================================================================================



                                AON CORPORATION


                                      AND


                              THE BANK OF NEW YORK


                                    TRUSTEE

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

                                   INDENTURE


                          DATED AS OF JANUARY 13, 1997


                         JUNIOR SUBORDINATED DEBENTURES



================================================================================

 
                         Reconciliation and Tie Sheet*
                                    between
           Provisions of the Trust Indenture Act of 1939, as amended
                                      and
                    Indenture Dated as of January 13, 1997
                                    between
                                Aon Corporation
                                      and
                         The Bank of New York, Trustee

 
 
   Section of Act                             Section of Indenture
   --------------                             --------------------
                                            
      310(a)(1)                                   7.09                  
      310(a)(2)                                   7.09                  
      310(a)(3)                                   Inapplicable           
      310(a)(4)                                   Inapplicable          
      310(b)                                      7.08, 7.10            
      310(c)                                      Inapplicable          
      311(a)                                      7.13(a), 7.13(c)      
      311(b)                                      7.13(b), 7.13(c)      
      311(c)                                      Inapplicable          
      312(a)                                      5.01, 5.02(a)         
      312(b)                                      5.02(b)               
      312(c)                                      5.03(c)               
      313(a)                                      5.04(a)               
      313(b)(1)                                   Inapplicable          
      313(b)(2)                                   5.04(b)               
      313(c)                                      5.04(c)               
      313(d)                                      5.04(d)               
      314(a)(1)                                   5.03(a)               
      314(a)(2)                                   5.03(b)               
      314(a)(3)                                   5.03(c)               
      314(a)(4)                                   4.06                  
      314(b)                                      Inapplicable          
      314(c)(1)                                   15.04                  
      314(c)(2)                                   15.04                  
      314(c)(3)                                   Inapplicable          
      314(d)                                      Inapplicable          
      314(e)                                      15.04                  
      314(f)                                      Omitted               
      315(a)                                      7.01                  
      315(b)                                      6.07                  
      315(c)                                      7.01                  
      315(d)                                      7.01                  
      315(e)                                      6.08                  
      316(a)(1)                                   6.06, 8.04                  
      316(a)(2)                                   Omitted               
      316(b)                                      6.04                  
      316(c)                                      10.05                  
      317(a)                                      6.02                  
      317(b)                                      4.04                  
      318(a)                                      15.06                        
________________________


*         This Reconciliation and Tie Sheet is not part of the Indenture.

                                      -i-

 
                               TABLE OF CONTENTS

 
 
                                                                                                  Page
                                                                                                  ----
                                 ARTICLE ONE 
                                  DEFINITIONS
 
                                                                                               
Section 1.01     Certain terms defined...........................................................    1
                 Act.............................................................................    2
                 Additional Interest.............................................................    2
                 Administrative Trustee..........................................................    2
                 Aon Guarantee...................................................................    2
                 Aon Trust.......................................................................    3
                 Applicants......................................................................    3
                 Authenticating Agent............................................................    3
                 Authorized Newspaper............................................................    3
                 Board of Directors..............................................................    3
                 Business Day....................................................................    3
                 Capital Securities..............................................................    3
                 Capital Stock...................................................................    3
                 Commission......................................................................    4
                 Common Securities...............................................................    4
                 Common Stock....................................................................    4
                 Company.........................................................................    4
                 Depositary......................................................................    4
                 Distributions...................................................................    4
                 Event of Default................................................................    5
                 Exchange Act....................................................................    5
                 Extension Period................................................................    5
                 Indenture.......................................................................    5
                 Investment Company Event........................................................    5
                 Maturity........................................................................    5
                 1940 Act........................................................................    5
                 Officers' Certificate...........................................................    5
                 Opinion of Counsel..............................................................    6
                 Original Issue Date.............................................................    6
                 Original Issue Discount Security................................................    6
                 Paying Agent....................................................................    6
                 Person..........................................................................    6
                 Preferred Securities............................................................    6
                 principal.......................................................................    6
                 Property Trustee................................................................    6
                 Ranking junior to the Securities................................................    7
                 Ranking on a parity with the Securities.........................................    7
                 record date.....................................................................    7
                 Register........................................................................    7
                 Resolution of the Company.......................................................    7
 

                                     -ii-

 
 
 
                                                                                                  Page
                                                                                                  ---- 
                                                                                                
                 Responsible Officer.............................................................     8 
                 Rights Plan.....................................................................     8
                 Security or Securities; outstanding.............................................     8
                 Securityholder; registered holder...............................................     9
                 Senior Indebtedness of the Company..............................................     9
                 Stated Maturity.................................................................     9
                 Subsidiary......................................................................     9 
                 Tax Event.......................................................................    10
                 Trust Agreement.................................................................    10
                 Trustee; Principal Office of the Trustee........................................    10
                 Trust Indenture Act of 1939.....................................................    10
                 Trust Securities................................................................    10 

                                  ARTICLE TWO
                ISSUE, DESCRIPTION, EXECUTION, REGISTRATION OF
                      TRANSFER AND EXCHANGE OF SECURITIES

Section 2.01.    Amount, series and delivery of Securities.......................................    11
Section 2.02     Form of Securities and Trustee's Certificate....................................    15
Section 2.03.    Denominations of and payment of interest on Securities..........................    17
Section 2.04.    Execution of Securities.........................................................    18
Section 2.05.    Registration, transfer and exchange of Securities...............................    18
Section 2.06.    Temporary Securities............................................................    20
Section 2.07.    Mutilated, destroyed, lost or stolen Securities.................................    20
Section 2.08.    Cancellation and destruction of surrendered Securities..........................    21
Section 2.09.    Authenticating Agents...........................................................    21
Section 2.10.    Deferrals of Interest Payment Dates.............................................    23
Section 2.11.    Right of Set-Off................................................................    24
Section 2.12.    Shortening or Extension of Stated Maturity......................................    24
Section 2.13.    Agreed tax treatment............................................................    24
Section 2.14.    CUSIP Numbers...................................................................    24 

                                 ARTICLE THREE
                           REDEMPTION OF SECURITIES

Section 3.01.    Applicability of Article........................................................    25
Section 3.02.    Mailing of notice of redemption.................................................    25
Section 3.03.    When Securities called for redemption become due and payable....................    26 


                                     -iii-

 
 
 
                                                                                                  Page
                                                                                                  ----
                                 ARTICLE FOUR
                      PARTICULAR COVENANTS OF THE COMPANY

                                                                                               
Section 4.01.    Payment of principal of and interest on Securities..............................    27
Section 4.02.    Maintenance of offices or agencies for registration of transfer,
                    exchange and payment of Securities...........................................    27
Section 4.03.    Appointment to fill a vacancy in the office of Trustee..........................    27
Section 4.04.    Duties of Paying Agent..........................................................    28
Section 4.05.    Further assurances..............................................................    28
Section 4.06.    Officers' Certificate as to defaults; notices of certain defaults...............    29
Section 4.07.    Waiver of covenants.............................................................    29
Section 4.08.    Additional Tax Sums.............................................................    29
Section 4.09.    Additional Covenants............................................................    30
Section 4.10.    Calculation of Original Issue Discount..........................................    30 

                                 ARTICLE FIVE
               SECURITYHOLDERS' LISTS AND REPORTS BY THE COMPANY
                                AND THE TRUSTEE

Section 5.01.    Company to furnish Trustee information as to the names and
                    addresses of Securityholders.................................................    31
Section 5.02.    Trustee to preserve information as to the names and addresses of
                    Securityholders received by it...............................................    31
Section 5.03.    Annual and other reports to be filed by Company with Trustee....................    32
Section 5.04.    Trustee to transmit annual report to Securityholders............................    33 

                                  ARTICLE SIX
                  REMEDIES OF THE TRUSTEE AND SECURITYHOLDERS
                              ON EVENT OF DEFAULT

Section 6.01.    Events of Default defined.......................................................    34
Section 6.02.    Covenant of Company to pay to Trustee whole amount due                              
                    on Securities on default in payment of interest or principal.................    37
Section 6.03.    Application of moneys collected by Trustee......................................    38      
Section 6.04.    Limitation on suits by holders of Securities....................................    39      
Section 6.05.    On default Trustee may take appropriate action..................................    40      
Section 6.06.    Rights of holders of majority in principal amount of Securities                                
                    to direct Trustee and to waive default.......................................    40
Section 6.07.    Trustee to give notice of defaults known to it, but may withhold
                    in certain circumstances.....................................................    41
Section 6.08.    Requirement of an undertaking to pay costs in certain suits under
                    the Indenture or against the Trustee.........................................    41


                                     -iv-

 


                                                                                                  Page
                                                                                                  ----
                                 ARTICLE SEVEN
                            CONCERNING THE TRUSTEE
                                                                                                
Section 7.01.    Upon Event of Default occurring and continuing, Trustee shall
                    exercise powers vested in it, and use same degree of care and
                    skill in their exercise, as a prudent man would use..........................    42
Section 7.02.    Reliance on documents, opinions, etc............................................    43    
Section 7.03.    Trustee not liable for recitals in Indenture or in Securities...................    44    
Section 7.04.    May hold Securities.............................................................    44    
Section 7.05.    Moneys received by Trustee to be held in trust without interest.................    44    
Section 7.06.    Trustee entitled to compensation, reimbursement and indemnity...................    44    
Section 7.07.    Right of Trustee to rely on Officers' Certificate where no other                             
                    evidence specifically prescribed.............................................    45
Section 7.08.    Disqualification; conflicting interests.........................................    45   
Section 7.09.    Requirements for eligibility of Trustee.........................................    45   
Section 7.10.    Resignation and Removal of Trustee..............................................    46   
Section 7.11.    Acceptance by successor Trustee.................................................    47   
Section 7.12.    Successor to Trustee by merger, consolidation or succession to business.........    48   
Section 7.13.    Limitations on rights of Trustee as a creditor to obtain payment of                         
                    certain claims within three months prior to default or during
                    default, or to realize on property as such creditor thereafter...............    48

                                 ARTICLE EIGHT
                        CONCERNING THE SECURITYHOLDERS

Section 8.01.    Evidence of action by Securityholders...........................................    52 
Section 8.02.    Proof of execution of instruments and of holding of Securities..................    52 
Section 8.03.    Who may be deemed owners of Securities..........................................    53 
Section 8.04.    Securities owned by Company or controlled or controlling persons                          
                    disregarded for certain purposes.............................................    53
Section 8.05.    Instruments executed by Securityholders bind future holders.....................    54

                                 ARTICLE NINE
                           SECURITYHOLDERS' MEETINGS

Section 9.01.    Purposes for which meetings may be called.......................................    54     
Section 9.02.    Manner of calling meetings......................................................    54     
Section 9.03.    Call of meeting by Company or Securityholders...................................    55     
Section 9.04.    Who may attend and vote at meetings.............................................    55     
Section 9.05.    Regulations may be made by Trustee..............................................    55     
Section 9.06.    Manner of voting at meetings and record to be kept..............................    56     
Section 9.07.    Exercise of rights of Trustee, Securityholders and holders of                                 
                    Preferred Securities not to be hindered or delayed...........................    56


                                      -v-

 
 
 
                                                                                                  Page
                                                                                                  ----
                                  ARTICLE TEN
                            SUPPLEMENTAL INDENTURES

                                                                                                
Section 10.01.   Purposes for which supplemental indentures may be entered
                    into without consent of Securityholders......................................    56
Section 10.02.   Modification of Indenture with consent of holders of a majority
                    in principal amount of Securities............................................    58
Section 10.03.   Effect of supplemental indentures...............................................    59
Section 10.04.   Securities may bear notation of changes by supplemental indentures..............    60
Section 10.05.   Revocation and effect of consents...............................................    60 

                                ARTICLE ELEVEN
                   CONSOLIDATION, MERGER, SALE OR CONVEYANCE

Section 11.01.   Company may consolidate, etc. on certain terms..................................    60
Section 11.02.   Successor corporation substituted...............................................    61
Section 11.03.   Opinion of Counsel to Trustee...................................................    61 

                                ARTICLE TWELVE
                   SATISFACTION AND DISCHARGE OF INDENTURE,
                               UNCLAIMED MONEYS

Section 12.01.   Satisfaction and discharge of Indenture........................................     61
Section 12.02.   Application by Trustee of funds deposited for payment of Securities............     62
Section 12.03.   Repayment of moneys held by Paying Agent.......................................     62
Section 12.04.   Repayment of moneys held by Trustee............................................     62 

                               ARTICLE THIRTEEN
              IMMUNITY OF INCORPORATORS, STOCKHOLDERS, OFFICERS,
                            DIRECTORS AND EMPLOYEES

Section 13.01.   Incorporators, stockholders, officers, directors and employees
                    of Company exempt from individual liability.................................     63

                               ARTICLE FOURTEEN
                          SUBORDINATION OF SECURITIES

Section 14.01.   Agreement to subordinate.......................................................     63
Section 14.02.   Obligation of the Company unconditional........................................     65
Section 14.03.   Limitations on duties to holders of Senior Indebtedness of the Company.........     65
Section 14.04.   Notice to Trustee of facts prohibiting payment.................................     65
Section 14.05.   Application by Trustee of moneys deposited with it.............................     66
Section 14.06.   Subrogation....................................................................     66 


                                     -vi-

 

 
                                                                                                  Page
                                                                                                  ----
                                                                                                
Section 14.07.   Subordination rights not impaired by acts or omissions of
                    Company or holders of Senior Indebtedness of the Company....................     66
Section 14.08.   Authorization of Trustee to effectuate subordination of Securities.............     67
Section 14.09.   No Payment when Senior Indebtedness in default.................................     67
Section 14.10.   Right of Trustee to hold Senior Indebtedness of the Company....................     67 

                                ARTICLE FIFTEEN
                           MISCELLANEOUS PROVISIONS

Section 15.01.   Successors and assigns of Company bound by Indenture...........................     68
Section 15.02.   Acts of board, committee or officer of successor corporation valid.............     68     
Section 15.03.   Required notices or demands may be served by mail..............................     68     
Section 15.04.   Officers' Certificate and Opinion of Counsel to be furnished                                
                    upon applications or demands by the Company.................................     68
Section 15.05.   Payments due on Saturdays, Sundays, and holidays...............................     69 
Section 15.06.   Provisions required by Trust Indenture Act of 1939 to control..................     69 
Section 15.07.   Indenture and Securities to be construed in accordance with the laws                    
                    of the State of New York....................................................     69
Section 15.08.   Provisions of the Indenture and Securities for the sole benefit                     
                    of the parties and the Securityholders......................................     69
Section 15.09.   Indenture may be executed in counterparts......................................     70
Section 15.10.   Securities in foreign currencies...............................................     70 


                                     -vii-

 
          THIS INDENTURE, dated as of the 13th day of January, 1997 between AON
CORPORATION, a corporation duly organized and existing under the laws of the
State of Delaware (hereinafter sometimes referred to as the "Company"), party of
the first part, and THE BANK OF NEW YORK, a New York banking corporation
(hereinafter sometimes referred to as the "Trustee"), party of the second part.


                                  WITNESSETH:

          WHEREAS, for its lawful corporate purposes, the Company has duly
authorized the issuance from time to time of its unsecured junior subordinated
debentures or other evidences of indebtedness (hereinafter referred to as the
"Securities"), without limit as to principal amount, issuable in one or more
series, the amount and terms of each such series to be determined as hereinafter
provided, including, without limitation, Securities issued to evidence loans
made to the Company of the proceeds from the issuance from time to time by one
or more business trusts (each an "Aon Trust," and collectively, the "Aon
Trusts") of preferred interests in such Trusts (the "Preferred Securities" which
may also be referred to, without limitation, as the "Capital Securities") and
common interests in such Trusts (the "Common Securities," and collectively with
the Preferred Securities, the "Trust Securities"); to be authenticated by the
certificate of the Trustee; and, to provide the terms and conditions upon which
the Securities are to be authenticated, issued and delivered, the Company has
duly authorized the execution of this Indenture; and

          WHEREAS, all acts and things necessary to make the Securities when
executed by the Company and authenticated and delivered by the Trustee as in
this Indenture provided, the valid, binding and legal obligations of the
Company, and to constitute these presents a valid indenture and agreement
according to its terms, have been done and performed and the execution of this
Indenture and the issue hereunder of the Securities have in all respects been
duly authorized, and the Company, in the exercise of the legal rights and power
vested in it, executes this Indenture and proposes to make, execute, issue and
deliver the Securities;

          NOW, THEREFORE, in order to declare the terms and conditions upon
which the Securities are authenticated, issued and delivered, and in
consideration of the premises and of the purchase and acceptance of the
Securities by the holders thereof, the Company covenants and agrees with the
Trustee, for the equal and proportionate benefit of the respective holders from
time to time of the Securities or of series thereof, as follows:


                                  ARTICLE ONE

                                  DEFINITIONS

          Section 1.01   CERTAIN TERMS DEFINED.  For all purposes of this
Indenture, except as otherwise expressly provided or unless the context
otherwise requires:

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

 
          (b)  All other terms used herein which are defined in the Trust
     Indenture Act of 1939, whether directly or by reference therein, have the
     meanings assigned to them therein;

          (c)  All accounting terms used herein and not expressly defined herein
     shall have the meanings assigned to them in accordance with generally
     accepted accounting principles in the United States of America, and, except
     as otherwise herein expressly provided, the term "generally accepted
     accounting principles" with respect to any computation required or
     permitted hereunder shall mean such accounting principles as are generally
     accepted in the United States of America at the date of such computation;
     provided, that when two or more principles are so generally accepted, it
     shall mean that set of principles consistent with those in use by the
     Company; and

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

Act:

          The term "Act" has the meaning specified in Section 2.01.

Additional Interest:

          The term "Additional Interest" means the interest, if any, that shall
accrue on any interest on the Securities of any series the payment of which has
not been made on the applicable interest payment date and which shall accrue at
the rate per annum specified or determined as specified in such Security.

Additional Tax Sums:

          The term "Additional Tax Sums" has the meaning specified in Section
4.08.

Administrative Trustee:

          The term "Administrative Trustee" means, in respect of any Aon Trust,
each Person identified as an "Administrative Trustee" in the related Trust
Agreement, solely in such Person's capacity as Administrative Trustee of such
Aon Trust under such Trust Agreement and not in such Person's individual
capacity, or any successor administrative trustee appointed as therein provided.

Aon Guarantee:

          The term "Aon Guarantee" means the guarantee by the Company of
distributions on the Preferred Securities of an Aon Trust to the extent provided
in the Guarantee Agreement.

                                      -2-

 
Aon Trust:

          The terms "Aon Trust" and "Aon Trusts" each have the meaning specified
in the recitals to this Indenture.

applicants:

          The term "applicants" has the meaning specified in Section 5.02(b).

Authenticating Agent:

          The term "Authenticating Agent" means any Authenticating Agent
appointed by the Trustee pursuant to Section 2.09.

Authorized Newspaper:

          The term "Authorized Newspaper" means a newspaper in the City of
Chicago, State of Illinois, and the Borough of Manhattan, The City of New York,
State of New York, each of which is printed in the English language and
customarily published at least once a day for at least five days in each
calendar week and of general circulation in the respective cities.  Whenever
successive publications are required to be made in an Authorized Newspaper, the
successive publications may be made in the same or in a different newspaper
meeting the foregoing requirements and in each case on any day of the week.  If
it is impossible or, in the opinion of the Trustee, impracticable to publish any
notice in the manner herein provided, then such publication in lieu thereof as
shall be made with the approval of the Trustee shall constitute a sufficient
publication of such notice.

