman of
       the committee on trust matters, any vice-president, any second
       vice-president, the secretary, any assistant secretary, the
       treasurer, any assistant treasurer, the cashier, any assistant
       cashier, any trust officer or assistant trust officer, the
       comptroller and any assistant comptroller.  Responsible Officer
       also means, with respect to the Pass Through Trustee, any
       Equipment Trust Trustee, the Indenture Trustee and the Owner
       Trustee, any other officer of the Pass Through Trustee, the Owner
       Trustee, such Equipment Trust Trustee or the Indenture Trustee
       customarily performing functions similar to those performed by
       the persons who at the time shall be any of the above designated
       officers, and with respect to a particular corporate trust
       matter,


                                     -10-

<PAGE>   16


       any other officer to whom such matter is referred because of his
       knowledge of and familiarity with the particular subject.

            "Scheduled Payment" means, with respect to a Regular
       Distribution Date, any payment (other than a Special Payment) of
       interest on or principal of and interest on:  (i) an Equipment
       Note due from the Owner Trustee which issued such Equipment Note,
       which payment represents the installment of principal at the
       stated maturity of such installment of principal on such
       Equipment Note, or the payment of regularly scheduled interest
       accrued on the unpaid principal amount of such Equipment Note, or
       both, to be made on such Regular Distribution Date pursuant to
       the terms of such Equipment Note; or (ii) an ETC, to be made on
       such Regular Distribution Date pursuant to the terms of such ETC.

            "Special Distribution Date" means (i) in the case of
       prepayments with respect to a voluntary termination of the Lease,
       the purchase of any Units by Union pursuant to Section 22.1 of
       the Lease or an ordinary Event of Loss under the Lease, on a
       Regular Distribution Date, (ii) in the case of prepayments with
       respect to a Multiple Loss under the Lease, a refunding or
       refinancing of the Equipment Notes or a purchase of the Equipment
       by Union from an Owner Trustee of a competitor Owner Participant,
       on any Business Day following 15 days notice from the Pass
       Through Trustee to The Depository Trust Company and (iii) in the
       case of payments received following a default in respect of any
       Equipment Note, on the second day of any month, and (iv) with
       respect to an ETC, the earliest day of a month for which it is
       practicable for the Pass Through Trustee to give notice pursuant
       to Section 4.2(c) 20 days prior thereto.

            "Special Payment" means (i) with respect to an Equipment
       Note (or portion thereof), any payment of principal of,
       Make-Whole Amount, if any, and interest on such Equipment Note
       (or portion thereof) resulting from the prepayment of such
       Equipment Note (or portion thereof) pursuant to Section 2.10 of
       the applicable Indenture, (ii) with respect to an Equipment Note,
       any payment of principal of and interest (including any interest
       accruing upon default) on, or any other amount in respect of,
       such Equipment Note upon an Indenture Default in respect thereof,
       including payments received on account of the purchase by the
       Owner Trustee of such Equipment Notes, (iii) the amounts required
       to be distributed pursuant to the fifth paragraph of Section
       2.1(b), (iv) any proceeds from the sale of any Equipment Note by
       the Pass Through Trustee pursuant to Article VI hereof; (v) with
       respect to an ETC, any payment of principal of and interest
       (including any interest accruing upon default) on, or any other
       amount in respect of, such ETC upon an Equipment Trust Default in
       respect thereof or upon an acceleration under the Equipment Trust
       Agreement relating to such ETC, or (vi) any proceeds from the
       sale of an ETC by the Pass Through Trustee pursuant to Article VI
       hereof; and "Special Payments" means all of such Special
       Payments.

            "Special Payments Account" means the account or accounts
       created and maintained pursuant to Section 4.1(b).

                                     -11-
 

<PAGE>   17



            "Specified Investments" means (i) direct obligations of the
       United States of America and agencies thereof for which the full
       faith and credit of the United States of America is pledged, (ii)
       obligations fully guaranteed by the United States of America,
       (iii) certificates of deposit issued by, or bankers' acceptances
       of, or time deposits (including overnight deposits) with, any
       bank, trust company or national banking association incorporated
       or doing business under the laws of the United States of America
       or one of the States thereof having combined capital and surplus
       and retained earnings of at least $500,000,000 (including the
       Indenture Trustee or Owner Trustee, in their respective
       individual capacities, if such conditions are met), (iv)
       commercial paper of companies, banks, trust companies or national
       banking associations incorporated or doing business under the
       laws of the United States of America or one of the States thereof
       and in each case having a rating of A-l/P-l or better assigned to
       such commercial paper by Standard & Poor's Corporation or Moody's
       Investors Service, Inc. (or, if neither such organization shall
       rate such commercial paper at any time, by any nationally
       recognized rating organization in the United States of America)
       and (v) repurchase agreements with any financial institution
       described in clause (iii) above having a combined capital and
       surplus of at least $750,000,000 fully collateralized by
       obligations of the type described in clauses (i) through (iv)
       above; provided, however, that if all of the above investments
       are unavailable, the entire amount to be invested may be used to
       purchase Federal Funds from an entity described in clause (iii)
       above; and provided further that no investment shall be eligible
       as a "Specified Investment" unless the final maturity or date of
       return of such investment occurs no later than _______.

            "Subsequent Cut-off Date" means __________.

            "Trust Indenture Act" means, except as otherwise provided in
       Section 9.6, the Trust Indenture Act of 1939 as in force at the
       date as of which this instrument was executed.

            "Trust Property" means the Union ETCs[, the Procor ETC,] the
       Guarantee and the Equipment Notes held as the property of the
       Pass Through Trust and all moneys at any time paid thereon and
       all moneys due and to become due thereunder, funds from time to
       time deposited in the Escrow Account (other than earnings on
       Specified Investments), the Certificate Account and the Special
       Payments Account and any proceeds from the sale by the Pass
       Through Trustee pursuant to Article VI hereof of any Equipment
       Note.

            "Trustee's Liens" means any Lien (within the meaning
       specified in Appendix A to the Participation Agreement) arising
       as a result of (a) any claim against the Pass Through Trustee or
       ____________, in its individual capacity, respectively, not
       resulting from the actions contemplated by the Operative
       Agreements (within the meaning specified in Appendix A to the
       Participation Agreement), (b) any act or omission of the Pass
       Through Trustee or ___________, in its individual capacity,
       respectively, which is not required or permitted by the Operative
       Agreements or is in violation of any of the terms of the
       Operative Agreements, (c) any claim against the Pass Through
       Trustee or _____________, in its individual capacity,
       respectively, with respect to Taxes (within the meaning specified
       in Appendix A to the Participation Agreement) or Transaction
       Costs


                                     -12-

<PAGE>   18


       (within the meaning specified in Appendix A to the Participation
       Agreement) against which Union is not required to indemnify the
       Pass Through Trustee, ______________, in its individual capacity,
       pursuant to the Participation Agreement or (d) any claim arising
       out of any transfer by the Pass Through Trustee, of all or any
       portion of its interests in the Equipment, the Trust Property or
       the Operative Agreements other than the transfer of title to or
       possession of any Equipment by the Pass Through Trustee pursuant
       to and in accordance with the applicable Equipment Trust
       Agreement or the Indenture or pursuant to the exercise of the
       remedies set forth in the Lease; provided, however, that any
       Trustee Lien which is attributable solely to the Pass Through
       Trustee or ____________, in its individual capacity and would
       otherwise constitute a Trustee Lien shall not constitute a
       Trustee Lien so long as (i) the existence of such Trustee Lien
       poses no material risk of the sale, forfeiture or loss of any
       Unit or any interest therein, including Equipment Notes, (ii) the
       existence of such Trustee Lien does not interfere in any way with
       the quiet enjoyment of any Unit by Union, as lessee and (iii) the
       Pass Through Trustee or ____________, in its individual capacity,
       is diligently contesting such Trustee Lien by appropriate
       proceedings.

            "Unit" has the meaning assigned to that term in the Lease.

            "Union Equipment Trust Trustee" means ____________, in its
       capacity as trustee under the Union Equipment Trust Agreement,
       and any other Person which may from time to time be acting as
       Equipment Trust Trustee in accordance with the provisions of the
       Union Equipment Trust Agreement.

            SECTION 1.2.  Compliance Certificates and Opinions.  Upon
       any application or request by the Companies to the Pass Through
       Trustee to take any action under any provision of this Pass
       Through Trust Agreement, Union shall furnish to the Pass Through
       Trustee an Officer's Certificate stating that, in the opinion of
       the signers, all conditions precedent, if any, provided for in
       this Pass Through Trust Agreement relating to the proposed action
       have been complied with and an Opinion of Counsel stating that in
       the opinion of such counsel all such conditions precedent, if
       any, have been complied with, except that in the case of any such
       application or request as to which the furnishing of such
       documents is specifically required by any provision of this Pass
       Through Trust Agreement relating to such particular application
       or request, no additional certificate or opinion need be
       furnished.

            Every certificate or opinion with respect to compliance with
       a condition or covenant provided for in this Pass Through Trust
       Agreement (other than a certificate provided pursuant to Section
       8.4(d)) shall include:

                 (i)  a statement that each individual signing such
            certificate or opinion has read such covenant or condition
            and the definitions herein relating thereto;

                                     -13-
 

<PAGE>   19



                 (ii)  a brief statement as to the nature and scope of
            the examination or investigation upon which the statements
            or opinions contained in such certificate or opinion are
            used;

                 (iii)  a statement that, in the opinion of each such
            individual, he or she has made such examination or
            investigation as necessary to enable him or her to express
            an informed opinion as to whether or not such covenant or
            condition has been complied with; and

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

            SECTION 1.3.  Form of Documents Delivered to Pass Through
       Trustee.  In any case where several matters are required to be
       certified by, or covered by an opinion of, any specified Person,
       it is not necessary that all such matters be certified by, or
       covered by the opinion of, only one such Person, or that they be
       so certified or covered by only one document, but one such Person
       may certify or give an opinion with respect to some matters and
       one or more other such Persons as to other matters and any such
       Person may certify or give an opinion as to such matters in one
       or several documents.

            Any Opinion of Counsel stated to be based on the opinion of
       other counsel shall be accompanied by a copy of such other
       opinion.

            Where any Person is required to make, give or execute two or
       more applications, requests, consents, certificates, statements,
       opinions or other instruments under this Pass Through Trust
       Agreement, they may, but need not, be consolidated and form one
       instrument.

            SECTION 1.4.  Acts of Certificateholders.

            (a)  Any direction, consent, waiver or other action provided
       by this Pass Through Trust Agreement to be given or taken by
       Certificateholders may be embodied in and evidenced by one or
       more instruments of substantially similar tenor signed by such
       Certificateholders in person or by an agent duly appointed in
       writing; and, except as herein otherwise expressly provided, such
       action shall become effective when such instrument or instruments
       are delivered to the Pass Through Trustee and, where it is hereby
       expressly required, to the Companies, any Equipment Trust Trustee
       or the Indenture Trustee.  Such instrument or instrument (and the
       action embodied therein and evidenced thereby) are herein
       sometimes referred to as the "Act" of the Certificateholders
       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 Pass Through Trust
       Agreement and conclusive in favor of the Pass Through Trustee,
       the Companies, any Equipment Trust Trustee and the Indenture
       Trustee, if made in the manner provided in this Section.


                                     -14-

<PAGE>   20



            (b)  The fact and date of the execution by any Person of any
       such instrument or writing may be proved by the certificate of
       any notary public or other officer of any jurisdiction authorized
       to take acknowledgments of deeds or administer oaths that the
       Person executing such instrument acknowledged to him the
       execution thereof, or by an affidavit of a witness to such
       execution sworn to before any such notary or such other officer
       and where such execution is by an officer of a corporation or
       association or a member of a partnership, on behalf of such
       corporation, association or partnership, 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 reasonable manner which
       the Pass Through Trustee deems sufficient.  In the absence of bad
       faith on the part of the Pass Through Trustee, an Officer's
       Certificate may be deemed to be conclusively proved.

            (c)  In determining whether the Certificateholders of the
       requisite Fractional Undivided Interests of Certificates
       Outstanding have given any direction, consent or waiver (a
       "Direction"), under this Pass Through Trust Agreement,
       Certificates owned by either of the Companies, the Owner Trustee,
       the Owner Participant or any Affiliate of any such Person shall
       be disregarded and deemed not to be Outstanding under this Pass
       Through Trust Agreement for purposes of any such determination.
       In determining whether the Pass Through Trustee shall be
       protected in relying upon any such Direction, only Certificates
       which the Pass Through Trustee knows to be so owned shall be so
       disregarded.  Notwithstanding the foregoing, (i) if any such
       Person owns 100% of the Certificates Outstanding, such
       Certificates shall not be so disregarded as aforesaid, and (ii)
       if any amount of Certificates so owned by any such Person have
       been pledged in good faith, such Certificates shall not be
       disregarded as aforesaid if the pledgee establishes to the
       satisfaction of the Pass Through Trustee the pledgee's right so
       to act with respect to such Certificates and that the pledgee is
       not either of the Companies, the Owner Trustee, the Pass Through
       Trustee, the Owner Participant or any Affiliate of any such
       Person.

            (d)  Union, on behalf of the Companies, may at its option by
       delivery of an Officer's Certificate to the Pass Through Trustee
       set a record date to determine the Certificateholders entitled to
       give any consent, request, demand, authorization, direction,
       notice, waiver or other Act.  Notwithstanding Section 316(c) of
       the Trust Indenture Act, such record date shall be the record
       date specified in such Officer's Certificate which shall be a
       date not more than 30 nor less than 15 days prior to the first
       solicitation of Certificateholders in connection therewith.  If
       such a record date is fixed, such consent, request, demand,
       authorization, direction, notice, waiver or other Act may be
       given before or after such record  date, but only the
       Certificateholders of record at the close of business on such
       record date shall be deemed to be Certificateholders for the
       purposes of determining whether Certificateholders of the
       requisite proportion of Outstanding Certificates have authorized
       or agreed or consented to such consent, request, demand,
       authorization, direction, notice, waiver or other Act, and for
       that purpose the Outstanding Certificates shall be computed as of
       such record date; provided that no such consent, request, demand,
       authorization, direction, notice, waiver or other act by the
       Certificateholders on such

                                     -15-
 

<PAGE>   21


       record date shall be deemed effective unless it shall become
       effective pursuant to the provisions of this Agreement not later
       than one year after the record date.

            (e)  Any direction, consent, waiver or other action by the
       Certificateholder of any Certificate shall bind the
       Certificateholder of every Certificate issued upon the transfer
       thereof or in exchange thereof or in lieu thereof, whether or not
       notation of such action is made upon such Certificate.

            (f)  Except as otherwise provided in Section 1.4(c),
       Certificates owned by or pledged to any Person shall have an
       equal and proportionate benefit under the provisions of this Pass
       Through Trust Agreement, without preference, priority, or
       distinction as among all of the Certificates.


                                   ARTICLE II

                    ACQUISITION OF EQUIPMENT NOTES AND ETCs;
                       ORIGINAL ISSUANCE OF CERTIFICATES

            SECTION 2.1.  Issuance of Certificates; Acquisition of
       Equipment Notes and ETCs.

            (a)  Upon request of Union, the Pass Through Trustee shall
       execute, authenticate and deliver Certificates with an aggregate
       principal amount equalling the aggregate principal amount of the
       Equipment Notes and ETCs, as the case may be, to be purchased by
       the Pass Through Trustee pursuant to the Equipment Trust
       Agreements, this Pass Through Trust Agreement and the
       Participation Agreement and evidencing the entire ownership of
       the Pass Through Trust.  The Pass Through Trustee, not in its
       individual capacity but solely as Pass Through Trustee, shall
       issue and sell such Certificates, in authorized denominations and
       in such Fractional Undivided Interests, so as to result in the
       receipt of consideration in an amount equal to the aggregate
       principal amount of the Equipment Notes and ETCs to be issued
       from time to time, as contemplated by the Participation Agreement
       and the Equipment Trust Agreements, respectively, and,
       concurrently therewith, the Pass Through Trustee shall purchase,
       in the case of the Equipment Notes pursuant to the terms and
       conditions of the Participation Agreement, the Equipment Notes
       (except Postponed Notes, if any) then issued and, in the case of
       the ETCs pursuant to the terms and conditions of the Union
       Equipment Trust Agreement, the ETCs (except Postponed Notes, if
       any) then issued, at a purchase price equal to the amount of
       consideration received by the Pass Through Trustee with respect
       to such Equipment Notes and ETCs, respectively.  Upon the
       issuance after the Issuance Date of any Equipment Notes and Union
       ETCs not previously purchased by the Pass Through Trustee, the
       Pass Through Trustee shall purchase at such time such Equipment
       Notes and Union ETCs at a purchase price equal to the amount of
       consideration received by the Pass Through Trustee with respect
       to such Equipment Notes and Union ETCs.  Except as provided in
       Sections 3.4 and 3.5 hereof, the Pass Through Trustee shall


                                     -16-

<PAGE>   22


       not execute, authenticate or deliver Certificates in excess of
       the aggregate amount specified in this paragraph.  The provisions
       of this Subsection (a) are subject to the provisions of
       Subsections (b) and (c) below.

            (b)  If Union shall deliver to the Pass Through Trustee on
       or prior to the Issuance Date a Postponement Notice, the Pass
       Through Trustee shall postpone the purchase of the Equipment
       Notes or ETCs (the "Postponed Notes") referred to in such
       Postponement Notice and shall promptly deposit into an escrow
       account (the "Escrow  Account") an amount equal to the purchase
       price of such Postponed Notes (the "Escrowed Funds").  The
       Escrowed Funds so deposited into the Escrow Account shall be
       invested by the Pass Through Trustee at the written direction and
       risk of, and for the benefit of, Union in Specified Investments
       maturing (i) no later than the Initial Cut-off Date or (ii) if
       Union has given notice to the Pass Through Trustee that the
       Postponed Notes will not be issued, on the next Special
       Distribution Date, if such investments are reasonably available
       for purchase.  The Pass Through Trustee shall make withdrawals
       from the Escrow Account only as provided in this Pass Through
       Trust Agreement.  An account statement delivered by the Pass
       Through Trustee to Union shall be deemed written confirmation by
       Union that the investment transactions identified therein
       accurately reflect the investment directions given to the Pass
       Through Trustee by Union, unless Union notifies the Pass Through
       Trustee in writing to the contrary within thirty (30) days of
       receipt of such statement.

            The Pass Through Trustee shall hold all Specified
       Investments until the maturity thereof and will not sell or
       otherwise transfer such Specified Investments.  If Specified
       Investments held in the Escrow Account mature prior to the
       Initial Cut-off Date, any proceeds received on the maturity of
       such Specified Investments (other than any earnings thereon)
       shall be reinvested by the Pass Through Trustee at the written
       direction and risk of, and for the benefit of, Union in Specified
       Investments maturing (i) no later than the Initial Cut-off Date
       or (ii) if Union has given notice to the Pass Through Trustee
       that the Postponed Notes will not be issued, on the next Special
       Distribution Date, if such investments are reasonably available
       for purchase.

            Any earnings on Specified Investments received from time to
       time by the Pass Through Trustee shall be promptly distributed to
       Union to an account specified in writing by Union.  Union shall
       pay to the Pass Through Trustee for deposit to the Escrow Account
       an amount equal to any losses on Specified Investments as
       incurred.

            On or prior to the Initial Cut-off Date, upon the written
       request of Union and the satisfaction of the closing conditions
       specified in the Participation Agreement and the Union Equipment
       Trust Agreement, as the case may be, the Pass Through Trustee
       shall purchase the Postponed Notes with the Escrowed Funds.  The
       purchase price shall equal the principal amount of such Postponed
       Notes.

            If any of the Postponed Notes will not be issued on or prior
       to the Initial Cut-off Date for any reason, Union shall so notify
       the Pass Through Trustee and Union shall pay to the Pass

                                     -17-
 

<PAGE>   23


       Through Trustee on _______ for deposit in the Special Payments
       Account, in immediately available funds, an amount equal to the
       interest that would have accrued on such Postponed Notes at a
       rate or rates equal to the interest rate or rates applicable to
       the Certificates issued under the Pass Through Trust from the
       Issuance Date to, but not including, ______ and the Pass Through
       Trustee shall transfer an amount equal to that amount of Escrowed
       Funds that would have been used to purchase such Postponed Notes
       and the amount paid by Union under this paragraph to the Special
       Payments Account for distribution as a Special Payment in
       accordance with the provisions hereof.

            (c)  Notwithstanding the foregoing Subsection (b), with
       respect to amounts received by the Pass Through Trustee for the
       purchase of Equipment Notes and Union ETCs to be issued after the
       Initial Cut-off Date pursuant to the terms and conditions of the
       Participation Agreement or the Union Equipment Trust Agreement,
       the Pass Through Trustee shall promptly deposit into the Escrow
       Account an amount equal to the purchase price of such Equipment
       Notes or Union ETCs.  The Escrowed Funds so deposited into the
       Escrow Account shall be invested by the Pass Through Trustee at
       the written direction and risk of, and for the benefit of, Union
       in Specified Investments maturing (i) no later than the
       Subsequent Cut-off Date or (ii) if Union has given notice to the
       Pass Through Trustee that the aforementioned Equipment Notes or
       Union ETCs will not be issued, on the next Special Distribution
       Date, if such investments are reasonably available for purchase.
       The Pass Through Trustee shall make withdrawals from the Escrow
       Account only as provided in this Pass Through Trust Agreement.
       An account statement delivered by the Pass Through Trustee to
       Union shall be deemed written confirmation by Union that the
       investment transactions identified therein accurately reflect the
       investment directions given to the Pass Through Trustee by Union,
       unless Union notifies the Pass Through Trustee in writing to the
       contrary within thirty (30) days of receipt of such statement.

            The Pass Through Trustee shall hold all Specified
       Investments until the maturity thereof and will not sell or
       otherwise transfer such Specified Investments.  If Specified
       Investments held in the Escrow Account mature prior to the
       Subsequent Cut-off Date, any proceeds received on the maturity of
       such Specified Investments (other than any earnings thereon)
       shall be reinvested by the Pass Through Trustee at the written
       direction and risk of, and for the benefit of, Union in Specified
       Investments maturing (i) no later than the Subsequent Cut-off
       Date or (ii) if Union has given notice to the Pass Through
       Trustee that the aforementioned Equipment Notes or Union ETCs
       will not be issued, on the next Special Distribution Date, if
       such investments are reasonably available for purchase.

            Any earnings on Specified Investments received from time to
       time by the Pass Through Trustee shall be promptly distributed to
       Union to an account specified in writing by Union.  Union shall
       pay to the Pass Through Trustee for deposit to the Escrow Account
       an amount equal to any losses on Specified Investments as
       incurred.

                                     -18-
 

<PAGE>   24



            On or prior to the Subsequent Cut-off Date, upon the written
       request of Union and the satisfaction of the closing conditions
       specified in the Participation Agreement and the Union Equipment
       Trust Agreement, the Pass Through Trustee shall purchase the
       applicable Equipment Notes and Union ETCs with the Escrowed
       Funds.  The purchase price shall equal the principal amount of
       such Postponed Notes.

            If any of the applicable Equipment Notes or Union ETCs will
       not be issued on or prior to the Subsequent Cut-off Date for any
       reason, Union shall so notify the Pass Through Trustee and Union
       shall pay to the Pass Through Trustee on _______ for deposit in
       the Special Payments Account, in immediately available funds, an
       amount equal to the interest that would have accrued on such
       Equipment Notes or Union ETCs, as the case may be, at a rate or
       rates equal to the interest rate or rates applicable to the
       Certificates issued under the Pass Through Trust from the
       Issuance Date to, but not including, ________ and the Pass
       Through Trustee shall transfer an amount equal to that amount of
       Escrowed Funds that would have been used to purchase such
       Equipment Notes or Union ETCs and the amount paid by Union under
       this paragraph to the Special Payments Account for distribution
       as a Special Payment in accordance with the provisions hereof.

            SECTION 2.2.  Declaration of Trust; Acceptance By Pass
       Through Trustee.  The Pass Through Trustee, upon the execution
       and delivery of this Pass Through Trust Agreement, acknowledges
       its acceptance of all right, title, and interest in and to the
       Equipment Notes and the ETCs, as the case may be, acquired
       pursuant to Section 2.1 hereof and, in the case of the Equipment
       Notes, the Participation Agreement, and declares that the Pass
       Through Trustee holds and will hold such right, title, and
       interest, together with all other property constituting the Trust
       Property, for the benefit of all present and future
       Certificateholders, upon the trusts herein set forth.  By its
       payment for and acceptance of each Certificate issued to it
       hereunder, each initial Certificateholder as grantor of the Trust
       thereby joins in the creation and declaration of the Trust.

            SECTION 2.3.  Limitation of Powers.  The Pass Through Trust
       is constituted solely for the purpose of making the investment in
       the Equipment Notes and the ETCs, and, except as set forth
       herein, the Pass Through Trustee is not authorized or empowered
       to acquire any other investments or engage in any other
       activities and, in particular, the Pass Through Trustee is not
       authorized or empowered to do anything that would cause the Pass
       Through Trust to fail to qualify as a "grantor trust" for federal
       income tax purposes (including as subject to this restriction,
       acquiring any Equipment (as defined in the Indenture) by bidding
       the Equipment Notes, the ETCs or otherwise, or taking any action
       with respect to any such Equipment once acquired).

                                     -19-
 

<PAGE>   25



            SECTION 2.4.  Sale of Equipment Notes Under Certain
       Circumstances.  If Union elects, in accordance with Section 10.2
       of the Participation Agreement, to refund or refinance Equipment
       Notes, the Pass Through Trustee shall, upon satisfaction of the
       conditions set forth in Section 10.2 of the Participation
       Agreement, transfer such Equipment Notes to the Person designated
       by Union and will take any other action reasonably required to
       effect such refunding.


 


                                  ARTICLE III

                                THE CERTIFICATES

            SECTION 3.1.  Form, Denomination and Execution of
       Certificates.  The Certificates shall be issued in fully
       registered form without coupons and shall be substantially in the
       form attached hereto as Exhibit A, together with the Guarantee of
       Union attached thereto in substantially the form attached hereto
       as Exhibit B, with such omissions, variations and insertions as
       are permitted by this Pass Through Trust Agreement, and may have
       such letters, numbers or other marks of identification and such
       legends or endorsements printed, lithographed, typewritten or
       engraved thereon, as may be required to comply with the rules of
       any securities exchange on which the Certificates may be listed
       or to conform to any usage in respect thereof, or as may,
       consistently herewith, be prescribed by the Pass Through Trustee
       or by the officer executing such Certificates, such determination
       by such officer to be evidenced by his or her signing of the
       Certificates.

            Except as provided in Section 3.9, the definitive
       Certificates (the "Registered Certificates") shall be printed,
       lithographed, typewritten or engraved or produced by any
       combination of these methods or may be produced in any other
       manner permitted by the rules of any securities exchange on which
       the Certificates may be listed, all as determined by the officer
       executing such Certificates, as evidenced by his execution of
       such Certificates.

            The Certificates shall be issued in minimum denominations of
       $1,000 or any integral multiple of $1,000 in excess thereof,
       except that one Certificate may be issued in a denomination of
       less than $1,000 (the "De Minimis Certificate").

            The Certificates shall be executed on behalf of the Pass
       Through Trustee by manual or facsimile signature of a Responsible
       Officer of the Pass Through Trustee.  Certificates bearing the
       manual or facsimile signature of an individual who was, at the
       time when such signature was affixed, authorized to sign on
       behalf of the Pass Through Trustee shall be valid and binding
       obligations of the Pass Through Trustee, notwithstanding that
       such individual has ceased to be so authorized prior to the
       authentication and delivery of such Certificates or did not hold
       such office at the date of such Certificates.  No Certificate
       shall be entitled to any benefit under this Pass Through Trust
       Agreement, or be valid for any purpose, unless there appears on
       such Certificate a certificate of authentication substantially in
       the form set forth in Exhibit A hereto executed by the Pass
       Through Trustee by manual signature, and such certificate of
       authentication upon any


                                     -20-

<PAGE>   26


       Certificate shall be conclusive evidence, and the only evidence,
       that such Certificate has been duly authenticated and delivered
       hereunder.  All Certificates shall be dated the date of their
       authentication.

            SECTION 3.2.  Authentication of Certificates.  The Pass
       Through Trustee shall duly authenticate and deliver Certificates
       in authorized denominations equalling in the aggregate principal
       amount of the Equipment Notes and the ETCs, as the case may be,
       to be purchased by the Pass Through Trustee pursuant to the
       Equipment Trust Agreements, this Pass Through Trust Agreement and
       the Participation Agreement, and evidencing the entire ownership
       of the Trust.

            SECTION 3.3.  Temporary Certificates.  Pending the
       preparation of Registered Certificates, the Pass Through Trustee
       may execute, authenticate and deliver temporary Certificates
       which are printed, lithographed, typewritten, or otherwise
       produced, in any denomination, containing substantially the same
       terms and provisions as set forth in Exhibit A, except for such
       appropriate insertions, omissions, substitutions and other
       variations relating to their temporary nature as the officer
       executing such temporary Certificates may determine, as evidenced
       by their execution of such temporary Certificates.

            The Companies will cause Registered Certificates to be
       prepared without unreasonable delay after such Registered
       Certificates are required to be issued pursuant to Section
       3.9(d).  After the preparation of Registered Certificates, the
       temporary Certificates shall be exchangeable for Registered
       Certificates upon surrender of the temporary Certificates at the
       Corporate Trust Office of the Pass Through Trustee, or at the
       office or agency of the Pass Through Trustee maintained in
       accordance with Section 7.12, without charge to the holder.  Upon
       surrender for cancellation of any one or more temporary
       Certificates, the Pass Through Trustee shall execute,
       authenticate and deliver in exchange therefor Registered
       Certificates of authorized denominations of a like aggregate
       Fractional Undivided Interest; shall destroy any such temporary
       Certificate(s) theretofore delivered and exchanged; and shall
       certify, in writing, to the Companies such destruction.  Until so
       exchanged, such temporary Certificates shall in all respects be
       entitled to the same benefits under this Pass Through Trust
       Agreement as Registered Certificates.

            SECTION 3.4.  Registration of Transfer and Exchange of
       Certificates.  The Pass Through Trustee shall cause to be kept at
       the Corporate Trust Office or the office or agency to be
       maintained by it in accordance with the provisions of Section
       7.12 a register (the "Register") in which, subject to such
       reasonable regulations as it may prescribe, the Pass Through
       Trustee shall provide for the registration of Certificates and of
       transfers and exchanges of Certificates as herein provided.  The
       Pass Through Trustee shall initially be the registrar (the
       "Registrar") for the purpose of registering Certificates and
       transfers and exchanges of Certificates as herein provided.

            Upon surrender for registration of transfer of any
       Certificate at the Corporate Trust Office or such other office or
       agency, the Pass Through Trustee shall execute, authenticate and
       deliver,


                                     -21-

<PAGE>   27


       in the name of the designated transferee or transferees, one or
       more new Certificates in authorized denominations of a like
       aggregate Fractional Undivided Interest.
            At the option of a Certificateholder, Certificates may be
       exchanged for other Certificates of authorized denominations of a
       like aggregate Fractional Undivided Interest, upon surrender of
       the Certificates to be exchanged at any such office or agency.
       Whenever any Certificates are so surrendered for exchange, the
       Pass Through Trustee shall execute, authenticate and deliver the
       Certificates that the Certificateholder making the exchange is
       entitled to receive.  Every Certificate presented or surrendered
       for registration of transfer or exchange shall be duly endorsed
       or accompanied by a written instrument of transfer in form
       satisfactory to the Pass Through Trustee and the Registrar duly
       executed by the Certificateholder thereof or its attorney duly
       authorized in writing.

            No service charge shall be made to a Certificateholder for
       any registration of transfer or exchange of Certificates, but the
       Pass Through Trustee shall 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 Certificates.

            All Certificates surrendered for registration of transfer
       and exchange shall be canceled and subsequently destroyed by the
       Pass Through Trustee.  The Pass Through Trustee shall provide the
       Companies with written certification as to the destruction of all
       such Certificates.

            SECTION 3.5.  Mutilated, Destroyed, Lost or Stolen
       Certificates.  If (a) any mutilated Certificate is surrendered to
       the Registrar, or the Registrar receives evidence to its
       satisfaction of the destruction, loss or theft of any
       Certificate, and (b) there is delivered to the Registrar and the
       Pass Through Trustee such security, indemnity or bond, as may be
       required by them to save each of them harmless, then, in the
       absence of notice to the Registrar or the Pass Through Trustee
       that such Certificate has been acquired by a bona fide purchaser,
       the Pass Through Trustee shall execute, authenticate and deliver,
       in exchange for or in lieu of any such mutilated, destroyed, lost
       or stolen Certificate, a new Certificate of like Fractional
       Undivided Interest with the same final Regular Distribution Date.
       In connection with the issuance of any new Certificate under
       this Section 3.5, the Pass Through Trustee shall require the
       payment of a sum sufficient to cover any tax or other
       governmental charge that may be imposed in relation thereto and
       any other expenses (including the fees and expenses of the Pass
       Through Trustee and the Registrar) connected therewith.  Any
       duplicate Certificate issued pursuant to this Section 3.5 shall
       constitute conclusive evidence of the appropriate Fractional
       Undivided Interest in the Pass Through Trust, as if originally
       issued, whether or not the lost, stolen or destroyed Certificate
       shall be found at any time.

            SECTION 3.6.  Persons Deemed Owners.  Prior to due
       presentation of a Certificate for registration of transfer, the
       Pass Through Trustee, the Registrar, and any Paying Agent of the
       Pass Through Trustee may treat the person in whose name any
       Certificate is registered as the

                                     -22-
 

<PAGE>   28


       owner of such Certificate for the purpose of receiving
       distributions pursuant to Section 4.2 and for all other purposes
       whatsoever, and neither the Pass Through Trustee, the Registrar,
       nor any Paying Agent of the Pass Through Trustee shall be
       affected by any notice to the contrary.

            SECTION 3.7.  Cancellation.  All Certificates surrendered
       for payment or transfer or exchange shall, if surrendered to any
       Person party hereto other than the Registrar, be delivered to the
       Registrar for cancellation.  No Certificates shall be
       authenticated in lieu of or in exchange for any Certificates
       canceled as provided in this Section, except as expressly
       permitted by this Pass Through Trust Agreement.  All canceled
       Certificates held by the Registrar shall be destroyed and a
       certification of their destruction delivered to the Pass Through
       Trustee and the Companies.

            SECTION 3.8.  Limitation of Liability for Payments.  All
       payments or distributions made to Certificateholders under this
       Pass Through Trust Agreement shall be made only from the Trust
       Property and only to the extent that the Pass Through Trustee
       shall have sufficient income or proceeds from the Trust Property
       to make such payments in accordance with the terms of Article IV
       of this Pass Through Trust Agreement.  Each Certificateholder, by
       its acceptance of a Certificate, agrees that it will look solely
       to the income and proceeds from the Trust Property to the extent
       available for distribution to the Certificateholder thereof as
       provided in this Pass Through Trust Agreement.

            SECTION 3.9.  Book-Entry and Registered Certificates.