Board of Directors:

          The term "Board of Directors," when used with reference to the
Company, means the Board of Directors of the Company or the Executive Committee
or any other committee of or created by the Board of Directors of the Company
duly authorized to act hereunder.

Business Day:

          The term "Business Day" means any day which is not a Saturday or
Sunday and which is neither a legal holiday nor a day on which banking
institutions in The City of New York are authorized or required by law or
executive order to close or a day on which the principal corporate trust office
of the Trustee is closed for business.

Capital Securities:

          The term "Capital Securities" has the meaning specified in the
recitals to this Indenture.

Capital Stock:

                                      -3-

 
          The term "Capital Stock" means shares of capital stock of any class of
any corporation whether now or hereafter authorized regardless of whether such
capital stock shall be limited to a fixed sum or percentage in respect of the
rights of the holders thereof to participate in dividends and in the
distribution of assets upon any voluntary or involuntary liquidation,
dissolution or winding up.

Commission:

          The term "Commission" means the Securities and Exchange Commission, as
from time to time constituted, created under the Securities Exchange Act of
1934, as amended, or, if at any time after the execution of this instrument such
Commission is not existing and performing the duties now assigned to it under
the Trust Indenture Act of 1939, then the body performing such duties on such
date.

Common Securities:

          The term "Common Securities" has the meaning specified in the recitals
to this Indenture.

Common Stock:

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

Company:

          The term "Company" means Aon Corporation, a corporation duly organized
and existing under the laws of the State of Delaware and, subject to the
provisions of Article Eleven, shall also include its successors and assigns.

Depositary:

          The term "Depositary" means, with respect to the Securities of any
series issuable or issued in whole or in part in the form of one or more global
Securities, the person designated as Depositary by the Company pursuant to
Section 2.01 until a successor Depositary shall have become such pursuant to the
applicable provisions of this Indenture, and thereafter the term "Depositary"
shall mean or include each person who is then a Depositary hereunder and if at
any time there is more than one such person, the term "Depositary" as used with
respect to the Securities of any series shall mean the Depositary with respect
to the Securities of such series.

Distributions:

          The term "Distributions," with respect to the Trust Securities issued
by an Aon Trust, means amounts payable in respect of such Trust Securities as
provided in the related Trust Agreement and referred to therein as
"Distributions."

                                      -4-

 
Event of Default:

          The term "Event of Default" with respect to Securities of any series
shall mean any event specified as such in Section 6.01 and any other event as
may be established with respect to the Securities of such series as contemplated
by Section 2.01.

Exchange Act:

          The term "Exchange Act" has the meaning specified in Section 2.02.

Extension Period:

          The term "Extension Period" has the meaning specified in Section 2.10.

Indenture:

          The term "Indenture" means this instrument as originally executed, or,
if amended or supplemented as herein provided, then as so amended or
supplemented, and shall include the form and terms of particular series of
Securities established as contemplated by Sections 2.01 and 2.02.

Investment Company Event:

          The term "Investment Company Event" means in respect of an Aon Trust,
the receipt by an Aon Trust of an Opinion of Counsel (as defined in the relevant
Trust Agreement) to the effect that, as a result of the occurrence of a change
in law or regulation or a change in interpretation or application of law or
regulation by any legislative body, court, governmental agency or regulatory
authority (a "Change in 1940 Act Law"), such Aon Trust is or will be considered
an investment company that is required to be registered under the 1940 Act,
which Change in 1940 Act Law becomes effective on or after the date of original
issuance of the Preferred Securities of such Aon Trust.

Maturity:

          The term "Maturity" when used with respect to any Security means the
date on which the principal of such Security becomes due and payable as therein
or herein provided, whether at the Stated Maturity or by declaration of
acceleration, call for redemption or otherwise.

1940 Act:

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

Officers' Certificate:

          The term "Officers' Certificate" shall mean a certificate signed by
the Chairman of the Board, any Vice Chairman of the Board, the Chief Executive
Officer, the President, any Vice Chairman or any Vice President of the Company
(whether or not designated by a number or a word or words added 

                                      -5-

 
before or after the title Vice President) and by the Treasurer, an Assistant
Treasurer, the Controller, the Secretary or an Assistant Secretary of the
Company and delivered to the Trustee. Each such certificate shall include the
statements provided for in Section 15.04, if and to the extent required by the
provisions thereof and will comply with Section 314 of the Trust Indenture Act
of 1939.

Opinion of Counsel:

          The term "Opinion of Counsel" shall mean an opinion in writing signed
by legal counsel, who shall be satisfactory to the Trustee, and who may be an
employee of, or counsel to, the Company and delivered to the Trustee.  Each such
opinion shall include the statements provided for in Section 15.04, if and to
the extent required by the provisions thereof and will comply with Section 314
of the Trust Indenture Act of 1939.

Original Issue Date:

          The term "Original Issue Date" means the first date of issuance of
each Security.

Original Issue Discount Security:

          The term "Original Issue Discount Security" shall mean any Security
which provides for an amount less than the principal amount thereof to be due
and payable upon declaration pursuant to Section 6.01.

Paying Agent:

          The term "Paying Agent" means the Trustee or any Person or Persons
authorized by the Company to pay the principal or interest on any Securities on
behalf of the Company.

Person:

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

Preferred Securities:

          The term "Preferred Securities" has the meaning specified in the
recitals to this Indenture.

principal:

          The term "principal," whenever used with reference to the Securities
or any Security or any portion thereof, shall be deemed to include "and premium,
if any."

Property Trustee:

                                      -6-

 
          The term "Property Trustee" means, in respect of any Aon Trust, the
commercial bank or trust company identified as the "Property Trustee" in the
related Trust Agreement, solely in its capacity as Property Trustee of such Aon
Trust under such Trust Agreement and not in its individual capacity, or its
successor in interest in such capacity, or any successor property trustee
appointed as therein provided.

Ranking junior to the Securities:

          The term "ranking junior to the Securities" when used with respect to
any obligation of the Company means (i) any Aon Guarantee of Preferred
Securities of any Aon Trust, and (ii) any other obligation of the Company which
(a) ranks junior to and not equally with or prior to the Securities (or any
other obligations of the Company ranking on a parity with the Securities) in
right of payment upon the happening of any event of the kind specified in the
first sentence of the first paragraph of Section 14.01, or (b) is specifically
designated as ranking junior to the Securities by express provision in the
instrument creating or evidencing such obligation.

          The securing of any obligations of the Company, otherwise ranking
junior to the Securities, shall be deemed to prevent such obligations from
constituting obligations ranking junior to the Securities.

Ranking on a parity with the Securities:

          The term "ranking on a parity with the Securities" when used with
respect to any obligation of the Company means any obligation of the Company
which (a) ranks equally with and not prior to the Securities in right of payment
upon the happening of any event of the kind specified in the first sentence of
the first paragraph of Section 14.01, or (b) is specifically designated as
ranking on a parity with the Securities by express provision in the instrument
creating or evidencing such obligation.

          The securing of any obligations of the Company, otherwise ranking on a
parity with the Securities, shall not be deemed to prevent such obligations from
constituting obligations ranking on a parity with the Securities.

record date:

          The term "record date" has the meaning specified in Section 2.03.

Register:

          The term "Register" has the meaning specified in Section 2.05.

Resolution of the Company:

          The term "Resolution of the Company" means a resolution of the
Company, in the form of a resolution of the Board of Directors, in the form of a
resolution of a duly constituted committee of the Board of Directors,  or in the
form of a resolution of two or more senior officers of the Company, authorizing,
ratifying, setting forth or otherwise validating agreements, execution and
delivery of 

                                      -7-

 
documents, the issuance, form and terms of Securities, or any other actions or
proceedings pursuant or with respect to this Indenture.

Responsible Officer:

          The term "Responsible Officer," when used with respect to the Trustee,
means the chairman and vice chairman of the board of directors, the president,
the chairman and vice chairman of the executive committee of the board of
directors, every vice president or officer senior thereto, every assistant vice
president, the secretary, every assistant secretary, the treasurer, every
assistant treasurer, every corporate trust officer, every assistant corporate
trust officer, and every other officer and 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.

Rights Plan:

          The term "Rights Plan" means a plan of the Company providing for the
issuance by the Company to all holders of its Common Stock of rights entitling
the holders thereof to subscribe for or purchase shares of Common Stock or any
class or series of preferred stock, which rights (i) are deemed to be
transferred with such shares of Common Stock, (ii) are not exercisable and (iii)
are also issued in respect of future issuances of Common Stock, in each case
until the occurrence of a specified event or events.

Security or Securities; outstanding:

          The term "Security" or "Securities" means any security or securities
of the Company, as the case may be, without regard to series, authenticated and
delivered under this Indenture.

          The term "outstanding," when used with reference to Securities and
subject to the provisions of Section 8.04, means as of any particular time, all
Securities authenticated and delivered by the Trustee under this Indenture,
except

          (a)  Securities theretofore cancelled by the Trustee or delivered to
     the Trustee for cancellation;

          (b)  Securities, or portions thereof, for the payment or redemption of
     which moneys in the necessary amount shall have been deposited in trust
     with the Trustee or with any Paying Agent (other than the Company) or shall
     have been set aside and segregated in trust by the Company (if the Company
     shall act as its own Paying Agent), provided that such Securities shall
     have reached their Stated Maturity or, if such Securities are to be
     redeemed prior to the Stated Maturity thereof, notice of such redemption
     shall have been given as in Article Three provided, or provision
     satisfactory to the Trustee shall have been made for giving such notice;
     and

          (c)  Securities in lieu of or in substitution for which other
     Securities shall have been authenticated and delivered or which have been
     paid pursuant to the terms of 

                                      -8-

 
     Section 2.07 unless proof satisfactory to the Trustee is presented that any
     such Securities are held by persons in whose hands any of such Securities
     is a valid, binding and legal obligation of the Company.

          In determining whether the holders of the requisite principal amount
of outstanding Securities have given any request, demand, authorization,
direction, notice, consent or waiver hereunder, 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 6.01.

Securityholder; registered holder:

          The terms "Securityholder," "holder of Securities," "registered
holder" or other similar term, mean any person who shall at the time be the
registered holder of any Security or Securities on the Register kept for that
purpose in accordance with the provisions of this Indenture.

Senior Indebtedness of the Company:

          The term "Senior Indebtedness of the Company" means (i) any
indebtedness of the Company for borrowed or purchased money, whether or not
evidenced by bonds, debentures, notes or other written instruments, (ii)
obligations under letters of credit, (iii) any indebtedness or other obligations
of the Company with respect to commodity contracts, interest rate and currency
swap agreements, cap, floor and collar agreements, currency spot and forward
contracts, and other similar agreements or arrangements designed to protect
against fluctuations in currency exchange or interest rates, and (iv) any
guarantees, endorsements (other than by endorsement of negotiable instruments
for collection in the ordinary course of business) or other similar contingent
obligations in respect of obligations of others of a type described in (i), (ii)
or (iii) above whether or not such obligation is classified as a liability on a
balance sheet prepared in accordance with generally accepted accounting
principles, in each case listed in (i), (ii), (iii) and (iv) above whether
outstanding on the date of execution of this Indenture or thereafter incurred,
other than obligations ranking on a parity with the Securities or ranking junior
to the Securities; provided, however, that "Senior Indebtedness of the Company"
does not include trade creditors.

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 pursuant to the terms of such Security as the date on which the
principal of such Security or such installment of interest is due and payable in
the case of such principal, as such date may be shortened or extended or
provided pursuant to the terms of such Security and this Indenture.

Subsidiary:

          The term "Subsidiary" means a corporation more than 50% of the
outstanding voting stock of which is owned, directly or indirectly, by the
Company or by one or more other Subsidiaries, or by the Company and one or more
other Subsidiaries.  For the purposes of this definition, "voting 

                                      -9-

 
stock" means stock which ordinarily has voting power for the election of
directors, whether at all times or only so long as no senior class of stock has
such voting power by reason of any contingency.

Tax Event:

          The term "Tax Event" means the receipt by the Company and an Aon Trust
of an Opinion of Counsel (as defined in the relevant Trust Agreement)
experienced in such matters to the effect that, as a result of any amendment to,
or change (including any announced prospective change) in, the laws (or any
regulations thereunder) of the United States or any political subdivision or
taxing authority thereof or therein, or as a result of any official
administrative pronouncement or judicial decision interpreting or applying such
laws or regulations, which amendment or change is effective or which
pronouncement or decision is announced on or after the date of issuance of the
Preferred Securities of such Aon Trust, there is more than an insubstantial risk
that (i) the Aon Trust is, or will be within 90 days after the date of such
Opinion of Counsel, subject to United States federal income tax with respect to
income received or accrued on the corresponding series of Securities issued by
the Company to such Aon Trust, (ii) interest payable by the Company on such
corresponding series of Securities is not, or within 90 days of the date of such
Opinion of Counsel, will not be, deductible by the Company, in whole or in part,
for United States federal income tax purposes, or (iii) the Aon Trust is, or
will be within 90 days after the date of such Opinion of Counsel, subject to
more than a de minimis amount of other taxes, duties or other governmental
charges.

Trust Agreement:

          The term "Trust Agreement" means any Trust Agreement governing any Aon
Trust, whether now existing or created in the future, relating to the Securities
of any series in each case.

Trustee; Principal Office of the Trustee:

          The term "Trustee" means the Person named as the "Trustee" in the
first paragraph of this instrument, and, subject to the provisions of Article
Seven, shall also include its successors.  The term "principal office" of the
Trustee shall mean the principal corporate trust office of the Trustee in The
City of New York, State of New York, at which the corporate trust business of
the Trustee shall, at any particular time, be administered.  The present address
of the office at which the corporate trust business of the Trustee is
administered is 101 Barclay Street, Floor 21 West, New York, New York 10286.

Trust Indenture Act of 1939:

          Except as herein otherwise expressly provided or unless the context
requires otherwise, the term "Trust Indenture Act of 1939" shall mean the Trust
Indenture Act of 1939, as amended by the Trust Indenture Reform Act of 1990, as
in force at the date as of which this Indenture was originally executed.

Trust Securities:

          The term "Trust Securities" has the meaning specified in the recitals
to this Indenture.

                                      -10-

 
                                  ARTICLE TWO

                ISSUE, DESCRIPTION, EXECUTION, REGISTRATION OF
                      TRANSFER AND EXCHANGE OF SECURITIES


          Section 2.01.  AMOUNT, SERIES AND DELIVERY OF SECURITIES.  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.  The terms of each
series (which terms shall not be inconsistent with the provisions of this
Indenture) including:

          (1)  The designation of the Securities of such series (which shall
     distinguish the Securities of the series from all other Securities and
     which shall include the word "subordinated" or a word of like meaning);

          (2)  Any limit upon the aggregate principal amount of the Securities
     of such series which may be executed, authenticated and delivered under
     this Indenture; provided, however, that nothing contained in this Section
     or elsewhere in this Indenture or in such Securities or in a Resolution of
     the Company or Officers' Certificate or supplemental indenture is intended
     to or shall limit execution by the Company or authentication and delivery
     by the Trustee of Securities under the circumstances contemplated by
     Sections 2.05, 2.06, 2.07, 3.02, 3.03 and 10.04;

          (3)  The date or dates (if any) on which the principal of the
     Securities of such series is payable;

          (4)  The rate or rates at which the Securities of such series shall
     bear interest, if any, the rate or rates and extent to which Additional
     Interest or other interest, if any, shall be payable, the date or dates
     from which such interest shall accrue, the dates on which such interest
     shall be payable, the record date for the interest payable on any interest
     payment date and the right of the Company to defer or extend an interest
     payment date;

          (5)  The place or places where Securities of such series may be
     presented for payment and for the other purposes provided in Section 4.02;

          (6)  Any price or prices at which, any period or periods within which,
     and any terms and conditions upon which Securities of such series may be
     redeemed, in whole or in part, at the option of the Company;

          (7)  The type or types (if any) of Capital Stock of the Company into
     which, any period or periods within which, and any terms and conditions
     upon which Securities of such series may be made payable, converted,
     exchanged in whole or in part, at the option of the holder or of the
     Company;

                                      -11-

 
          (8)  If other than denominations of $1,000 and any whole multiple
     thereof, the denominations in which Securities of such series shall be
     issuable;

          (9)  If other than the principal amount thereof, the portion of the
     principal amount of Securities of such series which shall be payable upon
     declaration of acceleration of the Maturity thereof pursuant to Section
     6.01;

          (10) If other than such coin or currency of the United States of
     America as at the time of payment is legal tender for payment of public or
     private debts, the coin or currency (which may be a composite currency) in
     which payment of the principal of (and premium, if any) and interest, if
     any, on the Securities of such series shall be payable;

          (11) If the principal of (and premium, if any) or interest, if any, on
     the Securities of such series are to be payable, at the election of the
     Company or a holder thereof, in a coin or currency (including composite
     currency) other than that in which the Securities of such series are stated
     to be payable, the period or periods within which, and the terms and
     conditions upon which, such election may be made;

          (12) If the amounts of payments of principal of (and premium, if any)
     or interest, if any, on the Securities of such series may be determined
     with reference to an index based on a coin or currency (including composite
     currency) other than that in which the Securities of such series are stated
     to be payable, the manner in which such amounts shall be determined;

          (13) If the Securities of such series are payable at Maturity or upon
     earlier redemption in Capital Stock, the terms and conditions upon which
     such payment shall be made;

          (14) The person or persons who shall be registrar for the Securities
     of such series, and the place or places where the Register of Securities of
     the series shall be kept;

          (15) Any Events of Default with respect to the Securities of such
     series, if not set forth herein;

          (16) Whether any Securities of such series are to be issuable in
     global form with or without coupons, and, if so, the Depositary for such
     global Securities and whether beneficial owners of interests in any such
     global Security may exchange such interests for definitive Securities of
     such series and of like tenor of any authorized form and denomination and
     the circumstances under which, and the place or places where, any such
     exchanges may occur, if other than in the manner provided in Section 2.05;

          (17) The form of Trust Agreement and Guarantee Agreement, if
     applicable;
     
          (18) If applicable, the relative degree to which Securities of such
     series shall be senior to or be subordinated to other series of such
     Securities or other indebtedness

                                      -12-

 
     of the Company in right of payment, whether such other series of Securities
     or other indebtedness are outstanding or not; and

          (19) Any other terms of the series (which terms shall not be
     inconsistent with the provisions of this Indenture);

or in any case, the method for determining such terms, the persons authorized to
determine such terms and the limits, if any, within which any such determination
of such terms is to be made shall either be established in or pursuant to a
Resolution of the Company and set forth in an Officers' Certificate, or set
forth in one or more indentures supplemental hereto, prior to the issuance of
Securities of any series.

          The Securities of all series shall be subordinate to Senior
Indebtedness of the Company as provided in Article Fourteen.  The applicable
Resolution of the Company set forth in an Officers' Certificate or supplemental
indenture may provide that Securities of any particular series may be issued at
various times, with different dates on which the principal or any installment of
principal is payable, with different rates of interest, if any, or different
methods by which interest may be determined, with different dates from which
such interest shall accrue, with different dates on which such interest may be
payable or with any different terms other than Events of Default but all such
Securities of a particular series shall for all purposes under this Indenture
including, but not limited to, voting and Events of Default, be treated as
Securities of a single series.

          If any of the terms of any series of Securities are established by
action taken pursuant to a Resolution of the Company, a copy of an appropriate
record of such action shall be certified by the Secretary or an Assistant
Secretary of the Company and delivered to the Trustee at or prior to the
delivery of the Officers' Certificate or supplemental indenture setting forth
the terms of the series.

          At any time and from time to time after the execution and delivery of
this Indenture, the Company may deliver Securities of any series executed by the
Company to the Trustee for authentication by it, and the Trustee shall thereupon
authenticate and deliver such Securities to or upon the written order of the
Company, signed by its Chairman of the Board, or its Chief Executive Officer, or
its President, or any Vice Chairman or any Vice President of the Company
(whether or not designated by a number or a word or words added before or after
the title Vice President), and by its Treasurer or an Assistant Treasurer or its
Controller or its Secretary or an Assistant Secretary, without any further
corporate action by the Company.  If the form or terms of the Securities of the
series have been established in or pursuant to a Resolution of the Company and
set forth in an Officers' Certificate, or set forth in one or more  supplemental
indentures hereto, as permitted by this Section and Section 2.02, 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 (subject to Section 7.01) shall be fully protected in
relying upon:

          (a)  an Opinion of Counsel stating:

               (i)    If the form and terms of such Securities have been
          established by or pursuant to a Resolution of the Company and set
          forth in an Officers' Certificate as permitted by Section 2.02, that
          such form and terms have been established in conformity with the
          provisions of this Indenture;

                                      -13-

 
               (ii)   If the form and terms of such Securities have been
          established by or pursuant to a Resolution of the Company and set
          forth in one or more indentures supplemental hereto as permitted by
          Section 2.02, that such form and terms have been established in
          conformity with the provisions of this Indenture;

               (iii)  That the issuance and sale of such Securities have been
          duly registered under the Securities Act of 1933, as amended (the
          "Act"), and a registration statement with respect thereto under the
          Act has become effective under the Act, or that such issuance and sale
          are exempt from the registration requirements of the Act; and that any
          other action by or before any governmental body or authority (except
          that the offer and sale of such Securities in certain jurisdictions
          may be subject to the Blue Sky or securities laws of such
          jurisdictions) required in connection with the issuance and sale of
          such Securities has been duly taken, specifying the nature thereof, or
          that no such action is required;

               (iv)   That the issuance and delivery of such Securities does not
          violate the charter or By-laws of the Company or violate any order or
          decree of any court or public authority having jurisdiction of which
          such counsel has knowledge; or result in a breach of the terms,
          conditions or provisions of, or constitute a default under, any
          mortgage, indenture, contract, agreement or undertaking known to
          counsel to which the Company is a party or by which it is bound;

               (v)   That such Securities, when executed by the Company and
          authenticated by the Trustee in accordance with the terms of this
          Indenture and delivered to the purchasers thereof against payment of
          the agreed consideration therefor in accordance with the terms of any
          purchase or similar agreement, will be entitled to the benefits of
          this Indenture and will constitute valid and binding obligations of
          the Company, enforceable against the Company in accordance with their
          terms, except as enforceability thereof may be limited by bankruptcy,
          insolvency, moratorium, reorganization, fraudulent transfer and other
          laws of general applicability relating to or affecting the enforcement
          of creditors' rights and to general principles of equity (regardless
          of whether considered in a proceeding at law or in equity);

               (vi)   If the terms of such Securities provide for the conversion
          of such Securities into shares of Capital Stock of the Company, or the
          payment thereof in Capital Stock upon Maturity or earlier redemption
          of such Securities, that the Company has reserved a sufficient number
          of shares of Capital Stock for issuance upon such conversion or
          payment, and such shares of Capital Stock, upon such issuance, will be
          duly and validly issued, fully paid and nonassessable;

               (vii)  That the Company has the corporate power to issue such
          Securities, and has duly taken all necessary corporate action with
          respect to such issuance;

                                      -14-

 
               (viii) That all laws and requirements in respect of the execution
          and delivery by the Company of such Securities and the related
          supplemental indenture, if any, have been complied with and that
          authentication and delivery of such Securities and the execution and
          delivery of the related supplemental indenture, if any, by the Trustee
          will not violate the terms of this Indenture; and

               (ix)   Such other matters as the Trustee may reasonably request;
          and
     
          (b)  An Officers' Certificate setting forth the form and terms of the
     Securities of such series pursuant to this Section and Section 2.02 hereof
     (but only if the form and terms of the Securities of such series are not
     set forth in one or more supplemental indentures hereto) and stating that
     all conditions precedent provided for in this Indenture relating to the
     issuance of such Securities have been complied with, that no Event of
     Default with respect to any series of Securities has occurred and is
     continuing and that the issuance of such Securities is not and will not
     result in (i) an Event of Default or an event or condition which, upon the
     giving of notice to, or the acquisition of knowledge by, each such officer,
     or the lapse of time or both, would become an Event of Default or (ii) a
     default under the provisions of any other instrument or agreement by which
     the Company is bound.

          The Trustee shall not be required to authenticate such Securities if
the issue of such Securities pursuant to this Indenture will 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.

          If all the Securities of any series are not to be issued at one time,
it shall not be necessary to deliver either an Opinion of Counsel or an
Officers' Certificate at the time of issuance of each Security, provided that
such Opinion of Counsel and Officers' Certificate, with appropriate
modifications, are instead delivered at or prior to the time of issuance of the
first Security of such series.

          Each Security shall be dated the date of its authentication.

          Section 2.02   FORM OF SECURITIES AND TRUSTEE'S CERTIFICATE.  The
Securities of each series shall be substantially of the tenor and terms as shall
be authorized in or pursuant to a Resolution of the Company and set forth in an
Officers' Certificate, or set forth in an indenture or indentures supplemental
hereto in each case with such appropriate insertions, omissions, substitutions
and other variations as are required or permitted by this Indenture, and may
have such letters, numbers or other marks of identification or designation and
such legends or endorsements thereon as the Company may deem appropriate and as
are not inconsistent with the provisions of this Indenture, or as may be
required to comply with any law or with any rule or regulation made pursuant
thereto or with any rule or regulation of any stock exchange or automated
quotation system on which the Securities may be listed, or to conform to usage.
If the form of Securities of any series is authorized by action taken pursuant
to a Resolution of the Company, a copy of an appropriate record of such action
shall be certified by the Secretary or an Assistant Secretary of the Company and
delivered to the Trustee at or prior to the delivery of the Officers'
Certificate contemplated by Section 2.01 setting forth the terms of the series.

          The Securities may be printed, lithographed or fully or partly
engraved.

                                      -15-

 
          The Trustee's certificate of authentication shall be in substantially
the following form:

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

                                        THE BANK OF NEW YORK, as Trustee



                                        By:  ______________________________
                                             Authorized Signatory
                                             (by manual signature only)"


          If Securities of a series are issuable in global form, as specified
pursuant to Section 2.01, then, notwithstanding clause (8) of Section 2.01 and
the provisions of Section 2.03, such Security shall represent such of the
outstanding Securities of such series as shall be specified therein and may
provide that it shall represent the aggregate amount of outstanding Securities
of such series from time to time endorsed thereon and that the aggregate amount
of outstanding Securities of such series represented thereby may from time to
time be increased or reduced to reflect exchanges or transfers.  Any endorsement
of a Security in global form to reflect the amount, or any increase or decrease
in the amount, of outstanding Securities represented thereby shall be made by
the Trustee in such manner and upon instructions given by such person or persons
as shall be specified in such Security or by the Company.  Subject to the
provisions of Section 2.04 and, if applicable, Section 2.06, the Trustee shall
deliver and redeliver any Security in global form in the manner and upon written
instructions given by the person or persons specified in such Security or by the
Company.  Any instructions by the Company with respect to endorsement or
delivery or redelivery of a Security in global form after the original issuance
of the Securities of such series shall be in writing but need not comply with
Section 15.04 and need not be accompanied by an Opinion of Counsel.

          Unless otherwise specified pursuant to Section 2.01, payment of
principal of and any premium and any interest on any Security in global form
shall be made to the person or persons specified therein.

          The owners of beneficial interests in any global Security shall have
no rights under this Indenture with respect to any global Security held on their
behalf by a Depositary, and such Depositary may be treated by the Company, the
Trustee, and any agent of the Company or the Trustee as the sole holder and
owner of such global Security for all purposes whatsoever.  Notwithstanding the
foregoing, nothing herein shall prevent the Company, the Trustee or any agent of
the Company or the Trustee from giving effect to any written certification,
proxy or other authorization furnished by a Depositary, or impair, as between a
Depositary and its participants in any global Security, the operation of
customary practices governing the exercise of the rights of a holder of a
Security of any series, including, without limitation, the granting of proxies
or other authorization of participants to give or take any request, demand,
authorization, direction, notice, consent, waiver or other action that a holder
is entitled to give or take under this Indenture.

                                      -16-

 
          Neither the Company, the Trustee nor any Authenticating 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 a global
Security or for maintaining, supervising or reviewing any records relating to
such beneficial ownership interests.

          Each Depositary designated pursuant to Section 2.01 for a global
Security must, at the time of its designation and at all times while it serves
as Depositary, be a clearing agency registered under the Securities Exchange Act
of 1934, as amended (the "Exchange Act"), and any other applicable statute or
regulation.

          Section 2.03.  DENOMINATIONS OF AND PAYMENT OF INTEREST ON SECURITIES.
The Securities of each series shall be issuable as fully registered Securities
without coupons in such denominations as shall be specified as contemplated by
Section 2.01 (except as provided in Section 2.02 and Section 2.06).  In the
absence of any such provisions with respect to the Securities of any series, the
Securities of such series shall be issuable in denominations of $1,000 and
integral multiples of $1,000 in excess thereof.

          If the Securities of any series shall bear interest, each Security of
such series shall bear interest from the applicable date at the rate or rates
per annum, and such interest shall be payable on the dates, specified on, or
determined in the manner provided in, the Security.  The person in whose name
any Security is registered at the close of business on any record date (as
defined below) for the Security with respect to any interest payment date for
such Security shall be entitled to receive the interest payable thereon on such
interest payment date notwithstanding the cancellation of such Security upon any
registration of transfer, exchange or conversion thereof subsequent to such
record date and prior to such interest payment date, unless such Security shall
have been called for redemption on a date fixed for redemption subsequent to
such record date and prior to such interest payment date or unless the Company
shall default in the payment of interest due on such interest payment date on
such Security, in which case such defaulted interest shall be paid to the person
in whose name such Security (or any Security or Securities issued upon
registration of or exchange thereof) is registered at the close of business on
the record date for the payment of such defaulted interest, or except as
otherwise specified as contemplated by Section 2.01. The term "record date" as
used in this Section with respect to any regular interest payment date for any
Security shall mean such day or days as shall be specified as contemplated by
Section 2.01; provided, however, that in the absence of any such provisions with
respect to any Security, such term shall mean: (1) if such interest payment date
is the first day of a calendar month, record date means the fifteenth day of the
calendar month next preceding such interest payment date; or (2) if such
interest payment date is the fifteenth day of a calendar month, record date
means the first day of such calendar month; provided, further, that (except as
otherwise specified as contemplated by Section 2.01) if the day which would be
the record date as provided herein is not a Business Day, then it shall mean the
Business Day next preceding such day. Such term, as used in this Section, with
respect to the payment of any defaulted interest on any Security shall mean
(except as otherwise specified as contemplated by Section 2.01) the fifth day
next preceding the date fixed by the Company for the payment of defaulted
interest, established by notice given by first class mail by or on behalf of the
Company to the holder of such Security not less than 10 days preceding such
record date, or, if such fifth day is not a Business Day, the Business Day next
preceding such fifth day.

                                      -17-

 
          Section 2.04.  EXECUTION OF SECURITIES.  The Securities shall be
signed on behalf of the Company, manually or in facsimile, by its Chairman of
the Board, or its Chief Executive Officer, or its President, or any Vice
Chairman, or any Vice President of the Company (whether or not designated by a
number or a word or words added before or after the title Vice President), and
by its Treasurer or an Assistant Treasurer or its Controller or its Secretary or
an Assistant Secretary under its corporate seal, which may be affixed thereto or
printed, engraved or otherwise reproduced thereon, by facsimile or otherwise.
Only such Securities as shall bear thereon a certificate of authentication
substantially in the form recited herein, executed by or on behalf of the
Trustee manually by an authorized signatory, shall be entitled to the benefits
of this Indenture or be valid or obligatory for any purpose.  Such certificate
of authentication by the Trustee upon any Security executed by the Company shall
be conclusive evidence that the Security so authenticated has been duly
authenticated and delivered hereunder and that the holder is entitled to the
benefits of this Indenture.  Typographical or other errors or defects in the
seal or facsimile signature on any Security or in the text thereof shall not
affect the validity or enforceability of such Security if it has been duly
authenticated and delivered by the Trustee.

          In case any officer of the Company who shall have signed any of the
Securities, manually or in facsimile, shall cease to be such officer before the
Securities so signed shall have been authenticated and delivered by the Trustee,
or disposed of by the Company, such Securities nevertheless may be authenticated
and delivered or disposed of as though the person who signed such Securities had
not ceased to be such officer of the Company; and any Security may be signed on
behalf of the Company, manually or in facsimile, by such persons as, at the
actual date of the execution of such Security, shall be the proper officers of
the Company, although at the date of the execution of this Indenture any such
person was not such officer.

          Section 2.05.  REGISTRATION, TRANSFER AND EXCHANGE OF SECURITIES.
Securities of any series (other than a global Security, except as set forth
below) may be exchanged for a like aggregate principal amount of Securities of
the same series of the same tenor and terms of other authorized denominations.
Securities to be exchanged shall be surrendered at the offices or agencies to be
maintained by the Company in accordance with the provisions of Section 4.02 and
the Company shall execute and the Trustee shall authenticate and deliver, or
cause to be authenticated and delivered, in exchange therefor the Security or
Securities which the Securityholder making the exchange shall be entitled to
receive.

          The Company shall keep, at one or more of the offices or agencies to
be maintained by the Company in accordance with the provisions of Section 4.02
with respect to the Securities of each series, a Register ( the "Register") in
which, subject to such reasonable regulations as it may prescribe, the Company
shall register the Securities of such series and the transfer of Securities of
such series as in this Article provided. Such Register shall be in written form
or in any other form capable of being converted into written form within a
reasonable time. At all reasonable times the Register shall be open for
inspection by the Trustee and any registrar of the Securities of such series
other than the Trustee. Upon due presentment for registration or transfer of any
Security of any series at the offices or agencies of the Company to be
maintained by the Company in accordance with Section 4.02 with respect to the
Securities of such series, the Company shall execute and register and the
Trustee shall authenticate and deliver in the name of the transferee or
transferees a new Security or Securities of the same series of like tenor and
terms for a like aggregate principal amount of authorized denominations.

                                      -18-

 
          Every Security issued upon registration of transfer or exchange of
Securities pursuant to this Section shall be the valid obligation of the
Company, evidencing the same debt, and entitled to the same benefits under this
Indenture, as the Security or Securities surrendered upon registration of such
transfer or exchange.

          All Securities of any series presented or surrendered for exchange,
registration of transfer, redemption, conversion or payment shall, if so
required by the Company or any registrar of the Securities of such series, be
accompanied by a written instrument or instruments of transfer, in form
satisfactory to the Company and such registrar, duly executed by the registered
holder or by his attorney duly authorized in writing.

          No service charge shall be made for any exchange or registration of
transfer of Securities, but the Company may require payment of a sum sufficient
to cover any tax or other governmental charge that may be imposed in relation
thereto.

          The Company shall not be required to exchange or register the transfer
of (a) any Securities of any series during a period beginning at the opening of
business fifteen days before the day of the mailing of a notice of redemption of
outstanding Securities of such series and ending at the close of business on the
relevant redemption date, or (b) any Securities or portions thereof called or
selected for redemption, except, in the case of Securities called for redemption
in part, the portion thereof not so called for redemption.

          Notwithstanding any other provision of this Section, unless and until
it is exchanged in whole or in part for Securities in definitive form, a global
Security representing all or a portion of the Securities of a series may not be
transferred, except as a whole by the Depositary for such series to a nominee of
such Depositary or by a nominee of such Depositary to such Depositary or another
nominee of such Depositary or by such Depositary or any such nominee to a
successor Depositary for such series or a nominee of such successor Depositary.

          Notwithstanding the foregoing, except as otherwise specified pursuant
to Section 2.01, any global Security shall be exchangeable pursuant to this
Section only as provided in this paragraph.  If at any time the Depositary for
the Securities of a series notifies the Company that it is unwilling or unable
to continue as Depositary for the Securities of such series, or if at any time
the Depositary for the Securities of such series shall no longer be eligible to
so act, the Company shall appoint a successor Depositary with respect to the
Securities of such series. If (a) a successor Depositary for the Securities of
such series is not appointed by the Company within 90 days after the Company
receives such notice or becomes aware of such ineligibility (thereby
automatically making the Company's election pursuant to Section 2.01 no longer
effective with respect to the Securities of such series), (b) the beneficial
owners of interests in a global Security are entitled to exchange such interests
for definitive Securities of such series and of the same tenor and terms, as
specified pursuant to Section 2.01, or (c) the Company in its sole discretion
determines that the Securities of any series issued in the form of one or more
global Securities shall no longer be represented by such global Security or
Securities, then without unnecessary delay, but, if appropriate, in any event
not later than the earliest date on which such interest may be so exchanged, the
Company shall deliver to the Trustee definitive Securities in aggregate
principal amount equal to the principal amount of such global Security, executed
by the Company and authenticated by the Trustee. On or after the earliest date
on which such interests are or may be so exchanged, such global

                                      -19-

 
Security shall be surrendered by the Depositary to the Trustee, as the Company's
agent for such purpose, to be exchanged, in whole or from time to time in part,
for definitive Securities upon payment by the beneficial owners of such
interest, at the option of the Company, of a service charge for such exchange
and of a proportionate share of the cost of printing such definitive Securities,
and the Trustee shall authenticate and deliver, (a) to each person specified by
the Depositary in exchange for each portion of such global Security, an equal
aggregate principal amount of definitive Securities of the same series of
authorized denominations and of the same tenor and terms as the portion of such
global Security to be exchanged, and (b) to such Depositary a 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; provided, however, that no such
exchanges may occur during a period beginning at the opening of business 15 days
before any selection of Securities of that series to be redeemed and ending on
the relevant redemption date. If a Security is issued in exchange for any
portion of a global Security after the close of business at the office or agency
where such exchange occurs on (i) any record date and before the opening of
business at such office or agency on the relevant interest payment date, or (ii)
any record date for the payment of defaulted interest and before the opening of
business at such office or agency on the related proposed date for payment of
defaulted interest, then interest or default interest, as the case may be, will
not be payable on such interest payment date or proposed date for payment of
defaulted interest, as the case may be, in respect of such Security, but will be
payable on such interest payment date or proposed date for payment of defaulted
interest, as the case may be, only to the person to whom interest in respect of
such portion of such global Security is payable in accordance with the
provisions of this Indenture and such global Security.

          Section 2.06.  TEMPORARY SECURITIES.  Pending the preparation of
definitive Securities of any series, the Company may execute and the Trustee
shall, upon the written order of the Company, authenticate and deliver temporary
Securities of such series (printed or lithographed) of any denomination and
substantially in the form of the definitive Securities of such series, but with
or without a recital of specific redemption prices or conversion provisions and
with such omissions, insertions and variations as may be appropriate for
temporary Securities, all as may be determined by the Company.  Temporary
Securities may contain such reference to any provisions of this Indenture as may
be appropriate.  Every such temporary Security shall be authenticated by the
Trustee upon the same conditions and in substantially the same manner, and with
the same effect, as the definitive Securities.  Without unreasonable delay the
Company will execute and deliver to the Trustee definitive Securities of such
series and thereupon any or all temporary Securities of such series may be
surrendered in exchange therefor, at the offices or agencies to be maintained by
the Company as provided in Section 4.02 with respect to the Securities of such
series, and the Trustee shall, upon the written order of the Company,
authenticate and deliver in exchange for such temporary Securities an equal
aggregate principal amount of definitive Securities of such series. Until so
exchanged, the temporary Securities of any series shall in all respects be
entitled to the same benefits under this Indenture as definitive Securities of
such series authenticated and delivered hereunder.