            (a)  Except for the De Minimis Certificate (if any), the
       Certificates may be issued in the form of one or more typewritten
       Certificates representing the Book-Entry Certificates, to be
       delivered to The Depository Trust Company, the initial Clearing
       Agency, by, or on behalf of, the Certificate Owners.  In such
       case, the Certificates delivered to The Depository Trust Company
       shall initially be registered on the Register in the name of Cede
       & Co., the nominee of the initial Clearing Agency, and no
       Certificate Owner will receive a Registered Certificate
       representing such Certificate Owner's interest in the
       Certificates, except as provided above and in Subsection (d)
       below.  Except with respect to the De Minimis Certificate (if
       any), unless and until Registered Certificates have been issued
       pursuant to Subsection (d) below:

                 (i)  the provisions of this Section 3.9 shall be in
            full force and effect;

                 (ii)  the Companies, the Paying Agent, the Registrar
            and the Pass Through Trustee may deal with the Clearing
            Agency for all purposes (including the making of
            distributions on the Certificates) as the authorized
            representative of the Certificate Owners;

                 (iii)  to the extent that the provisions of this
            Section 3.9 conflict with any other provisions of this Pass
            Through Trust Agreement, the provisions of this Section 3.9
            shall control;


                                     -23-

<PAGE>   29



                 (iv)  the rights of Certificate Owners shall be
            exercised only through the Clearing Agency and shall be
            limited to those established by law and agreements between
            such Certificate Owners and the Clearing Agency
            Participants; and until Registered Certificates are issued
            pursuant to Subsection (d) below, the Clearing Agency will
            make book-entry transfers among the Clearing Agency
            Participants and receive and transmit distributions of
            principal and interest and Make-Whole Amount, if any, on the
            Certificates to such Clearing Agency Participants; and

                 (v)  whenever this Pass Through Trust Agreement
            requires or permits actions to be taken based upon
            instructions or directions of Certificateholders holding
            Certificates evidencing a specified percentage of the
            Fractional Undivided Interests, the Clearing Agency shall be
            deemed to represent such percentage only to the extent that
            it has received instructions to such effect from Certificate
            Owners and/or Clearing Agency Participants owning or
            representing, respectively, such required percentage of the
            beneficial interest in Certificates and has delivered such
            instructions to the Pass Through Trustee.  The Pass Through
            Trustee shall have no obligation to determine whether the
            Clearing Agency has in fact received any such instructions.

            (b)  Except with respect to the De Minimis Certificate (if
       any), whenever notice or other communication to the
       Certificateholders is required under this Pass Through Trust
       Agreement, unless and until Registered Certificates shall have
       been issued pursuant to Subsection (d) below, the Pass Through
       Trustee shall give all such notices and communications specified
       herein to be given to Certificateholders to the Clearing Agency
       and/or the Clearing Agency Participants, and shall make available
       additional copies as requested by such Clearing Agency
       Participants.

            (c)  Unless and until Registered Certificates are issued
       pursuant to Subsection (d) below, on the Record Date prior to
       each Regular Distribution Date and Special Distribution Date, the
       Pass Through Trustee will request from the Clearing Agency a
       Securities Position Listing setting forth the names of all
       Clearing Agency Participants reflected on the Clearing Agency's
       books as holding interests in the Certificates on such Record
       Date.  The Pass Through Trustee will mail to each such Clearing
       Agency Participant the statements described in Section 4.3
       hereof.

            (d)  If (i) Union, on behalf of the Companies, advises the
       Pass Through Trustee in writing that the Clearing Agency is no
       longer willing or able to properly discharge its responsibilities
       and the Pass Through Trustee or Union, on behalf of the Companies
       is unable to locate a qualified successor, (ii) Union, on behalf
       of the Companies, at its option, advises the Pass Through Trustee
       in writing that it elects to terminate the book-entry system
       through the Clearing Agency or (iii) after the occurrence of an
       Event of Default, Certificate Owners of Book-Entry Certificates
       evidencing Fractional Undivided Interests aggregating not less
       than a majority in interest in the Pass Through Trust, by act of
       such Certificate Owners delivered to the Companies, and the Pass
       Through Trustee, advise the Pass Through Trustee and the Clearing
       Agency through the Clearing Agency Participants in writing that
       the continuation of a book-entry system through the Clearing


                                     -24-

<PAGE>   30


       Agency is no longer in the best interests of the Certificate
       Owners, then the Pass Through Trustee shall notify all
       Certificate Owners, through the Clearing Agency, of the
       occurrence of any such event and of the availability of
       Registered Certificates.  Upon surrender to the Pass Through
       Trustee of all the Certificates held by the Clearing Agency,
       accompanied by registration instructions from the Clearing Agency
       for registration of Registered Certificates in the names of
       Certificate Owners, the Pass Through Trustee shall issue and
       deliver the Registered Certificates in accordance with the
       instructions of the Clearing Agency.  Upon the issuance of
       Registered Certificates pursuant to this Section 3.9(d), the
       Record Date with respect to such Registered Certificates shall be
       the fifth Business Day preceding a Regular Distribution Date or
       Special Distribution Date, as applicable.  Neither the Companies,
       the Registrar, the Paying Agent nor the Pass Through Trustee
       shall be liable for any delay in delivery of such instructions
       and may conclusively rely on, and shall be protected in relying
       on, such registration instructions.  Upon the issuance of
       Registered Certificates, the Pass Through Trustee shall recognize
       the Persons in whose name the Registered Certificates are
       registered as the Certificateholders hereunder.  Neither the
       Companies nor the Pass Through Trustee shall be liable if the
       Pass Through Trustee or Union, on behalf of the Companies is
       unable to locate a qualified successor Clearing Agency.

            (e)  The Pass Through Trustee shall enter into the Letter of
       Representations and fulfill its responsibilities thereunder.


                                   ARTICLE IV

                          DISTRIBUTIONS; STATEMENTS TO
                               CERTIFICATEHOLDERS

            SECTION 4.1.  Certificate Account and Special Payments
       Account.

            (a)  The Pass Through Trustee shall establish and maintain
       on behalf of the Certificateholders the Certificate Account as
       one or more accounts, which shall be non-interest bearing
       accounts.  The Pass Through Trustee shall hold the Certificate
       Account in trust for the benefit of the Certificateholders, and
       shall make or permit withdrawals therefrom only as provided in
       this Pass Through Trust Agreement.  On each day when a Scheduled
       Payment is made under the Indenture or an Equipment Trust
       Agreement to the Pass Through Trustee, as holder of either the
       Equipment Notes or the ETCs issued under the Indenture or such
       Equipment Trust Agreement, as the case may be, the Pass Through
       Trustee upon receipt shall immediately deposit the aggregate
       amount of such Scheduled Payment in the Certificate Account.

            (b)  The Pass Through Trustee shall establish and maintain
       on behalf of the Certificateholders the Special Payments Account
       as one or more accounts, which shall be non-interest bearing
       except as provided in Section 4.4.  The Pass Through Trustee
       shall hold the Special Payments Account in trust for the benefit
       of the Certificateholders, and shall make or


                                     -25-
 

<PAGE>   31


       permit withdrawals therefrom only as provided in this Pass
       Through Trust Agreement.  On each day when one or more Special
       Payments (other than a Special Payment that represents the
       proceeds of any sale pursuant to Article VI by the Pass Through
       Trustee of an Equipment Note) are made under an Equipment Trust
       Agreement or the Indenture to the Pass Through Trustee, as holder
       of either the Equipment Notes or the ETCs issued under the
       Indenture or such Equipment Trust Agreement, as the case may be,
       the Pass Through Trustee upon receipt shall immediately deposit
       the aggregate amounts of such Special Payments in the Special
       Payments Account.  On the day Union makes the payment to the Pass
       Through Trustee described in the fifth paragraph of Section
       2.1(b), the Pass Through Trustee upon receipt shall immediately
       deposit the aggregate amount thereof in the Certificate Account.
       Upon the sale of any Equipment Note or ETC by the Pass Through
       Trustee pursuant to Article VI and the realization of any
       proceeds thereof, the Pass Through Trustee shall deposit the
       aggregate amount of such proceeds as a Special Payment in the
       Special Payments Account.

            (c)  The Pass Through Trustee shall present to the Indenture
       Trustee to which an Equipment Note relates such Equipment Note on
       the date of its stated final maturity, or in the case of any
       Equipment Note which is to be prepaid in whole pursuant to the
       relevant Indenture, on the applicable prepayment date under the
       Indenture.

            (d)  The Pass Through Trustee shall present to the Equipment
       Trust Trustee to which an ETC relates such ETC on the date of its
       stated final maturity.

            SECTION 4.2.  Distribution from Certificate Account and
       Special Payments Account.

            (a)  On each Regular Distribution Date or as soon thereafter
       as the Pass Through Trustee has confirmed receipt of the payment
       of the Scheduled Payments due with respect to the Equipment Notes
       or ETCs on such date, the Pass Through Trustee shall distribute
       to the Certificateholders of the Pass Through Trust out of the
       Certificate Account the entire amount deposited therein pursuant
       to Section 4.1(a).  There shall be so distributed to each
       Certificateholder of record on the Record Date with respect to
       such Regular Distribution Date (other than as provided in Section
       11.1 concerning the final distribution) by check mailed to such
       Certificateholder at the address appearing in the Register, such
       Certificateholder's pro rata share (based on the aggregate
       Fractional Undivided Interest held by such Certificateholder) of
       the aggregate amount in the Certificate Account; provided,
       however, that prior to the time that any Certificates are issued
       in the form of Registered Certificates, each Certificateholder
       may request in writing that such amounts be distributed by wire
       transfer of immediately available funds to an account specified
       by such Certificateholder.  If a Scheduled Payment is not
       received by the Pass Through Trustee on a Regular Distribution
       Date but is received on a later date, it shall be distributed on
       the date received in the manner described in the preceding
       sentence to the Certificateholders of record on the Record Date
       with respect to such Regular Distribution Date.

                                     -26-
 

<PAGE>   32



            (b)  On each Special Distribution Date with respect to any
       Special Payment or as soon thereafter as the Pass Through Trustee
       has confirmed receipt of the Special Payments due on the
       Equipment Notes or ETCs or realized upon the sale of any
       Equipment Note or ETCs, the Pass Through Trustee shall distribute
       out of the Special Payments Account the entire amount deposited
       therein pursuant to Section 4.1(b) of such Special Payment.
       There shall be so distributed to each Certificateholder of record
       on the Record Date with respect to such Special Distribution Date
       (other than as provided in Section 11.1 concerning the final
       distribution) by check mailed to such Certificateholder at the
       address appearing in the Register, such Certificateholder's pro
       rata share (based on the aggregate Fractional Undivided Interest
       held by such Certificateholder) of the aggregate amount in the
       Special Payments Account on account of such Special Payment;
       provided, however, that prior to the time that any Certificates
       are issued in the form of Registered Certificates, each
       Certificateholder may request in writing that such amount be
       distributed by wire transfer of immediately available funds to an
       account specified by such Certificateholder.

            (c)  The Pass Through Trustee shall at the expense of the
       Companies cause notice of each Special Payment to be mailed to
       each Certificateholder at his address as it appears in the
       Register.  In the case of a Special Payment other than pursuant
       to the fifth paragraph of Section 2.1(b) or the fifth paragraph
       of Section 2.1(c), such notice shall be mailed not less than 15
       days prior to the date any such Special Payment is scheduled to
       be distributed.  In the case of a Special Payment pursuant to the
       fifth paragraph of Section 2.1(b) or the fifth paragraph of
       Section 2.1(c) such notice should be given as promptly as
       practicable after the receipt of notice from the Companies that
       Postponed Notes or the Equipment Notes or Union ETCs referred to
       in Section 2.1(c) will not be issued.  In the case of any other
       Special Payments, such notice shall be mailed as soon as
       practicable after the Pass Through Trustee has confirmed that it
       has received funds for such Special Payment.  Notices mailed by
       the Pass Through Trustee shall set forth:

                 (i)  the Special Distribution Date and the Record Date
            therefor (except as otherwise provided in Section 11.1),

                 (ii)  the amount of the Special Payment for each $1,000
            face amount Certificate (taking into account any payment to
            be made by the Companies pursuant to Section 2.1(b) or (c),
            as applicable) and the amount thereof constituting
            principal, Make-Whole Amount, if any, and interest,

                 (iii)  the reason for the Special Payment, and

                 (iv)  if the Special Distribution Date is the same date
            as a Regular Distribution Date, the total amount to be
            received on such date for each $1,000 face amount
            Certificate.

            If the amount of Make-Whole Amount, if any, payable upon the
       prepayment of an Equipment Note has not been calculated at the
       time that the Pass Through Trustee mails notice


                                     -27-

<PAGE>   33

       of a Special Payment, it shall be sufficient if the notice sets
       forth the other amounts to be distributed and states that any
       Make-Whole Amount received will also be distributed.

            If any prepayment of the Equipment Notes is canceled, the
       Pass Through Trustee, as soon as possible after learning thereof,
       shall cause notice thereof to be mailed to each Certificateholder
       at its address as it appears on the Register.

            SECTION 4.3.  Statements to Certificateholders.

            (a)  On each Regular Distribution Date and Special
       Distribution Date, the Pass Through Trustee will include with
       each distribution of a Scheduled Payment or a Special Payment to
       Certificateholders a statement, giving effect to such
       distribution to be made on such Regular Distribution Date or
       Special Distribution Date, as the case may be, setting forth the
       following information (for each $1,000 face amount Certificate as
       to (i) and (ii) below):

                 (i)  The amount of such distribution allocable to
            principal and the amount allocable to Make-Whole Amount, if
            any;

                 (ii)  The amount of such distribution allocable to
            interest; and

                 (iii)  The Pool Balance and the Pool Factor.

            (b)  Within a reasonable period of time after the end of
       each calendar year but not later than the latest date permitted
       by law, the Pass Through Trustee shall furnish to each Person who
       at any time during such calendar year was a Certificateholder of
       record a statement containing the sum of the amounts determined
       pursuant to clauses (a)(i) and (a)(ii) of this Section 4.3 with
       respect to the Pass Through Trust for such calendar year or, in
       the event such Person was a Certificateholder of record during a
       portion of such calendar year, for the applicable portion of such
       year, and such other items as are readily available to the Pass
       Through Trustee and which a Certificateholder shall reasonably
       request as necessary for the purpose of such Certificateholder's
       preparation of its Federal income tax returns.  Such report and
       such other items shall be prepared on the basis of information
       supplied to the Pass Through Trustee by the Clearing Agency
       Participants and shall be delivered by the Pass Through Trustee
       to such Clearing Agency Participants to be available for
       forwarding by such Clearing Agency Participants to Certificate
       Owners.

            SECTION 4.4.  Investment of Special Payment Money.  Any
       money received by the Pass Through Trustee pursuant to Section
       4.1(b) representing a Special Payment which is not to be promptly
       distributed shall, to the extent practicable, be invested in
       Permitted Investments by the Pass Through Trustee pending
       distribution of such Special Payment pursuant to Section 4.2.
       Any investment made pursuant to this Section 4.4 shall be in such
       Permitted Investments having maturities not later than the date
       that such moneys are required to be used to make the payment

                                     -28-
 

<PAGE>   34


       required under Section 4.2 on the applicable Special Distribution
       Date and the Pass Through Trustee shall hold any such Permitted
       Investments until maturity.  The Pass Through Trustee shall have
       no liability with respect to any investment made pursuant to this
       Section 4.4, other than by reason of the willful misconduct or
       gross negligence of the Pass Through Trustee.  All income and
       earnings from such investments shall be distributed to the
       Certificateholders on such Special Distribution Date as part of
       such Special Payment.


                                   ARTICLE V

                                 THE COMPANIES

            SECTION 5.1.  Maintenance of Corporate Existence.  Each of
       the Companies, at its own cost and expense, will do or cause to
       be done all things necessary to preserve and keep in full force
       and effect its corporate existence, rights and franchises, except
       as otherwise specifically permitted in Section 5.2; provided,
       however, that neither of the Companies shall be required to
       preserve any right or franchise if it shall determine that the
       preservation thereof is no longer desirable in the conduct of its
       business.

            SECTION 5.2.  Consolidation, Merger or Sale of Assets
       Permitted.

            (a)  Union shall not consolidate with or merge into any
       other corporation or sell or convey all or substantially all of
       its assets to any Person[, nor shall Union permit Procor to
       consolidate with or merge into any other corporation or sell or
       convey all or substantially all of its assets to any Person
       (other than an Affiliate of Union)], unless the corporation
       formed by such consolidation or into which Union [or Procor, as
       applicable,] is merged or the Person which acquires by sale or
       conveyance all or substantially all of the assets of Union or
       Procor, as applicable, shall be a corporation organized and
       existing under the laws of the United States of America or any
       State or the District of Columbia [or, in the case of Procor any
       province of Canada], and shall execute and deliver to the Pass
       Through Trustee an agreement in form reasonably satisfactory to
       the Pass Through Trustee containing an assumption by such
       successor corporation of the due and punctual performance and
       observance of each covenant and condition of this Agreement to
       which Union [or Procor, as applicable,] is a party.

            (b)  Immediately after giving effect to such transaction, no
       Event of Default, no Indenture Default, no Equipment Trust
       Default, and no event that, after notice or lapse of time, or
       both, would become an Event of Default, an Indenture Default or
       an Equipment Trust Default, shall have occurred and be
       continuing.

            Upon any consolidation or merger, or any sale or conveyance,
       of all or substantially all of the assets of Union [or Procor, as
       the case may be], the successor corporation formed by such
       consolidation or into which Union [or Procor, as the case may
       be], is merged or to which such


                                     -29-

<PAGE>   35


       sale or conveyance is made shall succeed to, and be substituted
       for, and may exercise every right and power of, Union [or Procor,
       as the case may be], under this Agreement with the same effect as
       if such successor corporation had been named as Union [or Procor,
       as the case may be], herein.  No such sale or conveyance of all
       or substantially all of the assets of Union [or Procor, as the
       case may be], as an entirety shall have the effect of releasing
       Union [or Procor, as the case may be], or any successor
       corporation which shall theretofore have become such from its
       liability hereunder.

            (c)  The Pass Through Trustee may accept an Officer's
       Certificate and an Opinion of Counsel of Union, on behalf of the
       Companies, as conclusive evidence that any such consolidation,
       merger, sale, lease or conveyance, and any such assumption
       complies with the provisions of this Section 5.2.


                                   ARTICLE VI

                                    DEFAULT

            SECTION 6.1.  Events of Default.  If an Indenture Default
       under the Indenture or an Equipment Trust Default under either
       Equipment Trust Agreement (an "Event of Default") shall occur and
       be continuing, then, and in each and every case, so long as such
       Event of Default shall be continuing, the Pass Through Trustee
       may vote all of the Equipment Notes issued under the Indenture or
       ETCs issued under either of the Equipment Trust Agreements, as
       the case may be, to which such Event of Default relates that are
       held in the Trust Property, and upon the direction of the
       Certificateholders holding Certificates evidencing Fractional
       Undivided Interests aggregating not less than a majority in
       interest in the Pass Through Trust, the Trustee shall vote a
       corresponding majority of such Equipment Notes or such ETCs, as
       the case may be, in favor of directing the Indenture Trustee
       under the Indenture or the Equipment Trust Trustee under such
       Equipment Trust Agreement, as the case may be, to declare the
       unpaid principal amount of all Equipment Notes then outstanding
       under the Indenture or the ETCs then outstanding under such
       Equipment Trustee Agreement, as the case may be, and accrued
       interest thereon to be due and payable under, and in accordance
       with the provisions of, the Indenture or such Equipment Trust
       Agreement, as the case may be.  In addition, if an Indenture
       Default shall have occurred and be continuing under the Indenture
       or an Equipment Trust Default shall have occurred and be
       continuing under either Equipment Trust Agreement, the Pass
       Through Trustee may, and upon the direction of the
       Certificateholders holding Certificates evidencing Fractional
       Undivided Interests aggregating not less than a majority in
       interest in the Pass Through Trust, shall, vote all of the
       Equipment Notes issued under such Indenture or the ETCs issued
       under such Equipment Trust Agreement, as the case may be, to
       which such Event of Default relates that are held in the Pass
       Through Trust to direct such Indenture Trustee or such Equipment
       Trust Trustee, as the case may be, regarding the exercise of
       remedies provided in Article V of the Indenture or Article V of
       such Equipment Trust Agreement, as the case may be.  [In
       addition, if an Equipment Trust


                                     -30-

<PAGE>   36


       Default has occurred and is continuing under the Procor ETC, the
       Pass Through Trustee in its own name, or as trustee of an express
       trust, or as attorney-in-fact for the Certificateholders, may,
       and upon direction of Certificateholders holding Certificates
       evidencing Fractional Undivided Interests aggregating not less
       than a majority in interest in the Pass Through Trust, shall,
       pursue such remedies as available to the Pass Through Trustee
       against Union under the Guarantee.]

            In addition, after an Event of Default shall have occurred
       and be continuing with respect to any Equipment Notes or ETCs,
       the Pass Through Trustee may in its discretion, and upon the
       direction of the Certificateholders holding Certificates
       evidencing Fractional Undivided Interests aggregating not less
       than a majority in interest in the Pass Through Trust shall, by
       such officer or agent as it may appoint, sell, convey, transfer
       and deliver (to the extent permitted by applicable law) all or
       part of such Equipment Notes or ETCs, without recourse to or
       warranty by the Pass Through Trustee or any Certificateholder, to
       any Person.  In any such case, the Pass Through Trustee shall
       sell, assign, contract to sell or otherwise dispose of and
       deliver such Equipment Note or Equipment Notes or ETC or ETCs in
       one or more parcels at public or private sale or sales, at any
       location or locations at the option of the Pass Through Trustee,
       all upon such terms and conditions as it may reasonably deem
       advisable and at such prices as it may reasonably deem advisable,
       for cash.  If the Pass Through Trustee so decides or is required
       to sell or otherwise dispose of any Equipment Note or ETC
       pursuant to this Section, the Pass Through Trustee shall take
       such of the actions described above as it may reasonably deem
       most effectual to complete the sale or other disposition of such
       Equipment Note or ETC, so as to provide for the payment in full
       of all amounts due on the Certificates.  [Notwithstanding the
       foregoing, any action taken by the Pass Through Trustee under
       this Section shall not, in the reasonable judgment of the Pass
       Through Trustee, be adverse to the best interests of the
       Certificateholders and the Pass Through Trustee shall give
       written notice to Procor of its proposed sale of the Procor ETC
       or any part thereof at least 20 days prior to the proposed sale.
       Such notice shall constitute an offer to Procor to sell the
       Procor ETC or such part thereof to Procor for a price equal to
       the outstanding principal amount thereof, plus all accrued and
       unpaid interest thereon, including interest at the Penalty Rate
       (as defined in the Procor Equipment Trust Agreement), if any,
       plus all other amounts due and owing thereunder and the costs and
       expenses incurred by the Pass Through Trustee, the
       Certificateholders and the Certificate Owners in connection with
       the collection thereof and enforcement of remedies relating
       thereto.  If prior to the expiration of such 20 day period,
       Procor pays the purchase price aforesaid to the Pass Through
       Trustee, the Pass Through Trustee shall transfer all of its
       right, title and interest in and to the Procor ETC or such part
       thereof to Procor.  If Procor does not pay such purchase price to
       the Pass Through Trustee prior to the expiration of such 20 day
       period, the Pass Through Trustee shall be free to sell the Procor
       ETC under this paragraph to any Person.  The Pass Through Trustee
       shall be required to give no more than one notice under this
       paragraph and Procor acknowledges that the failure of any
       proposed sale of the Procor ETC or part thereof shall not entitle
       Procor to receive any additional notice hereunder.]

            If, with respect to any Equipment Notes, an Indenture
       Default shall have occurred and be continuing and the Owner
       Trustee, which is a party to the Indenture has elected, in
       accordance


                                     -31-

<PAGE>   37


       with the provisions of Section 5.04(b) of the Indenture, to
       purchase all of the then outstanding Equipment Notes issued under
       the Indenture at a price equal to the aggregate unpaid principal
       amount thereof, together with accrued interest thereon to the
       date of such purchase,  then the Pass Through Trustee shall sell
       to such Owner Trustee all of the Equipment Notes issued under the
       Indenture held in the Pass Through Trust at a price equal to the
       aggregate unpaid principal amount thereof, together with accrued
       interest thereon to the date of such sale.

            In no event shall (i) an Indenture Default constitute an
       Equipment Trust Default or (ii) an Equipment Trust Default
       constitute an Indenture Default.

            SECTION 6.2.  Incidents of Sale of Equipment Notes and ETCs.
       Upon any sale of all or any part of the Equipment Notes or ETCs,
       as the case may be, made either under the power of sale given
       under this Pass Through Trust Agreement or otherwise for the
       enforcement of this Pass Through Trust Agreement, the following
       shall be applicable:

                 (i)  Certificateholders and Pass Through Trustee May
            Purchase Equipment Notes or ETCs.  Any Certificateholder,
            the Pass Through Trustee in its individual or any other
            capacity or any other Person may bid for and purchase any of
            the Equipment Notes or ETCs, as the case may be, and upon
            compliance with the terms of sale, may hold, retain, possess
            and dispose of such Equipment Notes or ETCs, as the case may
            be, in their own absolute right without further
            accountability; provided, however, that this provision shall
            not apply to the sale of Equipment Notes or ETCs, as the
            case may be, pursuant to the last paragraph of Section 6.1.

                 (ii)  Receipt of Pass Through Trustee Shall Discharge
            Purchaser.  The receipt of the Pass Through Trustee or of
            the officer making such sale shall be a sufficient discharge
            to any purchaser for his purchase money, and, after paying
            such purchase money and receiving such receipt, such
            purchaser or its personal representative or assigns shall
            not be obliged to see to the application of such purchase
            money, or be in any way answerable for any loss,
            misapplication or non-application thereof.

                 (iii)  Application of Moneys Received Upon Sale.  Any
            moneys collected by the Pass Through Trustee upon any sale
            made either under the power of sale given by this Pass
            Through Trust Agreement or otherwise for the enforcement of
            this Pass Through Trust Agreement, shall be applied as
            provided in Section 4.2(b).

            SECTION 6.3.  Judicial Proceedings Instituted by Pass
       Through Trustee.
 
            (a)  Pass Through Trustee May Bring Suit.  If there shall be
       a failure to make payment of the principal of, Make-Whole Amount,
       if any, or interest on any Equipment Note or ETC, or if there
       shall be any failure to pay Rent (as defined in the Lease) under
       the Lease when due and payable, then the Pass Through Trustee, in
       its own name, and as trustee of an express trust, as


                                     -32-

<PAGE>   38


       holder of such Equipment Notes or ETC, shall be, to the extent
       permitted by and in accordance with the terms of the Note
       Documents or ETC Documents, entitled and empowered to institute
       any suits, actions or proceedings at law, in equity or otherwise,
       for the collection of the sums so due and unpaid on such
       Equipment Notes or ETCs or under the Lease and may prosecute any
       such claim or proceeding to judgment or final decree with respect
       to the whole amount of any such sums so due and unpaid.

            (b)  Pass Through Trustee May File Proofs of Claim;
       Appointment of Pass Through Trustee as Attorney-in-Fact in
       Judicial Proceedings.  The Pass Through Trustee in its own name,
       or as trustee of an express trust, or as attorney-in-fact for the
       Certificateholders, or in any one or more of such capacities
       (irrespective of whether distributions on the Certificates shall
       then be due and payable, or the payment of the principal on the
       Equipment Notes or ETCs, as the case may be, shall then be due
       and payable, as therein expressed or by declaration or otherwise
       and irrespective of whether the Pass Through Trustee shall have
       made any demand to the Indenture Trustee for the payment of
       overdue principal, Make-Whole Amount (if any) or interest on
       Equipment Notes or ETCs, as the case may be), shall be entitled
       and empowered to file such proofs of claim and other papers or
       documents as may be necessary or advisable in order to have the
       claims of the Pass Through Trustee and of the Certificateholders
       allowed in any receivership, insolvency, bankruptcy, liquidation,
       readjustment, reorganization or any other judicial proceedings
       relative to the Companies, the Owner Trustee, the Owner
       Participant, the Equipment Trust Trustees or their respective
       creditors or property.  Any receiver, assignee, trustee,
       liquidator, sequestrator (or similar official) in any judicial
       proceeding is hereby authorized by each Certificateholder to make
       payments in respect of such claim to the Pass Through Trustee
       and, in the event that the Pass Through Trustee shall consent to
       the making of such payments directly to the Certificateholders,
       to pay to the Pass Through Trustee any amount due to it for the
       reasonable compensation, expenses, disbursements and advances of
       the Pass Through Trustee, its agents and counsel.  Nothing
       contained in this Pass Through Trust Agreement shall be deemed to
       give to the Pass Through Trustee any right to accept or consent
       to any plan of reorganization or otherwise by action of any
       character in any such proceeding to waive of change in any way
       any right of any Certificateholder.

            SECTION 6.4.  Control by Certificateholders.  Subject to
       Section 2.3, the Certificateholders holding Certificates
       evidencing Fractional Undivided Interests aggregating not less
       than a majority in interest in the Pass Through Trust shall have
       the right to direct the time, method and place of conducting any
       proceeding for any remedy available to the Pass Through Trustee,
       or exercising any trust or power conferred on the Pass Through
       Trustee under this Pass Through Trust Agreement, including any
       right of the Pass Through Trustee as holder of the Equipment
       Notes or ETCs, provided that:

                 (i)  such direction shall not be in conflict with any
            rule of law or with this Pass Through Trust Agreement and
            would not involve the Pass Through Trustee in personal
            liability or expense,


                                     -33-

<PAGE>   39



                 (ii)  the Pass Through Trustee shall not determine that
            the action so directed would be unjustly prejudicial to the
            Certificateholders not taking part in such direction,

                 (iii)  the Pass Through Trustee may take any other
            action deemed proper by the Pass Through Trustee which is
            not inconsistent with such direction, and

                 (iv)  if an Indenture Default under the Indenture or an
            Equipment Trust Default under either Equipment Trust
            Agreement shall have occurred and be continuing, such
            direction shall not obligate the Trustee to vote more than a
            corresponding majority of the related Equipment Notes or
            ETCs, as the case may be, held by the Trust in favor of
            directing any action by the Indenture Trustee with respect
            to such Indenture Default or by the Equipment Trust Trustee
            with respect to such Equipment Trust Default, as the case
            may be.

            SECTION 6.5.  Waiver of Past Defaults.  The
       Certificateholders holding Certificates evidencing Fractional
       Undivided Interests aggregating not less than a majority in
       interest in the Pass Through Trust may on behalf of all of the
       Certificateholders waive any past Event of Default hereunder and
       its consequences or may instruct the Pass Through Trustee to
       waive any past default under the Indenture, either Equipment
       Trust Agreement or this Agreement and its consequences, except a
       default (i) in the payment of the principal of, Make-Whole
       Amount, if any, or interest on any Equipment Notes or ETCs, as
       the case may be, or (ii) in respect of a covenant or provision
       hereof which under Article IX hereof cannot be modified or
       amended without the consent of the Certificateholder holding each
       Outstanding Certificate affected.

            Upon any such waiver, such default shall cease to exist with
       respect to this Pass Through Trust Agreement, and any Event of
       Default arising therefrom shall be deemed to have been cured for
       every purpose of this Pass Through Trust Agreement and any
       direction given by the Pass Through Trustee on behalf of such
       Certificateholders to the Indenture Trustee or Equipment Trust
       Trustee, as the case may be, shall be annulled with respect
       thereto; but no such waiver shall extend to any subsequent or
       other default or Event of Default or impair any right consequent
       thereon.  Upon any such waiver, the Pass Through Trustee shall
       vote all the Equipment Notes issued under the Indenture or ETCs
       issued under the relevant Equipment Trust Agreement, as the case
       may be, to waive the corresponding Default.

            SECTION 6.6.  Undertaking to Pay Court Costs.  All parties
       to this Pass Through Trust Agreement, and each Certificateholder
       by his acceptance of a Certificate, shall be deemed to have
       agreed that any court may in its discretion require, in any suit,
       action or proceeding for the enforcement of any right or remedy
       under this Pass Through Trust Agreement, or in any suit, action
       or proceeding against the Pass Through Trustee for any action
       taken or omitted by it as Pass Through Trustee hereunder, the
       filing by any party litigant in such suit, action or proceeding
       of an undertaking to pay the costs of such suit, action or
       proceeding, and that such court may, in its discretion, assess
       reasonable costs, including reasonable attorney's fees, against
       any party


                                     -34-

<PAGE>   40


       litigant in such suit, action or proceeding, having due regard to
       the merits and good faith of the claims or defenses made by such
       party litigant; provided, however, that the provisions of this
       Section shall not apply to (a) any suit, action or proceeding
       instituted by any Certificateholder or group of
       Certificateholders evidencing Fractional Undivided Interests
       aggregating more than 10% of the Pass Through Trust, (b) any
       suit, action or proceeding instituted by any Certificateholder
       for the enforcement of the distribution of payments pursuant to
       Section 4.2 hereof on or after the respective due dates expressed
       herein or (c) any suit, action or proceeding instituted by the
       Pass Through Trustee or as to which the Pass Through Trustee is
       made a party.

            SECTION 6.7.  Right of Certificateholders to Receive
       Payments Not to Be Impaired.  Anything in this Pass Through Trust
       Agreement to the contrary notwithstanding, including without
       limitation Section 6.8 hereof, the right of any Certificateholder
       to receive distributions of payments required pursuant to Section
       4.2 hereof on the Certificates when due, or to institute suit for
       the enforcement of any such payment on or after the applicable
       Regular Distribution Date or Special Distribution Date, shall not
       be impaired or affected without the consent of such
       Certificateholder.

            SECTION 6.8.  Certificateholders May Not Bring Suit Except
       Under Certain Conditions.  A Certificateholder shall not have the
       right to institute any suit, action or proceeding at law or in
       equity or otherwise with respect to this Pass Through Trust
       Agreement, for the appointment of a receiver or for the
       enforcement of any other remedy under this Pass Through Trust
       Agreement, unless:

                 (i)  such Certificateholder previously shall have given
            written notice to the Pass Through Trustee of a continuing
            Event of Default;

                 (ii)  the Certificateholders holding Certificates
            evidencing Fractional Undivided Interests aggregating not
            less than 25% of the Pass Through Trust shall have requested
            the Pass Through Trustee in writing to institute such
            action, suit or proceeding and shall have offered to the
            Pass Through Trustee indemnity as provided in Section
            7.3(v);

                 (iii)  the Pass Through Trustee shall have refused or
            neglected to institute any such action, suit or proceeding
            for 60 days after receipt of such notice, request and offer
            of indemnity; and

                 (iv)  no direction inconsistent with such written
            request has been given to the Pass Through Trustee during
            such 60-day period by the Certificateholders holding
            Certificates evidencing Fractional Undivided Interests
            aggregating not less than an a majority in interest in the
            Pass Through Trust.

            It is understood and intended that no one or more of the
       Certificateholders shall have any right in any manner whatever
       hereunder or under the Certificates to (x) surrender, impair,
       waive,

                                     -35-
 

<PAGE>   41


       affect, disturb or prejudice any property in the Trust Property
       or the lien of the Indenture or any Equipment Trust Agreement on
       any property subject thereto, or the rights of the
       Certificateholders or the holders of the Equipment Notes or ETCs,
       as the case may be, (y) obtain or seek to obtain priority over or
       preference to any other such Certificateholder or (z) enforce any
       right under this Pass Through Trust Agreement, except in the
       manner herein provided and for the equal, ratable and common
       benefit of all the Certificateholders subject to the provisions
       of this Pass Through Trust Agreement.

            SECTION 6.9.  Remedies Cumulative.  Every remedy given
       hereunder to the Pass Through Trustee or to any of the
       Certificateholders shall not be exclusive of any other remedy or
       remedies, and every such remedy shall be cumulative and in
       addition to every other remedy given hereunder or now or
       hereafter given by statute, law, equity or otherwise.


                                  ARTICLE VII

                            THE PASS THROUGH TRUSTEE

            SECTION 7.1.  Certain Duties and Responsibilities.