          Section 2.07.  MUTILATED, DESTROYED, LOST OR STOLEN SECURITIES.  In
case any temporary or definitive Security shall become mutilated or be
destroyed, lost or stolen, the Company, in the case of any mutilated Security
shall, and in the case of any destroyed, lost or stolen Security in its
discretion may, execute, and upon its request the Trustee shall authenticate and
deliver, or cause to be authenticated and delivered, a new Security of the same
series of like tenor and terms in exchange and substitution for the mutilated
Security, or in lieu of and in substitution for the Security so destroyed, lost
or stolen.  In 

                                      -20-

 
case any such Security shall have matured or shall be about to mature, instead
of issuing a substituted Security, the Company may pay or authorize payment of
the same (without surrender thereof, except in the case of a mutilated
Security). In every case the applicant for a substituted Security or for such
payment shall furnish to the Company and the Trustee such security or indemnity
as may be required by them to save each of them harmless, and, in every case of
destruction, loss or theft, the applicant shall also 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. The Trustee may authenticate any
such substituted Security and deliver the same, or the Trustee or any Paying
Agent of the Company may make any such payment, upon the written request or
authorization of any officer of the Company. Upon the issue of any substituted
Security, the Company may 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 reasonable expenses connected therewith (including the fees and expenses
of the Trustee).

          To the extent permitted by mandatory provisions of law, every
substituted Security issued pursuant to the provisions of this Section in
substitution for any destroyed, lost or stolen Security shall constitute an
additional contractual obligation of the Company, whether or not the destroyed,
lost or stolen Security shall be found at any time, and shall be entitled to all
the benefits of this Indenture equally and proportionately with any and all
other Securities of the same series duly issued hereunder.

          To the full extent legally enforceable, all Securities shall be held
and owned upon the express condition that the foregoing provisions are 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.

          Section 2.08.  CANCELLATION AND DESTRUCTION OF SURRENDERED SECURITIES.
All Securities surrendered for the purpose of payment, redemption, exchange,
substitution or registration of transfer, shall, if surrendered to the Company
or any agent of the Company or of the Trustee, be delivered to the Trustee, and
the same, together with Securities surrendered to the Trustee for cancellation,
shall be cancelled by it, and no Securities shall be issued in lieu thereof
except as expressly permitted by any of the provisions of this Indenture.  The
Trustee shall return cancelled Securities to the Company.  If the Company shall
purchase or otherwise acquire any of the Securities, however, such purchase or
acquisition shall not operate as a payment, redemption or satisfaction of the
indebtedness represented by such Securities unless and until the Company, at its
option, shall deliver or surrender the same to the Trustee for cancellation.

          Section 2.09.  AUTHENTICATING AGENTS.  The Trustee may from time to
time appoint one or more Authenticating Agents with respect to one or more
series of Securities, which shall be authorized to act on behalf of the Trustee
and subject to its direction in authenticating and delivering Securities of such
series pursuant hereto as fully to all intents and purposes as though any such
Authenticating Agent had been expressly authorized to authenticate and deliver
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 though authenticated by the Trustee.   Wherever reference is made in
this Indenture to the authentication or delivery of Securities by the Trustee or
the Trustee's certificate of authentication, such reference shall be deemed to
include authentication or delivery on behalf of the Trustee by an Authenticating
Agent and a certificate of authentication executed on behalf of the Trustee by
an 

                                      -21-

 
Authenticating Agent. Each Authenticating Agent shall at all times be a
corporation (including a banking association) organized and doing business under
the laws of the United States or any State or territory thereof or of the
District of Columbia, having a combined capital and surplus of at least five
million dollars ($5,000,000) authorized under such laws to exercise corporate
trust powers and subject to supervision or examination by federal, state,
territorial, or District of Columbia authorities. If such corporation publishes
reports of condition at least annually, pursuant to law or to the requirements
of the aforesaid supervising or examining authority, then for the purposes of
this Section, 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. If at any time an Authenticating Agent shall
cease to be eligible in accordance with the provisions of this Section, it shall
resign immediately in the manner and with the effect herein specified in this
Section.

          The Trustee hereby initially appoints The Bank of New York, through
its trust offices at 101 Barclay Street, Floor 21 West, New York, New York 10286
as Authenticating Agent.

          Any corporation succeeding to the corporate agency business of an
Authenticating Agent shall continue to be an Authenticating Agent, if such
successor corporation is otherwise eligible under this Section, without the
execution or filing of any paper or any further act on the part of the Trustee
or the Authenticating Agent or such successor corporation.

          Any Authenticating Agent may at any time resign by giving written
notice of resignation to the Trustee and to the Company.  The Trustee may at any
time terminate the agency of an Authenticating Agent by giving written notice of
termination to such Authenticating Agent and to the Company.  Upon receiving
such a notice of resignation or upon such a termination, or in case at any time
an Authenticating Agent shall cease to be eligible in accordance with the
provisions of this Section, the Trustee may appoint a successor Authenticating
Agent.  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 herein.  No successor Authenticating Agent shall be
appointed unless eligible under the provisions of this Section.

          The Company agrees to pay to each Authenticating Agent from time to
time reasonable compensation for its services under this Section.

          Any Authenticating Agent by the acceptance of its appointment shall be
deemed to have agreed with the Trustee that:  it will perform and carry out the
duties of an Authenticating Agent as herein set forth, including among other
things the duties to authenticate and deliver Securities of any series for which
it has been appointed an Authenticating Agent when presented to it in connection
with exchanges, registrations of transfer or any redemptions or conversions
thereof; it will furnish from time to time as requested by the Trustee
appropriate records of all transactions carried out by it as Authenticating
Agent and will furnish the Trustee such other information and reports as the
Trustee may reasonably require; it is eligible for appointment as Authenticating
Agent under this Section and will notify the Trustee promptly if it shall cease
to be so qualified; and it will indemnify the Trustee against any loss,
liability or expense incurred by the Trustee and will defend any claim asserted
against the Trustee by reason of any acts or failures to act of the
Authenticating Agent but it shall have no liability for any action taken by it
at the specific written direction of the Trustee.

                                      -22-

 
          Section 2.10.  DEFERRALS OF INTEREST PAYMENT DATES.    If specified as
contemplated by Section 2.01 or Section 2.02 with respect to the Securities of a
particular series, so long as no Event of Default has occurred and is
continuing, the Company shall have the right, at any time during the term of
such series, from time to time to defer the payment of interest on such
Securities for such period or periods as may be specified as contemplated by
Section 2.01 (each, an "Extension Period") during which Extension Periods the
Company shall have the right to make partial payments of interest on any
interest payment date.  No Extension Period shall end on a date other than an
interest payment date or extend beyond the Stated Maturity or any earlier
prepayment date.  At the end of any such Extension Period the Company shall pay
all interest then accrued and unpaid on the Securities (together with Additional
Interest or other interest thereon, if any, at the rate specified for the
Securities of such series to the extent permitted by applicable law).  During
any such Extension Period, the Company shall not, and shall cause any Subsidiary
not to, (i) declare or pay any dividends or distributions on, or redeem,
purchase, acquire or make a liquidation payment with respect to, any of the
Company's Capital Stock (which includes Common Stock and preferred stock) or
(ii) make any payment of principal of or interest or premium, if any, on or
repay, repurchase or redeem any debt securities of the Company that rank on a
parity with or junior to the Securities of such series or make any guarantee
payments with respect to any Aon Guarantee or other guarantee by the Company of
the debt securities of any Subsidiary of the Company that by its terms ranks on
a parity with or junior to the Securities of such series (other than (a)
dividends or distributions in Common Stock; (b) any declaration of a dividend in
connection with the implementation of a Rights Plan, the issuance of any Capital
Stock of any class or series of preferred stock of the Company under any Rights
Plan or the redemption or repurchase of any rights distributed pursuant to a
Rights Plan; (c) payments under any Aon Guarantee relating to the Preferred
Securities issued by the Aon Trust holding the Securities of such series; and
(d) purchases of Common Stock related to the issuance of Common Stock or rights
under any of the Company's benefit plans for its directors, officers,
employees, consultants or advisors).  Before the termination of any Extension
Period, the Company may further extend such Extension Period; provided, however,
that no Extension Period shall exceed the period or periods specified in such
Securities or extend beyond the Stated Maturity of the principal of such
Securities or any earlier prepayment date.  At any time following the
termination of any Extension Period and upon the payment of all accrued and
unpaid interest and any Additional Interest or other interest then due, the
Company may elect to begin a new Extension Period, subject to the above
requirements.  No interest shall be due and payable during an Extension Period,
except at the end thereof.  If the Property Trustee of an Aon Trust is the only
registered holder of the Securities of a series at the time the Company elects
to begin or extend an Extension Period, the Company shall give written notice to
such Property Trustee and the Trustee of its election to begin or extend any
Extension Period at least five Business Days prior to the earlier of (i) the
next succeeding date on which Distributions on the corresponding Capital
Securities issued by such Aon Trust would have been payable but for the election
to begin or extend such Extension Period or (ii) the date the Administrative
Trustees of such Aon Trust are required to give notice to any securities
exchange or other applicable self-regulatory organization or to holders of such
Capital Securities of the record date or the date such Distributions are
payable, but in any event not less than five Business Days prior to such record
date.

          If the Property Trustee of an Aon Trust is not the only holder of the
Securities of a series at the time the Company elects to begin or extend an
Extension Period, the Company shall give the holders of such Securities and the
Trustee written notice of its election to begin or extend such Extension Period
at least ten Business Days prior to the earlier of (i) the next succeeding
interest payment date or

                                      -23-

 
(ii) the date the Company is required to give notice of the record or payment
date of such interest payment to any applicable self-regulatory organization or
to holders of such Securities.

          An Administrative Trustee shall give notice of the Company's election
to begin or extend an Extension Period to the holders of the outstanding
Preferred Securities of such Aon Trust.

          Section 2.11.  RIGHT OF SET-OFF.  With respect to the Securities of a
series issued to an Aon Trust, notwithstanding anything to the contrary in the
Indenture, the Company shall have the right to set off any payment it is
otherwise required to make thereunder in respect of any such Security to the
extent the Company has theretofore made, or is concurrently on the date of such
payment making, a payment under the Aon Guarantee relating to such Security or
under Section 6.05 of this Indenture.

          Section 2.12.  SHORTENING OR EXTENSION OF STATED MATURITY.  If
specified as contemplated by Section 2.01 or Section 2.02 with respect to the
Securities of a particular series, the Company shall have the right to (i)
shorten the Stated Maturity of the principal of the Securities of such series at
any time to any date not earlier than the first date on which the Company has
the right, if any,  to redeem the Securities of such series, and (ii) extend the
Stated Maturity of the principal of the Securities of such series at any time at
its election for one or more periods, but in no event to a date later than the
49th anniversary of the first interest payment date following the Original Issue
Date of the Securities of such series; provided that, if the Company elects to
exercise its right to extend the Stated Maturity of the principal of the
Securities of such series pursuant to this clause (ii), at the time such
election is made and at the time of extension (A) the Company is not in
bankruptcy, otherwise insolvent or in liquidation, (B) the Company is not in
default in the payment of any interest or principal on such Securities, (C) in
the case of any series of Securities issued to an Aon Trust, such Aon Trust is
not in arrears on payments of Distributions on the Preferred Securities issued
by such Aon Trust and no deferred Distributions are accumulated, and (D) such
Securities are rated not less than BBB- by Standard & Poor's Ratings Services or
Baa3 by Moody's Investors Service, Inc. or the equivalent by any other
nationally recognized statistical rating organization.  In the event the Company
elects to shorten or extend the Stated Maturity of the Securities of a
particular series, it shall give notice to the Trustee (not less than 45 days
prior to the effectiveness thereof), and the Trustee shall give notice of such
shortening or extension to the holders not less than 30 nor more than 60 days
prior to the effectiveness thereof.

          Section 2.13.  AGREED TAX TREATMENT.  Each Security issued hereunder
shall provide that the Company and, by its acceptance of a security or a
beneficial interest therein, the holder of, and any Person that acquires a
beneficial interest in, such Security agree that for United States federal,
state and local tax purposes it is intended that such Security constitute
indebtedness.

          Section 2.14  CUSIP NUMBERS.  The Company in issuing the Securities
may use "CUSIP" numbers (if then generally in use), and, if so, the Trustee
shall use "CUSIP" numbers in notices of redemption as a convenience to holders
of Securities; provided that any such notice may state that no representation is
made as to the correctness of such numbers either as printed on the Securities
or as contained in any notice of a redemption and that reliance may be placed
only on the other identification numbers printed on the Securities, and any such
redemption shall not be affected by any defect in or omission of such numbers.
The Company will promptly notify the Trustee of any change in the CUSIP numbers.

                                      -24-

 
                                 ARTICLE THREE

                           REDEMPTION OF SECURITIES

          Section 3.01.  APPLICABILITY OF ARTICLE.  Securities of any series
which are redeemable prior to Stated Maturity shall be redeemable in accordance
with their terms and (except as otherwise specified as contemplated by Section
2.01 for Securities of any series) in accordance with this Article.

          Section 3.02.  MAILING OF NOTICE OF REDEMPTION.  In case the Company
shall desire to exercise any right to redeem all or, as the case may be, any
part of the Securities of any series pursuant to this Indenture, it shall give
notice of such redemption to holders of the Securities to be redeemed as
hereinafter in this Section provided.

          The Company covenants that it will pay to the Trustee or one or more
Paying Agents, on or before the Business Day next preceding the date fixed for
each redemption of Securities, a sum in cash sufficient to redeem on the
redemption date all the Securities so called for redemption at the applicable
redemption price, together with any accrued interest on the Securities to be
redeemed to but excluding the date fixed for redemption.

          Notice of redemption shall be given to the holders of Securities to be
redeemed as a whole or in part by mailing by first class mail, postage prepaid,
a notice of such redemption not less than 30 nor more than 60 days prior to the
date fixed for redemption to their last addresses as they shall appear upon the
Register, but failure to give such notice by mailing in the manner herein
provided to the holder of any Security designated for redemption as a whole or
in part, or any defect therein, shall not affect the validity of the proceedings
for the redemption of any other Security.

          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.

          Each such notice of redemption shall identify the Securities to be
redeemed (including CUSIP numbers) and specify the date fixed for redemption and
the redemption price at which Securities are to be redeemed (or if the
redemption price cannot be calculated prior to the time the notice is required
to be given, the manner of calculation thereof), and shall state that payment of
the redemption price of the Securities or portions thereof to be redeemed will
be made at any of the offices or agencies to be maintained by the Company in
accordance with the provisions of Section 4.02 with respect to the Securities to
be redeemed, upon presentation and surrender of such Securities or portions
thereof, and that, if applicable, interest accrued to the date fixed for
redemption will be paid as specified in said notice and on and after said date
interest thereon will cease to accrue and shall also specify, if applicable, the
conversion price and the date on which the right to convert the Securities will
expire and that holders must comply with Article Fifteen hereof in order to
convert their Securities.  If less than all the Securities of any series are to
be redeemed, the notice of redemption to each holder shall specify such holder's
Securities of such series to be redeemed as a whole or in part.  In case any
Security is to be redeemed in part only, the notice which relates to such
Security shall state the portion of the principal amount thereof to be redeemed
(which shall be equal to the minimum authorized denomination for Securities of
such series or any whole multiple thereof), and shall state that on and after
the redemption date, upon 

                                      -25-

 
surrender of such Security, the holder will receive the redemption price in
respect to the principal amount thereof called for redemption and, without
charge, a new Security or Securities of the same series of authorized
denominations for the principal amount thereof remaining unredeemed.

          If the Securities of any series are to be redeemed, the Company shall
give the Trustee, at least 60 days in advance of the date fixed for redemption,
notice of the aggregate principal amount of Securities of such series to be
redeemed, and, if less than all the Securities of such series are to be
redeemed, thereupon the Trustee shall select, by lot, or in any manner it shall
deem fair, the Securities of such series to be redeemed as a whole or in part
and shall thereafter promptly notify the Company in writing of the particular
Securities of such series or portions thereof to be redeemed.  If the Securities
of any series to be redeemed consist of Securities having different dates on
which the principal or any installment of principal is payable or different
rates of interest, if any, or different methods by which interest may be
determined or have any other different tenor or terms, then the Company may, by
written notice to the Trustee, direct that Securities of such series to be
redeemed shall be selected from among groups of such Securities having specified
tenor or terms and the Trustee shall thereafter select the particular Securities
to be redeemed in the manner set forth in the preceding sentence from among the
group of such Securities so specified.

          Section 3.03.  WHEN SECURITIES CALLED FOR REDEMPTION BECOME DUE AND
PAYABLE.  If the giving of notice of redemption shall have been completed as
above provided, the Securities or portions of Securities specified in such
notice shall become due and payable on the date and at the place or places
stated in such notice at the applicable redemption price, together, if
applicable, with any interest accrued (including any Additional Interest or
other interest) to but excluding the date fixed for redemption, and on and after
such date fixed for redemption (unless the Company shall default in the payment
of such Securities at the applicable redemption price, together with any
interest accrued to the date fixed for redemption) any interest on the
Securities or portions of Securities so called for redemption shall cease to
accrue, and, except as provided in Sections 7.05 and 12.04, such Securities
shall cease from and after the date fixed for redemption to be entitled to any
benefit or security under this Indenture, and the holders thereof shall have no
right in respect of such Securities except the right to receive the redemption
price thereof and any unpaid interest accrued to but excluding the date fixed
for redemption.  On presentation and surrender of such Securities at said place
of payment in said notice specified, such Securities or portions thereof shall
be paid and redeemed by the Company at the applicable redemption price, together
with any interest accrued to but excluding the date fixed for redemption;
provided, however, that, except as otherwise specified as contemplated by
Section 2.01, any regular payment of interest becoming due on the date fixed for
redemption shall be payable to the holders of the Securities registered as such
on the relevant record date as provided in Article Two hereof.  Upon surrender
of any Security which is redeemed in part only, the Company shall execute and
the Trustee shall authenticate and deliver at the expense of the Company a new
Security of the same series of like tenor and terms of authorized denomination
in principal amount equal to the unredeemed portion of the Security so
surrendered; except that if a global Security is so surrendered, the Company
shall execute, and the Trustee shall authenticate and deliver to the Depositary
for such global Security, without service charge, a global Security in a
denomination equal to and in exchange for the unredeemed portion of the
principal of the global Security so surrendered.
 
          If any Security called for redemption shall not be so paid upon
surrender thereof for redemption, the principal shall, until paid, bear interest
from the date fixed for redemption at the rate 

                                      -26-

 
borne by or prescribed therefor in the Security, or, in the case of a Security
which does not bear interest, at the rate of interest set forth therefor in the
Security to the extent permitted by law.



                                 ARTICLE FOUR

                      PARTICULAR COVENANTS OF THE COMPANY

          The Company covenants as follows:

          Section 4.01.  PAYMENT OF PRINCIPAL OF AND INTEREST ON SECURITIES.
The Company will duly and punctually pay or cause to be paid the principal of
and interest, if any, on each of the Securities at the time and places and in
the manner provided herein and in the Securities.  Except as otherwise specified
as contemplated by Section 2.01, if the Securities of any series bear interest,
each installment of interest on the Securities of such series may at the option
of the Company be paid (i) by mailing a check or checks for such interest
payable to the Person entitled thereto pursuant to Section 2.03 to the address
of such person as it appears on the Register of the Securities of such series or
(ii) by transfer to an account maintained by the Person entitled thereto as
specified in the Register of Securities, provided that proper transfer
instructions have been received by the record date.

          Section 4.02.  MAINTENANCE OF OFFICES OR AGENCIES FOR REGISTRATION OF
TRANSFER, EXCHANGE AND PAYMENT OF SECURITIES.  So long as any of the Securities
shall remain outstanding, the Company will maintain an office or agency in the
City of Chicago, State of Illinois, or in The City of New York, State of New
York, where the Securities may be presented for registration, conversion,
exchange and registration of transfer as in this Indenture provided, and where
notices and demands to or upon the Company in respect of the Securities or of
this Indenture may be served, and where the Securities may be presented for
payment.  In case the Company shall designate and maintain some office or agency
other than the previously designated office or agency, it shall give the Trustee
prompt written notice thereof.  In case the Company shall fail to maintain any
such office or agency or shall fail to give such notice of the location or of
any change in the location thereof to the Trustee, presentations and demands may
be made and notices may be served at the principal office of the Trustee.

          In addition to such office or agency, the Company may from time to
time constitute and appoint one or more other offices or agencies for such
purposes with respect to Securities of any series, and one or more paying agents
for the payment of Securities of any series, in such cities or in one or more
other cities, and may from time to time rescind such appointments, as the
Company may deem desirable or expedient, and as to which the Company has
notified the Trustee; provided, however, that no such appointment or rescission
shall in any manner relieve the Company of its obligation to maintain such
office or agency in the said Cities of Chicago and New York, where Securities of
such series may be presented for payment.

          Section 4.03.  APPOINTMENT TO FILL A VACANCY IN THE OFFICE OF TRUSTEE.
The Company, whenever necessary to avoid or fill a vacancy in the office of
Trustee, will appoint, in the manner provided in Section 7.10, a Trustee, so
that there shall at all times be a Trustee with respect to each series of
Securities hereunder.

                                      -27-

 
          Section 4.04.  DUTIES OF PAYING AGENT.  (a) If the Company shall
appoint a Paying Agent other than the Trustee with respect to Securities of any
series, it will cause such Paying Agent to execute and deliver to the Trustee an
instrument in which such Paying Agent shall agree with the Trustee, subject to
the provisions of this Section and Section 12.03,

          (1)  That it will hold all sums held by it as such agent for the
     payment of the principal of or interest, if any, on the Securities of such
     series (whether such sums have been paid to it by the Company or by any
     other obligor on the Securities of such series) in trust for the benefit of
     the holders of the Securities of such series entitled to such principal or
     interest and will notify the Trustee of the receipt of sums to be so held,

          (2)  That it will give the Trustee notice of any failure by the
     Company (or by any other obligor on the Securities of such series) to make
     any payment of the principal of or interest on the Securities of such
     series when the same shall be due and payable, and

          (3)  That it will at any time during the continuance of any Event of
     Default, upon the written request of the Trustee, deliver to the Trustee
     all sums so held in trust by it.

          (b)  Whenever the Company shall have one or more Paying Agents with
respect to the Securities of any series, it will, prior to each due date of the
principal of or any interest on a Security of such series, deposit with a Paying
Agent of such series a sum sufficient to pay the principal or interest so
becoming due, such sum to be held in trust for the benefit of the holders of
Securities of such series entitled to such principal or interest, and (unless
such Paying Agent is the Trustee) the Company will promptly notify the Trustee
of its action or failure so to act.

          (c)  If the Company shall act as its own Paying Agent with respect to
the Securities of any series, it will, on or before each due date of the
principal of or any interest on a Security of such series, set aside, segregate
and hold in trust for the benefit of the holder of such Security, a sum
sufficient to pay such principal or interest so becoming due and will notify the
Trustee of such action, or any failure by it or any other obligor on the
Securities of such series to take such action and will at any time during the
continuance of any Event of Default, upon the written request of the Trustee,
deliver to the Trustee all sums so held in trust by it.

          (d)  Anything in this Section to the contrary notwithstanding, the
Company may, at any time, for the purpose of obtaining a satisfaction and
discharge of this Indenture with respect to one or more or all series of
Securities hereunder, or for any other reason, pay or cause to be paid to the
Trustee all sums held in trust for such series by it, or any Paying Agent
hereunder, as required by this Section, such sums are to be held by the Trustee
upon the trust herein contained.

          (e)  Anything in this Section to the contrary notwithstanding, the
agreement to hold sums in trust as provided in this Section is subject to the
provisions of Sections 12.03 and 12.04.

          Section 4.05.  FURTHER ASSURANCES.  From time to time whenever
reasonably demanded by the Trustee, the Company will make, execute and deliver
or cause to be made, executed and delivered 

                                      -28-

 
any and all such further and other instruments and assurances and take all such
further action as may be reasonably necessary or proper to carry out the
intention of or to facilitate the performance of the terms of this Indenture or
to secure the rights and remedies hereunder of the holders of the Securities of
any series.

          Section 4.06.  OFFICERS' CERTIFICATE AS TO DEFAULTS; NOTICES OF
CERTAIN DEFAULTS.  The Company will, so long as any of the Securities are
outstanding, deliver to the Trustee no later than 120 days after the end of each
calendar year, beginning with the year 1998, a certificate signed by the
Company's principal executive officer, principal financial officer or principal
accounting officer stating that a review has been made under his or her
supervision of the activities of the Company during such year and of the
performance under this Indenture and, to the best of his or her knowledge, the
Company has complied with all conditions and covenants under this Indenture
throughout such calendar year, or if there has been a default in the fulfillment
of any such obligation, specifying each such default known and the nature and
status thereof. For purposes of this Section, such compliance shall be
determined without regard to any period of grace or requirement of notice
provided under this Indenture.

          Section 4.07.  WAIVER OF COVENANTS.  The Company may omit in any
particular instance to comply with any covenant or condition specifically
contained in this Indenture for the benefit of one or more series of Securities,
if before the time for such compliance the holders of a majority in principal
amount of the Securities of all series affected (all series voting as one class)
at the time outstanding (determined as provided in Section 8.04) shall waive
such compliance in such instance, but no such waiver shall extend to or affect
such covenant or condition except to the extent so expressly waived, and, until
such waiver shall become effective, the obligations of the Company and the
duties of the Trustee in respect of any such covenant or condition shall remain
in full force and effect.

          Section 4.08.  ADDITIONAL TAX SUMS.  In the case of the Securities of
a series issued to an Aon Trust, so long as no Event of Default has occurred and
is continuing and except as otherwise specified as contemplated by Section 2.01
or Section 2.02, in the event that (i) an Aon Trust is the holder of all of the
Outstanding Securities of such series, (ii) a Tax Event in respect of such Aon
Trust shall have occurred and be continuing and (iii) the Company shall not have
(a) redeemed the Securities of such series or (b) terminated such Aon Trust
pursuant to the termination provisions of the related Trust Agreement, the
Company shall pay to such Aon Trust (and any permitted successor or assign under
the related Trust Agreement) for so long as such Aon Trust (or its permitted
successor or assignee) is the registered holder of any Securities of such
series, such additional amounts as may be necessary in order that the amount of
Distributions then due and payable by such Aon Trust on the related Preferred
Securities and Common Securities that at any time remain outstanding in
accordance with the terms thereof shall not be reduced as a result of any
additional taxes, duties and other governmental charges to which such Aon Trust
has become subject as a result of such Tax Event (but not including withholding
taxes imposed on holders of such Preferred Securities and Common Securities)
(the "Additional Tax Sums").  Whenever in this Indenture or the Securities there
is a reference in any context to the payment of principal of or interest on the
Securities, such reference shall be deemed to include payment of the Additional
Tax Sums provided for in this paragraph to the extent that, in such context,
Additional Tax Sums are, were or would be payable in respect thereof pursuant to
the provisions of this Section and express reference to the payment of
Additional Tax Sums (if applicable) in any provisions hereof shall not be
construed as excluding Additional Tax Sums in those provisions hereof where such
express reference is not made; provided, however, that the deferral of the
payment of interest pursuant to Section 

                                      -29-

 
2.10 or the Securities shall not defer the payment of any Additional Tax Sums
that may be then due and payable.

          Section 4.09.  ADDITIONAL COVENANTS.  The Company covenants and agrees
with each holder of Securities of a series issued to an Aon Trust that it shall
not, and it shall cause any Subsidiary not to, (i) declare or pay any dividends
or distributions on, or redeem, purchase, acquire, or make a liquidation payment
with respect to, any shares of the Company's Capital Stock (which includes
Common Stock and preferred stock), or (ii) make any payment of principal of or
interest or premium, if any, on or repay, repurchase or redeem any debt
securities of the Company that rank on a parity with or junior to the Securities
of such series or make any guarantee payments with respect to any Aon Guarantee
or other guarantee by the Company of debt securities of any Subsidiary that by
its terms ranks on a parity with or junior to the Securities of such series
(other than (a) dividends or distributions in Common Stock; (b) any declaration
of a dividend in connection with the implementation of a Rights Plan, the
issuance of any Capital Stock of any class or series of preferred stock of the
Company under any Rights Plan or the redemption or repurchase of any rights
distributed pursuant to a Rights Plan; (c) payments under any Aon Guarantee
relating to the Preferred Securities issued by the Aon Trust holding the
Securities of such series; and (d) purchases of Common Stock related to the
issuance of Common Stock or rights under any of the Company's benefit plans for
its directors, officers, employees, consultants or advisors) if at such time (i)
there shall have occurred any event of which the Company has actual knowledge
that (a) with the giving of notice or the lapse of time or both, would
constitute an Event of Default hereunder and (b) in respect of which the Company
shall not have taken reasonable steps to cure, (ii) the Company shall be in
default with respect to its payment of any obligations under the related Aon
Guarantee or (iii) the Company shall have given notice of its election to begin
an Extension Period as provided in Section 2.10 and shall not have rescinded
such notice, or such Extension Period, or any extension thereof, shall be
continuing.

          The Company also covenants with each holder of Securities of a series
issued to an Aon Trust (i) to maintain directly or indirectly 100% ownership of
the Common Securities of such Aon Trust; provided, however, that any permitted
successor or assignee of the Company hereunder may succeed to the Company's
ownership of such Common Securities, (ii) not to voluntarily terminate, wind up
or liquidate such Aon Trust, except (a) in connection with a prepayment in full
of the Securities or a distribution of the Securities of such series to the
holders of Preferred Securities in liquidation of such Aon Trust or (b) in
connection with certain mergers, consolidations or amalgamations permitted by
the relevant Trust Agreement and (iii) to use its reasonable efforts, consistent
with the terms and provisions of such Trust Agreement, to cause such Aon Trust
to remain classified as a grantor trust and not an association taxable as a
corporation for United States federal income tax purposes.

          Section 4.10.  CALCULATION OF ORIGINAL ISSUE DISCOUNT.  The Company
shall file with the Trustee promptly at the end of each calendar year (i) a
written notice specifying the amount of original issue discount (including daily
rates and accrual periods) accrued on outstanding Securities as of the end of
such year and (ii) such other specific information relating to such original
issue discount as may then be relevant under the Internal Revenue Code of 1986,
as amended from time to time.

                                      -30-

 
                                 ARTICLE FIVE

               SECURITYHOLDERS' LISTS AND REPORTS BY THE COMPANY
                                AND THE TRUSTEE

          Section 5.01.  COMPANY TO FURNISH TRUSTEE INFORMATION AS TO THE NAMES
AND ADDRESSES OF SECURITYHOLDERS.  The Company covenants and agrees that it will
furnish or cause to be furnished to the Trustee, semiannually not more than 5
days after January 15 and July 15 of each year beginning with July 1997, and at
such other times as the Trustee may request in writing within 30 days after
receipt by the Company of any such request, a list in such form as the Trustee
may reasonably require containing all information in the possession or control
of the Company, or any Paying Agent or any registrar of the Securities of each
series, other than the Trustee, as to the names and addresses of the holders of
Securities of such series obtained (in the case of each list other than the
first list) since the date as of which the next previous list was furnished;
provided, however, that if the Trustee shall be the registrar of the Securities
of such series, no such list need be furnished. Any such list may be dated as of
a date not more than fifteen days prior to the time such information is
furnished or caused to be furnished, and need not include information received
after such date.

          Section 5.02.  TRUSTEE TO PRESERVE INFORMATION AS TO THE NAMES AND
ADDRESSES OF SECURITYHOLDERS RECEIVED BY IT.  (a) The Trustee shall preserve, in
as current a form as is reasonably practicable, all information as to the names
and addresses of the holders of Securities of each series (1) contained in the
most recent list furnished to it as provided in Section 5.01 and (2) received by
it in the capacity of Paying Agent or registrar (if so acting).  The Trustee may
destroy any list furnished to it as provided in Section 5.01 upon receipt of a
new list so furnished.

          (b)  In case three or more holders of Securities of any series
(hereinafter referred to as "applicants") apply in writing to the Trustee, and
furnish to the Trustee reasonable proof that each such applicant has owned a
Security for a period of at least six months preceding the date of such
application, and such application states that the applicants desire to
communicate with other holders of Securities of any series or with holders of
all Securities with respect to their rights under this Indenture or under such
Securities, and is accompanied by a copy of the form of proxy or other
communication which such applicants propose to transmit, then the Trustee shall,
within five Business Days after the receipt of such application, at its
election, either

          (1)  afford such applicants access to the information preserved at the
     time by the Trustee in accordance with the provisions of subsection (a) of
     this Section, or

          (2)  inform such applicants as to the approximate number of holders of
     Securities of such series or all Securities, as the case may be, whose
     names and addresses appear in the information preserved at the time by the
     Trustee in accordance with the provisions of subsection (a) of this
     Section, and as to the approximate cost of mailing to such Securityholders
     the form of proxy or other communication, if any, specified in such
     application.

                                      -31-

 
          If the Trustee shall elect not to afford such access to such
information, the Trustee shall, upon the written request of such applicants,
mail to each of the holders of Securities of such series, or all Securities, as
the case may be, whose name and address appear in the information preserved at
the time by the Trustee in accordance with the provisions of subsection (a) of
this Section, a copy of the form of proxy or other communication which is
specified in such request, with reasonable promptness after a tender to the
Trustee of the material to be mailed and after payment, or provision for the
payment, of the reasonable expenses of mailing, unless within five days after
such tender, the Trustee shall mail to such applicants and file with the
Commission, together with a copy of the material to be mailed, a written
statement to the effect that, in the opinion of the Trustee, such mailing would
be contrary to the best interests of the holders of Securities of such series or
all Securities, as the case may be, or would be in violation of applicable law.
Such written statement shall specify the basis of such opinion.  If the
Commission, after opportunity for a hearing upon the objections specified in the
written statement so filed, shall enter an order refusing to sustain any of such
objections or if, after the entry of an order sustaining one or more of such
objections, the Commission shall find, after notice and opportunity for hearing,
that all the objections so sustained have been met and shall enter an order so
declaring, the Trustee shall mail copies of such material to all the holders of
Securities of such series or all Securities, as the case may be, with reasonable
promptness after the entry of such order and the renewal of such tender;
otherwise the Trustee shall be relieved of any obligation or duty to such
applicants respecting their application.

          (c)  Each and every holder of Securities, by receiving and holding the
same, agrees with the Company and the Trustee that neither the Company nor the
Trustee nor any Paying Agent nor any registrar shall be held accountable by
reason of the disclosure of any such information as to the names and addresses
of the holders of Securities in accordance with the provisions of subsection (b)
of this Section, regardless of the source from which such information was
derived, and that the Trustee shall not be held accountable by reason of mailing
any material pursuant to a request made under said subsection (b).

          (d)  If there shall be different Trustees acting hereunder with
respect to separate series of Securities, applicants shall make separate
applications hereunder to each such Trustee, and such Trustees shall
collaborate, if necessary, in acting under this Section.

          Section 5.03.  ANNUAL AND OTHER REPORTS TO BE FILED BY COMPANY WITH
TRUSTEE.  (a) The Company covenants and agrees to file with the Trustee within
fifteen days after the Company 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 the Company may be
required to file with the Commission pursuant to Section 13 or Section 15(d) of
the Exchange Act; or, if the Company is not required to file information,
documents or reports pursuant to either of such Sections, then it will file with
the Trustee and the Commission, in accordance with rules and regulations
prescribed from time to time by the Commission, such of the supplementary and
periodic information, documents and reports which may be required pursuant to
Section 13 of the Exchange Act 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.

                                      -32-

 
          (b)  The Company covenants and agrees to file with the Trustee and the
Commission, in accordance with the rules and regulations prescribed from time to
time by the Commission, 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.

          (c)  The Company covenants and agrees to transmit to the 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 5.04 with respect
to reports pursuant to subsection (a) of said Section 5.04, such summaries of
any information, documents and reports required to be filed by the Company
pursuant to subsections (a) and (b) of this Section as may be required by rules
and regulations prescribed from time to time by the Commission.

          (d)  Delivery of such reports, information and documents to the
Trustee is for informational purposes only and the Trustee's receipt of such
shall not constitute constructive notice of any information contained therein or
determinable from information contained therein, including the Company's
compliance with any of its covenants hereunder (as to which the Trustee is
entitled to rely exclusively on Officers' Certificates).

          Section 5.04.  TRUSTEE TO TRANSMIT ANNUAL REPORT TO SECURITYHOLDERS.
(a) On or before July 15, 1997, and on or before July 15 in every year
thereafter, if and so long as any Securities are outstanding hereunder, the
Trustee shall transmit to the Securityholders as hereinafter in this Section
provided, a brief report dated as of the preceding May 15 with respect to any of
the following events which may have occurred within the previous twelve (12)
months (but if no such event has occurred within such period no report need be
transmitted):

          (1)  Any change to its eligibility under Section 7.09, and its
     qualifications under Section 7.08;

          (2)  The creation of or any material change to a relationship which,
     with the occurrence of an Event of Default, would create a conflicting
     interest within the meaning of the Trust Indenture Act;

          (3)  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) which remain unpaid on the date of such report,
     and for the reimbursement of which it claims or may claim a lien or charge
     prior to that of the Securities of any series on any property or funds held
     or collected by it as Trustee, except that the Trustee shall not be
     required (but may elect) to report such advances if such advances so
     remaining unpaid aggregate not more than one-half of one percent of the
     principal amount of the Securities of all series outstanding as of the date
     of such report;

          (4)  Any change to the amount, interest rate, and maturity date of all
     other indebtedness owing by the Company (or by any other obligor on the
     Securities) to the Trustee in its individual capacity, on the date of such
     report, with a brief description of any property held as collateral
     security therefor, except indebtedness based upon a

                                      -33-

 
     creditor relationship arising in any manner described in paragraph (2),
     (3), (4), or (6) of subsection (b) of Section 7.13;

          (5)  Any change to the property and funds, if any, physically in the
     possession of the Trustee (as such) on the date of such report;

          (6)  Any additional issue of Securities which the Trustee has not
     previously reported to Securityholders; and

          (7)  Any action taken by the Trustee in the performance of its duties
     under this Indenture which it has not previously reported to
     Securityholders and which in its opinion materially affects the Securities
     of any series, except action in respect of a default, notice of which has
     been or is to be withheld by it in accordance with the provisions of
     Section 6.07.