            (a)  Except during the continuance of an Event of Default,

                 (i)  the Pass Through Trustee undertakes to perform
            only such duties as are specifically set forth in this Pass
            Through Trust Agreement, and no implied covenants, duties or
            obligations shall be read into this Pass Through Trust
            Agreement against the Pass Through Trustee; and

                 (ii)  in the absence of bad faith on its part, the Pass
            Through Trustee may conclusively rely, as to the truth of
            the statements and the correctness of the opinions expressed
            therein, upon certificates or opinions furnished to the Pass
            Through Trustee and conforming to the requirements of this
            Pass Through Trust Agreement; but in the case of any such
            certificates or opinions which by any provision hereof are
            specifically required to be furnished to the Pass Through
            Trustee, the Pass Through Trustee shall be under a duty to
            examine the form of the same to determine whether or not
            they substantially conform to the requirements of this Pass
            Through Trust Agreement, but shall be under no duty to
            investigate the facts contained therein.

            (b)  In case an Event of Default has occurred and is
       continuing, the Pass Through Trustee shall exercise such of the
       right and powers vested in it by this Pass Through Trust
       Agreement, and use the same degree of care and skill in its
       exercise, as a prudent man would exercise or use under the
       circumstances in the conduct of his own affairs.


                                     -36-

<PAGE>   42



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

                 (i)  this Subsection shall not be construed to limit
            the effect of Subsection (a) of this Section;

                 (ii)  the Pass Through Trustee shall not be liable for
            any error of judgement made in good faith by a Responsible
            Officer of the Pass Through Trustee;

                 (iii)  the Pass Through 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
            Certificateholders evidencing Fractional Undivided Interests
            aggregating not less than a majority in interest in the Pass
            Through Trust relating to the time, method and place of
            conducting any proceeding for any remedy available to the
            Pass Through Trustee, or exercising any trust or power
            conferred upon the Pass Through Trustee, under this Pass
            Through Trust Agreement; and

                 (iv)  no provision of this Pass Through Trust Agreement
            shall require the Pass Through Trustee to expend or risk its
            own funds in the performance of any of its duties hereunder,
            or in the exercise of any of its rights or powers, if it
            shall have reasonable grounds for believing that payment of
            such funds or adequate indemnity against such risk is not
            reasonably assured to it.

            (d)  Whether or not herein expressly so provided, every
       provision of this Pass Through Trust Agreement relating to the
       conduct or affecting the liability of or affording protection to
       the Pass Through Trustee shall be subject to the provisions of
       this Section.

            SECTION 7.2.  Notice of Defaults.  As promptly as
       practicable after, and in any event within 30 days after, the
       occurrence of any default (as such term is defined below)
       hereunder, the Pass Through Trustee shall transmit by mail to the
       Certificateholders, the Companies, the Owner Trustee, the
       Equipment Trust Trustees and the Indenture Trustees in accordance
       with Section 313(c) of the Trust Indenture Act, notice of such
       default hereunder known to the Pass Through Trustee, unless such
       default shall have been cured or waived; provided, however, that,
       except in the case of a default in the payment of the principal
       of (or Make-Whole Amount, if any) or interest on any Equipment
       Note or ETC, as the case may be, the Pass Through 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 Pass Through
       Trustee in good faith determine that the withholding of such
       notice is in the interests of the Certificateholders.  For the
       purpose of this Section, the term "default" means the occurrence
       of any Event of Default, except that in determining whether any
       such Event of Default has occurred

                                     -37-
 

<PAGE>   43


       for the purposes of this paragraph any grace period or notice in
       connection therewith shall be disregarded.

            SECTION 7.3.  Certain Rights of Trustee.  Except as
       otherwise provided in Section 7.1:

                 (i)  the Pass Through Trustee may rely and shall be
            protected in acting or refraining from acting in reliance
            upon any resolution, certificate, statement, instrument,
            opinion, report, notice, request, direction, consent, order,
            bond, debenture or other paper or document believed by it to
            be genuine and to have been signed or presented by the
            proper party or parties;

                 (ii)  any request or direction of the Companies
            mentioned herein shall be sufficiently evidenced by a
            Request;

                 (iii)  whenever in the administration of this Pass
            Through Trust Agreement the Pass Through Trustee shall deem
            it desirable that a matter be proved or established prior to
            taking, suffering or omitting any action hereunder, the Pass
            Through Trustee (unless other evidence be herein
            specifically prescribed) may, in the absence of bad faith on
            its part, rely upon an Officer's Certificate of Union, on
            behalf of the Companies, the Owner Trustee, the Equipment
            Trust Trustee or the Indenture Trustee;

                 (iv)  the Pass Through Trustee may consult with counsel
            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;

                 (v)  the Pass Through Trustee shall be under no
            obligation to exercise any of the rights or powers vested in
            it by this Pass Through Trust Agreement at the request or
            direction of any of the Certificateholders pursuant to this
            Pass Through Trust Agreement, unless such Certificateholders
            shall have offered to the Pass Through Trustee reasonable
            security or indemnity against the cost, expenses and
            liabilities which might be incurred by it in compliance with
            such request or direction;

                 (vi)  the Pass Through 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 or other paper or document;

                 (vii)  the Pass Through Trustee may execute any of the
            trusts or powers hereunder or perform any duties hereunder
            either directly or by or through agents or attorneys and the
            Pass Through Trustee shall not be responsible for any
            misconduct or negligence on the part of any agent or
            attorney appointed with due care by it hereunder; and


                                     -38-

<PAGE>   44



                 (viii)  to the extent the provisions of this Section
            7.3 are inconsistent with the duties of the Pass Through
            Trustee as required by Section 315 of the Trust Indenture
            Act, the requirements of such Section 315 shall prevail.

            SECTION 7.4.  Not Responsible for Recitals or Issuance of
       Certificates.  The recitals contained herein and in the
       Certificates, except the certificates of authentication, shall
       not be taken as the statements of the Pass Through Trustee, and
       the Pass Through Trustee assumes no responsibility for their
       correctness.  Subject to Section 7.15, the Pass Through Trustee
       makes no representations as to the validity or sufficiency of
       this Pass Through Trust Agreement, any Note Document, any ETC
       Document, the Participation Agreement, the Equipment Notes, the
       ETCs or the Certificates, except that the Pass Through Trustee
       hereby represents and warrants that this Pass Through Trust
       Agreement has been, and each Certificate will be, executed and
       delivered by one of its officers who is duly authorized to
       execute and deliver such document on its behalf.

            SECTION 7.5.  May Hold Certificates.  The Pass Through
       Trustee, any Paying Agent, Registrar or any of their Affiliates
       or any other agent, in their respective individual or any other
       capacity, may become the owner or pledgee of Certificates and,
       subject to Sections 310(b) and 311 of the Trust Indenture Act,
       may otherwise deal with the Companies, the Owner Trustee, the
       Equipment Trust Trustees or the Indenture Trustee with the same
       rights it would have if it were not Pass Through Trustee, Paying
       Agent, Registrar or such other agent.

            SECTION 7.6.  Money Held in Pass Through Trust.  Money held
       by the Pass Through Trustee or the Paying Agent in trust
       hereunder need not be segregated from other funds except to the
       extent required herein or by law and neither the Pass Through
       Trustee nor the Paying Agent shall have any liability for
       interest upon any such moneys except as provided for herein.

            SECTION 7.7.  Compensation and Reimbursement.  The Companies
       agree, severally and not jointly:

                 (i)  to pay, or cause to be paid, pursuant to separate
            agreements between the Companies and the Pass Through
            Trustee to the Pass Through Trustee from time to time
            reasonable compensation for all services rendered by it
            hereunder (which compensation shall not be limited by any
            provision of law in regard to the compensation of a trustee
            of an express trust), except for the  Pass Through Trustee's
            initial fees, which fees shall be paid by the Owner Trustee;

                 (ii)  except as otherwise expressly provided herein, to
            reimburse, or cause to be reimbursed, the Pass Through
            Trustee upon its request for all reasonable out-of-pocket
            expenses, disbursements and advances incurred or made by the
            Pass Through Trustee in accordance with any provision of
            this Pass Through 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,


                                     -39-

<PAGE>   45


            willful misconduct or bad faith or as may be incurred due to
            the Pass Through Trustee's breach of its representations and
            warranties set forth in Sections 7.4 and 7.15 and except for
            the initial reasonable actual disbursements made by the Pass
            Through Trustee, which disbursements shall be reimbursed by
            the Owner Trustee;

                 (iii)  to indemnify, or cause to be indemnified, the
            Pass Through Trustee, in its individual and trust
            capacities, for, and to hold it harmless against, any loss,
            liability or expense (other than for or with respect to any
            tax) incurred without negligence, willful misconduct or bad
            faith, on its part, arising out of or in connection with the
            acceptance or administration of this Pass Through Trust,
            including the 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, except
            for any such loss, liability or expense incurred by reason
            of the Pass Through Trustee's breach of its representations
            and warranties set forth in Sections 7.4 and 7.15.  The Pass
            Through Trustee shall notify the Companies promptly of any
            claim for which it may seek indemnity.  The Companies shall
            defend the claim and the Pass Through Trustee shall
            cooperate in the defense.  The Pass Through Trustee may have
            separate counsel with the consent of the Companies, and the
            Companies will pay the reasonable fees and expenses of such
            counsel.  The Companies need not pay for any settlement made
            without their consent; and

                 (iv)  to indemnify, or cause to be indemnified, the
            Pass Through Trustee, solely in its individual capacity,
            for, and to hold it harmless against, any tax (other than
            for or with respect to any tax referred to in the next
            paragraph, provided that no indemnification shall be
            available with respect to any tax attributable to the Pass
            Through Trustee's compensation for serving as such) incurred
            without negligence, willful misconduct or bad faith, on its
            part, arising out of or in connection with the acceptance or
            administration of this Pass Through Trust, including any
            costs and expenses reasonably incurred in contesting the
            imposition of any such tax.  The Pass Through Trustee, in
            its individual capacity, shall notify the Companies promptly
            of any tax for which it may seek indemnity.  The Companies
            shall defend against the imposition of such tax and the Pass
            Through Trustee, in its individual capacity, shall cooperate
            in the defense.  The Pass Through Trustee, in its individual
            capacity, may have separate counsel with the consent of the
            Companies, and the Companies will pay the reasonable fees
            and expenses of such counsel.  The Companies need not pay
            for any taxes paid, in settlement or otherwise, without
            their consent.

            In addition, the Pass Through Trustee shall be entitled to
       reimbursement from, and shall have a lien prior to the
       Certificates upon, all property and funds held or collected by
       the Pass Through Trustee in its capacity as Pass Through Trustee
       for any tax incurred without negligence, bad faith or willful
       misconduct, on its part, arising out of or in connection with the
       acceptance or administration of this Pass Through Trust (other
       than any tax attributable to the Pass Through Trustee's
       compensation for serving as such), including any costs and
       expenses reasonably incurred


 
                                     -40-
<PAGE>   46


       in contesting the imposition of any such tax.  If the Pass
       Through Trustee reimburses itself for any such tax, it will
       within 30 days mail a brief report setting forth the
       circumstances thereof to all Certificateholders as their names
       and addresses appear in the Register.

            The Pass Through Trustee shall have a lien prior to the
       Certificates upon all property and funds held or collected by the
       Pass Through Trustee in its capacity as Pass Through Trustee.

            SECTION 7.8.  Corporate Trustee Required; Eligibility.  This
       Agreement shall at all times have a Pass Through Trustee which
       shall be eligible to act as a trustee under Section 310(a) of the
       Trust Indenture Act and shall have a combined capital and surplus
       of at least $100,000,000 and the obligations of which, whether
       now in existence or hereafter incurred, are fully and
       unconditionally guaranteed by a corporation organized and doing
       business under the laws of the United States of America, any
       State or Territory thereof or of the District of Columbia and
       having a combined capital and surplus of at least $100,000,000.
       If such corporation publishes reports of condition at least
       annually, pursuant to law or the requirements of Federal, State,
       Territorial or District of Columbia supervising or examining
       authority, then for the purposes of this Section 7.8, 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.

            The Pass Through Trustee shall comply with Section 310(b) of
       the Trust Indenture Act.
            In case at any time the Pass Through Trustee shall cease to
       be eligible in accordance with the provisions of this Section
       7.8, the Pass Through Trustee shall resign immediately in the
       manner and with the effect specified in Section 7.9.

            SECTION 7.9.  Resignation and Removal; Appointment of
       Successor.

            (a)  No resignation or removal of the Pass Through Trustee
       and no appointment of a successor Pass Through Trustee pursuant
       to this Article shall become effective until the acceptance of
       appointment by the successor Pass Through Trustee under Section
       7.10.

            (b)  The Pass Through Trustee may resign at any time by
       giving written notice thereof to the Companies, the Authorized
       Agents, the Owner Trustees, the Equipment Trust Trustees and the
       Indenture Trustee.  If an instrument of acceptance by a successor
       Pass Through Trustee shall not have been delivered to the
       Companies, the Owner Trustee, the Equipment Trust Trustees and
       the Indenture Trustee within 30 days after the giving of such
       notice of resignation, the resigning Pass Through Trustee may
       petition any court of competent jurisdiction for the appointment
       of a successor Pass Through Trustee.

            (c)  The Pass Through Trustee may be removed at any time by
       Act of the Certificateholders holding Certificates evidencing
       Fractional Undivided Interests aggregating not less than a
       majority in interest in the Pass Through Trust delivered to the
       Pass Through Trustee


                                     -41-

<PAGE>   47


       and to the Companies, the Owner Trustee, the Equipment Trustee
       Trustees and the Indenture Trustee.

            (d)  If at any time:

                 (i)  the Pass Through Trustee shall fail to comply with
            Section 310 of the Trust Indenture Act after written request
            therefor by the Companies or by any Certificateholder who
            has been a bona fide Certificateholder for at least six
            months; or

                 (ii)  the Pass Through Trustee shall cease to be
            eligible under Section 7.8 and shall fail to resign after
            written request therefor by the Companies or by any such
            Certificateholder; or

                 (iii)  the Pass Through Trustee shall become incapable
            of acting or shall be adjudged a bankrupt or insolvent or a
            receiver of the Pass Through Trustee or of its property
            shall be appointed or any public officer shall take charge
            or control of the Pass Through Trustee or of its property or
            affairs for the purpose of rehabilitation, conservation or
            liquidation;

       then, in any case, (x) the Companies may remove the Pass Through
       Trustee or (y) subject to Section 6.6, any Certificateholder who
       has been a bona fide Certificateholder for at least six months
       may, on behalf of himself and all others similarly situated,
       petition any court of competent jurisdiction for the removal of
       the Pass Through Trustee and the appointment of a successor Pass
       Through Trustee.

            (e)  If a Responsible Officer of the Pass Through Trustee
       shall obtain actual knowledge of an Avoidable Tax (as hereinafter
       defined) which has been or is likely to be asserted, the Pass
       Through Trustee shall promptly notify the Companies and the Owner
       Trustee thereof and shall, within 30 days of such notification,
       resign hereunder unless within such 30-day period the Pass
       Through Trustee shall have received notice that the Companies or
       the Owner Trustees have agreed to pay such tax.  The Companies
       shall promptly appoint a successor Pass Through Trustee in a
       jurisdiction where there are no Avoidable Taxes.  As used herein,
       an "Avoidable Tax" means a state or local tax: (i) upon (w) the
       Pass Through Trust, (x) the Trust Property, (y)
       Certificateholders or (z) the Pass Through Trustee for which the
       Pass Through Trustee is entitled to seek reimbursement from the
       Trust Property, and (ii) which would be avoided if the Pass
       Through Trustee were located in another state, or jurisdiction
       within a state, within the United States.  A tax shall not be an
       Avoidable Tax if the Companies or the Owner Trustee shall agree
       to pay, and shall pay, such tax.

            (f)  If the Pass Through Trustee shall resign, be removed or
       become incapable of acting, or if a vacancy shall occur in the
       office of the Pass Through Trustee for any cause, Union shall
       promptly appoint a successor Pass Through Trustee. If, within one
       year after such resignation,


                                     -42-

<PAGE>   48


       removal or incapacity, or the occurrence of such vacancy, a
       successor Pass Through Trustee shall be appointed by Act of the
       Certificateholders holding Certificates evidencing Fractional
       Undivided Interests aggregating not less than a majority in
       interest in the Pass Through Trust delivered to the Companies,
       the Owner Trustee, the Indenture Trustee, the Equipment Trust
       Trustees and the retiring Pass Through Trustee, the successor
       Pass Through Trustee so appointed shall, forthwith upon its
       acceptance of such appointment, become the successor Pass Through
       Trustee and supersede the retiring Pass Through Trustee.  If no
       successor Pass Through Trustee shall have been so appointed as
       provided above and accepted appointment in the manner hereinafter
       provided, any Certificateholder who has been a bona fide
       Certificateholder for at least six months may, on behalf of
       himself and all others similarly situated, petition any court of
       competent jurisdiction for the appointment of a successor Pass
       Through Trustee.

            (g)  The successor Pass Through Trustee shall give notice of
       the resignation and removal of the Pass Through Trustee and
       appointment of the successor Pass Through Trustee by mailing
       written notice of such event by first-class mail, postage
       prepaid, to the Certificateholders as their names and addresses
       appear in the Register.  Each notice shall include the name of
       such successor Pass Through Trustee and the address of its
       Corporate Trust Office.

            SECTION 7.10.  Acceptance of Appointment by Successor.
       Every successor Pass Through Trustee appointed hereunder shall
       execute, acknowledge and deliver to the Companies and the
       retiring Pass Through Trustee an instrument accepting such
       appointment, and thereupon the resignation or removal of the
       retiring Pass Through Trustee shall become effective and such
       successor Pass Through Trustee, without any further act, deed or
       conveyance, shall become vested with all the rights, powers,
       trusts and duties of the retiring Pass Through Trustee; but, on
       request of the Companies or the successor Pass Through Trustee,
       such retiring Pass Through Trustee shall execute and deliver an
       instrument transferring to such successor Pass Through Trustee
       all the rights, powers and trusts of the retiring Pass Through
       Trustee and shall duly assign, transfer and deliver to such
       successor Pass Through Trustee all property and money held by
       such retiring Pass Through Trustee hereunder, subject
       nevertheless to its lien, if any, provided for in Section 7.7.
       Upon request of any such successor Pass Through Trustee, Union,
       the retiring Pass Through Trustee and such successor Pass Through
       Trustee shall execute and deliver any and all instruments
       containing such provisions as shall be necessary or desirable to
       transfer and confirm to, and for more fully and certainly vesting
       in, such successor Pass Through Trustee all such rights, powers
       and trusts.

            No successor Pass Through Trustee shall accept its
       appointment unless at the time of such acceptance such successor
       Pass Through Trustee shall be qualified and eligible under this
       Article.

            SECTION 7.11.  Merger, Conversion, Consolidation or
       Succession to Business.  Any corporation into which the Pass
       Through Trustee may be merged or converted or with which it may
       be consolidated, or any corporation resulting from any merger,
       conversion or consolidation to which the Pass Through Trustee
       shall be a party, or any corporation succeeding to all or


                                     -43-

<PAGE>   49


       substantially all of the corporate trust business of the Pass
       Through Trustee, shall be the successor of the Pass Through
       Trustee hereunder, provided such corporation 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.  In case any Certificates shall have been
       authenticated, but not delivered, by the Pass Through Trustee
       then in office, any successor by merger, conversion or
       consolidation to such authenticating Pass Through Trustee may
       adopt such authentication and deliver the Certificates so
       authenticated with the same effect as if such successor Pass
       Through Trustee had itself authenticated such Certificates.

            SECTION 7.12.  Maintenance of Agencies.

            (a)  There shall at all times be maintained in the Borough
       of Manhattan, The City of New York, an office or agency where
       Certificates may be presented or surrendered for registration of
       transfer or for exchange, and for payment thereof and where
       notices and demands to or upon the Pass Through Trustee in
       respect of the Certificates or of this Pass Through Trust
       Agreement may be served.  Such office or agency shall be
       initially at ________, [address].  Written notice of the location
       of each such other office or agency and of any change of location
       thereof shall be given by the Pass Through Trustee to Union, the
       Owner Trustee, the Indenture Trustee, the Equipment Trust
       Trustees and the Certificateholders. In the event that no such
       office or agency shall be maintained or no such notice of
       location or of change of location shall be given, presentations
       and demands may be made and notices may be served at the
       Corporate Trust Office of the Pass Through Trustee.

            (b)  There shall at all times be a Registrar and a Paying
       Agent hereunder.  Each such Authorized Agent shall be a bank or
       trust company, shall be a corporation organized and doing
       business under the laws of the United States of America or any
       State or Territory thereof or of the District of Columbia, with a
       combined capital and surplus of at least $75,000,000, or, if the
       Pass Through Trustee shall be acting as the Registrar or Paying
       Agent hereunder, a corporation the obligations of which are
       guaranteed by a corporation organized and doing business under
       the laws of the United States of America or any State or
       Territory thereof or of the District of Columbia, with a combined
       capital and surplus of at least $75,000,000, and shall be
       authorized under such laws to exercise corporate trust powers,
       subject to supervision by Federal or state authorities.  The Pass
       Through Trustee shall initially be the Paying Agent and, as
       provided in Section 3.4, Registrar hereunder.  Each Registrar
       shall furnish to the Pass Through Trustee, at stated intervals of
       not more than six months, and at such other times as the Pass
       Through Trustee may request in writing, a copy of the Register.

            (c)  Any corporation into which any Authorized Agent may be
       merged or converted or with which it may be consolidated, or any
       corporation resulting from any merger, consolidation or
       conversion to which any Authorized Agent shall be a party, or any
       corporation succeeding to the corporate trust business of any
       Authorized Agent, shall be the successor of such Authorized Agent
       hereunder, if such successor corporation is otherwise eligible
       under this Section, without


                                     -44-

<PAGE>   50


       the execution or filing of any paper or any further act on the
       part of the parties hereto or such Authorized Agent or such
       successor corporation.

            (d)  Any Authorized Agent may at any time resign by giving
       written notice of resignation to the Pass Through Trustee, the
       Companies, the Owner Trustee, the Equipment Trust Trustees and
       the Indenture Trustee.  The Companies may, and at the request of
       the Pass Through Trustee shall, at any time terminate the agency
       of any Authorized Agent by giving written notice of termination
       to such Authorized Agent and to the Pass Through Trustee.  Upon
       the resignation or termination of an Authorized Agent or in case
       at any time any such Authorized Agent shall cease to be eligible
       under this Section (when, in either case, no other Authorized
       Agent performing the functions of such Authorized Agent shall
       have been appointed), the Companies shall promptly appoint one or
       more qualified successor Authorized Agents, reasonably
       satisfactory to the Pass Through Trustee, to perform the
       functions of the Authorized Agent which has resigned or whose
       agency has been terminated or who shall have ceased to be
       eligible under this Section.  Union shall give written notice of
       any such appointment made by them to the Pass Through Trustee,
       the Owner Trustee, the Equipment Trust Trustees and the Indenture
       Trustee; and in each case the Pass Through Trustee shall mail
       notice of such appointment to all Certificateholders as their
       names and addresses appear on the Register.

            (e)  The Companies agree, severally and not jointly, to pay,
       or cause to be paid, pursuant to separate agreements from time to
       time to each Authorized Agent reasonable compensation for its
       services and to reimburse it for its reasonable expenses.

            SECTION 7.13.  Money for Certificate Payments to Be Held in
       Pass Through Trust.  All moneys deposited with any Paying Agent
       for the purpose of any payment on Certificates shall be deposited
       and held in trust for the benefit of the Certificateholders
       entitled to such payment, subject to the provisions of this
       Section.  Moneys so deposited and held in trust shall constitute
       a separate trust fund for the benefit of the Certificateholders
       with respect to which such money was deposited.

            The Pass Through Trustee will cause each Paying Agent other
       than the Pass Through Trustee to execute and deliver to it an
       instrument in which such Paying Agent shall agree with the Pass
       Through Trustee, subject to the provisions of this Section, that
       such Paying Agent will:

                 (i)  hold all sums held by it for payments on
            Certificates in trust for the benefit of the Persons
            entitled thereto until such sums shall be paid to such
            Persons or otherwise disposed of as herein provided;

                 (ii)  give the Pass Through Trustee notice of any
            default by any obligor upon the Certificates in the making
            of any such payment; and


                                     -45-

<PAGE>   51



                 (iii)  at any time during the continuance of any such
            default, upon the written request of the Pass Through
            Trustee, forthwith pay to the Pass Through Trustee all sums
            so held in trust by such Paying Agent.

            The Pass Through Trustee may at any time, for the purpose of
       obtaining the satisfaction and discharge of this Pass Through
       Trust Agreement or for any other purpose, direct any Paying Agent
       to pay to the Pass Through Trustee all sums held in trust by such
       Paying Agent, such sums to be held by the Pass Through Trustee
       upon the same trusts as those upon which such sums were held by
       such Paying Agent; and, upon such payment by any Paying Agent to
       the Pass Through Trustee, such Paying Agent shall be released
       from all further liability with respect to such money.

            SECTION 7.14.  Registration of Equipment Notes and ETCs in
       Pass Through Trustee's Name.  The Pass Through Trustee agrees
       that all Equipment Notes, ETCs, Permitted Investments, if any,
       and Specified Investments, if any, shall be issued in the name of
       the Pass Through Trustee or its nominee and held by the Pass
       Through Trustee, or, if not so held, the Pass Through Trustee or
       its nominee shall be reflected as the owner of such Equipment
       Notes, ETCs, Permitted Investments, or Specified Investments, as
       the case may be, in the register of the issuer of such Equipment
       Notes, ETCs, Permitted Investments or Specified Investments.  In
       no event shall the Pass Through Trustee invest in, or hold,
       Equipment Notes, ETCs, Permitted Investments or Specified
       Investments in a manner that would cause the Pass Through Trustee
       not to have the ownership interest in such Equipment Notes, ETCs,
       Permitted Investments or Specified Investments under the
       applicable provisions of the Uniform Commercial Code in effect
       where the Pass Through Trustee holds such Equipment Notes, ETCs,
       Permitted Investments or Specified Investments or other
       applicable law then in effect.

            SECTION 7.15.  Representations and Warranties of Pass
       Through Trustee.  The Pass Through Trustee hereby represents and
       warrants that:

                 (i)  the Pass Through Trustee is a national banking
            association, validly existing and holding a valid
            certificate to conduct business as a national banking
            association with trust powers under the laws of the United
            States of America;

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

                 (iii)  the execution, delivery and performance by the
            Pass Through Trustee of this Pass Through Trust Agreement
            and the Participation Agreement (a) will not violate any
            provision of any United States or Illinois law or regulation
            governing the banking and trust powers of the Pass Through
            Trustee or any order, writ, judgment, or decree of any
            court, arbitrator, or governmental authority applicable to
            the Pass Through Trustee or any of its


                                     -46-

<PAGE>   52


            assets, (b) will not violate any provision of the articles
            of association or by-laws of the Pass Through Trustee, or
            (c) will not violate any provision of, or constitute, with
            or without notice or lapse of time, a default under, or
            result in the creation or imposition of any lien on any
            properties included in the Trust Property pursuant to the
            provisions of any mortgage, indenture, contract, agreement
            or other undertaking to which it is a party, which
            violation, default or lien could reasonably be expected to
            have an adverse effect on the Pass Through Trustee's
            performance or ability to perform its duties hereunder or
            thereunder or on the transactions contemplated herein or
            therein;

                 (iv)  the execution, delivery and performance by the
            Pass Through Trustee of this Pass Through Trust Agreement
            and the Participation Agreement will not require the
            authorization, consent, or approval of, the giving of notice
            to, the filing or registration with, or the taking of any
            other action in respect of, any United States or Illinois
            governmental authority or agency regulating the banking and
            corporate trust activities of the Pass Through Trustee,
            other than any such authorization, consent or approval as
            has been duly obtained or given and is in full force and
            effect; and

                 (v)  this Pass Through Trust Agreement and the
            Participation Agreement have been duly executed and
            delivered by the Pass Through Trustee and constitute the
            legal, valid, and binding agreements of the Pass Through
            Trustee, enforceable against it in accordance with their
            respective terms, provided that enforceability may be
            limited by (x) applicable bankruptcy, insolvency,
            reorganization, moratorium or similar laws affecting the
            rights of creditors generally and (y) general principles of
            equity.

            SECTION 7.16.  Withholding Taxes; Information Reporting.
       The Pass Through Trustee, as trustee of a grantor trust, shall
       exclude and withhold from each distribution of principal,
       Make-Whole Amount, if any, and interest and other amounts due
       hereunder or under the Certificates any and all withholding taxes
       applicable thereto as required by law.  The Pass Through Trustee
       agrees to act as such withholding agent and, in connection
       therewith, whenever any present or future taxes or similar
       charges are required to be withheld with respect to any amounts
       payable in respect of the Certificates, to withhold such amounts
       and timely pay the same to the appropriate authority in the name
       of and on behalf of the Certificateholders, that it will file any
       necessary withholding tax returns or statements when due, and
       that, as promptly as possible after the payment thereof, it will
       deliver to each Certificateholder appropriate documentation
       showing the payment thereof, together with such additional
       documentary evidence as such Certificateholders may reasonably
       request from time to time.  The Pass Through Trustee agrees to
       file any other information reports as it may be required to file
       under United States law.  To the extent that the Pass Through
       Trustee fails, with respect to any Certificateholder, to withhold
       and pay over any such taxes to the appropriate taxing authority,
       the Pass Through Trustee shall, upon a claim being made for such
       taxes by such authority, and before making any claim to Union for
       indemnification under Section 7.1 of the Participation Agreement
       (if such indemnification would otherwise be permissible
       thereunder), take all reasonable steps to recover such taxes from
       such

                                     -47-
 

<PAGE>   53

       Certificateholder, including, without limitation, withholding the
       amount of such taxes from subsequent distributions, if any, to
       such Certificateholder.  To the extent that the Pass Through
       Trustee receives any amount from Union for indemnification of
       such taxes which the Pass Through Trustee thereafter recovers
       from the appropriate Certificateholder (including by withholding
       from subsequent distributions to such Certificateholder), the
       Pass Through Trustee shall reimburse Union therefor.  The Pass
       Through Trustee shall be permitted to rely upon any certificate
       presented by a Certificateholder claiming an exemption from
       withholding absent bad faith on the part of the Pass Through
       Trustee.

            SECTION 7.17.  Trustee's Liens.  The Pass Through Trustee in
       its individual capacity agrees that it will at its own cost and
       expense promptly take such actions as may be necessary to duly
       discharge and satisfy in full all Trustee's Liens.

            SECTION 7.18.  Preferential Collection of Claims.  The Pass
       Through Trustee shall comply with Sections 311(a) and (b) of the
       Trust Indenture Act, excluding any creditor relationship arising
       under Section 311(b) of the Trust Indenture Act.  A Pass Through
       Trustee who has resigned or been removed shall be subject to
       Section 311(a) of the Trust Indenture Act to the extent
       indicated.


                                  ARTICLE VIII

         CERTIFICATEHOLDERS' LISTS AND REPORTS BY PASS THROUGH TRUSTEE

            SECTION 8.1.  The Companies to Furnish Pass Through Trustee
       with Names and Addresses of Certificateholders.  The Companies
       will furnish to the Pass Through Trustee within 15 days after
       each Record Date with respect to a Scheduled Payment, and at such
       other times as the Pass Through Trustee may request in writing,
       within 30 days after receipt by the Companies of any such
       request, a list, in such form as the Pass Through Trustee may
       reasonably require, of all information in the possession or
       control of the Companies as to the names and addresses of the
       Certificateholders, in each case as of a date not more than 15
       days prior to the time such list is furnished; provided, however,
       that so long as the Pass Through Trustee is the sole Registrar,
       no such list need be furnished; and provided further,  however,
       that no such list need be furnished for so long as a copy of the
       Register is being furnished to the Pass Through Trustee pursuant
       to Section 7.12.

            SECTION 8.2.  Preservation of Information; Communications to
       Certificateholders.  The Pass Through Trustee shall preserve, in
       as current a form as is reasonably practicable, the names and
       addresses of Certificateholders contained in the most recent
       Register or list furnished to the Pass Through Trustee as
       provided in Section 7.12 or Section 8.1, as the case may be, and
       the names and addresses of Certificateholders received by the
       Pass Through Trustee in its capacity as Registrar, if so acting.
       The Pass Through Trustee may destroy any Register or list
       furnished


                                     -48-

<PAGE>   54


       to it as provided in Section 7.12 or Section 8.1, as the case may
       be, upon receipt of a new Register or list so furnished.

            SECTION 8.3.  Reports by Pass Through Trustee.

            (a)  Within 60 days after ________ of each year commencing
       with the year ______, the Pass Through Trustee shall transmit to
       the Certificateholders, as provided in Section 313(c) of the
       Trust Indenture Act, a report dated as of such __________, if
       required by Section 313(a) of the Trust Indenture Act.  The Pass
       Through Trustee shall also comply with Section 313(b) of the
       Trust Indenture Act.

            (b)  A copy of each such report shall, at the time of
       transmission to Certificateholders, be filed by the Pass Through
       Trustee with each stock exchange (if any) upon which the
       Certificates are listed, and also with the Commission.  The
       Companies will notify the Pass Through Trustee when the
       Certificates are listed on any stock exchange and any subsequent
       change with respect thereto.

            SECTION 8.4.  Reports by the Company.  Union shall [and, if
       Procor becomes subject to the periodic reporting requirements of
       Section 13 or 15(d) of the Exchange Act, Procor shall]:

            (a)  file with the Pass Through Trustee, within 30 days
       after it is required to file the same with the Commission, copies
       of the annual reports and of the information, documents and other
       reports (or copies of such portions of any of the foregoing as
       the Commission may from time to time by rules and regulations
       prescribe) which it is required to file with the Commission
       pursuant to Section 13 or Section 15(d) of the Securities
       Exchange Act of 1934, as amended; or if it is not required to
       file information, documents or reports pursuant to either of such
       sections, then to file with the Pass Through Trustee and the
       Commission, in accordance with rules and regulations prescribed
       by the Commission pursuant to Section 314(a)(1) of the Trust
       Indenture Act, such of the supplementary and periodic
       information, documents and reports which may be required pursuant
       to Section 13 of the Securities Exchange Act of 1934, as amended,
       in respect of a security listed and registered on a national
       securities exchange as may be prescribed in such rules and
       regulations;

            (b)  file with the Pass Through Trustee and the Commission,
       in accordance with the rules and regulations prescribed by the
       Commission, such additional information, documents and reports
       with respect to compliance by it with the conditions and
       covenants provided for in this Agreement, as may be required by
       such rules and regulations, including, in the case of annual
       reports, if required by such rules and regulations, certificates
       or opinions of independent public accountants, conforming to the
       requirements of Section 1.2;

            (c)  transmit to all Certificateholders, in the manner and
       to the extent provided in Section 313(c) of the Trust Indenture
       Act such summaries of any information, documents and

                                     -49-
 

<PAGE>   55

       reports required to be filed by Union [and Procor] pursuant to
       subsections (a) and (b) of this Section 8.4 as may be required by
       rules and regulations prescribed by the Commission; and

            (d)  furnish to the Pass Through Trustee, not less often
       than annually, a certificate from the principal executive
       officer, principal financial officer or principal accounting
       officer thereof as to his or her knowledge of Union's [and
       Procor's] compliance with all conditions and covenants under this
       Agreement.  For purposes of this subsection (d), such compliance
       shall be determined without regard to any period of grace or
       requirement of notice provided under this Agreement.  [Until such
       time as Procor becomes a reporting company under the Exchange
       Act, such annual certificate may be furnished as to both Union
       and Procor by a Responsible Officer of Union.]