          (b)  The Trustee shall transmit to the Securityholders, as hereinafter
provided, 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
(or if such report has not 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 any 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 so remaining unpaid
aggregate not more than ten percent of the principal amount of Securities of all
series outstanding as of the date of such report, such report to be transmitted
within 90 days after such time.

          (c)  Reports pursuant to this Section shall be transmitted by mail to
all holders of Securities of any series, as the names and addresses of such
holders shall appear upon the Register of the Securities of such series.

          (d)  A copy of each such report shall, at the time of such
transmission to Securityholders, be filed by the Trustee with each stock
exchange upon which the Securities of any series are listed and also with the
Commission. The Company will promptly notify the Trustee when and as the
Securities of any series become listed on any stock exchange.


                                  ARTICLE SIX

                  REMEDIES OF THE TRUSTEE AND SECURITYHOLDERS
                              ON EVENT OF DEFAULT

          Section 6.01.  EVENTS OF DEFAULT DEFINED.  The term "Event of Default"
whenever used herein with respect to Securities of any series shall mean any one
of the following events:

          (a)  Default in the payment of any installment of interest upon any of
     the Securities of such series as and when the same shall become due and
     payable, and 

                                      -34-

 
     continuance of such default for a period of 30 days (subject to the
     deferral of any due date in the case of an Extension Period); or

          (b)  Default in the payment of all or any part of the principal of any
     of the Securities of such series as and when the same shall become due and
     payable whether upon Maturity, upon any redemption, by declaration or
     otherwise; or

          (c)  Failure on the part of the Company duly to observe or perform in
     any material respect any covenants or agreements (other than covenants to
     pay interest, principal and premium, which are subject to subsections (a)
     and (b) above of this Section) on the part of the Company in the Securities
     or in this Indenture (including any supplemental indenture or pursuant to
     any Officers' Certificate as contemplated by Section 2.01) specifically
     contained for the benefit of the Securities of such series, for a period of
     60 days after there has been given, by registered or certified mail, to the
     Company by the Trustee, or to the Company and the Trustee by the holders of
     not less than 25% in principal amount of the Securities of such series and
     all other series so benefited (all series voting as one class) at the time
     outstanding under this Indenture a written notice specifying such failure
     and stating that such is a "Notice of Default" hereunder; or

          (d)  The commencement by the Company of a voluntary case under Chapter
     7 or Chapter 11 of the federal Bankruptcy Code or any other similar state
     or federal law now or hereafter in effect, or the consent by the Company to
     the entry of a decree or order for relief in an involuntary case under any
     such law, or the consent by the Company to the appointment of a liquidating
     agent or committee, conservator or receiver; or

          (e)  The entry of a decree or order for relief by a court having
     jurisdiction in the premises in respect of the Company in an involuntary
     case under Chapter 7 or Chapter 11 of the federal Bankruptcy Code or any
     other similar state or federal law now or hereafter in effect, and the
     continuance of any such decree or order unstayed and in effect for a period
     of 90 days, or the appointment of a liquidating agent or committee,
     conservator or receiver, and the continuance of any such appointment
     unstayed and in effect for a period of 90 days.

          If an Event of Default under clauses 6.01(a), 6.01(b) or 6.01(c) shall
have occurred and be continuing (but, in the case of clause 6.01(c), only if the
Event of Default is with respect to less than all series of Securities then
outstanding under this Indenture), unless the principal of all the Securities
shall have already become due and payable, either the Trustee or the holders of
not less than 25% in principal amount of all the then outstanding Securities of
the series as to which such Event of Default under clauses 6.01(a), 6.01(b) or
6.01(c) has occurred (each such series voting as a separate class in the case of
an Event of Default under clauses 6.01(a) or 6.01(b), and all such series voting
as one class in the case of an Event of Default under clause 6.01(c)), by notice
in writing to the Company (and to the Trustee if given by Securityholders) may
declare the principal amount (or if Securities of any series are Original Issue
Discount Securities, such portion of the principal amount as may be specified in
the terms of such series) of all the Securities of such series, or of all such
series in the case of an Event of Default

                                      -35-

 
under clause 6.01(c), in each case together with any accrued interest, to be due
and payable immediately, and upon any such declaration the same shall become and
shall be immediately due and payable; provided, however, that in the case of the
Securities of a series issued to an Aon Trust, if upon an Event of Default, the
Trustee or the holders of at least 25% in principal amount of the outstanding
Securities of such series fail to declare the principal of all the Securities of
that series to be immediately due and payable, the holders of at least 25% in
aggregate liquidation amount of the corresponding series of Preferred Securities
then outstanding shall have such right by a notice in writing to the Company and
the Trustee. If an Event of Default under clauses 6.01(c), 6.01(d), or 6.01(e)
shall have occurred and be continuing (but, in the case of clause 6.01(c)), only
if the Event of Default is with respect to all Securities then outstanding under
the Indenture), then and in each and every such case, unless the principal of
all the Securities shall have already become due and payable, either the Trustee
or the holders of not less than 25% in principal amount of all the then
outstanding Securities of each series as to which such Event of Default under
clauses 6.01(c), 6.01(d), or 6.01(e) above has occurred (voting as one class),
by notice in writing to the Company (and to the Trustee if given by
Securityholders) may declare the principal amount (or if Securities of any
series are Original Issue Discount Securities, such portion of the principal
amount as may be specified in the terms of such series) of all the Securities as
to which the Event of Default under clauses 6.01(c), 6.01(d), or 6.01(e) above
has occurred, together with any accrued interest, to be due and payable
immediately, and upon any such declaration the same shall become and shall be
immediately due and payable, anything contained in this Indenture or in the
Securities to the contrary notwithstanding; provided, however, that in the case
of the Securities of a series issued to an Aon Trust, if upon an Event of
Default, the Trustee or the holders of not less than 25% in principal amount of
the outstanding Securities of that series fail to declare the principal of all
the Securities of that series to be immediately due and payable, the holders of
at least 25% in aggregate liquidation amount of the corresponding series of
Preferred Securities then outstanding shall have such right by a notice in
writing to the Company and the Trustee. The foregoing provisions, however, are
subject to the condition that if, at any time after the principal amount (or
specified portion thereof) of the Securities of any one or more series (or of
all the Securities, as the case may be) shall have been so declared due and
payable, and before any judgment or decree for the payment of moneys due shall
have been obtained or entered as hereinafter provided, the Company shall pay or
shall deposit with the Trustee a sum sufficient to pay all matured installments
of interest upon all the Securities of such series (or upon all the Securities,
as the case may be) and the principal of any and all Securities of such series
(or of any and all the Securities, as the case may be) which shall have become
due otherwise than by declaration (with interest on overdue installments of
interest to the extent permitted by law and on such principal at the rate or
rates of interest borne by, or prescribed therefor in, the Securities of each
such series to the date of such payment or deposit) and the amounts payable to
the Trustee under Section 7.06, and any and all defaults under the Indenture
with respect to Securities of such series (or all Securities, as the case may
be), other than the nonpayment of principal of and any accrued interest on
Securities of such series (or any Securities, as the case may be) which shall
have become due by declaration, shall have been cured, remedied or waived as
provided in Section 6.06, then and in every such case the holders of a majority
in principal amount of the Securities of such series (or of all the Securities,
as the case may be) then outstanding and as to which such Event of Default has
occurred (such series or all series voting as one class, if more than one series
are so entitled) by written notice to the Company and to the Trustee, may
rescind and annul such declaration and its consequences. In the case of
Securities issued to an Aon Trust, should the holders of such Securities fail to
annul such declaration and waive such default, the holders of a majority in
aggregate liquidation preference of related Preferred Securities shall have such

                                      -36-

 
right; but no such rescission and annulment shall extend to or shall affect any
subsequent default, or shall impair any right consequent thereon.

          In case the Trustee, any holder of Securities or any holder of
Preferred Securities shall have proceeded to enforce any right under this
Indenture and such proceedings shall have been discontinued or abandoned because
of such rescission or annulment or for any other reason or shall have been
determined adversely to the Trustee, such holder of Securities or such holder of
Preferred Securities then and in every such case the Company, the Trustee, the
holders of the Securities of such series (or of all the Securities, as the case
may be) and the holders of Preferred Securities shall be restored respectively
to their former positions and rights hereunder, and all rights, remedies and
powers of the Company and the Trustee, the holders of the Securities of such
series (or of all the Securities, as the case may be) and the holders of
Preferred Securities shall continue as though no such proceedings had been
taken.

          Section 6.02.  COVENANT OF COMPANY TO PAY TO TRUSTEE WHOLE AMOUNT DUE
ON SECURITIES ON DEFAULT IN PAYMENT OF INTEREST OR PRINCIPAL.  The Company
covenants that (1) in case default shall be made in the payment of any
installment of interest on any of the Securities of any series as and when the
same shall become due and payable, and such default shall have continued for a
period of 30 days (subject to the deferral of any due date in the case of an
Extension Period), or (2) in case default shall be made in the payment of all or
any part of the principal of any of the Securities of any series as and when the
same shall become due and payable, whether upon Maturity, upon any redemption,
by declaration or otherwise, then, upon demand of the Trustee, the Company will
pay to the Trustee, for the benefit of the holders of the Securities of such
series, the whole amount that then shall have become due and payable on all such
Securities of such series for principal or interest, or both, as the case may
be, with interest upon the overdue principal and installments of interest (to
the extent permitted by law) at the rate or rates of interest borne by or
prescribed therefor in the Securities of such series; and, in addition thereto,
such further amount as shall be sufficient to cover the costs and expenses of
collection, including reasonable compensation to the Trustee, its agents and
counsel, and any expenses or disbursements reasonably incurred, and all
reasonable advances made hereunder by the Trustee, its agents, attorneys and
counsel, except as a result of its negligence or bad faith.

          In case the Company shall fail forthwith to pay such amounts upon such
demand, the Trustee, in its own name and as trustee of an express trust, shall
be entitled and empowered to institute any actions or proceedings at law or in
equity for the collection of the sums so due and unpaid, and may prosecute any
such action or proceeding to judgment or final decree, and may enforce any such
judgment or final decree against the Company or any other obligor upon such
Securities, and collect in the manner provided by law out of the property of the
Company or any other obligor upon such Securities wherever situated the moneys
adjudged or decreed to be payable.

          The Trustee shall be entitled and empowered, either in its own name or
as trustee of an express trust, or as attorney-in-fact for the holders of the
Securities of any series, or in any one or more of such capacities (irrespective
of whether the principal of the Securities of such series shall then be due and
payable, whether upon Maturity, upon any redemption, by declaration or
otherwise, and irrespective of whether the Trustee shall have made any demand
pursuant to the provisions of this Section) to file and prove a claim or claims
for the whole amount of principal (or, if the Securities of such series are
Original Issue Discount Securities, such portion of the principal amount as may
be specified in the terms of such 

                                      -37-

 
series) and interest owing and unpaid in respect of the Securities of such
series and to file such other documents as may be necessary or advisable in
order to have the claims of the Trustee (including any claim for reasonable
compensation of the Trustee, its agents and counsel, and for reimbursement of
all expenses and disbursements reasonably incurred, and all reasonable advances
made hereunder by the Trustee, its agents and counsel, except as a result of its
negligence or bad faith) and of the holders of the Securities of such series
allowed in any equity receivership, insolvency, bankruptcy, liquidation,
arrangement, readjustment, reorganization or any other judicial proceedings
relative to the Company or any other obligor on the Securities of such series or
their creditors, or their property. The Trustee is hereby irrevocably appointed
(and the successive respective holders of the Securities of each series by
taking and holding the same shall be conclusively deemed to have so appointed
the Trustee) the true and lawful attorney-in-fact of the respective holders of
the Securities of such series, with authority to make and file in the respective
names of the holders of the Securities of such series, or on behalf of the
holders of the Securities of such series as a class, any proof of debt,
amendment of proof of debt, claim, petition or other document in any such
proceeding and to receive payment of any sums becoming distributable on account
thereof, and to execute any such other papers and documents and to do and
perform any and all such acts and things for and on behalf of such holders of
the Securities of such series, as may be necessary or advisable in the opinion
of the Trustee in order to have the respective claims of the Trustee and of the
holders of the Securities of such series allowed in any such proceeding, and to
receive payment of or on account of such claims and to distribute the same, and
any receiver, assignee, trustee, liquidator, sequestrator or other similar
official in any such judicial proceeding is hereby authorized by each holder to
make such payments to the Trustee and, in the event that the Trustee shall
consent to the making of such payments directly to the holders, to pay to the
Trustee any amount due to it under Section 7.06; provided, however, that nothing
herein shall be deemed to authorize the Trustee to authorize or consent to or
vote for or accept or adopt on behalf of any Securityholder any plan of
reorganization, arrangement, adjustment or composition affecting the Securities
of such series or the rights of any holder thereof, or to authorize the Trustee
to vote in respect of the claim of any holder of Securities of such series in
any such proceeding.

          All rights of action and of asserting claims under this Indenture, or
under any of the Securities of any series, may be enforced by the Trustee
without the possession of any of the Securities of such series, or the
production thereof on any trial or other proceeding relative thereto, and any
such suit or proceeding instituted by the Trustee, shall be brought in its own
name as trustee of an express trust, and any recovery of judgment shall be,
after provision for the payment of the reasonable compensation, expenses,
disbursements and advances of such Trustee, its agents and counsel, for the
ratable benefit of the holders of the Securities of such series.

          Section 6.03.  APPLICATION OF MONEYS COLLECTED BY TRUSTEE.  Any moneys
collected by the Trustee pursuant to Section 6.02 shall be applied in the order
following, at the date or dates fixed by the Trustee for the distribution of
such moneys, upon presentation of the several Securities in respect of which
moneys have been collected, and stamping thereon the payment, if only partially
paid, and upon surrender thereof if fully paid:

          First:  To the payment of reasonable costs and expenses of
     collection, and of all amounts payable to the Trustee under Section
     7.06;

                                      -38-

 
          Second:  In case the principal of the outstanding Securities in
     respect of which moneys have been collected shall not have become due
     and be unpaid, to the payment of any unpaid interest on such
     Securities, in the order of the maturity of the installments of such
     interest, with interest upon the overdue installments of interest (so
     far as permitted by law and to the extent that such interest has been
     collected by the Trustee) at the rate or rates of interest borne by,
     or prescribed therefor in, such Securities, such payments to be made
     ratably to the persons entitled thereto, without discrimination or
     preference;

          Third:  In case the principal of the outstanding Securities in
     respect of which such moneys have been collected shall have become due
     and be unpaid, whether upon Maturity, upon any redemption, by
     declaration or otherwise, to the payment of the whole amount then
     owing and unpaid upon such Securities for principal and interest, if
     any, with interest on the overdue principal and any installments of
     interest (so far as permitted by law and to the extent that such
     interest has been collected by the Trustee) at the rate or rates of
     interest borne by, or prescribed therefor in, such Securities; and in
     case such moneys shall be insufficient to pay in full the whole amount
     so due and unpaid upon such Securities, then to the payment of such
     principal and interest, without preference or priority of principal
     over interest, or of interest over principal, or of any installment of
     interest over any other installment of interest, or of any Security
     over any other Security, ratably to the aggregate of such unpaid
     principal and interest; and

          Fourth:  To the payment of the remainder, if any, to the Company,
     its successors or assigns, or to whomsoever may be lawfully entitled
     to receive the same, or as a court of competent jurisdiction may
     direct.

          Section 6.04.  LIMITATION ON SUITS BY HOLDERS OF SECURITIES.  No
holder of any Security of any series shall have any right by virtue or by
availing of any provision of this Indenture to institute any suit, action or
proceeding in equity or at law upon or under or with respect to this Indenture
or for the appointment of a receiver or trustee, or for any other remedy
hereunder, unless such holder previously shall have given to the Trustee written
notice of default and of the continuance thereof, as hereinbefore provided, and
unless also the holders of not less than 25% in principal amount of all the
Securities at the time outstanding (considered as one class) shall have made
written request upon the Trustee to institute such action, suit or proceeding in
its own name as Trustee hereunder and shall have offered to the Trustee such
reasonable indemnity as it may require against the costs, expenses and
liabilities to be incurred therein or thereby, and the Trustee, for 60 days
after its receipt of such notice, request and offer of indemnity, shall have
neglected or refused to institute any such action, suit or proceeding and no
direction inconsistent with such written request shall have been given to the
Trustee pursuant to Section 6.06; it being understood and intended, and being
expressly covenanted by the taker and holder of every Security with every other
taker and holder and the Trustee, that no one or more holders of Securities
shall have any right in any manner whatever by virtue or by availing of any
provision of this Indenture to affect, disturb or prejudice the rights of the
holders of any other of such Securities, or to obtain or seek to obtain priority
over or preference to any other such holder, or to enforce any right under this
Indenture, except in the manner herein provided and for the equal, ratable and
common benefit of all holders of Securities. For the protection and enforcement
of the provisions 

                                      -39-

 
of this Section, each and every Securityholder and the Trustee
shall be entitled to such relief as can be given either at law or in equity.

          Notwithstanding any other provisions in this Indenture, the right of
any holder of any Security to receive payment of the principal of and interest
on such Security, on or after the respective due dates expressed in such
Security (or, in the case of redemption on or after the date fixed for
redemption), or to institute 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 6.05.  ON DEFAULT TRUSTEE MAY TAKE APPROPRIATE ACTION.  In
case of a default hereunder the Trustee may in its discretion proceed to protect
and enforce the rights vested in it by this Indenture by such appropriate
judicial proceedings as the Trustee shall deem most effectual to protect and
enforce any of such rights, either by suit in equity or by action at law or by
proceeding in bankruptcy or otherwise, whether for the specific enforcement of
any covenant or agreement contained in this Indenture or in aid of the exercise
of any power granted in this Indenture, or to enforce any other legal or
equitable right vested in the Trustee by this Indenture or by law.  All powers
and remedies given by this Article to the Trustee or to the Securityholders
shall, to the extent permitted by law, be deemed cumulative and not exclusive of
any thereof or of any other powers and remedies available to the Trustee or the
holders of the Securities, by judicial proceedings or otherwise, to enforce the
performance or observance of the covenants and agreements contained in this
Indenture, and no delay or omission of the Trustee, of any holder of any of the
Securities or any holder of Preferred Securities to exercise any right or power
accruing upon any default occurring and continuing as aforesaid shall impair any
such right or power, or shall be construed to be a waiver of any such default or
an acquiescence therein; and, subject to the provisions of Section 8.04, every
power and remedy given by this Article or by law to the Trustee, to the
Securityholders or the holders of Preferred Securities may be exercised from
time to time, and as often as shall be deemed expedient, by the Trustee, by the
Securityholders or by the holders of Preferred Securities, as the case may be.

          In the case of Securities of a series issued to an Aon Trust, any
holder of the corresponding series of Preferred Securities issued by such Aon
Trust shall have the right, upon the occurrence of an Event of Default described
in Section 6.01(a) or (b) above, to institute a suit directly against the
Company for enforcement of payment to such holder of principal of (including
premium, if any) and interest (including any Additional Interest) on the
Securities having a principal amount equal to the aggregate liquidation amount
of such Preferred Securities of the corresponding series held by such holder.