                                   ARTICLE IX

                  SUPPLEMENTS TO PASS THROUGH TRUST AGREEMENT

            SECTION 9.1.  Supplements to Pass Through Trust Agreement
       Without Consent of Certificateholders.  Without the consent of
       the Certificateholders, the Companies may, and the Pass Through
       Trustee (subject to Section 9.3) shall, at any time and from time
       to time enter into one or more agreements supplemental hereto, in
       form satisfactory to the Pass Through Trustee, for any of the
       following purposes:

                 (i)  to evidence the succession of another corporation
            to Union [or Procor] and the assumption by any such
            successor of the covenants of Union [or Procor] herein
            contained;

                 (ii)  to add to the covenants of either of the
            Companies for the benefit of the Certificateholders, or to
            surrender any right or power herein conferred upon the
            Companies;

                 (iii)  to cure any ambiguity, to correct any manifest
            error to correct or supplement any provision herein which
            may be defective or inconsistent with any other provision
            herein or to make any other provisions with respect to
            matters or questions arising under this Pass Through Trust
            Agreement, provided that any such action shall not adversely
            affect the interests of the Certificateholders; or

                 (iv)  to modify, eliminate or add to the provisions of
            this Pass Through Trust Agreement to such extent as shall be
            necessary to continue the qualification of this Pass Through
            Trust Agreement (including any supplemental agreement) under
            the Trust Indenture Act, or under any similar Federal
            statute hereafter enacted, and to add to this Pass Through
            Trust Agreement such other provisions as may be expressly
            permitted by the Trust Indenture Act, excluding, however,
            the provisions referred to in Section 316(a)(2) of the Trust
            Indenture Act as in effect at the date as of which this


                                     -50-

<PAGE>   56


            instrument was executed or any corresponding provision in
            any similar Federal statute hereafter enacted.

            SECTION 9.2.  Supplements to Pass Through Trust Agreement
       with Consent of Certificateholders.  With the consent of the
       Certificateholders holding Certificates evidencing Fractional
       Undivided Interests aggregating not less than a majority in
       interest, by Act of such Certificateholders delivered to the
       Companies and the Pass Through Trustee, the Companies may (with
       the consent of the Owner Trustee, if any, such consent not to be
       unreasonably withheld), and the Pass Through Trustee (subject to
       Section 9.3) shall, enter into an agreement or agreements
       supplemental hereto for the purpose of adding any provisions to
       or changing in any manner or eliminating any of the provisions of
       this Pass Through Trust Agreement or of modifying in any manner
       the rights and obligations of the Certificateholders under this
       Pass Through Trust Agreement; provided, however, that no such
       supplemental agreement shall, without the consent of each
       Certificateholder of an Outstanding Certificate affected thereby:

                 (i)  reduce in any manner the amount of, or delay the
            timing of, any receipt by the Pass Through Trustee of
            payments on the Equipment Notes or the ETCs held in the Pass
            Through Trust or distributions that are required to be made
            herein on any Certificate, or change any date of payment on
            any Certificate, or change the place of payment where, or
            the coin or currency in which, any Certificate is payable,
            or impair the right to institute suit for the enforcement of
            any such payment or distribution on or after the Regular
            Distribution Date or Special Distribution Date applicable
            thereto;

                 (ii)  permit the disposition of any Equipment Note or
            ETCs in the Trust Property except as permitted by this Pass
            Through Trust Agreement, or otherwise deprive any
            Certificateholder of the beneficial ownership of the
            Equipment Notes or ETCs in the Pass Through Trust;

                 (iii)  reduce the percentage of the aggregate
            Fractional Undivided Interests of the Pass Through Trust
            required for any such supplemental agreement, or reduce such
            percentage required for any waiver (of compliance with
            certain provisions of this Pass Through Trust Agreement or
            certain defaults hereunder and their consequences) provided
            or in this Pass Through Trust Agreement;

                 (iv)  modify Article XII or otherwise release Union
            from its obligations under the Guarantee; or

                 (v)  modify any of the provisions of this Section or
            Section 6.5, except to increase any such percentage or to
            provide that certain other provisions of this Pass Through
            Trust Agreement cannot be modified or waived without the
            consent of the Certificateholder of each Certificate
            affected thereby.


                                     -51-

<PAGE>   57



            It shall not be necessary for any Act of Certificateholders
       under this Section to approve the particular form of any proposed
       supplemental agreement, but it shall be sufficient if such Act
       shall approve the substance thereof.

            SECTION 9.3.  Documents Affecting Immunity or Indemnity.  If
       in the opinion of the Pass Through Trustee any document required
       to be executed by it pursuant to the terms of Section 9.1 or 9.2
       affects any interest, right, duty, obligation, immunity or
       indemnity in favor of the Pass Through Trustee under this Pass
       Through Trust Agreement, the Pass Through Trustee may in its
       discretion decline to execute such document.

            SECTION 9.4.  Execution of Supplements to Pass Through Trust
       Agreements.  In executing, or accepting the additional trusts
       created by, any supplemental agreement permitted by this Article
       or the modifications thereby of the trusts created by this Pass
       Through Trust Agreement, the Pass Through Trustee shall be
       entitled to receive, and shall be fully protected in relying
       upon, an Opinion of Counsel stating that the execution of such
       supplemental agreement is authorized or permitted by this Pass
       Through Trust Agreement.

            SECTION 9.5.  Effect of Supplements to Pass Through Trust
       Agreement.  Upon the execution of any supplemental agreement
       under this Article, this Pass Through Trust Agreement shall be
       modified in accordance therewith, and such supplemental agreement
       shall form a part of this Pass Through Trust Agreement for all
       purposes; and every Certificateholder of Certificates theretofore
       or thereafter authenticated and delivered hereunder shall be
       bound thereby.

            SECTION 9.6.  Conformity with Trust Indenture Act.  Every
       supplemental agreement executed pursuant to this Article shall
       conform to the requirements of the Trust Indenture Act as then in
       effect.

            SECTION 9.7.  Reference in Certificates to Supplements to
       Pass Through Trust Agreements.  Certificates authenticated and
       delivered after the execution of any supplemental agreement
       pursuant to this Article may bear a notation in form approved by
       the Pass Through Trustee as to any matter provided for in such
       supplemental agreement, and, in such case, suitable notation may
       be made upon Outstanding Certificates after proper presentation
       and demand.


                                   ARTICLE X

                    AMENDMENTS TO INDENTURE, NOTE DOCUMENTS,
                  EQUIPMENT TRUST AGREEMENTS AND ETC DOCUMENTS

            In the event that the Pass Through Trustee, as holder of any
       Equipment Note or an ETC in trust for the benefit of the
       Certificateholders, receives a request for a consent to any
       amendment, modification, waiver or supplement under the
       Indenture, other Note Document, either


 
                                     -52-
<PAGE>   58


       Equipment Trust Agreement, other ETC Document or the
       Participation Agreement, the Pass Through Trustee shall forthwith
       send a notice of such proposed amendment modification, waiver or
       supplement, to each Certificateholder registered on the Register
       as of such date.  The Pass Through Trustee shall request from the
       Certificateholders Directions as to (a) whether or not to direct
       the Indenture Trustee or such Equipment Trust Trustee, as the
       case may be, to take or refrain from taking any action which a
       holder of such Equipment Note or ETC, as the case may be, has the
       option to direct, (b) whether or not to give or execute any
       waivers, consents, amendments, modifications or supplements as a
       holder of such Equipment Note or ETC, as the case may be, and (c)
       how to vote any Equipment Note or ETC, as the case may be, if a
       vote has been called for with respect thereto.  Provided such a
       request for Certificateholder Direction shall have been made, in
       directing any action or casting any vote or giving any consent as
       the holder of any Equipment Note or ETC, as the case may be, the
       Pass Through Trustee shall vote or consent with respect to such
       Equipment Note or ETC, as the case may be, in the same proportion
       as the Certificates were actually voted by Acts of
       Certificateholders delivered to the Pass Through Trustee prior to
       two Business Days before the Pass Through Trustee directs such
       action or casts such vote or gives such consent.  Notwithstanding
       the foregoing, but subject to Section 6.4, in the case that an
       Event of Default hereunder shall have occurred and be continuing,
       the Pass Through Trustee may, in its own discretion and at its
       own direction, consent and notify the Indenture Trustee or
       Equipment Trust Trustee of such consent to any amendment,
       modification, waiver or supplement under the Indenture, and other
       Note Document, any Equipment Trust Agreement, any other ETC
       Document or the Participation Agreement.


                                   ARTICLE XI

                       TERMINATION OF PASS THROUGH TRUST

            The respective obligations and responsibilities of the
       Companies and the Pass Through Trustee created hereby and the
       Pass Through Trust created hereby shall terminate upon the
       distribution to all Certificateholders and the Pass Through
       Trustee of all amounts required to be distributed to them
       pursuant to this Pass Through Trust Agreement and the disposition
       of all property held as part of the Trust Property; provided,
       however, that in no event shall the trust created hereby continue
       beyond the expiration of 21 years from the death of the last
       survivor of the descendants of John D. Rockefeller, father of
       Nelson Rockefeller, former Vice President of the United States,
       living on the date of this Pass Through Trust Agreement.

            Notice of any termination, specifying the Regular
       Distribution Date (or Special Distribution Date, as the case may
       be) upon which the Certificateholders may surrender their
       Certificates to the Pass Through Trustee for payment of the final
       distribution and cancellation, shall be mailed promptly by the
       Pass Through Trustee to Certificateholders not earlier than the
       60th day and not later than the 20th day next preceding such
       final distribution, specifying (a) the Regular Distribution Date
       (or Special Distribution Date, as the case may be) upon which the

                                     -53-
 

<PAGE>   59


       proposed final payment of the Certificates will be made upon
       presentation and surrender of Certificates at the office or
       agency of the Pass Through Trustee therein specified, (b) the
       amount of any such proposed final payment, and (c) that the
       Record Date otherwise applicable to such Regular Distribution
       Date (or Special Distribution Date, as the case may be) is not
       applicable, payments being made only upon presentation and
       surrender of the Certificates at the office or agency of the Pass
       Through Trustee therein specified.  The Pass Through Trustee
       shall give such notice to the Registrar at the time such notice
       is given to Certificateholders. Upon presentation and surrender
       of the Certificates, the Pass Through Trustee shall cause to be
       distributed to Certificateholders amounts distributable on such
       Regular Distribution Date (or Special Distribution Date, as the
       case may be) pursuant to Section 4.2.

            In the event that all of the Certificateholders shall not
       surrender their Certificates for cancellation within six months
       after the date specified in the above-mentioned written notice,
       the Pass Through Trustee shall give a second written notice to
       the remaining Certificateholders to surrender their Certificates
       for cancellation and receive the final distribution with respect
       thereto.  In the event that any money held by the Pass Through
       Trustee for the payment of distributions on the Certificates
       shall remain unclaimed for two years and 11 months after the
       final distribution date with respect thereto, the Pass Through
       Trustee shall pay to the Indenture Trustee or each Equipment
       Trust Trustee the appropriate amount of money relating to the
       Indenture Trustee or such Equipment Trust Trustee and shall give
       written notice thereof to the Owner Trustee and Union.


                                  ARTICLE XII

                               GUARANTEE OF UNION

            [SECTION 12.1.  Guarantee.  Subject to the provisions of
       this Article XII, Union hereby irrevocably and unconditionally
       guarantees, as a primary obligor and not a surety, to each
       Certificateholder of a Certificate now or hereafter authenticated
       and delivered by the Pass Through Trustee and to the Pass Through
       Trustee and its successors and assigns, irrespective of the
       validity and enforceability of this Pass Through Trust Agreement,
       the Certificates hereunder, the Procor Equipment Trust Agreement
       or the Procor ETC thereunder, the due and punctual distribution
       to Certificateholders of the amounts of principal of, and
       interest (including post-petition interest in any proceeding
       under any applicable bankruptcy law whether or not permitted
       thereby), and interest on overdue principal and interest, if any,
       to the extent lawful, payable with respect to the Procor ETC when
       and as the same shall become due and payable, whether by
       acceleration thereof, or otherwise (including amounts that would
       become due but for the operation of the automatic stay under
       applicable bankruptcy law), in accordance with the terms of the
       Procor ETC and of this Pass Through Trust Agreement.  Union also
       hereby guarantees for the benefit of the Persons identified in
       the preceding sentence, the due and punctual performance by
       Procor of its obligations under the Procor Equipment Trust
       Agreement.   Union hereby agrees that its obligations

                                     -54-
 

<PAGE>   60


       hereunder shall be absolute and unconditional, irrespective of,
       and shall be unaffected by, any failure to enforce the provisions
       of the Procor ETC or this Pass Through Trust Agreement, any
       waiver, modification or indulgence granted to Procor with respect
       thereto by the Certificateholders, the Equipment Trust Trustee or
       the Pass Through Trustee, or any other circumstances which may
       otherwise constitute a legal or equitable discharge of a surety
       or guarantor.  Union hereby waives diligence, presentment, filing
       of claims with a court in the event of a merger or bankruptcy of
       Procor, any right to require a  proceeding first against Procor,
       the benefit of discussion, protest or notice with respect to the
       Procor ETC or the indebtedness evidenced thereby and all demands
       whatsoever, and covenants that this Guarantee shall not be
       discharged as to the Procor ETC except by payment in full of the
       principal thereof and all accrued interest thereon and all other
       amounts due with respect thereto.

            Union shall be subrogated to all rights of the
       Certificateholders against Procor in respect of any amounts paid
       to the Certificateholders by Union pursuant to the provisions of
       this Guarantee; provided, however, that Union shall not be
       entitled to enforce, or to receive any payments arising out of or
       based upon, such right of subrogation until all amounts payable
       to the Pass Through Trustee hereunder with respect to the Procor
       ETC shall have been paid in full.

            The Guarantee set forth in this Section 12.1 shall not be
       valid or become obligatory for any purpose with respect to a
       Certificate until the certificate of authentication on such
       Certificate shall have been signed by or on behalf of the Pass
       Through Trustee.

            The parties hereto acknowledge that payments by Union
       hereunder with respect to (i) principal attributable to the
       Procor ETC shall have the effect of reducing on a dollar for
       dollar basis the outstanding principal amount of the Procor ETC
       and (ii) accrued interest attributable to the Procor ETC shall
       have the effect of reducing on a dollar for dollar basis the
       outstanding accrued interest on the Procor ETC.  For the purposes
       of this paragraph only, payments by Union hereunder shall first
       be applied against outstanding accrued interest then against
       outstanding principal.

            SECTION 12.2.  Execution and Delivery of Guarantee.

            (a) To evidence the Guarantee set forth in this Article XII,
       Union hereby agrees that a notation of the Guarantee shall be
       placed on each Certificate authenticated and delivered by the
       Pass Through Trustee on or after the date the Trust Property
       includes the Procor ETC.
            (b) A Responsible Officer of Union shall sign the notation
       of Guarantee on the Certificates by manual or facsimile
       signature. If a Responsible Officer whose signature is on the
       notation of Guarantee no longer holds that office at the time the
       Pass Through Trustee authenticates the Certificate on which the
       Guarantee is endorsed, the Guarantee shall be valid nevertheless.
       Union hereby agrees that the Guarantee set forth in Section 12.1
       shall remain in full

                                     -55-
 

<PAGE>   61


       force and effect notwithstanding any failure to endorse on each
       Certificate a notation of the Guarantee.

            (c) The delivery of any Certificate by the Pass Through
       Trustee, after the authentication thereof hereunder, shall
       constitute due delivery of the Guarantee set forth in this Pass
       Through Trust Agreement on behalf of Union.

            SECTION 12.3.  Limitation of Union's Liability.  Union
       hereby confirms that it is its intention that the Guarantee not
       constitute a fraudulent transfer or conveyance for purposes of
       any bankruptcy law, fraudulent conveyance act, or any similar
       law.  To effectuate the foregoing intention, Union hereby
       irrevocably agrees that its obligations under the Guarantee shall
       be limited to the maximum amount as will, after giving effect to
       such maximum amount and all other (contingent or otherwise)
       liabilities of Union that are relevant under such laws, and after
       giving effect to any rights to contribution pursuant to any
       agreement providing for an equitable contribution among Union and
       other Affiliates of Procor, such maximum amount shall result in
       the obligations of Union in respect of such maximum amount not
       constituting a fraudulent transfer or conveyance.

            SECTION 12.4.  Guarantee Unconditional.  Upon failure of
       payment when due of any amount so guaranteed for whatever reason,
       Union will be obligated to pay the same immediately.  Union
       hereby agrees that its obligations hereunder shall be continuing,
       absolute and unconditional, irrespective of:  any delays in
       obtaining or realizing upon or failure to obtain or realize upon
       Trust Property; the recovery of any judgment against Procor or
       Union; any extension, renewal settlement, compromise, waiver or
       release in respect of any obligation of Procor under this Pass
       Through Trust Agreement or the Procor ETC, by operation of law or
       otherwise; any modification or amendment of or supplement to this
       Pass Through Trust Agreement or the Procor ETC; any change in the
       corporate existence, structure or ownership of Procor, or any
       insolvency, bankruptcy, reorganization or other similar
       proceeding affecting Procor or its assets or any resulting
       release or discharge of any obligation of Procor contained in
       this Pass Through Trust Agreement or the Procor ETC; the
       existence of any claim, set-off or other rights which Union may
       have at any time against Procor, the Pass Through Trustee, any
       Certificateholder or any other Person, whether in connection
       herewith or any unrelated transactions; provided, that nothing
       herein shall prevent the assertion of any such claim by separate
       suit or compulsory counterclaim; any invalidity or
       unenforceability relating to or against Procor for any reason of
       this Pass Through Trust Agreement or the Procor ETC, or any
       provision of applicable law or regulation purporting to prohibit
       the payment by Procor of the principal of or interest on the
       Procor ETC or any other amount payable by Procor under this Pass
       Through Trust Agreement, or the Procor ETC; or any other act or
       omission to act or delay of any kind by Procor, the Pass Through
       Trustee, any Certificateholder, or any other Person or any other
       circumstance whatsoever which might, but for the provisions of
       this paragraph, constitute a legal or equitable discharge of
       Union's obligations hereunder.  Union hereby waives diligence,
       presentment, demand of payment, filing of claims with a court in
       the event of insolvency or


                                     -56-

<PAGE>   62


       bankruptcy of Procor, any right to require a proceeding first
       against Procor, protest, notice and all demand whatsoever and
       covenants that this Guarantee will not be discharged except by
       the complete performance of the obligations contained in the
       Procor ETC, this Pass Through Trust Agreement and in this Article
       XII.  Union's obligations hereunder shall remain in full force
       and effect until this Pass Through Trust Agreement shall have
       terminated and the principal of and interest on the Procor ETC
       and all other obligations payable by Procor relating thereto
       shall have been paid in full.  If at any time the distribution of
       any payment of the principal of or interest with respect to the
       Procor ETC or any other amount payable by Procor under this Pass
       Through Trust Agreement is rescinded or must be otherwise
       restored or returned upon the insolvency, bankruptcy or
       reorganization of Procor or otherwise, Union's obligations
       hereunder with respect to such payment shall be reinstated as
       though such payment had been due but not made at such time, and
       this Article XII, to the extent theretofore discharged, shall be
       reinstated in full force and effect.  Union irrevocably waives
       any and all rights to which it may be entitled, by operation of
       law or otherwise, upon making any payment hereunder to be
       subrogated to the rights of the payee against Procor with respect
       to such payment or otherwise to be reimbursed, indemnified or
       exonerated by Procor in respect thereof until all obligations of
       Procor under the Procor ETC are satisfied.  Union further agrees
       that, as between Union, on the one hand, and the
       Certificateholders and the Pass Through Trustee, on the other
       hand, (i) the maturity of the obligations guaranteed hereby may
       be accelerated as provided in Article VI hereof for the purposes
       of this Guarantee, notwithstanding any stay, injunction or other
       prohibition preventing such acceleration in respect of the
       obligations guaranteed hereby and (ii) in the event of any
       declaration of acceleration of such obligations as provided in
       Article VI hereof, such obligations (whether or not due and
       payable) shall forthwith become due and payable by Union for the
       purpose of this Article XII.


                                  ARTICLE XIII

                            MISCELLANEOUS PROVISIONS

            SECTION 13.1.  Limitation on Rights of Certificateholders.
       The death or incapacity of any Certificateholder shall not
       operate to terminate this Pass Through Trust Agreement or the
       Pass Through Trust, nor entitle such Certificateholder's legal
       representatives or heirs to claim an accounting or to take any
       action or commence any proceeding in any court for a partition or
       winding up of the Pass Through Trust, nor otherwise affect the
       rights, obligations and liabilities of the parties hereto or any
       of them.

            SECTION 13.2.  Certificates Nonassessable and Fully Paid.
       Certificateholders shall not be personally liable for obligations
       of the Pass Through Trust, the Fractional Undivided Interests
       represented by the Certificates shall be nonassessable for any
       losses or expenses of the Pass Through Trust or for any reason
       whatsoever, and Certificates upon authentication thereof by the
       Pass Through Trustee pursuant to Section 3.2 are and shall be
       deemed fully paid.  No


                                     -57-

<PAGE>   63


       Certificateholder shall have any right (except as expressly
       provided herein) to vote or in any manner otherwise control the
       operation and management of the Trust Property, the Pass Through
       Trust established hereunder, or the obligations of the parties
       hereto, nor shall anything set forth herein, or contained in the
       terms of the Certificates, be construed so as to constitute the
       Certificateholders from time to time as partners or members of an
       association.

            SECTION 13.3.  Notices.

            (a) Unless otherwise expressly specified or permitted by the
       terms hereof, all communications and notices provided for herein
       shall be in writing, and any such notice shall become effective
       (i) upon personal delivery thereof, including, without limitation
       by overnight mail and courier service, (ii) in the case of notice
       by United States mail, certified or registered, postage prepaid,
       return receipt requested, three days after being so deposited in
       the United States mail, or (iii) in the case of notice by
       facsimile transmission, upon transmission thereof, provided such
       transmission is promptly confirmed (which conformation may be
       mechanical), in each case addressed to each party here to at the
       addresses set forth below:

            if to Union, to:


                    Union Tank Car Company
                    225 West Washington Street
                    Chicago, Illinois  60606
                    Attention:     Robert W. Webb, Secretary
                    Facsimile:     (312) 845-5305
                    Telephone:     (312) 372-9500


            if to Procor, to:


                    Procor Limited
                    2001 Speers Road
                    Oakville, Ontario
                    Canada L6J 5E1
                    Attention:  Frank Lester, President
                    Facsimile:  (905) 827-0800
                    Telephone:  (905) 827-4111



                                     -58-
 

<PAGE>   64

         with a copy to:

                   Neal, Gerber & Eisenberg
                   2 North LaSalle Street
                   Chicago, Illinois  60602
                   Attention: William M. Holzman, Esq.
                   Facsimile: (312) 269-1747
                   Telephone: (312) 269-8000

         if to the Pass Through Trustee, to:

                   [address]

                   Attention:
                   Facsimile:
                   Telephone:


            (b)  The Companies and the Pass Through Trustee, by notice
       to the other parties, may designate additional or different
       addresses for subsequent notices or communications.

            (c)  Any notice or communication to Certificateholders shall
       be mailed by first-class mail to the addresses for
       Certificateholders shown on the Register kept by the Registrar
       and to addresses filed with the Pass Through Trustee for
       Certificate Owners.  Failure so to mail a notice or communication
       or any defect in such notice or communication shall not affect
       its sufficiency with respect to other Certificateholders.

            (d)  If a notice or communication is mailed in the manner
       provided above within the time prescribed, it is conclusively
       presumed to have been duly given, whether or not the addressee
       receives it.

            (e)  If the Companies mail a notice or communication to the
       Certificateholders, it shall mail a copy to the Pass Through
       Trustee and to each Paying Agent at the same time.

            (f)  Notwithstanding the foregoing, all communications or
       notices to the Pass Through Trustee shall be deemed to be given
       only when received by a Responsible Officer of the Pass Through
       Trustee.

            (g)  The Pass Through Trustee shall promptly furnish the
       Companies with a copy of any demand, notice or written
       communication received by the Pass Through Trustee hereunder from
       any Certificateholder, the Owner Trustee, any Equipment Trust
       Trustee or the Indenture Trustee.

                                     -59-
 

<PAGE>   65



            SECTION 13.4.  Communication by Certificateholder with Other
       Certificateholders.  Certificateholders may communicate pursuant
       to Section 312(b) of the Trust Indenture Act with other
       Certificateholders with respect to their rights under this Pass
       Through Trust Agreement or under the Certificates, and the Pass
       Through Trustee shall comply with Section 312(b) of the Trust
       Indenture Act.  The Companies and the Pass Through Trustee shall
       have the protection of Section 312(c) of the Trust Indenture Act.

            SECTION 13.5.  Governing Law.  THIS PASS THROUGH TRUST
       AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH
       THE LAWS OF THE STATE OF NEW YORK WITHOUT GIVING EFFECT TO ANY
       CHOICE OF LAW OF CONFLICT OF LAW PROVISION OR RULE AND THE
       OBLIGATIONS, RIGHTS, AND REMEDIES OF THE PARTIES HEREUNDER SHALL
       BE DETERMINED IN ACCORDANCE WITH SUCH LAWS.

            SECTION 13.6.  Severability of Provisions.  Whenever
       possible, each provision of this Pass Through Trust Agreement
       shall be interpreted in such manner as to be effective and valid
       under applicable law, but if any provision of this Pass Through
       Trust Agreement shall be prohibited by or invalid under
       applicable law, such provision shall be ineffective to the extent
       of such prohibition or invalidity, without invalidating the
       remainder of such provision or the remaining provisions of this
       Pass Through Trust Agreement.

            SECTION 13.7.  Trust Indenture Act Controls.  This Agreement
       is subject to the provisions of the Trust Indenture Act and
       shall, to the extent applicable, be governed by such provisions.

            SECTION 13.8.  Effect of Headings and Table of Contents. The
       Article and Section headings herein and the Table of Contents are
       for convenience only and shall not affect the construction
       hereof.

            SECTION 13.9.  Successors and Assigns.  All covenants,
       agreements, representations and warranties in this Pass Through
       Trust Agreement by the Pass Through Trustee, the Companies shall
       bind and, to the extent permitted hereby, shall inure to the
       benefit of and be enforceable by their respective successors and
       assigns, whether so expressed or not.

            SECTION 13.10.  Benefits of Pass Through Trust Agreement.
       Nothing in this Pass Through Trust Agreement or in the
       Certificates, express or implied, shall give to any Person, other
       than the parties hereto and their successors hereunder, and the
       Certificateholders, any benefit or any legal or equitable right,
       remedy or claim under this Pass Through Trust Agreement.

            SECTION 13.11.  Legal Holidays.  In any case where any
       Regular Distribution Date or Special Distribution Date relating
       to any Certificate shall not be a Business Day, then
       (notwithstanding any other provision of this Pass Through Trust
       Agreement) payment need not


 
                                     -60-
<PAGE>   66

       be made on such date, but may be made on the next succeeding
       Business Day with the same force and effect as if made on such
       Regular Distribution Date or Special Distribution Date, and no
       interest shall accrue during the intervening period.

            SECTION 13.12.  Counterparts.  For the purpose of
       facilitating the execution of this Pass Through Trust Agreement
       and for other purposes, this Pass Through Trust Agreement may be
       executed simultaneously in any number of counterparts, each of
       which counterparts shall be deemed to be an original, and all of
       which counterparts shall constitute but one and the same
       instrument.


                                     -61-

<PAGE>   67


            IN WITNESS WHEREOF, Union, Procor and the Pass Through
       Trustee have caused this Pass Through Trust Agreement to be duly
       executed by their respective officers, duly attested, all on the
       day and year first above written.

                                   UNION TANK CAR COMPANY




Attest:                            By______________________________
                                     Title:


__________________________
Title:                     

                                   PROCOR LIMITED




Attest:                            By______________________________
                                     Title:


__________________________ 
Title:
                                   By______________________________
                                      Title:
Attest:


__________________________
Title:                    

                                   ___________________,
                                   as Pass Through Trustee



Attest:                            By______________________________
                                     Title:



__________________________
Title:

 

                                     -62-

<PAGE>   68


                                                                       EXHIBIT A

                              FORM OF CERTIFICATE

            Unless this certificate is presented by an authorized
       representative of The Depository Trust Company, a New York
       corporation ("DTC"), to issuers or their 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 the registered owner hereof, Cede & Co., has an
       interest herein.


                             UNION TANK CAR COMPANY

                                 PROCOR LIMITED

                           _______ PASS THROUGH TRUST

                           Pass Through Certificate,
                                 Series _______

                   Final Distribution Date:  ________________

              evidencing a fractional undivided interest in a
              trust, the property of which includes certain
              equipment notes (the "Equipment Notes") and
              Equipment Trust Certificates ("ETCs") each secured
              by equipment leased to Union Tank Car Company or
              conditionally sold to Procor Limited.


             Certificate
             No. ___      $__________ Fractional Undivided Interest
                          representing 100% of the Trust


            THIS CERTIFIES THAT Cede & Co., for value received, is the
       registered owner of a $___________
       (____________________________________________________________
       ___________________________________________________ dollars)
       Fractional Undivided Interest in the Union Tank Car Company
       ______ Pass Through Trust (the "Trust") created by
       _______________, a national banking association, as trustee (the
       "Pass Through Trustee"), pursuant to a Pass Through Trust
       Agreement ______ dated _______ (the "Pass Through Trust
       Agreement") among the Pass Through Trustee, Union Tank Car
       Company, a Delaware


 

<PAGE>   69

       corporation ("Union"), and Procor Limited, a Canadian corporation
       and an indirect, wholly-owned subsidiary of Union ("Procor"),
       (Union and Procor are referred to herein collectively as the
       "Companies"), a summary of certain of the pertinent provisions of
       which is set forth below.  To the extent not otherwise defined
       herein, the capitalized terms used herein have the meanings
       assigned to them in the Pass Through Trust Agreement.  This
       Certificate is one of the duly authorized Certificates designated
       as "Pass Through Certificates, Series ______" (herein called the
       "Certificates").  This Certificate is issued under and is subject
       to the terms, provisions, and conditions of the Pass Through
       Trust Agreement, to which Pass Through Trust Agreement the
       Certificateholder of this Certificate by virtue of the acceptance
       hereof assents and by which such Certificateholder is bound.  The
       property of the Pass Through Trust (the "Trust Property")
       includes certain Equipment Notes and ETCs and rights under a
       Union guarantee of the due and punctual distribution to
       Certificateholders of principal and interest payable with respect
       to the Procor ETC.  Each issue of Equipment Notes and ETCs is
       secured by, among other things, a security interest in Equipment
       leased to Union or conditionally sold to Procor, as the case may
       be.

            Subject to and in accordance with the terms of the Pass
       Through Trust Agreement, from funds then available to the Pass
       Through Trustee, there will be distributed on _______ and ______
       of each year (each a "Regular Distribution Date"), commencing on
       _________, to the Person in whose name this Certificate is
       registered at the close of business on the Business Day preceding
       the Regular Distribution Date, an amount in respect of the
       Scheduled Payments on the Equipment Notes and the ETCs due on
       such Regular Distribution Date, the receipt of which has been
       confirmed by the Pass Through Trustee, equal to the product of
       the percentage interest in the Pass Through Trust evidenced by
       this Certificate and an amount equal to the sum of such Scheduled
       Payments.  Subject to and in accordance with the terms of the
       Pass Through Trust Agreement, in the event that Special Payments
       on the Equipment Notes or the ETCs are received by the Pass
       Through Trustee, from funds then available to the Pass Through
       Trustee, there shall be distributed on the applicable Special
       Distribution Date, to the Person in whose name this Certificate
       is registered at the close of business on the Business Day
       preceding the Special Distribution Date, an amount in respect of
       such Special Payments on the Equipment Notes or the ETCs, the
       receipt of which has been confirmed by the Pass Through Trustee,
       equal to the product of the percentage interest in the Pass
       Through Trust evidenced by this Certificate and an amount equal
       to the sum of such Special Payments so received.  If a Regular
       Distribution Date or Special Distribution Date is not a Business
       Day, distribution shall be made on the immediately following
       Business Day with the same force and effect as if made on such
       Regular Distribution Date or Special Distribution Date and no
       interest shall accrue during the intervening period.  The Special
       Distribution Date shall be the second day of the month, or such
       other date, if any, determined as provided in the Pass Through
       Trust Agreement.  The Pass Through Trustee shall mail notice of
       each Special Payment and the Special Distribution Date therefor
       to the Certificateholder of this Certificate.


                                     A-2

<PAGE>   70
            Distributions on this Certificate will be made by the Pass
       Through Trustee by wire transfer of funds to the Person entitled
       thereto, without the presentation or surrender of this
       Certificate or the making of any notation hereon, provided,
       however, that in the event Certificates are issued in the form of
       Registered Certificates, distributions on this Certificate will
       be made by check mailed to the Person entitled thereto.  Except
       as otherwise provided in the Pass Through Trust Agreement and
       notwithstanding the above, the final distribution on this
       Certificate will be made after notice mailed by the Pass Through
       Trustee of the pendency of such distribution and only upon
       presentation and surrender of this Certificate at the office or
       agency of the Pass Through Trustee specified in such notice.

            THIS CERTIFICATE SHALL BE GOVERNED BY AND CONSTRUED IN
       ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

            Reference is hereby made to the further provisions of this
       Certificate set forth on the reverse hereof, which further
       provisions shall for all purposes have the same effect as if set
       forth at this place.

            Unless the certificate of authentication hereon has been
       executed by the Pass Through Trustee, by manual signature, this
       Certificate shall not be entitled to any benefit under the Pass
       Through Trust Agreement or be valid for any purpose.

            IN WITNESS WHEREOF, the Pass Through Trustee has caused this
       Certificate to be duly executed.


                                UNION TANK CAR COMPANY
                                _______ PASS THROUGH TRUST

                                By:   ___________________,
                                      as Pass Through Trustee


                                By: __________________________________________
                                    Title:


                                     A-3
 

<PAGE>   71


                            [Reverse of Certificate]



            The Certificates do not represent a direct obligation of, or
       an obligation guaranteed by (except to the extent provided in the
       Pass Through Trust Agreement), or an interest in Union, Procor,
       the Pass Through Trustee, in its individual or trust capacities,
       any Owner Participant, any Owner Trustee in its individual
       capacity, either Equipment Trust Trustee in its individual
       capacity, or any affiliate of any thereof.  The Certificates are
       limited in right of payment, all as more specifically set forth
       on the face hereof and in the Pass Through Trust Agreement.  All
       payments or distributions made to Certificateholders under the
       Pass Through Trust Agreement shall be made only from the Trust
       Property and only to the extent that the Pass Through Trustee
       shall have sufficient income or proceeds from the Trust Property
       to make such payments in accordance with the terms of the Pass
       Through Trust Agreement.  Each Certificateholder of this
       Certificate, by its acceptance hereof, agrees that it will look
       solely to the income and proceeds from the Trust Property to the
       extent available for distribution to such Certificateholder as
       provided in the Pass Through Trust Agreement.  This Certificate
       does not purport to summarize the Pass Through Trust Agreement
       and reference is made to the Pass Through Trust Agreement for
       information with respect to the interests, rights, benefits,
       obligations, proceeds, and duties evidenced hereby.  A copy of
       the Pass Through Trust Agreement may be examined during normal
       business hours at the principal office of the Pass Through
       Trustee, and at such other places, if any, designated by the Pass
       Through Trustee, by any Certificateholder upon request.

            The Pass Through Trust Agreement permits, with certain
       exceptions therein provided, the amendment thereof and the
       modification of the rights and obligations of the Companies and
       the rights of the Certificateholders under the Pass Through Trust
       Agreement at any time by the Companies and the Pass Through
       Trustee with the consent of the Certificateholders holding
       Certificates evidencing Fractional Undivided Interests
       aggregating not less than a majority in interest in the Pass
       Through Trust.  Any such consent by the Certificateholder of this
       Certificate shall be conclusive and binding on such
       Certificateholder and upon all future Certificateholders of this
       Certificate and of any Certificate issued upon the transfer
       hereof or in exchange hereof or in lieu hereof whether or not
       notation of such consent is made upon this Certificate.  The Pass
       Through Trust Agreement also permits the amendment thereof, in
       certain limited circumstances, without the consent of the
       Certificateholders of any of the Certificates.

            As provided in the Pass Through Trust Agreement and subject
       to certain limitations therein set forth, the transfer of this
       Certificate is registrable in the Register upon surrender of this
       Certificate for registration of transfer at the offices or
       agencies maintained by the Pass Through Trustee in its capacity
       as Registrar, or by any successor Registrar, in the Borough of
       Manhattan, the City of New York, duly endorsed or accompanied by
       a written instrument of transfer in form satisfactory to the Pass
       Through Trustee and the Registrar duly executed by the
       Certificateholder hereof or such Certificateholder's attorney
       duly authorized in writing, and thereupon one or more


                                     A-4

<PAGE>   72


       new Certificates of authorized denominations evidencing the same
       aggregate Fractional Undivided Interest in the Pass Through Trust
       will be issued to the designated transferee or transferees.

            The Certificates are issuable only as registered
       Certificates without coupons in minimum denominations of $1,000
       and $1,000 integral multiples thereof, except that one
       Certificate may be in a denomination of less than $1,000.  As
       provided in the Pass Through Trust Agreement and subject to
       certain limitations therein set forth, Certificates are
       exchangeable for new Certificates of authorized denominations
       evidencing the same aggregate Fractional Undivided Interest in
       the Pass Through Trust, as requested by the Certificateholder
       surrendering the same.

            No service charge will be made for any such registration of
       transfer or exchange, but the Pass Through Trustee shall require
       payment of a sum sufficient to cover any tax or governmental
       charge payable in connection therewith.

            The Pass Through Trustee, the Registrar, and any agent of
       the Pass Through Trustee or the Registrar may treat the person in
       whose name this Certificate is registered as the owner hereof for
       all purposes, and neither the Pass Through Trustee, the
       Registrar, nor any such agent shall be affected by any notice to
       the contrary.

            The obligations and responsibilities created by the Pass
       Through Trust Agreement and the Pass Through Trust created
       thereby shall terminate upon the distribution to
       Certificateholders of all amounts required to be distributed to
       them pursuant to the Pass Through Trust Agreement and the
       disposition of all property held as part of the Trust Property.


                                     A-5
 

<PAGE>   73


            [FORM OF THE PASS THROUGH TRUSTEE'S CERTIFICATE OF
       AUTHENTICATION]

       Dated:

                 This is one of the Certificates referred to in the
            within-mentioned Pass Through Trust Agreement.


                                _____________________,
                                as Pass Through Trustee



                                By:________________________________
                                    Authorized Officer



                                     A-6

<PAGE>   74


                                                                       EXHIBIT B

                                   GUARANTEE



            Union Tank Car Company, a Delaware corporation ("Union"),
       which term includes any successor or assign under the Pass
       Through Trust Agreement ______, dated _______, among Union,
       Procor Limited, a Canadian corporation ("Procor"), and
       ______________, as Pass Through Trustee, (the "Pass Through Trust
       Agreement"), has irrevocably and unconditionally guaranteed the
       due and punctual distribution to Certificateholders of principal
       and interest payable with respect to the Procor ETC (as defined
       in the Pass Through Trust Agreement), whether at stated maturity
       or otherwise, and certain other obligations of Procor as
       specified in Article XII of the Pass Through Trust Agreement and
       has agreed to pay any and all costs and expenses (including
       reasonable attorneys' fees) incurred by the Pass Through Trustee
       or any Certificateholder in enforcing any rights under this
       Guarantee.

            The obligations of Union to the Certificateholders and to
       the Pass Through Trustee pursuant to this Guarantee and the Pass
       Through Trust Agreement are expressly set forth in Article XII of
       the Pass Through Trust Agreement and reference is hereby made to
       such for the precise terms of this Guarantee.

            No stockholder, officer, director or incorporator, as such,
       past, present or future of Union shall have any liability under
       this Guarantee by reason of his or its status as such
       stockholder, officer, director or incorporator.

            This is a continuing Guarantee and shall remain in full
       force and effect and shall be binding upon Union and its
       successors and assigns until full and final payment of all of the
       guaranteed obligations under the Pass Through Trust Agreement and
       shall inure to the benefit of the successors and assigns of the
       Pass Through Trustee and the Certificateholders and, in the event
       of any transfer or assignment of rights by any Certificateholder
       or the Pass Through Trustee, the rights and privileges herein
       conferred upon that party shall automatically extend to and be
       vested in such transferee or assignee, all subject to the terms
       and conditions hereof.  This is a Guarantee of payment and not of
       collectibility.

            This Guarantee shall not be valid or obligatory for any
       purpose until the certificate of authentication on the
       Certificate upon which this Guarantee is noted shall have been
       executed by the Pass Through Trustee under the Pass Through Trust
       Agreement by the manual signature of one of its authorized
       officers.

            THE TERMS OF ARTICLE XII OF THE PASS THROUGH TRUST AGREEMENT
       ARE INCORPORATED HEREIN BY REFERENCE.


 

<PAGE>   75


                                                                       EXHIBIT C


                                  FORM OF DTC
                           LETTER OF REPRESENTATIONS



 

<PAGE>   76


                                   SCHEDULE I


<TABLE>
<CAPTION>
                      Equipment Notes
                    to be Issued under                       Principal
                      the Indenture:                          Amount         Maturity
                    -------------------                      --------        --------
<S>                                                          <C>             <C>
                   On the Issuance Date                              $

                     Subsequent to the
                       Issuance Date

                        Total Notes                                  $


      Equipment Trust Certificates to be issued under
                Equipment Trust Agreements

                   On the Issuance Date

                            UTC                                      $

                          Procor                                     $

                     Subsequent to the
                       Issuance Date

                            UTC                                      $

                        Total ETC's                                  $

                   Total Notes and ETC's                             $
</TABLE>



 

<PAGE>   77



                                  SCHEDULE II


<TABLE>
<CAPTION>
           ETCs
    to be Issued under                      Principal
Equipment Trust Agreements                   Amount                 Maturity
- --------------------------                  ---------               --------
<S>                                         <C>                  <C>
                                             $
          Total                              $









</TABLE>

<PAGE>   78
Reconciliation and tie between Pass Through Trust Agreement _____ dated
________ and the Trust Indenture Act of 1939.  This reconciliation does not
constitute part of the Pass Through Trust Agreement.


<TABLE>
<CAPTION>
Trust Indenture Act                                  Pass Through Trust
of 1939 Section                                      Agreement Section
- -------------------                                  ------------------
<S>                                                     <C>
                                                   
    310(a)(1) ...........................................  7.8
          (2) ...........................................  7.8
          (3) ...........................................  Inapplicable
          (4) ...........................................  6.2; 6.3 (a) & (b)
       (b)    ...........................................  7.8; 7.9; 7.10
       (c)    ...........................................  Inapplicable
    311(a)    ...........................................  7.18
       (b)    ...........................................  7.18
       (c)    ...........................................  Inapplicable
    312(a)    ...........................................  3.9; 8.1; 8.2
       (b)    ...........................................  13.4
       (c)    ...........................................  13.4
    313       ...........................................  8.3
    314(a)    ...........................................  8.4
       (b)    ...........................................  Inapplicable
       (c)(1) ...........................................  1.2
          (2) ...........................................  1.2
          (3) ...........................................  Inapplicable
       (d)(1) ...........................................  Inapplicable
          (2) ...........................................  Inapplicable
          (3) ...........................................  Inapplicable
       (e)    ...........................................  1.2
    315(a)    ...........................................  7.1(a)
       (b)    ...........................................  7.2
       (c)    ...........................................  7.1(b)
       (d)    ...........................................  7.1(c)
       (e)    ...........................................  6.6
    316(a)(last sentence) ...............................  1.4(c)
          (1)(A) ........................................  6.4
             (B) ........................................  6.5
          (2) ...........................................  Inapplicable
       (b)    ...........................................  6.7
       (c)    ...........................................  1.4(d)
    317(a)(1) ...........................................  6.3(a)
          (2) ...........................................  6.3(b)
       (b)    ...........................................  7.13
    318(a)    ...........................................  13.7
                                                   
</TABLE>                                           
                                                   



 

<PAGE>   1

================================================================================



                             UNION TANK CAR COMPANY


                                       TO


                         [____________________________]
                                    Trustee




                                   INDENTURE

                        Dated as of ____________, _____





                         PROVIDING FOR ISSUANCE OF DEBT
                              SECURITIES IN SERIES



================================================================================
<PAGE>   2

                             UNION TANK CAR COMPANY

         RECONCILIATION AND TIE BETWEEN INDENTURE DATED AS OF ____________,
_____ AND THE TRUST INDENTURE ACT OF 1939.  THIS RECONCILIATION SECTION DOES
NOT CONSTITUTE PART OF THE INDENTURE.

<TABLE>
<CAPTION>
  TRUST INDENTURE ACT                                                  INDENTURE
   OF 1939 SECTION                                                      SECTION 
  ------------------                                                   ---------
  <S>                                                                <C>
  310(a)(1)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    7.10
     (a)(2)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  7.10
     (a)(3)  . . . . . . . . . . . . . . . . . . . . . . . . . . .  Inapplicable
     (a)(4)  . . . . . . . . . . . . . . . . . . . . . . . . . . .  Inapplicable
     (b)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  7.08; 7.10
     (c)   . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Inapplicable
  311(a) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  7.11
     (b)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  7.11
     (c)   . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Inapplicable
  312(a) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.07
     (b)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   10.03
     (c)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   10.03
  313(a) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  7.06
     (b)(1)  . . . . . . . . . . . . . . . . . . . . . . . . . . .  Inapplicable
     (b)(2)  . . . . . . . . . . . . . . . . . . . . . . . . . . . .  4.03; 7.06
     (c)   . . . . . . . . . . . . . . . . . . . . . . . . .   4.03; 7.06; 10.02
     (d)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  7.06
  314(a) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4.03; 10.02
     (b)   . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Inapplicable
     (c)(1)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   10.04
     (c)(2)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   10.04
     (c)(3)  . . . . . . . . . . . . . . . . . . . . . . . . . . .  Inapplicable
     (d)   . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Inapplicable
     (e)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   10.05
     (f)   . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Inapplicable
  315(a) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   7.01(b)
     (b)   . . . . . . . . . . . . . . . . . . . . . . . . . . . .   7.05; 10.02
     (c)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   7.01(a)
     (d)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   7.01(c)
     (e)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.11
  316(a) (last sentence) . . . . . . . . . . . . . . . . . . . . . . . . .  2.11
     (a)(1)(A)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.05
     (a)(1)(B)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.04
     (a)(2)  . . . . . . . . . . . . . . . . . . . . . . . . . . .  Inapplicable
     (b)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.07
  317(a)(1)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.08
     (a)(2)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  6.09
     (b)   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.06
  318(a) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   10.01
                                                                                
</TABLE>
<PAGE>   3


         THIS INDENTURE dated as of ____________, _____, between UNION TANK CAR
COMPANY, a Delaware corporation (hereinafter sometimes referred to as the
"Company"), and [____________________________], a
[____________________________], as trustee (hereinafter sometimes referred to
as the "Trustee") sets forth certain of its provisions in full and incorporates
others by reference to specified portions of the Trust Indenture Act of 1939,
as amended, as in effect on the date of this Indenture.  The provisions as are
set forth in full, the provisions as are incorporated by reference and the
provisions as are set forth in all supplements hereto shall constitute a single
instrument.

         WHEREAS, the Company has duly authorized the execution and delivery of
this Indenture to provide for the issuance from time to time of its
"securities" as herein provided; and

         WHEREAS, all things necessary to make this Indenture a valid and
binding agreement of the Company, in accordance with its terms, have been done;

         NOW THEREFORE:  For and in consideration of the premises and the
purchase of the Securities by the Holders thereof, it is mutually covenanted
and agreed as follows for the equal and ratable benefit of the Holders of the
Securities:


                                   ARTICLE I

                    DEFINITIONS, INCORPORATION BY REFERENCE
                           AND RULES OF CONSTRUCTION

SECTION 1.1.  Definitions.

         The terms defined in this Section 1.1. (except as herein otherwise
expressly provided or unless the context otherwise requires) for all purposes
of this Indenture and of any indenture supplemental hereto shall have the
respective meanings specified in this Section 1.1.

Affiliate:                        The term "Affiliate" means any Person
                                  directly or indirectly controlling or
                                  controlled by, or under direct or indirect
                                  common control with, the Company.

Agent:                            The term "Agent" means any Paying Agent or
                                  Registrar.

Authenticating Agent:             The term "Authenticating Agent" means any
                                  person or persons authorized by the Trustee
                                  to act on behalf of the Trustee to
                                  authenticate one or more Series of
                                  Securities.

Authorized Newspaper:             The term "Authorized Newspaper" means a 
                                  newspaper of  general circulation, in the
                                  official language of the country of
                                  publication or in the English language,
                                  customarily published on each business day. 
                                  Whenever successive weekly publications in an
                                  Authorized Newspaper are required hereunder
                                  they may be made (unless otherwise expressly





                                      -3-
<PAGE>   4

                                  provided herein) on the same or different days
                                  of the week and in the same or
                                  different Authorized Newspapers.

Board of Directors:               The term "Board of Directors" means the Board
                                  of Directors of the Company or any duly
                                  authorized committee thereof.

Board Resolution:                 The term "Board Resolution" means a copy of a
                                  resolution of the Board of Directors,
                                  certified by the Secretary or an Assistant
                                  Secretary of the Company to have been adopted
                                  by the Board of Directors and to be in full
                                  force and effect on the date of the
                                  certificate, and delivered to the Trustee.

Business Day:                     The term "Business Day" means, except as may
                                  otherwise be provided in the form of
                                  Securities of any particular Series, with
                                  respect to any Place of Payment, any day,
                                  other than a Saturday or Sunday, that is not
                                  a legal holiday, or a day on which banking
                                  institutions are authorized or required by
                                  law or regulation to close in that Place of
                                  Payment, and with respect to Securities
                                  denominated in a Foreign Currency, the
                                  capital city of the country of such Foreign
                                  Currency, and with respect to Securities
                                  denominated in ECU, Brussels, Belgium.

Capital Stock:                    The term "Capital Stock" means any and all
                                  shares (however designated) of corporate
                                  stock now or hereafter outstanding.

CEDEL:                            The term "CEDEL" means Centrale de 
                                  Livraisons de Valeurs Mobilieres SA.

Company:                          The term "Company" means the party named as
                                  such in this Indenture until a successor
                                  replaces it pursuant to the applicable
                                  provisions hereof and thereafter means the
                                  successor.

Company Notice:                   The term "Company Notice" means the 
                                  confirmation of the Company, transmitted
                                  by telex, telecopy or in writing to the
                                  Trustee of the terms of the issuance of any
                                  Securities issuable in Tranches.

Company Order or
Company Request:                  The term "Company Order" or "Company Request"
                                  means an order or request signed by two
                                  Officers or by any Officer and an Assistant
                                  Treasurer or an Assistant Secretary of the
                                  Company.


                                      -4-
<PAGE>   5

Default:                          The term "Default" means any event which is,
                                  or after notice or passage of time would be,
                                  an Event of Default.

Depositary:                       The term "Depositary" means, with respect to
                                  Securities of any Series offered for sale in
                                  the United States and for which the Company
                                  shall determine that such Securities will be
                                  issued as a Global Security, The Depository
                                  Trust Company, New York, New York, another
                                  clearing agency or any successor registered
                                  under the Securities Exchange Act of 1934, as
                                  amended, or other applicable statute or
                                  regulation, and with respect to Securities of
                                  any Series which are offered for sale solely
                                  outside of the United States,
                                  [____________________________],
                                  [______________] office as common depositary
                                  for Euro-clear and CEDEL or any successor
                                  thereto, which in each case shall be
                                  designated by the Company pursuant to either
                                  Section 2.2 or 2.15.

Dollar:                   The term "Dollar" means the coin or currency of the
                          United States of America which as of the time of
                          payment is legal tender for the payment of public and
                          private debts.

ECU:                              The term "ECU" means the European Currency
                                  Unit as defined and revised from time to time
                                  by the Council of the European Communities.

Euro-clear:                       The term "Euro-clear" means Morgan Guaranty
                                  Trust Company of New York, Brussels office,
                                  as operator of the Euro-clear System.

European Communities:             The term "European Communities" means the 
                                  European Economic Community, the European
                                  Coal and Steel Community and the European
                                  Atomic Energy Community.

Exchange Rate
Officer's Certificate:            The term "Exchange Rate Officer's
                                  Certificate" means a telex or a certificate
                                  setting forth the applicable Official ECU
                                  Exchange Rate and the Dollar or Foreign
                                  Currency amounts payable on the basis of such





                                      -5-
<PAGE>   6

                                  Official ECU Exchange Rate in respect of the
                                  Principal of and interest on Registered
                                  Securities, sent (in the case of a telex) or
                                  signed (in the case of a certificate) by the
                                  treasurer or any assistant treasurer of the
                                  Issuer, and delivered to the Trustee.

Foreign Currency:                 The term "Foreign Currency" means a currency
                                  issued by the government of any country other
                                  than the United States of America.

GAAP:                             The term "GAAP" means, with respect to any
                                  computation required or permitted hereunder,
                                  generally accepted accounting principles in
                                  the United States on the date of such
                                  computation.

Global Security:                  The term "Global Security" means, with
                                  respect to any Series of Securities, a
                                  Security executed by the Company and
                                  authenticated and delivered by the Trustee to
                                  the Depositary or pursuant to the
                                  Depositary's instruction, all in accordance
                                  with this Indenture and pursuant to a Company
                                  Order, which (i) shall be registered in the
                                  name of the Depositary or its nominee and
                                  (ii) shall represent, and shall be
                                  denominated in an amount equal to the
                                  aggregate Principal amount of, all of the
                                  Outstanding Securities of such Series or,
                                  pursuant to a Company Order, all of the
                                  Outstanding Securities of such Series not
                                  issued in definitive form.

Holder or Securityholder:         The term "Holder" or "Securityholder" means a
                                  bearer of an Unregistered Security or of a
                                  coupon appertaining thereto, or a person in
                                  whose name a Registered Security is
                                  registered on the Registrar's books.

Indenture:                        The term "Indenture" means this Indenture as
                                  amended or supplemented from time to time and
                                  shall include the forms and terms of
                                  particular Series of Securities established
                                  as contemplated hereunder.

Investment:                       The term "Investment" means all loans,
                                  advances, purchases of Capital Stock, capital
                                  contributions and transfers of assets, and
                                  all sales and other dispositions of assets
                                  for consideration consisting of evidences of
                                  indebtedness, Capital Stock or other
                                  securities of the purchaser.

Officer:                          The term "Officer" means the President, any
                                  Vice-President, the Treasurer, the Secretary
                                  or the Controller of the Company.

Officers' Certificate:            The term "Officers' Certificate" means a
                                  certificate signed by two Officers or by any
                                  Officer and an Assistant Treasurer or an
                                  Assistant Secretary of the Company.

Official ECU Exchange Rate:       The term "Official ECU Exchange Rate"
                                  applicable to any currency with respect to
                                  any payment to be made hereunder means the
                                  exchange rate between the ECU and such
                                  currency reported by the Commission





                                      -6-
<PAGE>   7

                                  of the European Communities (currently based
                                  on the rates in effect at 2:30 p.m., Brussels
                                  time, on the relevant exchange markets) or,
                                  if such exchange rate ceases to be so
                                  reported, then such exchange rate shall be
                                  determined by the Trustee using, in its sole
                                  discretion and without liability on its part,
                                  quotations from one or more major banks in
                                  New York City or such other quotations as the
                                  Trustee shall deem appropriate, on the
                                  applicable record date.

Opinion of Counsel:               The term "Opinion of Counsel" means a written
                                  opinion of legal counsel who is acceptable to
                                  the Company.  The counsel may be an employee
                                  of or counsel to the Company.

Original Issue Discount
Security:                         The term "Original Issue Discount Security"
                                  means any Security which provides for an
                                  amount less than the stated Principal amount
                                  thereof to be due and payable upon
                                  declaration of acceleration of the maturity
                                  thereof pursuant to Section 6.2.

Person:                           The term "Person" means any individual,
                                  corporation, partnership, joint venture,
                                  association, joint-stock company, trust,
                                  unincorporated organization or government, or
                                  any agency or political subdivision thereof.

Place of Payment:                 The term "Place of Payment," when used with
                                  respect to the Securities of any Series,
                                  means the Principal office of the Trustee in
                                  New York and the office of any Paying Agent,
                                  unless the Company shall have otherwise
                                  instructed the Trustee in writing.

Principal:                        The term "Principal" of a Security means the
                                  principal amount of the security plus, when
                                  appropriate, the premium, if any, on the
                                  security.

Principal office of
the Trustee:                      The term "Principal office of the Trustee,"
                                  or other similar term, shall mean the
                                  principal office of the Trustee at which at
                                  any particular time its corporate trust
                                  business shall be administered.

Redemption Date:                  The term "Redemption Date," when used with
                                  respect to any Security to be redeemed, means
                                  the date fixed for such redemption by or
                                  pursuant to this Indenture.

Redemption Price:                 The term "Redemption Price," when used with
                                  respect to any Security to be redeemed, means
                                  the price at which it is to be redeemed
                                  pursuant to this Indenture.

Registered Security:              The term "Registered Security" means any
                                  Security issued hereunder and registered as
                                  to Principal and interest by the Registrar.





                                      -7-
<PAGE>   8

Related Parties:                  The term "Related Parties" means "related
                                  parties" as defined in Rule 1.02 (t) of
                                  Regulation S-X of the SEC as in effect on the
                                  date hereof.

Responsible Officer:              The term "Responsible Officer", when used
                                  with respect to the Trustee, shall mean the
                                  chairman or any vice- chairman of the board
                                  of directors or trustees, the chairman or any
                                  vice-chairman of the executive committee of
                                  the board of directors or trustees, the
                                  president, any vice president, the treasurer,
                                  the secretary, any trust officer, any second
                                  or assistant vice-president or any other
                                  officer or assistant officer of the Trustee
                                  customarily performing functions similar to
                                  those performed by the persons who at the
                                  time shall be such officers, respectively, or
                                  to whom any corporate trust matter is
                                  referred because of his knowledge of and
                                  familiarity with a particular subject.

SEC:                              The term "SEC" means the Securities and
                                  Exchange Commission.

Security:                         The term "Security" means any debenture, note
                                  or other obligation of the Company issued,
                                  authenticated and delivered under this
                                  Indenture.

Series or Series
of Securities:                    The term "Series" or "Series of Securities"
                                  means a series of Securities.  Except in
                                  Sections 2.1, 2.10 and 2.11 and Articles Six,
                                  Seven, Nine and Ten, the terms "Series" or
                                  "Series of Securities" shall also mean a
                                  Tranche in the event that the applicable
                                  Series may be issued in separate Tranches.

Stated Maturity:                  The term "Stated Maturity", when used with
                                  respect to any Security or any installment of
                                  Principal thereof or interest thereon, means
                                  the date specified in such Security as the
                                  fixed date on which the Principal of such
                                  Security or such installment of Principal or
                                  interest is due and payable.

Subsidiary:                       The term "Subsidiary" shall mean any
                                  corporation of which the Company, or the
                                  Company and one or more Subsidiaries, or any
                                  one or more Subsidiaries, directly or
                                  indirectly own voting securities entitling
                                  the holders thereof to elect a majority of
                                  the directors, either at all times or so long
                                  as there is no default or contingency which
                                  permits the holders of any other class or
                                  classes of securities to vote for the
                                  election of one or more directors.

TIA:                              The term "TIA" means the Trust Indenture Act
                                  of 1939, as amended, as in effect on the 
                                  date of this Indenture.

Tranche:                          The term "Tranche" means all Securities of
                                  the same Series which have the same issue
                                  date, Stated Maturity, interest rate or
                                  method of determining interest, and, in the
                                  case of Original Issue Discount Securities,
                                  which have the same issue price.





                                      -8-
<PAGE>   9

Trustee:                          The term "Trustee" means the party named as
                                  such in this Indenture until a successor
                                  replaces it pursuant to the applicable
                                  provisions hereof and thereafter means the
                                  successor, and if, at any time, there is more
                                  than one Trustee, "Trustee" as used with
                                  respect to the Securities of any Series,
                                  including all Tranches thereof, shall mean
                                  the Trustee with respect to that Series,
                                  including all Tranches thereof.

U.S. Government Obligations:      The term "U.S. Government Obligations" means
                                  securities which are (i) direct obligations
                                  of the United States of America for the
                                  payment of which its full faith and credit is
                                  pledged, or (ii) obligations of a Person
                                  controlled or supervised by and acting as an
                                  agency 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 are not
                                  callable or redeemable at the option of the
                                  issuer thereof.  U.S.  Government Obligations
                                  shall also include a depositary receipt
                                  issued by a bank or trust company as
                                  custodian with respect to any such U.S.
                                  Government Obligation or a specific payment
                                  of interest on or principal of any such U.S.
                                  Government Obligation held by such custodian
                                  for the account of the holder of a depositary
                                  receipt, provided, however, 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 interest on or principal of the U.S.
                                  Government Obligation evidenced by such
                                  depositary receipt.

United States:                    The term "United States" means the United
                                  States of America (including the States and
                                  the District of Columbia), its territories,
                                  its possessions and any other areas subject
                                  to its jurisdiction.

U.S. Person:                      The term "U.S. Person" means a citizen or
                                  resident of the United States, any
                                  corporation, partnership or other entity
                                  created or organized in or under the laws of
                                  the United States or any political
                                  subdivision thereof, or any estate or trust
                                  the income of which is subject to United
                                  States federal income taxation regardless of
                                  its source.

Unregistered Security:            The term "Unregistered Security" means any
                                  Security issued hereunder which is not a 
                                  Registered Security.

Wholly-Owned Subsidiary:          The term "Wholly-Owned Subsidiary" shall mean
                                  a Subsidiary of which all of the stock (other
                                  than directors' qualifying shares) is at the
                                  time, directly or indirectly, owned by the
                                  Company or by one or more Wholly- Owned
                                  Subsidiaries of the Company or by the Company
                                  and one or more Wholly-Owned Subsidiaries.





                                      -9-
<PAGE>   10

Yield to Maturity:                The term "Yield to Maturity" means the yield
                                  to maturity, calculated by the Company at the
                                  time of issuance of a Series of Securities
                                  or, if applicable, at the most recent
                                  determination of interest on such Series in
                                  accordance with accepted financial practice.

SECTION 1.2.  Other Definitions.


<TABLE>
<CAPTION>

 TERM                                                                       SECTION
- ------                                                                    ---------
<S>                                                                           <C>
"Account Holder"  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.16 
"Bankruptcy Law"  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   6.1 
"Component Currency"  . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2.5 
"Conversion Date" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2.5
"Custodian" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   6.1 
"Definitive Security" . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.16 
"Dollar Equivalent of the ECU"  . . . . . . . . . . . . . . . . . . . . . . .   2.5 
"Dollar Equivalent of the Foreign Currency" . . . . . . . . . . . . . . . . .   2.5 
"Event of Default"  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   6.1 
"Final Certificate" . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.16 
"Legal Holiday" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  10.7 
"Market Exchange Rate"  . . . . . . . . . . . . . . . . . . . . . . . . . . .   2.5 
"Outstanding" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2.10 
"Paying Agent"  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2.4 
"Permanent Global Security" . . . . . . . . . . . . . . . . . . . . . . . . .  2.16 
"Registrar" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2.4 
"Specified Amount"  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2.5
"Temporary Global Security" . . . . . . . . . . . . . . . . . . . . . . . . .  2.16 
"Valuation Date"  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2.5

</TABLE>

SECTION 1.3.  Incorporation by Reference of Trust Indenture Act.

         Whenever this Indenture refers to a provision of the TIA, such
provision is incorporated by reference in and made a part of this Indenture.
The following TIA terms used in this Indenture have the following meanings:

         "Commission" means the SEC.

         "indenture securities" means the Securities.

         "indenture security holder" means a Holder or a Securityholder.

         "indenture to be qualified" means this Indenture.

         "indenture trustee" or "institutional trustee" means the Trustee.

         "obligor" on the indenture securities means the Company.





                                     -10-
<PAGE>   11

         All other terms used in this Indenture which are defined in the TIA,
defined by SEC rule under the TIA or defined by TIA reference to the Securities
Act of 1933, as amended, shall (except as herein otherwise expressly provided
or unless the context otherwise requires) have the meanings assigned to such
terms in said TIA and in said Securities Act as in force at the date of this
Indenture as originally executed.

SECTION 1.4.  Rules of Construction.

         Unless the context otherwise requires:

                 (1)  a term has the meaning assigned to it;

                 (2)  an accounting term not otherwise defined has the meaning
          assigned to it in accordance with GAAP;

                 (3)  "or" is not exclusive; and

                 (4)  words in the singular include the plural, and words in 
          the plural include the singular.


                                   ARTICLE II

                                 THE SECURITIES

SECTION 2.1.  Issuable in Series; Series Issuable in Tranches.

         Subject to Section 2.9, the aggregate principal amount of Securities
which may be authenticated and delivered under this Indenture is unlimited.
The Securities may be issued in one or more Series.  There may be Registered
Securities and Unregistered Securities within a Series and the Securities may
be subject to such restrictions, and contain such legends, as required by law
or as the Company deems necessary or appropriate.  Except as provided in the
foregoing sentence, and except as to Series issuable in Tranches, all
Securities of a Series shall be identical in all respects except that
Securities of a Series with serial maturities may differ with respect to
maturity date, interest rate, redemption price and denomination.  Securities of
different Series may differ in any respect; provided that all Series of
Securities shall be equally and ratably entitled to the benefits of this
Indenture.

         Each Series may be issued in one or more Tranches.  Except as provided
in the foregoing paragraph, all Securities of a Tranche shall have the same
issue date, Stated Maturity, interest rate or method of determining interest,
and, in the case of Original Issue Discount Securities, the same issue price.

SECTION 2.2.  Establishment of Terms and Form of Series of Securities.

         (a)  At or prior to the issuance of any Series (including any Tranche)
of Securities, the following shall be established at the Company's discretion
either by or pursuant to a Board Resolution or by one or more indentures
supplemental hereto:





                                      -11-
<PAGE>   12

                 (1)  the title of the Securities of the Series (which title
         shall distinguish the Securities of the Series from the Securities of
         any other Series and from any other securities issued by the Company);

                 (2)  any limit upon the aggregate principal amount of the
         Securities of the Series (or any limit upon the total aggregate
         principal amount of more than one specified Series) which may be
         authenticated and delivered under this Indenture (which limit shall
         not pertain to Securities authenticated and delivered upon
         registration of transfer of, or in exchange for, or in lieu of, other
         Securities of the Series pursuant to Section 2.8, 2.9, 2.12, 3.6 or
         9.5);

                 (3)  the date or dates on which the Principal of the
         Securities of the Series is payable;

                 (4)  the rate or rates, which may be fixed or variable, at
         which the Securities of the Series shall bear interest, if any, or the
         method of calculating such rate or rates of interest, the date or
         dates from which such interest shall accrue, the dates on which such
         interest shall be payable and, with respect to Registered Securities,
         the record date for the interest payable on any interest payment date;

                 (5)  the place or places where the Principal of and interest,
         if any, and additional amounts, if any, on Securities of the Series
         shall be payable (if other than Place of Payment);

                 (6)  the period or periods within which, the price or prices
         at which, and the terms and conditions upon which, Securities of the
         Series may be redeemed, in whole or in part, if at all;

                 (7)  the obligation, if any, of the Company to redeem or
         purchase Securities of the Series pursuant to any sinking fund or
         analogous provisions or upon the happening of a specified event or at
         the option of a Holder thereof and the period or periods within which,
         the price or prices at which, and the terms and conditions upon which,
         Securities of the Series shall be redeemed or purchased, in whole or
         in part, pursuant to such obligation;

                 (8)  if in other than denominations of $1,000 and any integral
         multiple thereof, the denominations, which may be in Dollars, any
         Foreign Currency or ECU, in which Securities of the Series shall be
         issuable;

                 (9)  if other than the principal amount thereof, the portion
         of the principal amount of Securities of the Series which shall be
         payable upon declaration of acceleration of the maturity thereof
         pursuant to Section 6.2 or provable in bankruptcy pursuant to Section
         6.3;

                 (10)  whether Securities of the Series shall be issuable as
         Registered Securities or Unregistered Securities (with or without
         interest coupons), or both, and any restrictions applicable to the
         offering, sale or delivery of Securities and whether, and the terms
         upon which, Unregistered Securities of a Series may be exchanged for
         Registered Securities of the same Series and vice versa;

                 (11)  whether and under what circumstances Securities of the
         Series shall be convertible into, or exchangeable for, Securities of
         any other Series or any other securities of the Company or any
         Affiliate of the Company;





                                      -12-
<PAGE>   13

                 (12)  whether Securities of the Series are issuable as, or
         exchangeable for, one or more Global Securities and, in such case,
         whether interests in such Global Security or Global Securities shall
         be exchangeable for definitive Securities, and the identity of the
         Depositary with respect to such Series;

                 (13)  whether and under what circumstances the Company will
         pay additional amounts on the Securities of that Series held by a
         person who is not a U.S. person in respect of taxes or similar charges
         withheld or deducted and, if so, whether the Company will have the
         option to redeem such Securities rather than pay such additional
         amounts;

                 (14)  the form of the Securities (or forms thereof if
         Unregistered and Registered Securities shall be issuable in such
         Series), including such legends as required by law or as the Company
         deems necessary or appropriate, the form of any coupons or Temporary
         Global Security which may be issued and the forms of any certificates
         which may be required hereunder or which the Company may require in
         connection with the offering, sale, delivery or exchange of
         Unregistered Securities;

                 (15)  the monies or currency units in which payments of
         interest or Principal are payable with respect to the Securities;

                 (16)  whether Securities of the Series are issuable in 
         Tranches: and

                 (17)  whether the principal amount of the Securities of the
         Series payable at maturity is to be determined by the relationship
         between a denominated currency and another currency; and

                 (18)  any other terms of the Series (which terms shall not be
         inconsistent with the provisions of this Indenture) including any
         terms which may be required by or advisable under United States laws
         or regulations or advisable in connection with the marketing of
         Securities of that Series.

         (b)     If the terms and form or forms of any Series of Securities are
established by or pursuant to a Board Resolution, the Company shall deliver a
copy of such Board Resolution to the Trustee prior to the issuance of such
Series together with (1) the form or forms of Securities which have been
approved attached thereto, or (2) if such Board Resolution authorizes a
specific Officer or Officers to approve the terms and form or forms of the
Securities, a certificate of such Officer or Officers approving the terms and
form or forms of Securities with such form or forms of Securities attached
thereto.

SECTION 2.3.  Execution, Authentication and Delivery.

         (a)  Securities shall be executed on behalf of the Company by its
President or a Vice-President, and by its Treasurer or an Assistant Treasurer
or its Secretary or an Assistant Secretary.  Signatures shall be manual or
facsimile.  The Company's seal shall be reproduced on the Securities and may,
but need not, be attested.  The coupons of Unregistered Securities shall bear
the facsimile signature of the Treasurer or an Assistant Treasurer of the
Company.





                                      -13-
<PAGE>   14

         (b)  If an Officer, an Assistant Treasurer or an Assistant Secretary
whose signature is on a Security or coupon no longer holds that office at the
time the Security is authenticated, the Security or coupon shall be valid and
binding nevertheless.

         (c)  A Security shall not be valid until authenticated by the manual
signature of the Trustee or an Authenticating Agent and no coupon shall be
valid until the Security to which it appertains has been so authenticated.
Such signature shall be conclusive evidence that the Security has been
authenticated under this Indenture.  Each Unregistered Security shall be dated
as provided in connection with the establishment of the Series thereof or, if
no such date is so specified, the date of its original issuance and each
Registered Security shall be dated the date of its authentication.