          Section 6.06.  RIGHTS OF HOLDERS OF MAJORITY IN PRINCIPAL AMOUNT OF
SECURITIES TO DIRECT TRUSTEE AND TO WAIVE DEFAULT.  The holders of at least a
majority in principal amount of the Securities of any one or more series or of
all the Securities, as the case may be (voting as one class), at the time
outstanding (determined as provided in Section 8.04) shall have the right to
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 the
Trustee under this Indenture with respect to such one or more series; provided,
however, that subject to Section 7.01, the Trustee shall have the right to
decline to follow any such direction if the Trustee being advised by Opinion of
Counsel determines that the action so directed may not lawfully be taken, or if
the Trustee in good faith shall, by a Responsible Officer or Officers of the
Trustee, determine that the proceedings so directed would be illegal or involve
it in personal liability 

                                      -40-

 
or be unduly prejudicial to the rights of Securityholders of such one or more
series not parties to such direction, and provided further that nothing in this
Indenture shall impair the right of the Trustee to take any action deemed proper
by the Trustee and which is not inconsistent with such direction by such
Securityholders of such one or more series. The holders of at least a majority
in principal amount of the Securities of all series as to which an Event of
Default hereunder has occurred (all series voting as one class) at the time
outstanding (determined as provided in Section 8.04) and, in the case of any
Preferred Securities of a series issued to an Aon Trust, the holders of at least
a majority in aggregate liquidation amount of the Preferred Securities issued by
such Aon Trust, may waive any past default hereunder with respect to such series
and its consequences, except a default in the payment of the principal of or
interest on any of such Securities or Preferred Securities or in respect of a
covenant or provision hereof which under Article Ten cannot be modified or
amended without the consent of the holder of each Security so affected. Upon any
such waiver, such default shall cease to exist and any Event of Default arising
therefrom shall be deemed to have been cured for every purpose of this
Indenture, but no such waiver shall extend to any subsequent or other default or
impair any right consequent thereon. Any such waiver shall be deemed to be on
behalf of the holders of all the Securities of such series or, in the case of a
waiver by holders of Preferred Securities issued by such Aon Trust, by all
holders of Preferred Securities issued by such Aon Trust.

          Section 6.07.  TRUSTEE TO GIVE NOTICE OF DEFAULTS KNOWN TO IT, BUT MAY
WITHHOLD IN CERTAIN CIRCUMSTANCES.  The Trustee shall, within 90 days after the
occurrence of any default hereunder with respect to the Securities of any
series, give to the holders of the Securities of such series in the manner and
to the extent provided in subsection (c) of Section 5.04 with respect to reports
pursuant to subsection (a) of said Section 5.04, notice of such default actually
known to the Trustee unless such default shall have been cured, remedied or
waived before the giving of such notice (the term "default" for the purposes of
this Section being hereby defined to be the events specified in clauses (c),
(d), (e) and (f) of Section 6.01 and default in the payment of the principal of
or interest on Securities of any series, not including any periods of grace
provided for therein, and irrespective of the giving of written notice specified
in any such terms, and irrespective of the delivery of any Officers' Certificate
provided for in any such terms); provided, however, that, except in the case of
default in the payment of the principal of or interest on any of the Securities
of such series, the 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 Trustee in good faith determines
that the withholding of such notice is in the interest of the holders of the
Securities of such series.

          Section 6.08.  REQUIREMENT OF AN UNDERTAKING TO PAY COSTS IN CERTAIN
SUITS UNDER THE INDENTURE OR AGAINST THE TRUSTEE.  All parties to this Indenture
agree, and each holder of any Security by his acceptance thereof shall be deemed
to have agreed, that any court may in its discretion require, 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, the filing
by any party litigant in such suit of an undertaking to pay the costs of such
suit, and that such court may in its discretion assess reasonable costs,
including reasonable attorneys' fees and expenses, against any party litigant in
such suit, having due regard to the merits and good faith of the claims or
defenses made by such party litigant; but the provisions of this Section shall
not apply to any suit instituted by the Trustee, to any suit instituted by any
holder of Securities of any series, or group of such Securityholders, holding in
the aggregate more than ten percent in principal amount of all the Securities
(all series considered as one class) outstanding, or to any suit instituted by
any Securityholder for the enforcement of the payment of the principal of or

                                      -41-

 
interest on any Security, on or after the due date expressed in such Security
(or in the case of any redemption, on or after the date fixed for redemption).


                                 ARTICLE SEVEN

                            CONCERNING THE TRUSTEE

          Section 7.01.  UPON EVENT OF DEFAULT OCCURRING AND CONTINUING, TRUSTEE
SHALL EXERCISE POWERS VESTED IN IT, AND USE SAME DEGREE OF CARE AND SKILL IN
THEIR EXERCISE, AS A PRUDENT MAN WOULD USE.  The Trustee, prior to the
occurrence of an Event of Default and after the curing, remedying or waiving of
all Events of Default which may have occurred, undertakes to perform such duties
and only such duties as are specifically set forth in this Indenture.  In case
an Event of Default has occurred (which has not been cured, remedied or waived)
the Trustee shall exercise such of the rights and powers vested in it by 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.

          No provision of this Indenture shall be construed  to relieve the
Trustee from liability for its own negligent action, its own negligent failure
to act, or its own willful misconduct; provided, however, that

     (a)  Prior to the occurrence of an Event of Default and after the curing,
remedying or waiving of all Events of Default which may have occurred:

          (1)  The duties and obligations of the Trustee shall be determined
     solely by the express provisions of this Indenture and the Trustee shall
     not be liable except for the performance of such duties and obligations as
     are specifically set forth in this Indenture, and no implied covenants or
     obligations shall be read into this Indenture against the Trustee; and

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

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

          (c)  The Trustee shall not be liable with respect to any action taken
or omitted to be taken by it in good faith in accordance with the direction of
the holders of Securities pursuant to Section 6.06 relating to the time, method
and place of conducting any proceeding for any remedy available to the Trustee,
or exercising any trust or power conferred upon the Trustee, under this
Indenture;

                                      -42-

 
          (d)  Whether or not therein expressly so provided, every provision of
this Indenture relating to the conduct or affecting the liability of or
affording protection to the Trustee shall be subject to the provisions of this
Section 7.01; and

          (e)  None of the provisions contained in this Indenture shall require
the Trustee to expend or risk its own funds or otherwise incur any financial
liability in the performance of any of its duties hereunder or in the exercise
of any of its rights or powers, if there is reasonable ground for believing that
the repayment of such funds or adequate indemnity against such risk or liability
is not reasonably assured to it.

          Section 7.02.  RELIANCE ON DOCUMENTS, OPINIONS, ETC.  Except as
otherwise provided in Section 7.01:

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

          (b)  Any request, direction, order or demand of the Company mentioned
herein shall be sufficiently evidenced by an Officers' Certificate (unless other
evidence in respect thereof be herein specifically prescribed); and any
Resolution of the Company may be evidenced to the Trustee by a copy thereof
certified by the Secretary or an Assistant Secretary of the Company;

          (c)  The Trustee may consult with counsel of its selection and the
advice of such counsel or any Opinion of Counsel with respect to legal matters
shall be full and complete authorization and protection in respect of any action
taken, suffered or omitted to be taken by it hereunder in good faith and in
accordance with such advice or Opinion of Counsel;

          (d)  The Trustee shall be under no obligation to exercise any of the
rights or powers vested in it by this Indenture at the request or direction of
any of the Securityholders pursuant to this Indenture, unless such
Securityholders shall have offered to the Trustee such adequate security or
indemnity against the costs, expenses (including attorneys' fees and expenses)
and liabilities that might be incurred by it in complying with such request or
direction;

          (e)  The Trustee shall not be liable for any action taken or omitted
to be taken by it in good faith and believed by it to be authorized or within
the discretion or rights or powers conferred upon it by this Indenture;

          (f)  The 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, approval, bond,
debenture, note, other evidence of indebtedness or other paper or document,
unless requested in writing to do so by the holders of Securities pursuant to
Section 6.06, but the Trustee may make such further inquiry or investigation
into such facts or matters as it may see fit; provided, however, that if the
payment within a reasonable time to the Trustee of the costs, expenses or
liabilities likely to be incurred by it in the making of such investigation is,
in the opinion of the Trustee, 

                                      -43-

 
not reasonably assured to the Trustee by the security afforded to it by the
terms of this Indenture, the Trustee may require adequate indemnity against such
costs, expenses or liabilities as a condition to so proceeding; and provided
further, that nothing in this subsection (f) shall require the Trustee to give
the Securityholders any notice other than that required by Section 6.07. The
reasonable expense of every such examination shall be paid by the Company or, if
paid by the Trustee, shall be repaid by the Company upon demand;

          (g)  The 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 Trustee shall not be responsible for any misconduct or
negligence on the part of any agent or attorney appointed by it hereunder;
provided, however, that the Trustee shall be responsible for its own negligence
or recklessness with respect to the selection of any such agent or attorney;

          (h)  The Trustee shall be under no responsibility for the approval by
it in good faith of any expert for any of the purposes expressed in this
Indenture; and

          (i)  The Trustee shall not be deemed to have notice of any Event of
Default unless a Responsible Officer of the Trustee has actual knowledge thereof
or unless written notice of any event which is in fact such a default is
received by the Trustee at the Corporate Trust Office of the Trustee, and such
notice references the Securities and this Indenture.

          Section 7.03.  TRUSTEE NOT LIABLE FOR RECITALS IN INDENTURE OR IN
SECURITIES.  The recitals contained herein and in the Securities (other than the
certificate of authentication on the Securities) shall be taken as the
statements of the Company, and the Trustee does not assume any responsibility
for their correctness.  The Trustee makes no representations as to the validity
or sufficiency of this Indenture or of the Securities.  The Trustee shall not be
accountable for the use or application by the Company of the proceeds of the
Securities of any series.

          Section 7.04.  MAY HOLD SECURITIES.  The Trustee or any agent of the
Trustee or the Trust, in its individual or any other capacity, may become the
owner or pledgee of Securities and, subject to Section 7.08, with the same
rights it would have if it were not Trustee or such agent.

          Section 7.05.  MONEYS RECEIVED BY TRUSTEE TO BE HELD IN TRUST WITHOUT
INTEREST.  Subject to the provisions of Section 12.04, all moneys received by
the Trustee shall, until used or applied as herein provided, be held in trust
for the purposes for which they were received, but need not be segregated from
other funds except to the extent required by law.  The Trustee shall be under no
liability for interest on any moneys received by it hereunder.

          Section 7.06.  TRUSTEE ENTITLED TO COMPENSATION, REIMBURSEMENT AND
INDEMNITY.  The Company covenants and agrees to pay to the Trustee from time to
time, and the Trustee shall be entitled to, such compensation as shall be agreed
to in writing between the Company and the Trustee (which shall not be limited by
any provision of law in regard to the compensation of a trustee of any express
trust), and, the Company will pay or reimburse the Trustee upon its request for
all reasonable expenses, disbursements and advances incurred or made by the
Trustee in connection with the acceptance or administration of its trust under
this Indenture (including the reasonable compensation and the reasonable
expenses and disbursements of its agents and counsel and of all persons not
regularly in its employ) 

                                      -44-

 
except any such expense, disbursement or advance as may arise from its
negligence or bad faith. The Company also covenants and agrees to indemnify each
of the Trustee, any predecessor Trustee and their agents for, and to hold them
harmless against, any loss, liability or expense incurred without negligence or
bad faith on their part and arising out of or in connection with the acceptance
or administration of this trust and performance of their duties hereunder,
including the reasonable costs and expenses (including reasonable fees and
disbursements of their counsel) of defending themselves against any claim or
liability in connection with the exercise or performance of any of the powers or
duties hereunder. The obligations of the Company under this Section to
compensate the Trustee, to pay or reimburse the Trustee for expenses,
disbursements and advances and to indemnify and hold harmless the Trustee shall
constitute additional indebtedness hereunder and shall survive the satisfaction
and discharge of this Indenture and the resignation or removal of the Trustee.
Such additional indebtedness shall be secured by a lien prior to that of the
Securities upon all property and funds held or collected by the Trustee as such,
except funds held in trust for the payment of principal of or interest, if any,
on the Securities.

          When the Trustee incurs expenses or renders services in connection
with an Event of Default specified in Section 6.01(d) or Section 6.01(e), the
expenses (including the reasonable charges and expenses of its counsel) and the
compensation for the services are intended to constitute expenses of
administration under any applicable federal or state bankruptcy, insolvency or
other similar law.

          Section 7.07.  RIGHT OF TRUSTEE TO RELY ON OFFICERS' CERTIFICATE WHERE
NO OTHER EVIDENCE SPECIFICALLY PRESCRIBED.  Except as otherwise provided in
Section 7.01, whenever in the administration of this Indenture the Trustee shall
deem it necessary or desirable that a matter be proved or established prior to
taking, suffering or omitting to take any action hereunder, the Trustee (unless
other evidence in respect thereof be herein specifically prescribed) may, in the
absence of negligence or bad faith on its part, request and rely upon an
Officers' Certificate which, upon receipt of such request, shall be promptly
delivered by the Company.

          Section 7.08.  DISQUALIFICATION; CONFLICTING INTERESTS.  If the
Trustee has or shall acquire any conflicting interest, within the meaning of the
Trust Indenture Act, the Trustee shall either eliminate such interest or resign,
to the extent and in the manner provided by, and subject to the provisions of,
the Trust Indenture Act and this Indenture.

          Section 7.09.  REQUIREMENTS FOR ELIGIBILITY OF TRUSTEE.  The Trustee
hereunder shall at all times be a corporation organized and doing business under
the laws of the United States or any State or territory thereof or of the
District of Columbia authorized under such laws to exercise corporate trust
powers, having a combined capital and surplus of at least $50,000,000, subject
to supervision or examination by federal, state, territorial, or District of
Columbia authority and having its principal office and place of business in the
City of Chicago or in the Borough of Manhattan, The City of New York, if there
be such a corporation having its principal office and place of business in said
places willing to act upon reasonable and customary terms and conditions.  If
such corporation publishes reports of condition at least annually, pursuant to
law or  the requirements of the aforesaid supervising or examining authority,
then, for the purposes of this Section and to extent permitted by the Trust
Indenture Act, the combined capital and surplus of such corporation shall be
deemed to be its combined capital and surplus as set forth in its most recent
report of condition so published. If at any time the Trustee shall cease to be
eligible in accordance with the provisions of this Section, the Trustee shall
resign immediately in the manner and with the effect specified in Section 7.10.
Neither the Company, any other obligor upon the 

                                      -45-

 
Securities, nor any person directly or indirectly controlling, controlled by, or
under common control with the Company or any such obligor shall serve as Trustee
under this Indenture.

          Section 7.10.  RESIGNATION AND REMOVAL OF TRUSTEE.  (a) The Trustee,
or any trustee or trustees hereafter appointed, may at any time resign with
respect to one or more or all series of Securities by giving written notice of
such resignation to the Company and by giving to the holders of Securities of
the applicable series notice thereof in the manner and to the extent provided in
subsection (c) of Section 5.04 with respect to reports pursuant to subsection
(a) of Section 5.04.  Upon receiving such notice of resignation and if the
Company shall deem it appropriate evidence satisfactory to it of such mailing,
the Company shall promptly appoint a successor Trustee with respect to the
applicable series (it being understood that any successor Trustee may be
appointed with respect to the Securities of one or more or all of such series
and at any time there shall be only one Trustee with respect to the Securities
of any particular series) by written instrument, in duplicate, executed pursuant
to a Resolution of the Company, one copy of which instrument shall be delivered
to the resigning Trustee and one copy to the successor Trustee.  If no successor
Trustee shall have been so appointed with respect to any series and have
accepted appointment within 30 days after the mailing of such notice of
resignation, the resigning Trustee may petition any court of competent
jurisdiction for the appointment of a successor Trustee, or any Securityholder
who has been a bona fide holder of a Security or Securities of the applicable
series for at least six months may, subject to the provisions of Section 6.08,
on behalf of himself and all others similarly situated, petition any such court
for the appointment of a successor Trustee.  Such court may thereupon after such
notice, if any, as it may deem proper and prescribe, appoint a successor
Trustee.

          (b)  In case at any time any of the following shall occur:

          (1)  The Trustee shall fail to comply with Section 7.08 after written
     request therefor by the Company or by any Securityholder who has been a
     bona fide holder of a Security or Securities of the applicable series for
     at least six months, or

          (2)  The Trustee shall cease to be eligible in accordance with the
     provisions of Section 7.09 and shall fail to resign after written request
     therefor by the Company or by any such Securityholder, or

          (3)  The Trustee shall become incapable of acting, or shall be
     adjudged a bankrupt or insolvent, or a receiver of the Trustee or of its
     property shall be appointed, or any public officer shall take charge or
     control of the Trustee or of its property or affairs for the purpose of
     rehabilitation, conservation or liquidation,

then, in any such case, the Company may remove the Trustee with respect to the
applicable series and appoint a successor Trustee with respect to the applicable
series by written instrument, in duplicate, executed pursuant to a Resolution of
the Company, one copy of which instrument shall be delivered to the Trustee so
removed and one copy to the successor Trustee, or, subject to the provisions of
Section 6.08, any Securityholder who has been a bona fide holder of a Security
or Securities of the applicable series 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 Trustee and the appointment of a successor
Trustee with respect to the applicable series. Such court may thereupon, after
such notice, if any, as it may deem proper and prescribe, remove the Trustee and
appoint a successor Trustee.

                                      -46-

 
          (c)  The holders of a majority in principal amount of the Securities
of any one series voting as a separate class or all series voting as one class
at the time outstanding (determined as provided in Section 8.04) may at any time
remove the Trustee with respect to the applicable series or all series, as the
case may be, and appoint a successor Trustee with respect to the applicable
series or all series, as the case may be, by written instrument or instruments
signed by such holders or their attorneys-in-fact duly authorized, or by the
affidavits of the permanent chairman and permanent secretary of a meeting of the
Securityholders (as elected in accordance with Section 9.05) evidencing the vote
upon a resolution or resolutions submitted thereto with respect to such removal
and appointment (as provided in Article Nine), and by delivery thereof to the
Trustee so removed, to the successor Trustee and to the Company.

          (d)  Any resignation or removal of the Trustee and any appointment of
a successor Trustee pursuant to any of the provisions of this Section shall
become effective upon acceptance of appointment by the successor Trustee as
provided in Section 7.11.

          Section 7.11.  ACCEPTANCE BY SUCCESSOR TRUSTEE.  Any successor Trustee
with respect to all series of Securities appointed as provided in Section 7.10
shall execute, acknowledge and deliver to the Company and to its predecessor
Trustee an instrument accepting such appointment hereunder, and thereupon the
resignation or removal of the predecessor Trustee with respect to all or any
applicable series shall become effective and such successor Trustee, without any
further act, deed or conveyance, shall become vested with all the rights,
powers, trusts and duties with respect to such series of its predecessor
hereunder, with like effect as if originally named as Trustee herein; but, on
the written request of the Company or of the successor Trustee, the Trustee
ceasing to act shall, upon payment of any amounts then due it pursuant to the
provisions of Section 7.06, execute and deliver an instrument transferring to
such successor Trustee all the rights and powers with respect to such series of
the Trustee so ceasing to act.  Upon the request of any such successor Trustee,
the Company shall execute any and all instruments in writing for more fully and
certainly vesting in and confirming to such successor Trustee all such rights
and powers.  Any Trustee ceasing to act shall, nevertheless, retain a lien upon
all property or funds held or collected by such Trustee or any successor Trustee
to secure any amounts then due it pursuant to the provisions of Section 7.06.