         (d)  The Trustee shall at any time, and from time to time,
authenticate and deliver Securities of any Series executed and delivered by the
Company for original issue, upon receipt by the Trustee of (i) a Company Order
for the authentication and delivery of such Securities, (ii) if the terms and
form or forms of the Securities of such Series have been established by or
pursuant to a Board Resolution as permitted by Section 2.2, a copy of such
Board Resolution and any certificate that may be required pursuant to Section
2.2(b) and (iii) an Opinion of Counsel stating:

                 (1)  if the form of such Securities has been established by or
         pursuant to a Board Resolution as permitted by Section 2.2, that such
         form has been established in conformity with the provisions of this
         Indenture;

                 (2)  if the terms of such Securities have been established by
         or pursuant to a Board Resolution as permitted by Section 2.2, that
         such terms have been established in conformity with the provisions of
         this Indenture; and

                 (3)  that such Securities, when authenticated and delivered by
         the Trustee and issued by the Company in the manner and subject to any
         conditions specified in such Opinion of Counsel, will constitute valid
         and legally binding obligations of the Company, enforceable in
         accordance with their terms, subject to bankruptcy, insolvency,
         reorganization and other laws of general applicability relating to or
         affecting the enforcement of creditors' rights and to general equity
         principles;

provided, however, that in the case of any Series issuable in Tranches, if the
Trustee has previously received the documents referred to in Section 2.3(d)
(i), (ii) and (iii) with respect to any Tranche of such Series, the Trustee
shall authenticate and deliver Securities of such Series executed and delivered
by the Company for original issue upon receipt by the Trustee of the applicable
Company Notice.

         Notwithstanding the foregoing, until the Company has delivered an
Officers' Certificate to the Trustee and the Registrar stating that, as a
result of the action described, the Company would not suffer adverse
consequences under the provisions of United States law or regulations in effect
at the time of the delivery of Unregistered Securities, (i) delivery of
Unregistered Securities will be made only outside the United States and (ii)
Unregistered Securities will be released in definitive form, whether in the
form of a Global Security or otherwise, to the person entitled to physical
delivery thereof only upon presentation of a certificate in the form prescribed
by the Company in such Officers' Certificate.





                                      -14-
<PAGE>   15

         (e)  The aggregate Principal amount of Securities of any Series
outstanding at any time may not exceed any limit upon the maximum Principal
amount for such Series set forth in the Board Resolution (or certificate of an
Officer or Officers) or supplemental indenture pursuant to Section 2.2.

         (f)  At any time the Trustee may appoint an Authenticating Agent or
Agents with respect to one or more Series of Securities which Authenticating
Agent shall be authorized to act on behalf of the Trustee to authenticate
Securities of such Series, and Securities so authenticated shall be entitled to
the benefits of this Indenture and shall be valid and obligatory for all
purposes as if authenticated by the Trustee hereunder.  Wherever reference is
made in this Indenture to the authentication and delivery of Securities by the
Trustee or the Trustee's certificate of authentication, such reference shall be
deemed to include authentication and delivery on behalf of the Trustee by an
Authenticating Agent and a certificate of authentication executed on behalf of
the Trustee by an Authenticating Agent.  Each Authenticating Agent shall be
acceptable to the Company.

         An Authenticating Agent may resign at any time by giving written
notice thereof to the Trustee and to the Company.  The Trustee may at any time
terminate the agency of an Authenticating Agent by giving written notice
thereof to such Authenticating Agent and to the Company.  Upon receiving such a
notice of resignation or upon such a termination, the Trustee may appoint a
successor Authenticating Agent which shall be acceptable to the Company.  Any
successor Authenticating Agent upon acceptance of its appointment hereunder
shall become vested with all the rights, powers and duties of its predecessor
hereunder, with like effect as if originally named as an Authenticating Agent.

         The Company agrees to pay to each Authenticating Agent from time to
time (unless such Authenticating Agent shall otherwise agree) reasonable
compensation for its services under this Section.

SECTION 2.4.  Registrar and Paying Agent.

         The Company may maintain in the Borough of Manhattan, The City of New
York, State of New York, an office or agency where, unless otherwise restricted
by the provisions of Section 2.15, Registered Securities may be presented for
registration of transfer or for exchange ("Registrar") and an office or agency
where (subject to Sections 2.5(c) and 2.8(b)) Securities may be presented for
payment or, in the case of Unregistered Securities, for exchange ("Paying
Agent").  With respect to any Series of Securities issued in whole or in part
as Unregistered Securities, the Company shall maintain one or more Paying
Agents located outside the United States and shall maintain such Paying Agents
for a period of two years after the Principal of such Unregistered Securities
has become due and payable.  During any period thereafter for which it is
necessary in order to conform to United States tax law or regulations, the
Company shall maintain a Paying Agent outside the United States to which the
Unregistered Securities or coupons appertaining thereto may be presented for
payment and will provide the necessary funds therefor to such Paying Agent upon
reasonable notice.  The Registrar shall keep a register with respect to each
Series of Securities issued in whole or in part as Registered Securities and to
their transfer and exchange.  The Company may appoint one or more co-Registrars
and one or more additional Paying Agents for each Series of Securities and the
Company may terminate the appointment of any co-Registrar or Paying Agent at
any time upon written notice.  The term "Registrar" includes any co-Registrar.
The term "Paying Agent" includes any additional Paying Agent.  The Company
shall notify the Trustee of the name and address of any Agent not a party to
this Indenture.  If the Company fails to maintain a Registrar or Paying Agent,
the Trustee shall act as such.





                                      -15-
<PAGE>   16

SECTION 2.5.  Currency and Manner of Payments in Respect of Securities.

         (a)  With respect to Securities denominated in Dollars or Foreign
Currency and with respect to Registered Securities denominated in ECU with
respect to which the Holders of such Securities have not made the election
provided for in paragraph (b) below, the following payment provisions shall
apply:

                 (1)  Except as provided in subparagraph (a) (2) below, in
         paragraphs (e) and (j) below, in the applicable Company Notice, if
         any, or in the form or forms of any Series of Security, payment of the
         Principal of any Security will be made at the Place of Payment by
         delivery of a check in the currency in which the Security is
         denominated on the payment date against surrender of such Security,
         and any interest on any Security which is a Registered Security will
         be paid at the Place of Payment by mailing a check in the currency in
         which the Securities were issued to the Person entitled thereto at the
         address of such Person appearing on the Security register.  Unless
         otherwise provided in the Board Resolution establishing a Series or in
         the applicable Company Notice, if any, interest on any Security which
         is an Unregistered Security will be paid in the currency in which the
         Securities were issued in accordance with the provisions of
         subparagraph (c) below.

                 (2)  Payment of the Principal of and interest on such Security
         may also, subject to applicable laws and regulations, be made at such
         other place or places as may be designated by the Company by any
         appropriate method.

         (b)  With respect to Registered Securities denominated in ECU, the
following payment provisions shall apply, except as otherwise provided in
paragraphs (e) and (f) below:

                 (1)  The Board of Directors may provide that with respect to
         any Series of such Securities that Holders shall have the option to
         receive payments of Principal of and interest on such Security in any
         of the currencies which may be designated for such election in such
         Security by delivering to the Trustee and the Company a written
         election, to be in form and substance satisfactory to the Trustee and
         the Company, not later than the close of business on the record date
         immediately preceding the applicable payment date.  Such election will
         remain in effect for such Holder until changed by the Holder by
         written notice to the Trustee (but any such change must be made not
         later than the close of business on the record date immediately
         preceding the next payment date to be effective for the payment to be
         made on such payment date and no such change may be made with respect
         to payments to be made on any Security with respect to which notice of
         redemption has been given by the Company pursuant to Article Three).
         Any Holder of any such Security who shall not have delivered any such
         election to the Trustee not later than the close of business on the
         applicable record date will be paid the amount due on the applicable
         payment date in ECU as provided in paragraph (a) of this Section 2.5.
         Payment of Principal shall be made on the payment date against
         surrender of such Securities.  Payment of Principal and interest shall
         be made at the Place of Payment by mailing at such location a check in
         the applicable currency to the Person entitled thereto at the address
         of such Person appearing on the Security register.





                                      -16-
<PAGE>   17

                 (2)  Payment of the Principal of and interest on such Security
         may also, subject to applicable laws and regulations, be made at such
         other place or places as may be designated by the Company.

         (c)  To the extent provided in the Securities of a Series, (i)
interest, if any, on Unregistered Securities shall be paid only against
presentation and surrender of the coupons for such interest installments as are
evidenced thereby as they mature and (ii) original issue discount (as defined
in Section 1273 of the Internal Revenue Code of 1986 as it may be amended from
time to time), if any, on Unregistered Securities shall be paid only against
presentation and surrender of such Securities, in either case at the office of
a Paying Agent located outside of the United States, unless the Company shall
have otherwise instructed the Trustee in writing and only in the currency in
which the Security is denominated (except as provided in paragraph (e) below).
Principal of Unregistered Securities shall be paid only against presentation
and surrender thereof as provided in the Securities of a Series and only in the
currency in which the Security is denominated (except as provided in paragraph
(e) below, the Board Resolution establishing such Series, or the applicable
Company Notice, if any).  If at the time a payment of Principal or interest, if
any, or original issue discount, if any, on an Unregistered Security or coupon
shall become due, the payment of the full amount so payable at the office or
offices of all the Paying Agents is illegal or effectively precluded because of
the imposition of exchange controls or other similar restrictions on the
payment of such amount in Dollars or Foreign Currency, then the Company may
instruct the Trustee to make such payments at the office of a Paying Agent
located in the United States, provided that provision for such payment in the
United States would not cause such Unregistered Security to be treated as a
"registration-required obligation" under United States tax law and regulations.

         (d)  Not later than the fourth Business Day after the record date for
each payment date, the Trustee will deliver to the Company a written notice
specifying the aggregate amounts of Principal of and interest on the Securities
to be made on such payment date, specifying the amounts so payable in respect
of the Registered and the Unregistered Securities and the currencies or
currency units in which such payments are to be made.  If the Board of
Directors has provided for the election referred to in paragraph (b) above and
if at least one Holder has made such election, then not later than the eighth
Business Day following each record date the Company will deliver to the Trustee
an Exchange Rate Officer's Certificate in respect of the Dollar or Foreign
Currency payments to be made on such payment date.  The Dollar or Foreign
Currency amount receivable by Holders of Registered Securities denominated in
ECU who have elected payment in such currency as provided in paragraph (b)
above shall be determined by the Company on the basis of the applicable
Official ECU Exchange Rate set forth in the applicable Exchange Rate Officer's
Certificate.

         (e)  If the Foreign Currency in which any payments of Principal or
interest are to be made ceases to be used both by the government of the country
which issued such currency and for the settlement of transactions by public
institutions of or within the international banking community, or if the ECU
ceases to be used both within the European Monetary System and for the
settlement of transactions by public institutions of or within the European
Communities, then with respect to each date for the payment of Principal of and
interest on the applicable Securities occurring after the last date on which
the Foreign Currency or ECU was so used (the "Conversion Date"), the Dollar
shall be the currency of payment for use on each such payment date.  The Dollar
amount to be paid by the Company to the Trustee and by the Trustee or any
Paying Agent to the Holders of such Securities with respect to such payment
date shall be the Dollar Equivalent of the Foreign Currency or, in the case of





                                      -17-
<PAGE>   18
ECU, the Dollar Equivalent of the ECU as determined by the Trustee as of
the record date (the "Valuation Date") in the manner provided in paragraphs (g)
or (h) below.

         (f)  If the Holder of a Registered Security with respect to which
payments of Principal or interest are to be made in ECU elects payment in a
specified Foreign Currency as provided for by paragraph (b) and such Foreign
Currency ceases to be used both by the government of the country which issued
such currency and for the settlement of transactions by public institutions of
or within the international banking community, such Holder shall receive
payment in ECU, and if ECU ceases to be used both within the European Monetary
System and for the settlement of transactions by public institutions of or
within the European Communities, such Holder shall receive payment in Dollars.

         (g)  The "Dollar Equivalent of the Foreign Currency" shall be
determined by the Trustee as of each Valuation Date and shall be obtained by
converting the specified Foreign Currency into Dollars at the Market Exchange
Rate on the Valuation Date.

         (h)  The "Dollar Equivalent of the ECU" shall be determined by the
Trustee as of each Valuation Date and shall be the sum obtained by adding
together the results obtained by converting the Specified Amount of each
Component Currency into Dollars at the Market Exchange Rate on the Valuation
Date for such Component Currency.

         (i)  For purposes of this Section 2.5 the following terms shall have
the following meanings:

         A "Component Currency" shall mean any currency which, on the
Conversion Date, was a component currency of the ECU.

         A "Specified Amount" of a Component Currency shall mean the number of
units or fractions thereof which such Component Currency represented in the ECU
on the Conversion Date.  If after the Conversion Date the official unit of any
Component Currency is altered by way of combination or subdivision, the
Specified Amount of such Component Currency shall be divided or multiplied in
the same proportion.  If after the Conversion Date two or more Component
Currencies are consolidated into a single currency, the respective Specified
Amounts of such Component Currencies shall be replaced by an amount in such
single currency equal to the sum of the respective Specified Amounts of such
consolidated Component Currencies expressed in such single currency, and such
amount shall thereafter be a Specified Amount and such single currency shall
thereafter be a Component Currency. If after the Conversion Date any Component
Currency shall be divided into two or more currencies, the Specified Amount of
such Component Currency shall be replaced by specified amounts of such two or
more currencies, the sum of which, at the Market Exchange Rate of such two or
more currencies on the date of such replacement, shall be equal to the
Specified Amount of such former Component Currency divided by the number of
currencies into which such Component Currency was divided, and such amounts
shall thereafter be Specified Amounts and such currencies shall thereafter be
Component Currencies.

         "Market Exchange Rate" shall mean for any currency the noon Dollar
buying rate for that currency for cable transfers quoted in New York City on
the Valuation Date as quoted by the Federal Reserve Bank of New York.  If such
rates are not available for any reason with respect to one or more currencies
for which an Exchange Rate is required, the Trustee shall use, in its sole
discretion and without liability on its part, such quotation of the Federal
Reserve Bank of New York as of the most





                                      -18-
<PAGE>   19

recent available date, or quotations from one or more major banks in New York
City or in the country of issue of the currency in question, or such other
quotations as the Trustee shall deem appropriate.  Unless otherwise specified
by the Trustee, if there is more than one market for dealing in any currency by
reason of foreign exchange regulations or otherwise, the market to be used in
respect of such currency shall be that upon which a nonresident issuer of
securities designated in such currency would purchase such currency in order to
make payments in respect of such securities.

         All decisions and determinations of the Trustee regarding the Dollar
Equivalent of the Foreign Currency, the Dollar Equivalent of the ECU and the
Market Exchange Rate shall be in its sole discretion and shall, in the absence
of manifest error, be conclusive for all purposes and irrevocably binding upon
the Company and all Holders of the Securities.  In the event that the Foreign
Currency ceases to be used both by the government of the country which issued
such currency and for the settlement of transactions by public institutions of
or within the international banking community, the Company, after learning
thereof, will immediately give notice thereof to the Trustee (and the Trustee
will promptly thereafter give notice in the manner provided in Section 10.2 to
the Holders) specifying the Conversion Date.  In the event the ECU ceases to be
used both within the European Monetary System and for the settlement of
transactions by public institutions of or within the European Communities, the
Company, after learning thereof, will immediately give notice thereof to the
Trustee (and the Trustee will promptly thereafter give notice in the manner
provided in Section 10.2 to the Holders) specifying the Conversion Date and the
Specified Amount of each Component Currency on the Conversion Date.  In the
event of any subsequent change in any Component Currency as set forth in the
definition of Specified Amount above, the Company, after learning thereof, will
similarly give notice to the Trustee (and the Trustee will promptly thereafter
give notice in the manner provided in Section 10.2 to the Holders).

         The Trustee shall be fully justified and protected in relying on and
acting upon the information so received by it from the Company and shall not
otherwise have any duty or obligation to determine such information
independently.

         (j)  Principal and interest payable on a Security represented by an
interest in a Temporary Global Security pursuant to Section 2.16 will not be
paid until the Holder thereof exchanges the appropriate portion of such
Temporary Global Security for an interest in the Permanent Global Security
except as provided in the next paragraph.

         Interest, if any, payable on a Security represented by a Temporary
Global Security in respect of an interest payment date occurring prior to the
Exchange Date will be paid to Euro-clear and CEDEL, as the case may be, with
respect to that portion of such Temporary Global Security held for its account;
provided, however, that no interest will be paid to Euroclear and CEDEL, as the
case may be, until delivery by it to the Trustee of a certificate in form and
substance acceptable to the Company, dated no earlier than such interest
payment date.  Such a certificate of Euro-clear or CEDEL, as the case may be,
shall be based on certificates of their Account Holders in form and substance
acceptable to the Company, and dated no earlier than 5 days prior to such
interest payment date.  The delivery to the Trustee by Euro-clear or CEDEL of
any such certificate may be relied upon by the Company and the Trustee as
conclusive evidence that a corresponding certificate or certificates has or
have been delivered to Euro-clear or CEDEL, as the case may be, pursuant to the
terms of this Indenture.  Each of Euro- clear or CEDEL will in such
circumstances credit the interest received by it in respect of such





                                      -19-
<PAGE>   20

Security represented by such Temporary Global Security to the accounts of or
for the beneficial owners thereof.

         The Permanent Global Securities will provide that interest, if any,
payable in respect of any interest payment date will be paid to each of
Euro-clear and CEDEL with respect to that portion of such Permanent Global
Security held for its account.  Each of Euro-clear and CEDEL will in such
circumstances credit the interest received by it in respect of such Permanent
Global Security to the accounts of or for the beneficial owners thereof.

         Interest, if any, will be payable in respect of Definitive Securities
upon the presentation and surrender of the appropriate coupons appertaining
thereto.

         (k)  Notwithstanding anything contained herein to the contrary, any
payment of principal of or interest on any Security may be made in the manner
specified on the form of such Security.

SECTION 2.6.  Paying Agent to Hold Money in Trust.

         The Company shall require each Paying Agent other than the Trustee to
agree in writing that the Paying Agent will hold in trust, for the benefit of
Securityholders of any or all Series of Securities, or the Trustee, all money
held by the Paying Agent for the payment of principal of or interest on such
Series of Securities, and that the Paying Agent will notify the Trustee of any
default by the Company in the making of any such payment.  While any such
default continues, the Trustee may require a Paying Agent to pay all money held
by it to the Trustee.  If the Company or a subsidiary thereof acts as Paying
Agent, it shall segregate the money held by it for the payment of principal or
interest on any Series of Securities and hold such money as a separate trust
fund.  The Company at any time may require a Paying Agent to pay all money held
by it to the Trustee.  Upon so doing the Paying Agent shall have no further
liability for the money so paid.

SECTION 2.7.  Securityholder Lists; Ownership of Securities.

         (a)  The Trustee shall preserve in as current a form as is reasonably
practicable the most recent list available to it of the names and addresses of
Holders of each Series of Securities.  If the Trustee is not the Registrar, the
Company shall furnish to the Trustee semiannually on or before the last day of
June and December in each year, and at such other times as the Trustee may
request in writing, a list, in such form and as of such date as the Trustee may
reasonably require, containing all the information in the possession or control
of the Registrar, the Company or any of its Paying Agents other than the
Trustee as to the names and addresses of Holders of each such Series of
Securities.  If there are Unregistered Securities of any Series outstanding,
even if the Trustee is the Registrar, the Company shall furnish to the Trustee
such a list containing such information with respect to Holders of such
Unregistered Securities only.

         (b)  Ownership of Registered Securities of a Series shall be proved by
the register for such Series kept by the Registrar.  Ownership of Unregistered
Securities may be proved by the production of such Unregistered Securities or
by a certificate or affidavit executed by the person holding such Unregistered
Securities or by a depositary with whom such Unregistered Securities were
deposited, if the certificate or affidavit is satisfactory to the Trustee.  The
Company, the Trustee and any agent of





                                      -20-
<PAGE>   21

the Company may treat the bearer of any Unregistered Security or coupon and the
person in whose name a Registered Security is registered as the absolute owner
thereof for all purposes.

SECTION 2.8.  Transfer and Exchange.

         (a)  Where Registered Securities of a Series are presented to the
Registrar with a request to register their transfer or to exchange them for an
equal principal amount of Registered Securities of the same Series and date of
maturity of other authorized denominations, the Registrar shall, unless
otherwise restricted by the provisions of Section 2.15, register the transfer
or make the exchange if its customary requirements for such transactions are
met.

         (b)  If both Registered and Unregistered Securities are authorized for
a Series of Securities and the terms of such Securities permit, (i)
Unregistered Securities may be exchanged for an equal principal amount of
Registered or Unregistered Securities of the same Series and date of maturity
in any authorized denominations upon delivery to the Registrar (or a Paying
Agent, if the exchange is for Unregistered Securities) of the Unregistered
Security with all unmatured coupons and all matured coupons in default
appertaining thereto and if all other requirements of the Registrar (or such
Paying Agent) and such Securities for such exchange are met, and (ii)
Registered Securities may be exchanged for an equal principal amount of
Unregistered Securities of the same Series and date of maturity in any
authorized denominations (except that any coupons appertaining to such
Unregistered Securities which have matured and have been paid shall be
detached) upon delivery to the Registrar of the Registered Securities and if
all other requirements of the Registrar (or such Paying Agent) and such
Securities for such exchange are met.

         Notwithstanding the foregoing, the exchange of Unregistered Securities
for Registered Securities or Registered Securities for Unregistered Securities
will be subject to the satisfaction of the provisions of United States laws and
regulations in effect at the time of such exchange, and no exchange of
Registered Securities for Unregistered Securities will be made until the
Company has notified the Trustee and the Registrar that, as a result of such
exchange, the Company would not suffer adverse consequences under such law or
regulations.

         (c)  To permit registrations of transfers and exchanges, the Trustee
shall, unless otherwise restricted by the provisions of Section 2.15,
authenticate Securities upon surrender of Securities for registration of
transfer or for exchange as provided in this Section.  The Company will make
any charge for any registration of transfer or exchange but may require the
payment by the party requesting such registration of transfer exchange of a sum
sufficient to cover any tax or other governmental charge payable in connection
therewith, but not for any exchange pursuant to Section 2.12, 3.6 or 9.5.

         (d)  Neither the Company nor the Registrar shall be required (i) to
issue, register the transfer of or exchange Securities of any Series for the
period of 15 days immediately preceding the selection of any such Securities to
be redeemed and ending at the close of business on the first publication of the
relevant notice of redemption, or (ii) to register the transfer of or exchange
Securities of any Series selected, called or being called for redemption as a
whole or the portion being redeemed of any such Securities selected, called or
being called for redemption in part.

         (e)  Notwithstanding the foregoing, no Securities of one Tranche may
be transferred or exchanged for Securities of any other Tranche.





                                      -21-
<PAGE>   22

         (f)  Unregistered Securities or any coupons appertaining thereto shall
be transferable by delivery.

SECTION 2.9.  Replacement Securities.

         (a)  If a mutilated Security or a Security with a mutilated coupon
appertaining to it is surrendered to the Trustee, the Company shall issue and
the Trustee shall authenticate and deliver in exchange therefor a replacement
Registered Security, if such surrendered security was a Registered Security, or
a replacement Unregistered Security with coupons corresponding to the coupons
appertaining to the surrendered Security, if such surrendered Security was an
Unregistered Security, of the same Series and date of maturity, if the
Trustee's requirements are met.

         (b)  If the Holder of a Security claims that the Security or any
coupon appertaining thereto has been lost, destroyed or wrongfully taken, the
Company shall issue and the Trustee shall authenticate a replacement Registered
Security, if such Holder's claim pertains to a Registered Security, or a
replacement Unregistered Security with coupons corresponding to the coupons
appertaining to the lost, destroyed or wrongfully taken Unregistered Security
or the Unregistered Security to which such lost, destroyed or wrongfully taken
coupon appertains, if such Holder's claim pertains to an Unregistered Security,
of the same Series and date of maturity, if the Trustee's requirements are met;
provided, however, that the Holder shall furnish to the Company and to the
Trustee evidence to their satisfaction of the destruction, loss or theft of
such Security and of the ownership thereof, and that the Trustee or the Company
may require any such Holder to provide to the Trustee or the Company security
or indemnity sufficient in the judgment of the Company and the Trustee to
protect the Company, the Trustee, any Agent or any Authenticating Agent from
any loss which any of them may suffer if a Security is replaced.  The Company
and the Trustee may charge the party requesting a replacement Security for its
expenses in replacing a Security.

         (c)  In case any Security which has matured or is about to mature
shall become mutilated or be destroyed, lost or stolen, the Company may,
instead of issuing a substitute Security, pay or authorize the payment of such
Security (without surrender thereof except in the case of a mutilated Security)
if the applicant for such payment shall furnish to the Company such security or
indemnity as it may require to save it harmless and, in case of destruction,
loss or theft, evidence to the satisfaction of the Company of the destruction,
loss or theft of such Security and of the ownership thereof.

         (d)  Every substituted Security issued pursuant to the provisions of
this Section 2.9 by virtue of the fact that any Security is mutilated,
destroyed, lost or stolen shall, with respect to such Security, constitute an
additional contractual obligation of the Company, whether or not the destroyed,
lost or stolen Security shall at any time be enforceable by anyone, and shall
be entitled to all the benefits of this Indenture equally and proportionately
with any and all other Securities duly issued under this Indenture.  All
Securities shall be held and owned upon the express condition that (to the
extent lawful) the foregoing provisions shall be exclusive with respect to the
replacement or payment of mutilated, destroyed, lost or stolen Securities and
shall preclude any and all other rights or remedies, notwithstanding any law or
statute now existing or hereafter enacted to the contrary with respect to the
replacement or payment of negotiable instruments or other securities without
their surrender.

         (e)  Notwithstanding the foregoing, a Security of one Tranche may not
be replaced with a Security of any other Tranche.





                                      -22-
<PAGE>   23

SECTION 2.10.  Outstanding Securities.

         (a)  Securities outstanding at any time are all Securities
authenticated and delivered by the Trustee in accordance with the provisions of
this Indenture, except:

         (i)  Those cancelled by the Trustee and those delivered to it for
cancellation;

         (ii)  Securities which have been paid pursuant to Section 2.9 or in
exchange for or in lieu of which other Securities have been authenticated and
delivered pursuant to this Indenture, unless proof satisfactory to the Trustee
is presented that any such Securities are held by bona fide Holders in due
course; and

         (iii)  Securities or portions thereof for whose payment, redemption or
repayment at the option of the Holder money in the necessary amount has been
theretofore deposited with the Trustee or any Paying Agent (as defined in
Section 2.4) (other than the Company) 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 Securities; provided that, if such Securities or portions
thereof are to be redeemed, notice of such redemption has been duly given
pursuant to this Indenture or provision therefor satisfactory to the Trustee
has been made.

         (b)  A Security does not cease to be outstanding because the Company
or an Affiliate holds the Security.

         (c)  In determining whether the Holders of the requisite principal
amount of outstanding Securities of any Series have given any request, demand,
authorization, direction, notice, consent or waiver hereunder, or whether
sufficient funds are available for redemption or for any other purpose, the
principal amount of an Original Issue Discount Security that shall be deemed to
be outstanding for such purposes shall be the amount of the principal thereof
that would be due and payable as of the date of such determination upon a
declaration of acceleration of the maturity thereof pursuant to Section 6.2 or
6.3 and the principal amount of any Securities denominated in a Foreign
Currency or ECU that shall be deemed to be outstanding for such purposes shall
be determined by converting the Specified Foreign Currency or the Specified
Amount of each Component Currency into Dollars at the Market Exchange Rate as
of the date of such determination.

SECTION 2.11.  Securities Held by the Company or an Affiliate.

         In determining whether the Holders of the requisite principal amount
of Securities of any Series have concurred in any direction, waiver or consent,
Securities of such Series owned by the Company or an Affiliate shall be
disregarded, except that for the purposes of determining whether the Trustee
shall be protected in relying on any such direction, waiver or consent, only
Securities of such Series which the Trustee knows are so owned shall be so
disregarded.

SECTION 2.12.  Temporary Securities.

         (a)  Until definitive Registered Securities of any Series are ready
for delivery, the Company may prepare and execute and the Trustee shall
authenticate temporary Registered Securities of such Series.  Temporary
Registered Securities of any Series shall be substantially in the form of
definitive





                                      -23-
<PAGE>   24

Registered Securities of such Series but may have variations that the Company
considers appropriate for temporary Securities.  Every temporary Registered
Security shall be executed by the Company and authenticated by the Trustee, and
registered by the Registrar, upon the same conditions, and with like effect, as
a definitive Registered Security.  Without unreasonable delay, the Company
shall prepare and the Trustee shall authenticate definitive Registered
Securities of the same Series and date of maturity in exchange for temporary
Registered Securities.

         (b)  Until definitive Unregistered Securities of any Series are ready
for delivery, the Company may prepare and execute and the Trustee shall
authenticate one or more temporary Unregistered Securities, which may have
coupons attached or which may be in the form of a single temporary global
Unregistered Security of that Series without coupons.  The temporary
Unregistered Security or Securities of any Series shall be substantially in the
form approved by or pursuant to a Board Resolution or one or more Indentures
supplemental hereto and shall be delivered to one of the Paying Agents located
outside the United States or to such other person or persons as the Company
shall direct against such certification as the Company may from time to time
prescribe by or pursuant to a Board Resolution.  The temporary Unregistered
Security or Securities of a Series shall be executed by the Company and
authenticated by the Trustee upon the same conditions, and with like effect, as
a definitive Unregistered Security of such Series, except as provided herein or
therein.  A temporary Unregistered Security or Securities shall be exchangeable
for definitive Unregistered Securities (which may be Global Securities), at the
time and on the conditions, if any, specified in the temporary Security.

         Upon any exchange of a part of a temporary Unregistered Security of a
Series for definitive Unregistered Securities of such Series, the temporary
Unregistered Security shall be endorsed by the Trustee or Paying Agent to
reflect the reduction of its principal amount by an amount equal to the
aggregate principal amount of definitive Unregistered Securities of such Series
so exchanged and endorsed.

SECTION 2.13.  Cancellation.

         The Company at any time may deliver Securities and coupons to the
Trustee for cancellation.  The Registrar and the Paying Agent shall forward to
the Trustee any Securities and coupons surrendered to them, for registration of
transfer, for exchange or payment or for credit against any payment in respect
of a sinking or analogous fund.  The Trustee shall cancel all Securities and
coupons surrendered for registration of transfer, or for exchange, payment or
cancellation and may dispose of cancelled Securities and coupons as the Company
directs; provided, however, that any Unregistered Securities of a Series
delivered to the Trustee for exchange prior to maturity shall be retained by
the Trustee for reissue as provided herein or in the Securities of such Series.
The Company may not issue new Securities to replace Securities that it has paid
or delivered to the Trustee for cancellation.

SECTION 2.14.  Defaulted Interest.

         If the Company defaults on a payment of interest on a Series of
Securities, it shall pay the defaulted interest as provided in such Securities
or in any lawful manner not inconsistent with the requirements of any
securities exchange on which such Securities may be listed and acceptable to
the Trustee.  With respect to any Registered Securities, the Trustee may pay
defaulted interest, plus any interest payable on the defaulted interest, to the
Holders of such Registered Securities on a subsequent





                                      -24-
<PAGE>   25

special record date.  The Company shall fix the record date and the payment
date.  At least 15 days before the record date, the Company shall mail to such
Holders a notice that states the record date, the payment date and the amount
of interest to be paid.

SECTION 2.15.  Securities Issuable in the Form of a Global Security.

         (a)  If the Company shall establish pursuant to Section 2.2 that the
Securities of a particular Series are to be issued as one or more Global
Securities, then the Company shall execute and the Trustee shall, in accordance
with Section 2.3 and the Company Order delivered to the Trustee thereunder,
authenticate and deliver one or more Global Securities which (i) shall
represent, and shall be denominated in an amount equal to the aggregate
principal amount of, all of the Outstanding Securities of such Series, (ii)
shall be registered in the name of the Depositary for such Global Security or
its nominee, (iii) shall be delivered by the Trustee to the Depositary or
pursuant to the Depositary's instruction and (iv) shall bear a legend
substantially to the following effect: "Except as otherwise provided in Section
2.15 of the Indenture, this Security may be transferred, in whole but not in
part, only to another nominee of the Depositary or to a successor Depositary or
to a nominee of such successor Depositary."

         (b)  Notwithstanding any other provision of this Section 2.15 or of
Section 2.4, unless and until it is exchanged in whole or in part for
Securities in definitive form, the Global Security of a Series may be
transferred, in whole but not in part and in the manner provided in Section
2.4, to another nominee of the Depositary for such Series, or to a successor
Depositary for such Series selected or approved by the Company or to a nominee
of such successor Depositary.

         (c)  If at any time the Depositary for a Series of Securities notifies
the Company that it is unwilling or unable to continue as Depositary for such
Series or if at any time the Depositary for such Series shall no longer be
registered or in good standing under the Securities Exchange Act of 1934, as
amended, or other applicable statute or regulation and a successor Depositary
for such Series is not appointed by the Company within 90 days after the
Company receives such notice or becomes aware of such condition, as the case
may be, this Section 2.15 shall no longer be applicable to the Security of such
Series and the Company will execute, and the Trustee will authenticate and
deliver, Securities of such Series in definitive registered form without
coupons, or in definitive bearer form with coupons, as applicable, in
authorized denominations, and in an aggregate principal amount equal to the
principal amount of the Global Security of such Series in exchange for such
Global Security.  In addition, the Company may at any time determine that some
or all of the Securities of any Series shall no longer be represented by a
Global Security.  In such event, the Company will execute and the Trustee, upon
receipt of an Officers' Certificate evidencing such determination by the
Company, will authenticate and deliver Securities of such Series in definitive
form, in authorized denominations, to (i) the Person specified by such
Depositary equal to and in exchange for such Person's beneficial interest in
the Global Security and (ii) to such Depositary a new Global Security in a
denomination equal to the difference, if any, between the principal amount of
the surrendered Global Security and the aggregate principal amount of
definitive Securities delivered to Holders thereof, or interests in applicable
portions thereof.  Upon the exchange of the Global Security for all such
Securities in definitive form, in authorized denominations, the surrendered
Global Security shall be cancelled by the Trustee.  Such Securities in
definitive registered form issued in exchange for the Global Security or
portion thereof pursuant to this Section 2.15(c) shall be issued in such
authorized denominations as the Depositary, pursuant to instructions from its
direct or indirect participants or otherwise, shall instruct the Trustee.





                                      -25-
<PAGE>   26

The Trustee shall deliver such Securities to the Persons in whose name such
Securities are so registered.  Securities in definitive bearer form shall be
issued in exchange for the Global Security or portion thereof in the manner
provided for the issuance of Unregistered Securities in Section 2.12(b) above.

SECTION 2.16.  Unregistered Securities Represented by Global Security.

         (a)  Unless otherwise specified by the applicable Company Order, the
Securities of any Series issued as Unregistered Securities will initially be
represented by one or more temporary global Securities, without interest
coupons (each, a "Temporary Global Security").  Upon receipt of a Company Order
with respect to a Series of Securities, the Trustee, in accordance with such
Company Order, shall (1) insert on the face of the Temporary Global Security
for such Series (a) the principal amount, (b) the issue date, (c) the maturity
date, (d) the interest rate or the method of determining such rate, and (e) any
other terms required by the form of the Security of such Series to be inserted,
as specified in the Company Order, (2) manually authenticate such Temporary
Global Security and (3) deliver such Temporary Global Security to the
Depositary designated by the Company pursuant to either Sections 2.2 or 2.15.

         (b)  On or after the date which is 45 days after the issue date of a
Temporary Global Security (the "Exchange Date"), the Securities represented by
such Temporary Global Security may be exchanged for Securities to be
represented thereafter by a single permanent global Security, without interest
coupons (a "Permanent Global Security"), provided, however, that no Security
represented by a Temporary Global Security shall be exchanged for a Security
represented by a Permanent Global Security unless the Trustee shall have
received a certificate (a "Final Certificate"), in form and substance
reasonably satisfactory to the Company, signed by Euro-clear or CEDEL, as the
case may be, in respect of such Security.  On or after the Exchange Date and
upon receipt of the Final Certificate in respect of a Security, dated no
earlier than such Exchange Date, the Trustee shall (1) endorse the Temporary
Global Security to reflect the reduction of its principal amount by the
aggregate principal amount of such Security, (2) insert on the face of the
Permanent Global Security for such Series (a) the principal amount, (b) the
issue date, (c) the maturity date, (d) the interest rate or method of
determining such rate, and (e) any other terms required by the form of the
Security of such Series to be inserted, as set forth on the face of the
Temporary Global Security for such Series, (3) manually authenticate such
Permanent Global Security and (4) deliver such Permanent Global Security to the
Depositary to be held outside the United States for the accounts of Euro-clear
and CEDEL, for credit to the respective accounts at Euro-clear and CEDEL
designated by or on behalf of the beneficial owner of such Security.  Final
Certificates of Euro-clear or CEDEL, as the case may be, shall be based on
certificates of the account holders listed in the records of Euro-clear or
CEDEL, as the case may be, as being entitled to all or any portion of the
applicable Temporary Global Security (as to each, its "Account Holder").  An
Account Holder of Euro-clear or CEDEL, as the case may be, desiring to effect
the exchange of an interest in a Temporary Global Security for an interest in a
Permanent Global Security shall instruct Euro-clear or CEDEL, as the case may
be, to request such exchange on its behalf and shall deliver to Euro-clear or
CEDEL, as the case may be, a certificate in form and substance reasonably
satisfactory to Euro-clear or CEDEL, as applicable, and dated no earlier than
10 days prior to the Exchange Date.  Until so exchanged, Temporary Global
Securities shall in all respects be entitled to the same benefits under this
Indenture as Permanent Global Securities of the same Series authenticated and
delivered hereunder, except as to payment of interest, if any.





                                      -26-
<PAGE>   27

         (c)  The delivery to the Trustee by Euro-clear or CEDEL of any Final
Certificate referred to above may be relied upon by the Company and the Trustee
as conclusive evidence that a corresponding certificate or certificates has or
have been delivered to Euro-clear or to CEDEL, as the case may be, pursuant to
the terms of this Indenture.

         (d)  At any time, upon 30 days' notice to the Trustee by Euro-clear or
CEDEL, as the case may be, acting at the request of or on behalf of the
beneficial owner, a Security represented by a Permanent Global Security may be
exchanged for a definitive Security or Securities (each a "Definitive
Security").  On the thirtieth day following receipt by the Trustee of such
notice with respect to a Security, or, if such day is not a Business Day, the
next succeeding Business Day, the Trustee shall (1) endorse the applicable
Permanent Global Security to reflect the reduction of its principal amount by
the aggregate principal amount of such Security, (2) cause the terms of such
Security and coupons, if any, to be entered on a Definitive Security, (3)
manually authenticate such Definitive Security, and (4) deliver such Definitive
Security outside the United States to Euro-clear or CEDEL, as the case may be,
for or on behalf of the beneficial owner thereof.

         (e)  Any exchange of a portion of a Temporary Global Security for a
portion of a Permanent Global Security or of a portion of a Permanent Global
Security for a Definitive Security with coupons, if any, shall be made at the
Company's expense and without any charge therefor to the Holder or beneficial
owner of such Security; provided, however, that a person accepting the delivery
of Definitive Securities with coupons, if any, must bear the risk and cost of
insurance, postage, transportation and the like in the event that such person
does not receive such Definitive Securities with coupons, if any, in person at
the London office of the Trustee, if any, or at the London office of any Paying
Agent.  Until so exchanged, Temporary Global Securities and Permanent Global
Securities shall in all respects be entitled to the same benefits under this
Indenture as Definitive Securities of the same Series authenticated and
delivered hereunder.

         (f)  The provisions of this Section are subject to any restrictions or
limitations on the issuance and delivery of Securities of any Series that may
be established pursuant to Section 2.2 (including any provision that Securities
of such Series initially issued in the form of a Temporary Global Security to
be delivered outside the United States and the procedures pursuant to which a
Permanent Global Security or Definitive Securities of such Series would be
issued in exchange for a Temporary Global Security.)

         (g)  If the form or terms of the Securities of a Series have been
established in or pursuant to one or more Board Resolutions as permitted by
Section 2.2, in authenticating such Securities and accepting the additional
responsibilities under this Indenture in relation to such Securities, the
Trustee shall be entitled to receive, and shall be fully protected in relying
upon, an Opinion of Counsel stating:

                 (i)  if the form of such Securities and coupons, if any,
         appertaining thereto has been established by or pursuant to a Board
         Resolution as permitted by Section 2.2, that such form has been
         established in conformity with the provisions of this Indenture;

                 (ii)  if the terms of such Securities and coupons, if any,
         appertaining thereto have been established by or pursuant to a Board
         Resolution as permitted by Section 2.2, that such terms have been
         established in conformity with the provisions of this Indenture; and





                                      -27-
<PAGE>   28

                 (iii)  that such Securities and coupons, if any, appertaining
         thereto, when authenticated and delivered by the Trustee and issued by
         the Company in the manner and subject to any conditions specified in
         such Opinion of Counsel, will constitute valid and legally binding
         obligations of the Company, enforceable in accordance with their
         terms, subject, as to enforcement, to bankruptcy, insolvency,
         reorganization, moratorium and other laws of general applicability
         relating to or affecting the enforcement of creditors' rights and to
         general equity principles.

If such form or terms have been so established, the Trustee shall not be
required to authenticate such Securities if the issuance of such Securities
pursuant to this Indenture shall affect the Trustee's own rights, duties or
immunities under the Securities and this Indenture or otherwise in a manner
which is not reasonably acceptable to the Trustee.


                                  ARTICLE III

                   REDEMPTION OF SECURITIES AND SINKING FUNDS

SECTION 3.1.  Notice to Trustee.

         The Company may, with respect to any Series of Securities, reserve the
right to redeem and pay the Series of Securities or any part thereof, or may
covenant to redeem and pay the Series of Securities or any part thereof, before
maturity at such time and on such terms as provided for in such Securities.  If
a Series of Securities is redeemable and the Company wants or is obligated to
redeem all or part of the Series of Securities pursuant to the terms of such
Securities, it shall notify the Trustee of the redemption date and the
principal amount of the Series of Securities to be redeemed.  The Company shall
give such notice at least 60 days before the redemption date (or such shorter
notice as may be acceptable to the Trustee).

SECTION 3.2.  Selection of Securities to be Redeemed.

         If less than all the Securities of a Series are to be redeemed, the
Trustee, not more than 60 days prior to the redemption date, shall select the
Securities of the Series to be redeemed in such manner as the Trustee shall
deem fair and appropriate.  The Trustee shall make the selection from
Securities of the Series that are outstanding and that have not previously been
called for redemption.  Securities of the Series and portions of them selected
by the Trustee shall be in amounts of $1,000 or integral multiples of $1,000
or, with respect to Securities of any Series issuable in other denominations
pursuant to Section 2.2 (a) (8), in amounts equal to the minimum principal
denomination for each such Series and integral multiples thereof.  Provisions
of this Indenture that apply to Securities of a Series called for redemption
also apply to portions of Securities of that Series called for redemption.  The
Trustee shall promptly notify the Company in writing of the Securities selected
for redemption and, in the case of any Securities selected for partial
redemption, the principal amount thereof to be redeemed.

SECTION 3.3.  Notice of Redemption.





                                      -28-
<PAGE>   29

         (a)  At least 30 days but not more than 60 days before a redemption
date, the Company shall mail a notice of redemption by first-class mail to each
Holder of Registered Securities that are to be redeemed.

         (b)  If Unregistered Securities are to be redeemed, the Company shall
cause notice of redemption to be published in an Authorized Newspaper in each
of The City of New York, London and, if such Securities to be redeemed are
listed on The Luxembourg Stock Exchange, Luxembourg once in each of four
successive calendar weeks, the first publication to be not less than 30 nor
more than 60 days before the redemption date.

         (c)  All notices shall identify the Series of Securities to be
redeemed and shall state:

                 (1)  the redemption date;

                 (2)  the redemption price;

                 (3)  if less than all the outstanding Securities of a Series 
         are to be redeemed, the identification (and, in the case of partial
         redemption, the principal amounts) of the particular Securities to
         be redeemed;

                 (4)  in case any Security is to be redeemed in part only, the
         notice shall state the portion of the principal amount thereof to be
         redeemed and shall state that on and after the date fixed for
         redemption, upon presentation and surrender of such Security, a new
         Security or Securities in principal amount equal to the unredeemed
         portion thereof will be issued;

                 (5)  the name and address of the Paying Agent;

                 (6)  that Securities of the Series called for redemption and 
         all unmatured coupons, if any, appertaining thereto must be 
         surrendered to the Paying Agent to collect the redemption price;

                 (7)  that interest on Securities of the Series called for
         redemption ceases to accrue on and after the redemption date;

                 (8)  whether such redemption is pursuant to the mandatory or
         optional sinking fund, or both; and

                 (9)  the CUSIP Number, if applicable.

         At the Company's request, the Trustee shall give the notice of
redemption in the Company's name and at its expense.  Any notice which is
mailed in the manner herein provided shall be conclusively presumed to have
been duly given, whether or not the Holder receives the notice.  In any case,
failure duly to give notice by mail, or any defect in the notice, to the Holder
of any Security designated for redemption as a whole or in part shall not
affect the validity of the proceedings for the redemption of any other
Security.





                                      -29-
<PAGE>   30

SECTION 3.4.  Effect of Notice of Redemption.

         Once notice of redemption is mailed or published, Securities of a
Series called for redemption become due and payable on the redemption date, and
unless the Company shall default in the payment of such Securities at the
redemption price, together with interest accrued to said date, interest on the
Securities or portions of the Securities so called for redemption shall cease
to accrue on and after said date.  Upon surrender to the Paying Agent of such
Securities together with all unmatured coupons, if any, appertaining thereto,
such Securities shall be paid at the redemption price plus interest accrued to
the redemption date, but installments of interest due on or prior to the
redemption date will be payable, in the case of Unregistered Securities, to the
bearers of the coupons for such interest upon surrender thereof, and, in the
case of Registered Securities, to the Holders of such Securities of record at
the close of business on the relevant record dates.

SECTION 3.5.  Deposit of Redemption Price.

         On or before the redemption date, the Company shall deposit with, or
at the direction of, the Trustee money sufficient to pay the redemption price
of and (unless the redemption date shall be an interest payment date) interest
accrued to the redemption date on all Securities to be redeemed on that date,
in the currencies or currency units in which such redemption price shall be
payable.

SECTION 3.6.  Securities Redeemed in Part.

         Upon surrender of a Security that is redeemed in part, the Company
shall issue and the Trustee shall authenticate for the Holder of the Security a
new Security or Securities of the same Series, in the same form and the same
maturity in authorized denominations equal in aggregate Principal amount to the
unredeemed portion of the Security surrendered.

SECTION 3.7.  Securities Acquired by the Company.

         If the Company shall acquire any of the Securities or coupons, such
acquisition shall not operate as a redemption or satisfaction of the
indebtedness or rights represented by such Securities or coupons unless and
until the same are delivered or surrendered to the Trustee for cancellation.

SECTION 3.8.  Mandatory and Optional Sinking Funds.

         The minimum amount of any sinking fund payment provided for by the
terms of any Series of Securities is herein referred to as a "mandatory sinking
fund payment," and any payment in excess of such minimum amount provided for by
the terms of any Series of Securities is herein referred to as an "optional
sinking fund payment." The date on which a sinking fund payment is to be made
is herein referred to as the "sinking fund payment date."

         In lieu of making all or any part of any mandatory sinking fund
payment with respect to any Series of Securities in cash, the Company may at
its option (a) deliver to the Trustee Securities of such Series theretofore
purchased or otherwise acquired (except upon redemption pursuant to the
mandatory sinking fund) by the Company or receive credit for Securities of such
Series (not previously so credited) theretofore purchased or otherwise acquired
(except as aforesaid) by the Company and delivered to the Trustee for
cancellation pursuant to Section 2.13, (b) receive credit for optional sinking





                                      -30-
<PAGE>   31

fund payments (not previously so credited) made pursuant to this Section, or
(c) receive credit for Securities of such Series (not previously so credited)
redeemed by the Company through any optional redemption provision contained in
the terms of such Series.  Securities so delivered or credited shall be
received or credited by the Trustee at the sinking fund redemption price
specified in such Securities.

         On or before the sixtieth day next preceding each sinking fund payment
date for any Series, the Company will deliver to the Trustee an Officers'
Certificate (a) specifying the portion of the mandatory sinking fund payment to
be satisfied by payment of cash and the portion to be satisfied by credit of
Securities of such Series, (b) stating that none of the Securities of such
Series has theretofore been so credited, (c) stating that no defaults in the
payment of interest or Events of Default with respect to such Series have
occurred (which have not been waived or cured) and are continuing, (d) stating
whether or not the Company intends to exercise its right to make an optional
sinking fund payment with respect to such Series and, if so, specifying the
amount of such optional sinking fund payment which the Company intends to pay
on or before the next succeeding sinking fund payment date and (e) specifying
such sinking fund payment date.  Any Securities of such Series to be credited
and required to be delivered to the Trustee in order for the Company to be
entitled to credit therefor as aforesaid which have not theretofore been
delivered to the Trustee shall be delivered for cancellation pursuant to
Section 2.13 to the Trustee with such written statement (or reasonably promptly
thereafter if acceptable to the Trustee).  Such written statement shall be
irrevocable and upon its receipt by the Trustee the Company shall become
unconditionally obligated to make all the cash payment or payments therein
referred to, if any, on or before the next succeeding sinking fund payment
date.  Failure of the Company, on or before any such sixtieth day, to deliver
such written statement and Securities specified in this paragraph, if any,
shall not constitute a default but shall constitute, on and as of such date,
the irrevocable election of the Company (i) that the mandatory sinking fund
payment for such Series due on the next succeeding sinking fund payment date
shall be paid entirely in cash without the option to deliver or credit
Securities of such Series in respect thereof and (ii) that the Company will
make no optional sinking fund payment with respect to such Series as provided
in this Section.

         If the sinking fund payment or payments (mandatory or optional or
both) to be made in cash on the next succeeding sinking fund payment date plus
any unused balance of any preceding sinking fund payments made in cash shall
exceed $50,000 (or a lesser sum if the Company shall so request) with respect
to the Securities of any particular Series, such cash shall be applied on the
next succeeding sinking fund payment date to the redemption of Securities of
such Series at the sinking fund redemption price together with accrued interest
to the date fixed for redemption.  If such amount shall be $50,000 or less and
the Company makes no such request then it shall be carried over until a sum in
excess of $50,000 is available.  The Trustee shall select, in the manner
provided in Section 3.2, for redemption on such sinking fund payment date a
sufficient principal amount of Securities of such Series to absorb said cash,
as nearly as may be possible, and shall (if requested in writing by the
Company) inform the Company of the serial numbers of the Securities of such
Series (or portions thereof) so selected.  Securities of any Series which are
(a) owned by the Company or an entity known by the Trustee to be directly or
indirectly controlling or controlled by or under direct or indirect common
control with the Company, as shown by the Security register, and not known to
the Trustee to have been pledged or hypothecated by the Company or any such
entity or (b) identified in an Officers' Certificate at least 60 days prior to
the sinking fund payment date as being beneficially owned by, and not pledged
or hypothecated by, the Company or an entity directly or indirectly controlling
or controlled by or under direct or indirect common control with the Company
shall be excluded from Securities of such Series eligible for selection for
redemption.  The Trustee, in the name and at the expense of the Company (or





                                      -31-
<PAGE>   32

the Company, if it shall so request the Trustee in writing) shall cause notice
of redemption of the Securities of such Series to be given in substantially the
manner provided in Section 3.3 (and with the effect provided in Section 3.4)
for the redemption of Securities of such Series in part at the option of the
Company.  The amount of any sinking fund payments not so applied or allocated
to the redemption of Securities of such Series shall be added to the next cash
sinking fund payment for such Series and, together with such payment, shall be
applied in accordance with the provisions of this Section.  Any and all sinking
fund moneys held on the stated maturity date of the Securities of any
particular Series (or earlier, if such maturity is accelerated), which are not
held for the payment or redemption of particular Securities of such Series
shall be applied, together with other moneys, if necessary, sufficient for the
purpose, to the payment of the Principal of, and interest on, the Securities of
such Series at maturity.

         At least one Business Day before each sinking fund payment date, the
Company shall pay to the Trustee in cash or shall otherwise provide for the
payment of all interest accrued to the date fixed for redemption on Securities
to be redeemed on the next following sinking fund payment date.

         The Trustee shall not redeem or cause to be redeemed any Securities of
a Series with sinking fund moneys or mail any notice of redemption of
Securities for such Series by operation of the sinking fund during the
continuance of a Default in payment of interest on such Securities or of any
Event of Default except that, where the mailing of notice of redemption of any
Securities shall theretofore have been made, the Trustee shall redeem or cause
to be redeemed such Securities, provided that it shall have received from the
Company a sum sufficient for such redemption.  Except as aforesaid, any moneys
in the sinking fund for such Series at the time when any such Default or Event
of Default shall occur, and any moneys thereafter paid into such sinking fund,
shall, during the continuance of such Default or Event of Default, be deemed to
have been collected under Article Six and held for the payment of all such
Securities.  In case such Event of Default shall have been waived as provided
in Section 6.4 or the default cured on or before the sixtieth day preceding the
sinking fund payment date in any year, such moneys shall thereafter be applied
on the next succeeding sinking fund payment date in accordance with this
Section to the redemption of such Securities.

                                   ARTICLE IV

                      PARTICULAR COVENANTS OF THE COMPANY

SECTION 4.1.  Payment of Securities.

         The Company shall pay or cause to be paid the Principal of and
interest on the Securities on the dates and in the manner provided herein and
in the Securities.  An installment of Principal or interest shall be considered
paid on the date it is due if the Trustee or Paying Agent holds on that date
money designated for and sufficient to pay the installment.

         The Company shall pay interest on overdue Principal of a Security of
any Series at the rate of interest (or Yield to Maturity in the case of
Original Issue Discount Securities) borne by the Securities of that Series,
and, to the extent lawful, it shall pay interest on overdue installments of
interest at the same rate.





                                      -32-
<PAGE>   33

SECTION 4.2.  Reports by the Company.

         The Company covenants:

         (a)  to file with the Trustee, within 15 days after the Company is
required to file the same with the SEC, copies of the annual reports and of the
information, documents and other reports (or copies of such portions of any of
the foregoing as the SEC may from time to time by rules and regulations
prescribe) which the Company may be required to file with the SEC pursuant to
section 13 or section 15(d) of the Securities Exchange Act of 1934, as amended;
or, if the Company is not required to file information, documents or reports
pursuant to either of such sections, then to file with the Trustee and the SEC,
in accordance with rules and regulations prescribed from time to time by the
SEC, such of the supplementary and periodic information, documents and reports
which may be required pursuant to section 13 of the Securities Exchange Act of
1934, as amended, in respect of a security listed and registered on a national
securities exchange as may be prescribed from time to time in such rules and
regulations;

         (b)  to file with the Trustee and the SEC, in accordance with the
rules and regulations prescribed from time to time by the SEC, such additional
information, documents, and reports with respect to compliance by the Company
with the conditions and covenants provided for in this Indenture as may be
required from time to time by such rules and regulations; and

         (c)  to transmit by mail to all Holders of Securities within 30 days
after the filing thereof with the Trustee, in the manner and to the extent
provided in subsection (c) of Section 7.6, such summaries of any information,
documents and reports required to be filed by the Company pursuant to
subsections (a) and (b) of this Section 4.2 as may be required by rules and
regulations prescribed from time to time by the SEC.

SECTION 4.3.  Statement of Officers as to Default.

         The Company will deliver to the Trustee, on or before a date not more
than four months after the end of each of its fiscal years ending after the
date hereof during which any Securities are outstanding, an Officers'
Certificate stating that neither of the signers thereof has any knowledge after
due investigation of the existence of any Event of Default, or any event which
could with the passage of time or notice mature into an Event of Default, by
the Company under this Indenture or stating that they have knowledge of the
existence of such an event of which the signers have knowledge and the nature
thereof.

SECTION 4.4.  Filing with Listing Agent.

         If Unregistered Securities of any series are Outstanding, to file with
the listing agent of the Company with respect to such series such documents and
reports of the Company as may be required from time to time by the rules and
regulations of any stock exchange on which such Unregistered Securities are
listed.





                                      -33-
<PAGE>   34

                                   ARTICLE V

                             SUCCESSOR CORPORATION

SECTION 5.1.  When Company May Merge, etc.

         The Company may not consolidate with, or merge into, or be merged
into, or transfer or lease its properties and assets substantially as an
entirety to, any Person unless such Person is a corporation organized under the
laws of the United States, any State thereof or the District of Columbia, such
Person assumes by supplemental indenture all the obligations of the Company
under the Securities and any coupons appertaining thereto and under this
Indenture, after giving effect thereto, no Default or Event of Default shall
have occurred and be continuing and the Company shall have delivered to the
Trustee an Officers' Certificate and an Opinion of Counsel, each stating that
such consolidation, merger or conveyance, transfer or lease, as the case may
be, and such supplemental indenture comply with this Article and that all
conditions precedent herein provided for relating to such transaction have been
complied with.

SECTION 5.2.  Successor Corporation Substituted.

         Upon any consolidation by the Company with, or merger by the Company
into, any other corporation, or any conveyance, transfer or lease to, any
Person by the Company in accordance with Section 5.1. the successor corporation
formed by such consolidation or into which the Company is merged or to which
such conveyance, transfer or lease is made shall succeed to, and be substituted
for, and may exercise every right and power of, the Company under this
Indenture with the same effect as if such successor corporation had been named
as the Company in this Indenture, and thereafter, except in the case of a
conveyance by lease, the predecessor corporation shall be relieved of all
obligations and covenants under this Indenture.


                                   ARTICLE VI

                             DEFAULTS AND REMEDIES

SECTION 6.1.  Events of Default.

         An "Event of Default" occurs with respect to the Securities of any
Series if:

                 (1)  the Company defaults in the payment of interest on any
         Security of that Series when the same becomes due and payable and the
         Default continues for a period of 30 days;

                 (2)  the Company defaults in the payment of the Principal of
         any Security of that Series when the same becomes due and payable at
         maturity, upon redemption or otherwise;

                 (3)  the Company defaults in the payment of any sinking fund
         installment as and when the same becomes due and payable by the terms
         of the Series of Securities;

                 (4)  the Company fails to comply with any of its other
         agreements in the Securities of that Series, in this Indenture or in
         any supplemental indenture under which the Securities of that





                                      -34-
<PAGE>   35

Series may have been issued and the Default continues for the period
and after the notice specified below;

                 (5)  the Company pursuant to or within the meaning of any
                      Bankruptcy Law:

                          (A)  commences a voluntary case,

                          (B)  consents to the entry of an order for relief
                 against it in an involuntary case,

                          (C)  consents to the appointment of a Custodian of 
                 it or for all or substantially all of its property, or

                          (D)  makes a general assignment for the benefit of 
                 its creditors; or

                 (6)  a court of competent jurisdiction enters an order or
         decree under any Bankruptcy Law that:

                          (A)  is for relief against the Company in an 
         involuntary case,

                          (B)  appoints a Custodian of the Company or for all 
         or substantially all of its property, or

                          (C)  orders the liquidation of the Company, and the 
         order or decree remains unstayed and in effect for 90 days.

         The term "Bankruptcy Law" means Title 11, U.S. Code or any similar
federal or state law for the relief of debtors.  The term "Custodian" means any
receiver, trustee, assignee, liquidator or similar official under any
Bankruptcy Law.

         A Default under clause (4) is not an Event of Default until the
Trustee or the Holders of at least 25% in principal amount of all the
outstanding Securities of that Series notify the Company (and the Trustee in
the case of notification by such Holders) in writing of the Default and the
Company does not cure the Default within 90 days after receipt of the notice.
The notice must specify the Default, demand that it be remedied and state that
the notice is a "Notice of Default".

SECTION 6.2.  Acceleration.

         If an Event of Default occurs with respect to the Securities of any
Series and is continuing, the Trustee, by notice to the Company, or the Holders
of at least 25% in principal amount of all of the outstanding Securities of
that Series, by notice to the Company and to the Trustee, may declare the
Principal (or, if the 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, and any accrued interest on, all the Securities of
that Series to be due and payable.  Upon such declaration, such Principal (or,
in the case of Original Issue Discount Securities, such specified amount) and
any accrued interest shall be due and payable immediately.  The Holders of a
majority in principal amount of all of the Securities of that Series, by notice
to the Trustee, may rescind such a declaration and its consequences if the
rescission would not conflict with any judgment or decree and if all existing
Events of Default have been cured or





                                      -35-
<PAGE>   36

waived except nonpayment of Principal or interest that has become due solely
because of the acceleration.  In case the Trustee shall have proceeded to
enforce any right under this Indenture and such proceedings shall have been
discontinued or abandoned because of such waiver or rescission or annulment or
for any other reason or shall have been determined adversely to the Trustee,
then and in every such case the Company, the Trustee and the Holders of the
Securities shall be restored respectively to their former positions and rights
hereunder, and all rights, remedies and powers of the Company, the Trustee and
the Holders of the Securities shall continue as though no such proceedings had
been taken.

SECTION 6.3.  Other Remedies Available to Trustee.

         (a)  If an Event of Default occurs and is continuing, the Trustee may
pursue any available remedy to collect payment of Principal or interest on the
Securities of the Series that is in default or to enforce the performance of
any provision of the Securities of that Series or this Indenture.

         (b)  The Trustee may maintain a proceeding even if it does not possess
any of the Securities or does not produce any of them in the proceeding.  A
delay or omission by the Trustee or any Securityholder in exercising any right
or remedy accruing upon an Event of Default shall not impair the right or
remedy or constitute a waiver of or acquiescence in the Event of Default.  No
remedy is exclusive of any other remedy.  All available remedies are
cumulative.

SECTION 6.4.  Waiver of Existing Defaults.

         The Holders of a majority in principal amount of any Series of
Securities by notice to the Trustee may waive an existing Default with respect
to that Series and its consequences except a Default in the payment of the
Principal of or interest on any Security.

SECTION 6.5.  Control by Majority.

         The Holders of a majority in principal amount of the Securities of
each Series affected (with each such Series voting as a class) may direct the
time, method and place of conducting any proceeding for any remedy available to
the Trustee or exercising any trust or power conferred on it with respect to
the Securities of that Series.  However, the Trustee may refuse to follow any
direction that conflicts with law or this Indenture or that is unduly
prejudicial to the rights of the Securityholders of that Series.

SECTION 6.6.  Limitation on Suits by Securityholders.

         A Securityholder may pursue a remedy with respect to this Indenture or
the Securities of any Series only if:

                 (1)  the Holder gives to the Trustee written notice of a
         continuing Event of Default with respect to Securities of that Series;

                 (2)  the Holders of at least 25% in principal amount of the
         Securities of that Series make a written request to the Trustee to
         pursue the remedy;





                                      -36-
<PAGE>   37

                 (3)  such Holder or Holders offer to the Trustee indemnity
         satisfactory to the Trustee against any loss, liability or expense to
         be, or which may be, incurred by the Trustee in pursuing the remedy;

                 (4)  the Trustee does not comply with the request within 60
         days after receipt of the request and the offer of indemnity; and

                 (5)  during such 60-day period, the Holders of a majority in
         principal amount of the Securities of that Series do not give the
         Trustee a direction inconsistent with the request.

         A Securityholder of any Series may not use this Indenture to prejudice
the rights of another Securityholder of that Series or any other Series or to
obtain a preference or priority over another Securityholder of that Series or
any other Series.

SECTION 6.7.  Rights of Holders to Receive Payment.

         Notwithstanding any other provision of this Indenture, the right of
any Holder of a Security to receive payment of Principal and interest on the
Security, on or after the respective due dates expressed in the Security, and
the right of any Holder of a coupon to receive payment of interest due as
provided in such coupon, or to bring suit for the enforcement of any such
payment on or after such respective dates, shall not be impaired or affected
without the consent of such Holder.

SECTION 6.8.  Collection Suits by Trustee.

         If an Event of Default specified in Section 6.1 (1) or (2) occurs and
continues for the period, if any, specified therein, the Trustee may recover
judgment in its own name and as trustee of an express trust against the Company
for the whole amount of such Principal and interest then remaining unpaid.

SECTION 6.9.  Trustee May File Proofs of Claim.

         The Trustee may file such proofs of claim and other papers or
documents as may be necessary or advisable in order to have the claims of the
Trustee and the Securityholders allowed in any judicial proceedings relating to
the Company, its creditors or its property.

SECTION 6.10.  Priorities.

         If the Trustee collects any money pursuant to this Article, it shall
pay out the money in the following order:

                 FIRST:  to the Trustee for amounts due under Section 7.7;

                 SECOND:  to Holders of Securities in respect of which or for
         the benefit of which such money has been collected for amounts due and
         unpaid on such Securities for Principal and interest, ratably, without
         preference or priority of any kind, according to the amounts due and
         payable on such Securities for Principal and interest, respectively;
         and

                 THIRD:  to the Company.





                                      -37-
<PAGE>   38

         The Trustee may fix a record date (with respect to Registered
Securities) and payment date for any such payment to Holders of Securities.

SECTION 6.11.  Undertaking for Costs.

         In any suit for the enforcement of any right or remedy under this
Indenture or in any suit against the Trustee for any action taken or omitted by
it as Trustee, a court in its discretion may require the filing by any party
litigant in the suit of an undertaking to pay the costs of the suit, and the
court in its discretion may assess reasonable costs, including reasonable
attorneys' fees, against any party litigant in the suit, having due regard to
the merits and good faith of the claims or defenses made by the party litigant.
This Section does not apply to a suit by the Company, a suit by the Trustee, a
suit by a Holder for the enforcement of the payment of the Principal of, or
interest on and any additional amounts on any Security, or a suit by a Holder
or Holders of more than 10% in Principal amount of the Securities of any
Series.

                                  ARTICLE VII

                                    TRUSTEE

SECTION 7.1.  Duties of Trustee.

         (a)  If an Event of Default has occurred and is continuing, the
Trustee shall exercise its rights and powers under this Indenture and use the
same degree of care and skill in their exercise as a prudent man would exercise
or use under the circumstances in the conduct of his own affairs.

         (b)  Except during the continuance of an Event of Default:

                 (1)  The Trustee need perform only those duties that are
         specifically set forth in this Indenture and no implied covenants or
         obligations shall be read into this Indenture against the Trustee.

                 (2)  In the absence of bad faith on its part, the Trustee may
         conclusively rely, as to the truth of the statements and the
         correctness of the opinions expressed therein, upon certificates or
         opinions furnished to the Trustee and conforming to the requirements
         of this Indenture.  However, the Trustee shall examine the
         certificates and opinions to determine whether or not they conform to
         the requirements of this Indenture.

         (c)  The Trustee may not be relieved from liability for its own
negligent action, its own negligent failure to act or its own willful
misconduct, except that:

                 (1)  This paragraph does not limit the effect of paragraph 
         (b) of this Section.

                 (2)  The Trustee shall not be liable for any error of judgment
         made in good faith by a Responsible Officer, unless it is proved that
         the Trustee was negligent in ascertaining the pertinent facts.





                                      -38-
<PAGE>   39

                 (3)  The Trustee shall not be liable with respect to any
         action it takes or omits to take in good faith in accordance with a
         direction received by it pursuant to Section 6.5.

         (d)  Every provision of this Indenture that in any way relates to the
Trustee is subject to paragraphs (a), (b) and (c) of this Section.

         (e)  The Trustee shall not be liable for interest on any money
received by it except as the Trustee may agree with the Company.  Money held in
trust by the Trustee need not be segregated from other funds except to the
extent required by law.

         (f)  The Trustee may refuse to perform any duty or exercise any right
or power unless it receives indemnity satisfactory to it against any loss,
liability or expense.

SECTION 7.2.  Rights of Trustee.

         (a)  The Trustee may rely on any document believed by it to be genuine
and to have been signed or presented by the proper person.  The Trustee need
not investigate any fact or matter stated in the document.

         (b)  Before the Trustee acts or refrains from acting, it may consult
with counsel or require an Officers' Certificate or an Opinion of Counsel.  The
Trustee shall not be liable for any action it takes or omits to take in good
faith in reliance on a Board Resolution, the written advice of counsel, a
certificate of an Officer or Officers delivered pursuant to Section 2.2(b), an
Officers' Certificate or an Opinion of Counsel.

         (c)  The Trustee may act through agents and shall not be responsible
for the misconduct or negligence of any agent appointed with due care.

         (d)  The Trustee shall not be liable for any action it takes or omits
to take in good faith which it believes to be authorized or within its rights
or powers.

SECTION 7.3.  Individual Rights of Trustee.

         The Trustee in its individual or any other capacity may become the
owner or pledgee of Securities and may otherwise deal with the Company or an
Affiliate with the same rights it would have if it were not Trustee.  Any Agent
may do the same with like rights.  However, the Trustee is subject to Sections
7.10 and 7.11.

SECTION 7.4.  Trustee's Disclaimer.

         The Trustee makes no representation as to the validity or adequacy of
this Indenture or the Securities.  It shall not be accountable for the
Company's use of the proceeds from the Securities or for monies paid over to
the Company pursuant to the Indenture, and it shall not be responsible for any
statement in the Securities other than its certificate of authentication.





                                      -39-
<PAGE>   40

SECTION 7.5.  Notice of Defaults.

         If a Default occurs and is continuing with respect to the Securities
of any Series and if it is known to the Trustee, the Trustee shall mail to each
Holder of a Security of that Series entitled to receive reports pursuant to
Section 4.2(c) (and, if Unregistered Securities of that Series are outstanding,
shall cause to be published at least once in an Authorized Newspaper in each of
The City of New York, London and, if Securities of that Series are listed on
The Luxembourg Stock Exchange, Luxembourg) notice of the Default within 90 days
after it occurs.  Except in the case of a Default in payment of Principal,
interest or additional amounts on the Securities of any Series, or in the
payment of any sinking fund installment, the Trustee may withhold the notice if
and so long as a committee of its Responsible Officers in good faith determines
that withholding such notice is in the interests of Securityholders of that
Series.

SECTION 7.6.  Reports by Trustee to Holders.

         (a)  On or before the first anniversary date of the first issue of a
Series of Securities and thereafter at intervals of not more than 12 months,
the Trustee shall mail to each Securityholder of that Series entitled to
receive reports pursuant to Section 4.2(c) a brief report dated as of such date
that complies with TIA Section  313(a).  The Trustee also shall comply with TIA
Section  313(b).

         (b)  The Trustee shall transmit to Securityholders of each Series, as
hereinafter provided, and to the Company a brief report with respect to the
character and amount of any advances (and if the Trustee elects so to state,
the circumstances surrounding the making thereof) made by the Trustee (as such)
since the date of the last report transmitted pursuant to the provisions of
subsection (a) of this Section 7.6 (or if no such report has yet been so
transmitted, since the date of execution of this Indenture), for the
reimbursement of which it claims or may claim a lien or charge prior to that of
the Securities of such Series on property or funds held or collected by it as
Trustee, and which it has not previously reported pursuant to this subsection,
except that the Trustee shall not be required (but may elect) to report such
advances if such advances remaining unpaid at any time aggregate ten percent or
less of the principal amount at Stated Maturity of Securities of such Series
outstanding at such time, such report to be transmitted within 90 days after
such time.

         (c)  Reports to Securityholders pursuant to this Section 7.6 shall be
transmitted by mail:

                 (1)  to all Holders of Registered Securities of each Series,
         as the names and addresses of such Holders appear upon the register
         for each Series of Securities;

                 (2)  to such Holders of Unregistered Securities as have,
         within two years preceding such transmission, filed their names and
         addresses with the Trustee for that purpose; and

                 (3)  except in the case of reports pursuant to subsection (b)
         of this Section 7.6, to each Holder whose name and address is
         preserved at the time by the Trustee, as provided in Section 2.7(a).

                 (4)  At the time that it mails such a report to
         Securityholders of any Series, the Trustee shall file a copy of that
         report with the SEC and with each stock exchange on which the





                                      -40-
<PAGE>   41

         Securities of that Series are listed.  The Company shall provide
         written notice to the Trustee when the Securities of any Series are
         listed on any stock exchange.

SECTION 7.7.  Compensation and Indemnity.

         (a)  The Company shall pay to the Trustee from time to time reasonable
compensation for its services.  The Trustee's compensation shall not be limited
by any law on compensation of a trustee of an express trust.  The Company shall
reimburse the Trustee upon request for all reasonable out-of-pocket expenses
incurred by it in connection with the performance of its duties under this
Indenture.  Such expenses shall include the reasonable compensation and
expenses of the Trustee's agents and counsel.

         (b)  The Company shall indemnify the Trustee against any loss,
liability or expense incurred by it arising out of or in connection with its
acceptance or administration of the trust or trusts hereunder.  The Trustee
shall notify the Company promptly of any claim for which it may seek indemnity.

         (c)  The Company need not reimburse any expense or indemnify against
any loss or liability incurred by the Trustee through negligence or bad faith.

         (d)  To secure the payment obligations of the Company pursuant to this
Section, the Trustee shall have a lien prior to the Securities of any Series on
all money or property held or collected by the Trustee, except that held in
trust to pay Principal and interest on particular Securities of a Series.

         (e)  If the Trustee incurs expenses or renders services after an Event
of Default specified in Section 6.1(5) or (6) occurs, such expenses and the
compensation for such services are intended to constitute expenses of
administration under any Bankruptcy Law.

SECTION 7.8.  Replacement of Trustee.

         (a)  The resignation or removal of the Trustee and the appointment of
a successor Trustee shall become effective only upon the successor Trustee's
acceptance of appointment as provided in this Section.

         (b)  The Trustee may resign with respect to the Securities of any
Series by so notifying the Company.  The Holders of a majority in principal
amount of the Securities of any Series may remove the Trustee with respect to
that Series by so notifying the Trustee and the Company and may appoint a
successor Trustee for such Series with the Company's consent.  The Company may
remove the Trustee with respect to Securities of any Series if:

                 (1)  the Trustee fails to comply with Section 7.10;

                 (2)  the Trustee is adjudged a bankrupt or an insolvent;

                 (3)  a receiver or public officer takes charge of the Trustee
         or its property; or

                 (4)  the Trustee becomes incapable of acting.





                                      -41-
<PAGE>   42

         (c)  If the Trustee resigns or is removed or if a vacancy exists in
the office of Trustee for any reason, with respect to Securities of any Series,
the Company shall promptly appoint a successor Trustee for such Series.

         (d)  If a successor Trustee with respect to the Securities of any
Series does not take office within 30 days after the retiring Trustee resigns
or is removed, the retiring Trustee, the Company or the Holders of at least 10%
in principal amount of the Securities of the applicable Series may petition any
court of competent jurisdiction for the appointment of a successor Trustee with
respect to the Securities of such Series.

         (e)  If the Trustee with respect to the Securities of any Series fails
to comply with Section 7.10, any Securityholder of the applicable Series may
petition any court of competent jurisdiction for the removal of such Trustee
and the appointment of a successor Trustee.

         (f)  Upon the execution of the supplemental indenture referred to in
Section 7.8 (h), the resignation or removal of the retiring Trustee for any
Series of Securities shall become effective, and the successor Trustee shall
have all the rights, powers and duties of the retiring Trustee with respect to
all Series of Securities for which the successor Trustee is to be acting as
Trustee under this Indenture.  The retiring Trustee shall promptly transfer all
property held by it as Trustee with respect to such Series of Securities to the
successor Trustee subject to the lien provided for in Section 7.7. The Company
shall give notice of each appointment of a successor Trustee for any Series of
Securities by mailing written notice of such event by first-class mail to the
Holders of Registered Securities of such Series entitled to receive reports
pursuant to Section 4.2(c) and, if any Unregistered Securities are outstanding,
by publishing notice of such event once in an Authorized Newspaper in each of
The City of New York, London, and, if Securities of that Series are listed on
The Luxembourg Stock Exchange, Luxembourg.

         (g)  All provisions of this Section 7.8 except subparagraphs (b) (1),
(e) and (h) and the words "subject to the lien provided for in Section 7.7" in
subparagraph (f) shall apply also to any Paying Agent located outside the U.S.
and its possessions and required by Section 2.4.

         (h)  In case of the appointment hereunder of a successor Trustee with
respect to the Securities of one or more Series, the Company, the retiring
Trustee and such successor Trustee shall execute and deliver a supplemental
indenture wherein such successor Trustee shall accept such appointment and
which (1) shall contain such provisions as shall be necessary or desirable to
transfer and confirm to, and to vest in, such successor Trustee all the rights,
powers, trusts and duties of the retiring Trustee with respect to the
Securities of that or those Series to which the appointment of such successor
Trustee relates, (2) if the retiring Trustee is not retiring with respect to
all Securities, shall contain such provisions as shall be deemed necessary or
desirable to confirm that all the rights, powers, trusts and duties of the
retiring Trustee with respect to the Securities of that or those Series as to
which the retiring Trustee is not retiring shall continue to be vested in the
retiring Trustee, and (3) shall add to or change any of the provisions of this
Indenture as shall be necessary to provide for or facilitate the administration
of the trusts hereunder by more than one Trustee, it being understood that
nothing herein or in such supplemental indenture shall constitute such Trustees
co-trustees of the same trust and that each such Trustee shall be trustee of a
trust or trusts hereunder separate and apart from any trust or trusts
administered by any other such Trustee.





                                      -42-
<PAGE>   43

         (i)  No successor Trustee shall accept appointment as provided in this
Section 7.8 unless at the time of such acceptance such successor Trustee shall
be qualified and eligible under the provisions of Section 7.10.

SECTION 7.9.  Successor Trustee, Agents by Merger, etc.

         If the Trustee or any Agent consolidates with, merges or converts
into, or transfers all or substantially all of its corporate trust business
assets to, another corporation, the successor corporation, without any further
act, shall be the successor Trustee or Agent, as the case may be.

SECTION 7.10.  Eligibility; Disqualification.

         This Indenture shall always have a Trustee with respect to each Series
of Securities who satisfies the requirements of TIA Section  310 (a) (1).  The
Trustee shall always have a combined capital and surplus of at least
$10,000,000 as set forth in its most recent published annual report of
condition.  The Trustee is subject to and shall comply with TIA Section
310(b), including the optional provision permitted by the second sentence of
TIA Section  310 (b) (9), except that in determining whether the Trustee has a
conflicting interest, as defined in TIA Section  310 (b) (1), there shall be
excluded all indentures of the Company now or hereafter existing which may be
excluded under the proviso of TIA Section  310(b) (1).

SECTION 7.11.  Preferential Collection of Claims Against Company.

         The Trustee is subject to and shall comply with TIA Section  311 (a),
excluding any creditor relationship listed in TIA Section  311 (b).  A Trustee
who has resigned or been removed shall be subject to TIA Section  311 (a) to
the extent indicated.


                                  ARTICLE VIII

                     SATISFACTION AND DISCHARGE; DEFEASANCE

SECTION 8.1.  Satisfaction and Discharge of Securities of any Series.

         Unless provided otherwise in the Board Resolution establishing the
Series of Securities, or in any indenture supplemental hereto, the Company
shall be deemed to have paid and discharged the entire indebtedness on all the
Securities of a Series, the provisions of this Indenture (except as to (x) the
rights of Holders of Securities of such Series to receive, from the money and
U.S. Government Obligations deposited with the Trustee pursuant to this Article
Eight or the interest and Principal received by the Trustee in respect of such
U.S. Government Obligations, payment of the Principal of and any installment of
Principal of or interest on such Securities on the Stated Maturities thereof or
upon the Redemption Dates for Securities required to be redeemed pursuant to
any mandatory sinking fund or analogous provisions relating to Securities of
that Series or pursuant to any call for redemption relating to Securities of
that Series, and (y) all rights and obligations of the Company and the Trustee
with respect to such Securities under Sections 2.4, 2.5, 2.6, 2.7, 2.8, 2.9,
4.1, 6.5, 6.7, 6.11, 7.7, 7.8, 8.3 and Article Five, so long as the Securities
of such Series remain Outstanding and, thereafter, only the Company's and the
Trustee's rights and obligations under Sections 2.6, 7.7 and 8.3) as it





                                      -43-
<PAGE>   44

relates to such Securities shall no longer be in effect, and the Trustee, at
the expense of the Company, shall, upon Company Request, execute proper
instruments acknowledging the same if either:

                 (a) (1)  all Securities of such Series theretofore
         authenticated and delivered (other than (i) Securities which have been
         destroyed, lost or stolen and which have been replaced or paid as
         provided in Section 2.9 and (ii) Securities for whose payment money
         has theretofore been deposited in trust or segregated and held in
         trust by the Company) have been delivered to the Trustee for
         cancellation;

                 (2)  the Company has paid or caused to be paid all other sums
         payable under this Indenture in respect of the Securities of such
         Series; and

                 (3)  the Company has delivered to the Trustee an Officers'
         Certificate and an Opinion of Counsel, each stating that all
         conditions precedent herein provided for relating to the satisfaction
         of the entire indebtedness on all Securities of any such Series and
         the discharge of the Indenture as it relates to such Securities have
         been complied with; or

                 (b) (1)  all Securities of such Series not theretofore
         delivered to the Trustee for cancellation (i) have become due and
         payable, or (ii) will become due and payable at their Stated Maturity
         within one year, or (iii) are to be called for redemption within one
         year under arrangements satisfactory to the Trustee for the giving of
         notice of redemption by the Trustee in the name, and at the expense,
         of the Company;

                 (2)  the condition described in paragraph (1) of Section 8.2
         has been satisfied;

                 (3)  the conditions described in paragraphs (a) (2) and (a)
         (3) of this Section 8.1 have been satisfied; and

                 (4)  the Company has received an Opinion of Counsel to the
         effect that the satisfaction and discharge contemplated by this
         Section 8.1 will not violate the then applicable rules of, or any
         related undertaking of the Company to, any national securities
         exchange on which Securities of that Series are listed; or

                 (c) (1)  the conditions referred to or described in paragraphs
         (b)(2), (b)(3) and (b)(4) of this Section 8.1 have been satisfied;

                 (2)  no Event of Default or event which with notice or lapse
         of time would become an Event of Default shall have occurred and be
         continuing on the date of the deposit referred to in paragraph (1) of
         Section 8.2 or on the 91st day after the date of such deposit;
         provided, however, that should that condition fail to be satisfied on
         or before such 91st day, the Trustee shall promptly, upon satisfactory
         receipt of evidence of such failure, return such deposit to the
         Company; and

                 (3)  the Company has delivered to the Trustee an Opinion of
         Counsel of a nationally-recognized independent tax counsel to the
         effect that Holders of the Securities of such Series will not
         recognize income, gain or loss for Federal income tax purposes as a
         result of such deposit and the satisfaction, discharge and defeasance
         contemplated by this paragraph (c) of this





                                      -44-
<PAGE>   45

         Section 8.1 and will be subject to Federal income tax on the same
         amounts and in the same manner and at the same times as would have
         been the case if such deposit and defeasance had not occurred.

SECTION 8.2.  Defeasance of Securities of any Series.


                          Unless provided otherwise in the Board Resolution
         establishing the Series of Securities, or in any indenture supplemental
         hereto, the Company may omit to comply with paragraph 4 of Section 6.01
         of this Indenture shall not apply, as all of such provisions
         relate to Securities of any Series, so long as the Securities of such
         Series remain Outstanding and, thereafter, all provisions of this
         Indenture in respect of such Securities shall no longer be in effect
         except the Company's and the Trustee's rights and obligations under
         Sections 2.06, 7.07 and 8.03, and the Trustee at the expense of the
         Company shall, upon Company Request, execute proper instruments
         acknowledging the same if:

                          (1)     the Company has deposited or caused to be
                 deposited with the Trustee as trust funds in trust for the
                 purpose (A) money in an amount, or (B) U.S. Government
                 Obligations which through the payment of interest and
                 Principal in respect thereof in accordance with their terms
                 will provide on or before the due date of any payment in
                 respect of such Series of Securities money in an amount, or
                 (C) a combination thereof, sufficient, after payment, based on
                 then applicable law, of all Federal, state and local taxes in
                 respect thereof payable by the Trustee, in the opinion of a
                 nationally-recognized firm of independent public accountants
                 selected by the Company expressed in a written certification
                 thereof delivered to the Trustee, to pay and discharge (i) the
                 Principal of and each installment of Principal of and interest
                 on the Outstanding Securities of that Series on the Stated
                 Maturity of such Principal or installment of Principal or
                 interest and (ii) any mandatory sinking fund payments or
                 analogous payments or payments pursuant to any call for
                 redemption applicable to Securities of such Series on the day
                 on which such payments are due and payable in accordance with
                 the terms of the Indenture and of such Securities;

                          (2)     no Event of Default or event which with
                 notice or lapse of time would become an Event of Default shall
                 have occurred and be continuing on the date of such deposit;

                          (3)     the interest of the Holders in such deposit
                 shall have been duly perfected under the applicable provisions
                 of the Uniform Commercial Code;

                          (4)     such deposit will not result in a breach or
                 violation of, or constitute a default under, this Indenture or
                 any other material agreement or instrument to which the
                 Company is a party or by which it is bound; and

                          (5)     the Company has delivered to the Trustee an
                 Officers' Certificate and an Opinion of Counsel, each stating
                 that all conditions precedent





                                      -45-
<PAGE>   46

                 herein provided for relating to the defeasance contemplated by
                 this Section have been complied with.

SECTION 8.3.  Application of Trust Funds; Indemnification.

         (a)  Subject to the provisions of paragraph (c) of this Section, all
money and U.S. Government Obligations deposited with the Trustee pursuant to
Section 8.1 or 8.2 and all money received by the Trustee in respect of U.S.
Government Obligations deposited with the Trustee, shall be held in trust and
applied by it, in accordance with the provisions of the Securities and this
Indenture, to the payment, either directly or through any Paying Agent
(including the Company acting as its own Paying Agent) as the Trustee may
determine, to the Persons entitled thereto, of the Principal and interest for
whose payment such money and U.S. Government Obligations have been deposited
with or received by the Trustees as contemplated by Section 8.1 or 8.2.

         (b)  The Company shall pay and shall indemnify the Trustee against any
tax, fee or other charge imposed on or assessed against U.S.  Government
Obligations deposited pursuant to Section 8.1 or 8.2 or the interest and
Principal received in respect of such obligations, other than any such tax, fee
or other charge payable by or on behalf of Holders.  The Company shall be
entitled to prompt notice of an assessment or the commencement of any
proceeding for which indemnification may be sought hereunder.

         (c)  The Trustee shall deliver or pay to the Company from time to time
upon Company Request any U.S. Government Obligations or money held by it as
provided in Section 8.1 or 8.2 which, in the opinion of a nationally-recognized
firm of independent public accountants expressed in a written certification
thereof delivered to the Trustee, are then in excess of the amount thereof
which then would have been required to be deposited for the purpose for which
such obligations or money were deposited or received.  The Trustee shall also
deliver or pay to the Company from time to time upon Company Request any U.S.
Government Obligations or money held by it as provided in Section 8.1 or 8.2,
in exchange for other U.S. Government Obligations or money, upon the following
conditions:

                 (1)  such exchange shall occur simultaneously;

                 (2)  the Company has delivered to the Trustee an Officers'
         Certificate and an Opinion of Counsel, each stating that all
         conditions precedent herein provided for relating to the exchange
         contemplated by paragraph (c) of this Section have been complied with;
         and

                 (3)  in the opinion of a nationally-recognized firm of
         independent public accountants expressed in a written certification
         thereof delivered to the Trustee, immediately after such exchange the
         U.S. Government Obligations or money then held by the Trustee as
         provided in Section 8.1 or 8.2 shall be in such amount as then would
         have been required to be deposited in order to comply with Section
         8.2(1) hereof.





                                      -46-
<PAGE>   47

                                   ARTICLE IX

                            SUPPLEMENTAL INDENTURES

SECTION 9.1.  Without Consent of Holders.

         The Company and the Trustee may enter into one or more supplemental
indentures without consent of any Securityholder for any of the following
purposes:

                 (1)  to cure any ambiguity, defect or inconsistency herein or
                      in the Securities of any Series;

                 (2)  to comply with Article 5;

                 (3)  to secure the Securities;

                 (4)  to provide for uncertificated Securities in addition to
                      or in place of certificated Securities;

                 (5)  to make any change that does not adversely affect the
                      rights of any Securityholder;

                 (6)  to provide for the issuance of and establish the form and
                      terms and conditions of Securities of any Series as
                      provided in Section 2.2, to establish the form of any
                      certifications required to be furnished pursuant to the
                      term of this Indenture or any Series of Securities, to
                      add to the rights of the Holders of any Series of
                      Securities, or to surrender any right or power conferred
                      on the Company;

                 (7)  to add to the rights of the Holders of any series of 
                      Securities; or

                 (8)  to provide for the appointment of a successor Trustee.

SECTION 9.2.  With Consent of Holders.

         (a)  With the written consent of the Holders of a majority in
principal amount of the outstanding Securities of each Series affected by such
supplemental indenture (with each Series voting as a class), the Company and
the Trustee may enter into a supplemental indenture to add any provisions to or
to change or eliminate any provisions of this Indenture or of any supplemental
indenture or to modify, in each case in any manner not covered by Section 9.1,
the rights of the Securityholders of each such Series.  The Holders of a
majority in principal amount of the outstanding Securities of each Series
affected by such waiver (with each Series voting as a class), by notice to the
Trustee, may waive compliance by the Company with any provision of this
Indenture, any supplemental indenture or the Securities of any such Series
except a Default in the payment of the Principal of or interest on any
Security.  However, without the consent of each Securityholder affected, an
amendment or waiver may not:

                 (1)  reduce the amount of Securities whose Holders must
         consent to an amendment or waiver;





                                      -47-
<PAGE>   48

                 (2)  change the rate of or change the time for payment of
                      interest on any Security;

                 (3)  change the Principal of or change the Stated Maturity of
                      any Security;

                 (4)  reduce any premium payable upon the redemption of any
                      Security;

                 (5)  waive a Default in the payment of the Principal of or
                      interest on any Security;

                 (6)  make any Security payable in money other than that 
                      stated in the Security; or

                 (7)  make any change in Section 6.4, 6.7 or 9.2(a) (third
                      sentence).

         (b)  It is not necessary under this Section 9.2 for the
Securityholders to consent to the particular form of any proposed supplemental
indenture, but it is sufficient if they consent to the substance thereof.

         (c)  Upon the request of the Company, accompanied by a copy of a
resolution of the Board of Directors certified by the Secretary or an Assistant
Secretary of the Company authorizing the execution of any such supplemental
indenture, and upon the filing with the Trustee of evidence of the consent of
Securityholders as aforesaid, the Trustee shall join with the Company in the
execution of such supplemental indenture unless such supplemental indenture
affects the Trustee's own rights, duties or immunities under this Indenture or
otherwise, in which case the Trustee may in its discretion, but shall not be
obligated to, enter into such supplemental indenture.

         (d)  Promptly after the execution by the Company and the Trustee of
any supplemental indenture pursuant to the provisions of this Section 9.2, the
Company shall transmit by mail a notice, setting forth in general terms the
substance of such supplemental indenture, to all Holders of Registered
Securities, as the names and addresses of such Holders appear on the register
for each Series of Securities, and to such Holders of Unregistered Securities
as are entitled to receive reports pursuant to Section 4.2(c).  Any failure of
the Company to mail such notice, or any defect therein, shall not, however, in
any way impair or affect the validity of any such supplemental indenture.

         (e)  Upon the execution of any supplemental indenture pursuant to the
provisions of this Article Nine, this Indenture shall be and be deemed to be
modified and amended in accordance therewith and the respective rights,
limitation of rights, obligations, duties and immunities under this Indenture
of the Trustee, the Company and the Securityholders shall thereafter be
determined, exercised and enforced hereunder subject in all respects to such
modifications and amendments, and all the terms and conditions of any such
supplemental indenture shall be and be deemed to be part of the terms and
conditions of this Indenture for any and all purposes.

SECTION 9.3.  Compliance with Trust Indenture Act.

         Every amendment to this Indenture or the Securities of one or more
Series shall be set forth in a supplemental indenture that complies with the
TIA as then in effect.





                                      -48-
<PAGE>   49

SECTION 9.4.  Revocation and Effect of Consents.

         Until an amendment or waiver becomes effective, a consent to it by a
Holder of a Security is a continuing consent by the Holder and every subsequent
Holder of a Security or portion of a Security that evidences the same debt as
the consenting Holder's Security, even if notation of the consent is not made
on any Security.  However, any such Holder or subsequent Holder may revoke the
consent as to his Security or portion of a Security if the Trustee receives the
notice of revocation before the date the amendment or waiver becomes effective.
After an amendment or waiver becomes effective, it shall bind every
Securityholder of each Series affected by such amendment or waiver.

SECTION 9.5.  Notation on or Exchange of Securities.

         The Trustee may place an appropriate notation about an amendment or
waiver on any Security of any Series thereafter authenticated.  The Company in
exchange for Securities of that Series may issue and the Trustee shall
authenticate new Securities of that Series that reflect the amendment or
waiver.


                                   ARTICLE X

                                 MISCELLANEOUS

SECTION 10.1.  Trust Indenture Act Controls.

         If any provision of this Indenture limits, qualifies, or conflicts
with a provision which is required to be included in this Indenture by the TIA,
the required provision shall control.

SECTION 10.2.  Notices.

         (a)  Any notice or communication by the Company or the Trustee to the
other is duly given if in writing and delivered in person or mailed by
first-class mail:

         if to the Company to:

                 Union Tank Car Company
                 225 West Washington Street
                 Chicago, Illinois  60606

                 Attn: ________________________

         if to the Trustee to:

                 [____________________________]
                 [____________________________]
                 [____________________________]
                 [____________________________]





                                      -49-
<PAGE>   50

         (b)  The Company or the Trustee by notice to the other may designate
additional or different addresses for subsequent notices or communications.

         (c)  Any notice or communication to Holders of Securities entitled to
receive reports pursuant to Section 4.2(c) shall be mailed by firstclass mail
to the addresses for Holders of Registered Securities shown on the register
kept by the Registrar and to addresses filed with the Trustee for other
Holders.  Failure to so mail a notice or communication or any defect in such
notice or communication shall not affect its sufficiency with respect to other
Holders of Securities of that or any other Series entitled to receive notice.

         (d)  If a notice or communication is mailed in the manner provided
above within the time prescribed, it is duly given, whether or not the
addressee receives it.

         (e)  If the Company mails a notice or communication to
Securityholders, it shall mail a copy to the Trustee and to each Agent at the
same time.

         (f)  If it shall be impractical in the opinion of the Trustee or the
Company to make any publication of any notice required hereby in an Authorized
Newspaper, any publication or other notice in lieu thereof which is made or
given with the approval of the Trustee shall constitute a sufficient
publication of such notice.

SECTION 10.3.  Communication by Holders with Other Holders.

         Securityholders of any Series may communicate pursuant to TIA Section
312(b) with other Securityholders of that Series or of all Series with respect
to their rights under this Indenture or under the Securities of that Series or
of all Series.  The Company, the Trustee, the Registrar and everyone else shall
have the protection of TIA Section  312(c).

SECTION 10.4.  Certificate and Opinion as to Conditions Precedent.

         Upon any request or application by the Company to the Trustee to take
under this Indenture any action under any provisions of this Indenture, the
Company shall furnish to the Trustee:

                 (1)  an Officers' Certificate stating that, in the opinion of
         the signers, all conditions precedent, if any, relating to the
         proposed action have been complied with; and

                 (2)  an Opinion of Counsel stating that, in the opinion of
         such counsel, all such conditions have been complied with.

SECTION 10.5.  Statements Required in Certificate or Opinion.

         Each certificate or opinion with respect to compliance with a
condition or covenant provided for in this Indenture shall include:

                 (1)  a statement that the person making such certificate or
          opinion has read such covenant or condition;





                                      -50-
<PAGE>   51

                 (2)  a brief statement as to the nature and scope of the
         examination or investigation upon which the statements or opinions
         contained in such certificate or opinion are based;

                 (3)  a statement that, in the opinion of such person, he has
         made such examination or investigation as is necessary to enable him
         to express an informed opinion as to whether or not such covenant or
         condition has been complied with; and

                 (4)  a statement as to whether or not, in the opinion of such
         person, such condition or covenant has been complied with.

SECTION 10.6.  Rules by Trustee and Agents.

         The Trustee may make reasonable rules for action by or at a meeting of
Securityholders of one or more Series.  The Paying Agent or Registrar may make
reasonable rules and set reasonable requirements for its functions.

SECTION 10.7.  Payments on Business Day.

         If a payment date is not a Business Day, payment may be made at such
place on the next succeeding Business Day with the same force and effect as if
made on such payment date, and no interest shall accrue for the intervening
period.

SECTION 10.8.  Governing Law.

         The laws of the State of New York shall govern this Indenture, the
Securities and any coupons appertaining thereto.

SECTION 10.9.  No Adverse Interpretation of Other Agreements.

         This Indenture may not be used to interpret another indenture, loan or
debt agreement of the Company or an Affiliate.  No such indenture, loan or debt
agreement may be used to interpret this Indenture.

SECTION 10.10.  No Recourse Against Others.

         No director, officer, employee or stockholder, as such, of the Company
shall have any liability for any obligation of the Company under the Securities
or the Indenture or for any claim based on, in respect of or by reason of such
obligation or its creation.  Each Securityholder by accepting a Security waives
and releases all such liability.  The waiver and release are part of the
consideration for the issue of the Securities.

SECTION 10.11.  Acts of Successor Corporation.

         Any act or proceeding by any provision of this Indenture authorized or
required to be done or performed by any board, committee or officer of the
Company shall and may be done and performed with like force and effect by the
like board, committee or officer of any corporation that shall at the time be
the lawful sole successor of the Company.





                                      -51-
<PAGE>   52



SECTION 10.12.  Execution in Counterparts.

         This Indenture may be executed in any number of counterparts, each of
which shall be an original, but such counterparts shall together constitute but
one instrument.

                                                   UNION TANK CAR COMPANY


                                                   By:__________________________
                                                      Name:
                                                      Title:


(Seal)

Attest:


By:__________________________
   Name:
   Title:



[____________________________],
                                                     Trustee


                                                   By:__________________________
                                                      Name:
                                                      Title:


(Seal)

Attest:


By:__________________________
   Name:
   Title:





                                      -52-
<PAGE>   53

STATE OF ILLINOIS)
                          :       ss.:
COUNTY OF COOK   )

         On the _____ day of ____________, in the year ______________,  before
me personally came ________________, to me known, who, being by me duly sworn,
did depose and say that ___ resides _____________________; that ___ is the
__________of the UNION TANK CAR COMPANY, one of the corporations described in
and which executed the above instrument; that ___ knows the corporate seal of
said corporation; that the seal affixed to the said instrument is such
corporate seal; that it was so affixed by authority of the Board of Directors
of said corporation, and that ___ signed ____ name thereto by like authority.


[NOTARIAL SEAL]
                                         _________________________            
                                         My Commission Expires:  ______, _____
                                                                               




STATE OF ILLINOIS         )
                          :       ss.:
COUNTY OF COOK            )

         On the _____ day of ____________, in the year ______________,  before
me personally came ________________, to me known, who, being by me duly sworn,
did depose and say that ___ resides _____________________; that ___ is the
__________of the [____________________________] [Trustee], one of the
corporations described in and which executed the above instrument; that ___
knows the corporate seal of said corporation; that the seal affixed to the said
instrument is such corporate seal; that it was so affixed by authority of the
Board of Directors of said corporation, and that ___ signed ____ name thereto
by like authority.


[NOTARIAL SEAL]

                                         _________________________
                                         My Commission Expires:  ______, _____
<PAGE>   54

<TABLE>
<CAPTION>
                                                                TABLE OF CONTENTS                                      
                                                                -----------------                                      
                                                                                                                       
SECTION                                                                                                                         PAGE
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<S>                                                                                                                             <C>
                                                                                                                       
                                                                    ARTICLE I                                          
                                                                                                                       
                                                     DEFINITIONS, INCORPORATION BY REFERENCE                           
                                                            AND RULES OF CONSTRUCTION                                  
                                                                                                                       
  1.1.  Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    2
  1.2.  Other Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    9
  1.3.  Incorporation by Reference of Trust Indenture Act . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    9
  1.4.  Rules of Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   10
                                                                                                                       
                                                                   ARTICLE II                                          
                                                                                                                       
                                                                 THE SECURITIES                                        
                                                                                                                       
  2.1.  Issuable in Series; Series Issuable in Tranches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   10
  2.2.  Establishment of Terms and Form of Series of Securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   11
  2.3.  Execution, Authentication and Delivery  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   13
  2.4.  Registrar and Paying Agent  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   14
  2.5.  Currency and Manner of Payments in Respect of Securities  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   15
  2.6.  Paying Agent to Hold Money in Trust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   19
  2.7.  Securityholder Lists; Ownership of Securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   19
  2.8.  Transfer and Exchange . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   20
  2.9.  Replacement Securities  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   21
  2.10. Outstanding Securities  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   22
  2.11. Securities Held by the Company or an Affiliate  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   23
  2.12. Temporary Securities  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   23
  2.13. Cancellation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   23
  2.14. Defaulted Interest  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   24
  2.15. Securities Issuable in the Form of a Global Security  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   24
  2.16. Unregistered Securities Represented by Global Security  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   25
                                                                                                                       
                                                                   ARTICLE III                                         
                                                                                                                       
                                                   REDEMPTION OF SECURITIES AND SINKING FUNDS                          
                                                                                                                       
  3.1.  Notice to Trustee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   27
  3.2.  Selection of Securities to be Redeemed  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   28
  3.3.  Notice of Redemption  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   28
  3.4.  Effect of Notice of Redemption  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   29
  3.5.  Deposit of Redemption Price . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   29
  3.6.  Securities Redeemed in Part . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   29
  3.7.  Securities Acquired by the Company  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   29
  3.8.  Mandatory and Optional Sinking Funds  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   30
                                                                                                                       
                                                                                                                       
                                                                                                                       
</TABLE>
                                   
                                   
                                     -i-
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<TABLE>
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<S>                                                                                                                             <C>
                                                                                                                       
                                                                   ARTICLE IV                                          
                                                                                                                       
                                                       PARTICULAR COVENANTS OF THE COMPANY                             
                                                                                                                       
  4.1.  Payment of Securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   32
  4.2.  Reports by the Company  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   32
  4.3.  Statement of Officers as to Default . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   32
  4.4.  Filing with Listing Agent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   33
                                                                                                                       
                                                                    ARTICLE V                                          
                                                                                                                       
                                                              SUCCESSOR CORPORATION                                    
                                                                                                                       
  5.1.  When Company May Merge, etc.  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   33
  5.2.  Successor Corporation Substituted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   33
                                                                                                                       
                                                                   ARTICLE VI                                          
                                                                                                                       
                                                              DEFAULTS AND REMEDIES                                    
                                                                                                                       
  6.1.  Events of Default . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   34
  6.2.  Acceleration  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   35
  6.3.  Other Remedies Available to Trustee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   35
  6.4.  Waiver of Existing Defaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   35
  6.5.  Control by Majority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   36
  6.6.  Limitation on Suits by Securityholders  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   36
  6.7.  Rights of Holders to Receive Payment  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   36
  6.8.  Collection Suits by Trustee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   37
  6.9.  Trustee May File Proofs of Claim  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   37
  6.10. Priorities  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   37
  6.11. Undertaking for Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   37
                                                                                                                       
                                                                   ARTICLE VII                                         
                                                                                                                       
                                                                     TRUSTEE                                           
                                                                                                                       
  7.1.  Duties of Trustee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   38
  7.2.  Rights of Trustee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   39
  7.3.  Individual Rights of Trustee  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   39
  7.4.  Trustee's Disclaimer  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   39
  7.5.  Notice of Defaults  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   39
  7.6.  Reports by Trustee to Holders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   40
                                                                                                                       

</TABLE>



                                     -ii-
<PAGE>   56

<TABLE>
<CAPTION>
                                                                                                                       
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                                                                -----------------                                      
                                                                   (CONTINUED)                                         
SECTION                                                                                                                     PAGE
- -------                                                                                                                     ----
<S>                                                                                                                         <C>
  7.7.  Compensation and Indemnity  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   40
  7.8.  Replacement of Trustee  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   41
  7.9.  Successor Trustee, Agents by Merger, etc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   42
  7.10. Eligibility; Disqualification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   43
  7.11. Preferential Collection of Claims Against Company . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   43
                                                                                                                            
                                                                  ARTICLE VIII                                              
                                                                                                                            
                                                     SATISFACTION AND DISCHARGE; DEFEASANCE                                 
                                                                                                                            
  8.1.  Satisfaction and Discharge of Securities of any Series  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   43
  8.2.  Defeasance of Securities of any Series  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   44
  8.3.  Application of Trust Funds; Indemnification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   45
                                                                                                                            
                                                                   ARTICLE IX                                               
                                                                                                                            
                                                             SUPPLEMENTAL INDENTURES                                        
                                                                                                                            
  9.1.  Without Consent of Holders  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   46
  9.2.  With Consent of Holders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   47
  9.3.  Compliance with Trust Indenture Act . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   48
  9.4.  Revocation and Effect of Consents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   48
  9.5.  Notation on or Exchange of Securities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   49
                                                                                                                            
                                                                    ARTICLE X                                               
                                                                                                                            
                                                                  MISCELLANEOUS                                             
                                                                                                                            
  10.1.  Trust Indenture Act Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   49
  10.2.  Notices  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   49
  10.3.  Communication by Holders with Other Holders  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   50
  10.4.  Certificate and Opinion as to Conditions Precedent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   50
  10.5.  Statements Required in Certificate or Opinion  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   50
  10.6.  Rules by Trustee and Agents  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   51
  10.7.  Payments on Business Day . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   51
  10.8.  Governing Law  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   51
  10.9.  No Adverse Interpretation of Other Agreements  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   51
  10.10. No Recourse Against Others . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   51
  10.11. Acts of Successor Corporation  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   51
  10.12. Execution in Counterparts  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   52
                                                                                                                       
                                                                                                                       
                                                                                                                       
                                                                                                                       

</TABLE>
                                    -iii-

<PAGE>   1
                       CONSENT OF INDEPENDENT AUDITORS

We consent to the reference to our firm under the caption "Experts" in the
Registration Statement (Form S-3) and related Prospectus of Union Tank Car
Company for the registration of $400,000,000 of debt securities, and to the
incorporation by reference therein of our report dated March 7, 1996, with
respect to the consolidated financial statements of Union Tank Car Company 
included in its Annual Report (Form 10-K/A) for the year ended December 31,
1995, filed with the Securities and Exchange Commission.


                                        /s/ Ernst & Young LLP

                                        ERNST & YOUNG LLP


Chicago, Illinois
November 26, 1996



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