          In case of the appointment hereunder of a successor Trustee with
respect to the Securities of one or more (but not all) series, the Company, the
retiring Trustee and each successor Trustee with respect to the Securities of
such series shall execute and deliver an indenture supplemental hereto wherein
each 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, each successor Trustee all the rights, powers, trusts and duties
of the retiring Trustee with respect to the Securities of such 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 such
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 hereunder administered by any other such Trustee; and upon
the execution and delivery of such supplemental indenture the resignation or
removal of the retiring Trustee shall become effective

                                      -47-

 
to the extent provided therein and each such successor Trustee, without any
further act, deed or conveyance, shall become vested with all the rights,
powers, trusts and duties of the retiring Trustee with respect to the Securities
of such series to which the appointment of such successor Trustee relates; but,
on written request of the Company or any successor Trustee, such retiring
Trustee shall duly assign, transfer and deliver to such successor Trustee all
property and money held by such retiring Trustee hereunder with respect to the
Securities of such series to which the appointment of such successor Trustee
relates.

          No successor Trustee shall accept appointment as provided in this
Section unless at the time of such acceptance such successor Trustee shall be
qualified under the provisions of Section 7.08 and eligible under the provisions
of Section 7.09.

          Upon acceptance of appointment by a successor Trustee as provided in
this Section, the successor Trustee shall at the expense of the Company transmit
notice of the succession of such Trustee hereunder to the holders of Securities
of any applicable series in the manner and to the extent provided in subsection
(c) of Section 5.04 with respect to reports pursuant to subsection (a) of said
Section 5.04.

          Section 7.12.  SUCCESSOR TO TRUSTEE BY MERGER, CONSOLIDATION OR
SUCCESSION TO BUSINESS.  Any corporation into which the 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 Trustee shall be a
party, or any corporation succeeding to all or substantially all of the
corporate trust business of the Trustee, shall be the successor of the Trustee
hereunder, provided such corporation shall be qualified under the provisions of
Section 7.08 and eligible under the provisions of Section 7.09, without the
execution or filing of any paper or any further act on the part of any of the
parties hereto, anything herein to the contrary notwithstanding.

          In case at the time such successor to the Trustee shall succeed to the
trusts created by this Indenture any of the Securities shall have been
authenticated but not delivered, any such successor to the Trustee may adopt the
certificate of authentication of any predecessor Trustee, and deliver such
Securities so authenticated; and in case at that time any of the Securities
shall not have been authenticated, any successor to the Trustee may authenticate
such Securities either in the name of any predecessor hereunder or in the name
of the successor Trustee; and in all such cases such certificates shall have the
full force which it is anywhere in the Securities or in this Indenture provided
that the certificate of the Trustee shall have; provided, however, that the
right to adopt the certificate of authentication of any predecessor Trustee or
to authenticate Securities in the name of any predecessor Trustee shall apply
only to its successor or successors by merger, conversion or consolidation.

          Section 7.13.  LIMITATIONS ON RIGHTS OF TRUSTEE AS A CREDITOR TO
OBTAIN PAYMENT OF CERTAIN CLAIMS WITHIN THREE MONTHS PRIOR TO DEFAULT OR DURING
DEFAULT, OR TO REALIZE ON PROPERTY AS SUCH CREDITOR THEREAFTER.  (a) Subject to
the provisions of subsection (b) of this Section, if the Trustee shall be or
shall become a creditor, directly or indirectly, secured or unsecured, of the
Company or of any other obligor on the Securities within three months prior to a
default, as defined in subsection (c) of this Section, or subsequent to such a
default, then, unless and until such default shall be cured, waived or remedied,
the Trustee shall set apart and hold in a special account for the benefit of the
Trustee individually, the holders of the Securities of the one or more other
indenture securities (as defined in subsection (c) of this Section):

                                      -48-

 
          (1)  An amount equal to any and all reductions in the amount due and
     owing upon any claim as such creditor in respect of principal or interest,
     effected after the beginning of such three-month period, and valid as
     against the Company and its other creditors, except any such reduction
     resulting from the receipt or disposition of any property described in
     paragraph (2) of this subsection, or from the exercise of any right of set-
     off which the Trustee could have exercised if a petition in bankruptcy had
     been filed by or against the Company upon the date of such default; and

          (2)  All property received by the Trustee in respect of any claims as
     such creditor, either as security therefor, or in satisfaction or
     composition thereof, or otherwise, after the beginning of such three-month
     period, or an amount equal to the proceeds of any such property if disposed
     of, subject, however, to the rights, if any, of the Company and its other
     creditors in such property or such proceeds.

          Nothing herein contained, however, shall affect the right of the
Trustee:

          (A)  To retain for its own account (i) payments made on account of any
     such claim by any person (other than the Company) who is liable thereon,
     (ii) the proceeds of the bona fide sale of any such claim by the Trustee to
     a third person, and (iii) distributions made in cash, securities, or other
     property in respect of claims filed against the Company in bankruptcy or
     receivership or in proceedings for reorganization pursuant to title 11 of
     the United States Code or applicable state laws;

          (B)  To realize, for its own account, upon any property held by it as
     security for any such claim, if such property was so held prior to the
     beginning of such three- month period;

          (C)  To realize, for its own account, but only to the extent of the
     claim hereinafter mentioned, upon any property held by it as security for
     any such claim, if such claim was created after the beginning of such 
     three-month period and such property was received as security therefor
     simultaneously with the creation thereof, and if the Trustee shall sustain
     the burden of proving that at the time such property was so received, the
     Trustee had no reasonable cause to believe that a default, as defined in
     subsection (c) of this Section, would occur within three months; or

          (D)  To receive payment on any claim referred to in paragraph (B) or
     (C) against the release of any property held as security for such claim as
     provided in such paragraph (B) or (C), as the case may be, to the extent of
     the fair value of such property.

          For the purposes of paragraphs (B), (C), and (D), property substituted
after the beginning of such three-month period for property held as security at
the time of such substitution shall, to the extent of the fair value of the
property released, have the same status as the property released, and to the
extent that any claim referred to in any such paragraphs is created in renewal
of or in substitution for or for the purpose of repaying or refunding any pre-
existing claim of the Trustee as such creditor, such claim shall have the same
status as such pre-existing claim.

                                      -49-

 
          If the Trustee shall be required to account, the funds and property
held in such special account and the proceeds thereof shall be apportioned
between the Trustee, the holders of Securities of the one or more series for
which it is acting as Trustee, and the holders of other indenture securities in
such manner that the Trustee, such Securityholders and the holders of other
indenture securities realize, as a result of payments from such special account
and payments of dividends on claims filed against the Company in bankruptcy or
receivership or in proceedings for reorganization pursuant to title 11 of the
United States Code or applicable state law, the same percentage of their
respective claims, figured before crediting to the claim of the Trustee anything
on account of the receipt by it from the Company of the funds and property in
such special account and before crediting to the respective claims of the
Trustee, such Securityholders, and the holders of other indenture securities
dividends on claims filed against the Company in bankruptcy or receivership or
in proceedings for reorganization pursuant to title 11 of the United States Code
or applicable state law, but after crediting thereon receipts on account of the
indebtedness represented by their respective claims from all sources other than
from such dividends and from the funds and property so held in such special
account.  As used in this paragraph, with respect to any claim, the term
"dividends" shall include any distribution with respect to such claim in
bankruptcy or receivership or in proceedings for reorganization pursuant to
title 11 of the United States Code or applicable state law, whether such
distribution is made in cash, securities, or other property, but shall not
include any such distribution with respect to the secured portion, if any, of
such claim.  The court in which such bankruptcy, receivership or proceeding for
reorganization is pending shall have jurisdiction (i) to apportion among the
Trustee, such Securityholders, and the holders of other indenture securities, in
accordance with the provisions of this paragraph, the funds and property held in
such special account and the proceeds thereof, or (ii) in lieu of such
apportionment, in whole or in part, to give to the provisions of this paragraph
due consideration in determining the fairness of the distributions to be made to
the Trustee, such Securityholders and the holders of other indenture securities
with respect to their respective claims, in which event it shall not be
necessary to liquidate or to appraise the value of any securities or other
property held in such special account or as security for any such claim, or to
make a specific allocation of such distributions as between the secured and
unsecured portions of such claim, or otherwise to apply the provisions of this
paragraph as a mathematical formula.

          Any Trustee who has resigned or been removed after the beginning of
such three-month period shall be subject to the provisions of this subsection
(a) as though such resignation or removal had not occurred.  If any Trustee has
resigned or been removed prior to the beginning of such three-month period, it
shall be subject to the provisions of this subsection (a) if and only if the
following conditions exist:

          (i)   The receipt of property or reduction of claim which would have
     given rise to the obligation to account, if such Trustee had continued as
     trustee, occurred after the beginning of such three-month period; and

          (ii)  Such receipt of property or reduction of claim occurred within
     three months after such resignation or removal;

          (b)   There shall be excluded from the operation of subsection (a) of
this Section a creditor relationship arising from:

                                      -50-

 
          (1)  The ownership or acquisition of securities issued under any
     indenture, or any security or securities having a maturity of one year or
     more at the time of acquisition by the Trustee;

          (2)  Advances authorized by a receivership or bankruptcy court of
     competent jurisdiction, or by this Indenture, for the purpose of preserving
     any property which shall at any time be subject to the lien of this
     Indenture or of discharging tax liens or other prior liens or encumbrances
     thereon, if notice of such advances and of the circumstances surrounding
     the making thereof is given to the Securityholders at the time and in the
     manner provided in Section 5.04(c) with respect to reports pursuant to
     subsections (a) and (b) thereof, respectively;

          (3)  Disbursements made in the ordinary course of business in the
     capacity of Trustee under an indenture, transfer agent, registrar,
     custodian, paying agent, fiscal agent or depositary, or other similar
     capacity;

          (4)  An indebtedness created as a result of services rendered or
     premises rented; or an indebtedness created as a result of goods or
     securities sold in a cash transaction as defined in subsection (c) of this
     Section;

          (5)  The ownership of stock or of other securities of a corporation
     organized under the provisions of Section 25(a) of the Federal Reserve Act,
     as amended, which is directly or indirectly a creditor of the Company; or

          (6)  The acquisition, ownership, acceptance or negotiation of any
     drafts, bills of exchange, acceptances or obligations which fall within the
     classification of self-liquidating paper as defined in subsection (c) of
     this Section.

          (c)  As used in this Section:

          (1)  The term "default" shall mean any failure to make payment in full
     of the principal of or interest upon any of the Securities or upon the
     other indenture securities when and as such principal or interest becomes
     due and payable.

          (2)  The term "other indenture securities" shall mean securities upon
     which the Company is an obligor (as defined in the Trust Indenture Act of
     1939) outstanding under any other indenture (A) under which the Trustee is
     also trustee, (B) which contains provisions substantially similar to the
     provisions of subsection (a) of this Section, and (C) under which a default
     exists at the time of the apportionment of the funds and property held in
     said special account.

          (3)  The term "cash transaction" shall mean any transaction in which
     full payment for goods or securities sold is made within seven days after
     delivery of the goods or securities in currency or in checks or other
     orders drawn upon banks or bankers and payable upon demand.

                                      -51-

 
          (4) The term "self-liquidating paper" shall mean any draft, bill of
     exchange, acceptance or obligation which is made, drawn, negotiated or
     incurred by the Company for the purpose of financing the purchase,
     processing, manufacture, shipment, storage or sale of goods, wares or
     merchandise and which is secured by documents evidencing title to,
     possession of, or a lien upon, the goods, wares or merchandise, or the
     receivables or proceeds arising from the sale of the goods, wares or
     merchandise previously constituting the security, provided the security is
     received by the Trustee simultaneously with the creation of the creditor
     relationship with the Company arising from the making, drawing, negotiating
     or incurring of the draft, bill of exchange, acceptance or obligation.

          (5) The term "Company" shall mean any obligor upon the Securities.


                                 ARTICLE EIGHT

                         CONCERNING THE SECURITYHOLDERS

          Section 8.01.  EVIDENCE OF ACTION BY SECURITYHOLDERS.  Whenever in
this Indenture it is provided that the holders of a specified percentage in
principal amount of the Securities of any or all series may take any action
(including the making of any demand or request, the giving of any notice,
consent, or waiver or the taking of any other action), the fact at the time of
taking any such action the holders of such specified percentage have joined
therein may be evidenced (a) by any instrument or any number of instruments of
similar tenor executed by such Securityholders in person or by agent or proxy
appointed in writing, or (b) by the record of such holders of Securities voting
in favor thereof at any meeting of such Securityholders duly called and held in
accordance with the provisions of Article Nine, or (c) by a combination of such
instrument or instruments and any such record of such a meeting of such
Securityholders.

          If there shall be more than one Trustee acting hereunder with respect
to separate series of Securities, such Trustees shall collaborate, if necessary,
in acting under Article Nine and in determining whether the holders of a
specified percentage in principal amount of the Securities of any or all series
have taken any such action.

          Section 8.02.  PROOF OF EXECUTION OF INSTRUMENTS AND OF HOLDING OF
SECURITIES.  Subject to the provisions of Sections 7.01, 7.02 and 9.05, proof of
the execution of any instrument by a Securityholder or his agent or proxy and
proof of the holding by any person of any of the Securities shall be sufficient
if made in the following manner:

          The fact and date of the execution by any such person of any
instrument may be proved in any reasonable manner acceptable to the Trustee.

          The ownership of Securities of any series shall be proved by the
Register of such Securities of such series, or by certificates of the Security
registrar or registrars thereof.

                                      -52-

 
          The Trustee shall not be bound to recognize any person as a
Securityholder unless and until title to the Securities held by him is proved in
the manner in this Article Eight provided.

          The record of any Securityholders' meeting shall be proved in the
manner provided in Section 9.06.

          The Trustee may accept such other proof or require such additional
proof of any matter referred to in this Section as it shall deem reasonable.

          Section 8.03.  WHO MAY BE DEEMED OWNERS OF SECURITIES.  Prior to due
presentment for registration of transfer of any Security, the Company, the
Trustee and any agent of the Company or the Trustee may deem and treat the
person in whose name such Security shall be registered upon the Register of
Securities of the series of which such Security is a part as the absolute owner
of such Security (whether or not payments in respect of such Security shall be
overdue and notwithstanding any notation of ownership or other writing thereon)
for the purpose of receiving payment of or an account of the principal of and
interest, subject to Section 2.03, on such Security and for all other purposes;
and neither the Company nor the Trustee nor any agent of the Company or the
Trustee shall be affected by any notice to the contrary.  All such payments so
made to any such holder for the time being, or upon his order, shall be valid,
and, to the extent of the sum or sums so paid, effectual to satisfy and
discharge the liability of moneys payable upon any such Security.

          Section 8.04.  SECURITIES OWNED BY COMPANY OR CONTROLLED OR
CONTROLLING PERSONS DISREGARDED FOR CERTAIN PURPOSES.  In determining whether
the holders of the requisite principal amount of Securities have concurred in
any demand, direction, request, notice, vote, consent, waiver or other action
under this Indenture, Securities which are owned by the Company or any other
obligor on the Securities or by any person directly or indirectly controlling or
controlled by or under direct or indirect common control with the Company or any
other obligor on the Securities shall be disregarded and deemed not to be
outstanding for the purpose of any such determination, provided that for the
purposes of determining whether the Trustee shall be protected in relying on any
such demand, direction, request, notice, vote, consent, waiver or other action,
only Securities which a Responsible Officer of the Trustee assigned to its
principal office actually knows are so owned shall be so disregarded.
Securities so owned which have been pledged in good faith may be regarded as
outstanding for the purposes of this Section, if the pledgee shall establish to
the satisfaction of the Trustee the pledgee's right to vote such Securities and
that the pledgee is not a person directly or indirectly controlling or
controlled by or under direct or indirect common control with the Company or any
such other obligor.  Upon request of the Trustee, the Company shall furnish to
the Trustee promptly an Officers' Certificate listing and identifying all
Securities, if any, known by the Company to be owned or held by or for the
account of the Company or any other obligor on the Securities or by any person
directly or indirectly controlling or controlled by or under direct or indirect
common control with the Company or any other obligor on the Securities; and,
subject to the provisions of Section 7.01, the Trustee shall be entitled to
accept such Officers' Certificate as conclusive evidence of the facts therein
set forth and of the fact that all Securities not listed therein are outstanding
for the purpose of any such determination.

                                      -53-

 
          Section 8.05.  INSTRUMENTS EXECUTED BY SECURITYHOLDERS BIND FUTURE
HOLDERS.  At any time prior to (but not after) the evidencing to the Trustee, as
provided in Section 8.01, of the taking of any action by the holders of the
percentage in principal amount of the Securities specified in this Indenture in
connection with such action, any holder of a Security which is shown by the
evidence to be included in the Securities the holders of which have consented to
such action may, by filing written notice with the Trustee at its principal
office and upon proof of holding as provided in Section 8.02, revoke such action
so far as concerns such Security.  Except as aforesaid any such action taken by
the holder of any Security and any direction, demand, request, notice, waiver,
consent, vote or other action of the holder of any Security which by any
provisions of this Indenture is required or permitted to be given shall be
conclusive and binding upon such holder and upon all future holders and owners
of such Security, and of any Security issued in lieu thereof or upon
registration of transfers thereof, irrespective of whether any notation in
regard thereto is made upon such Security. Any action taken by the holders of
the percentage in principal amount of the Securities of any or all series
specified in this Indenture in connection with such action shall be conclusively
binding upon the Company, the Trustee and the holders of all of the Securities
of such series subject, however, to the provisions of Section 7.01.


                                  ARTICLE NINE

                           SECURITYHOLDERS' MEETINGS

          Section 9.01.  PURPOSES FOR WHICH MEETINGS MAY BE CALLED.  A meeting
of holders of Securities of any or all series may be called at any time and from
time to time pursuant to the provisions of this Article for any of the following
purposes:

          (1) To give any notice to the Company or to the Trustee, or to give
     any directions to the Trustee, or to consent to the waiving of any default
     hereunder and its consequences, or to take any other action authorized to
     be taken by holders of Securities of any or all series, as the case may be,
     pursuant to any of the provisions of Article Six;

          (2) To remove the Trustee and appoint a successor Trustee pursuant to
     the provisions of Article Seven;

          (3) To consent to the execution of an indenture or indentures
     supplemental hereto pursuant to the provisions of Section 10.02; or

          (4) To take any other action authorized to be taken by or on behalf of
     the holders of any specified principal amount of the Securities of any or
     all series, as the case may be, under any other provision of this Indenture
     or under applicable law.

          Section 9.02.  MANNER OF CALLING MEETINGS.  The Trustee may at any
time call a meeting of Securityholders to take any action specified in Section
9.01, to be held at such time and at such place in the Borough of Manhattan,
State of New York, as the Trustee shall determine.  Notice of every meeting of
Securityholders setting forth the time and place of such meeting and in general
terms the action proposed to be taken at such meeting, shall be mailed not less
than 20 nor more than 60 days prior to the date fixed for the meeting.

                                      -54-

 
          Section 9.03.  CALL OF MEETING BY COMPANY OR SECURITYHOLDERS.  In case
at any time the Company, pursuant to a resolution of its Board of Directors, or
the holders of not less than ten percent in principal amount of the Securities
of any or all series, as the case may be, then outstanding, shall have requested
the Trustee to call a meeting of holders of Securities of any or all series, as
the case may be, to take any action authorized in Section 9.01 by written
request setting forth in reasonable detail the action proposed to be taken at
the meeting, and the Trustee shall not have mailed notice of such meeting within
20 days after receipt of such request, then the Company or such holders of
Securities in the amount above specified may determine the time and place in the
Borough of Manhattan, State of New York for such meeting and may call such
meeting to take any action authorized in Section 9.01, by mailing notice thereof
as provided in Section 9.02.

          Section 9.04.  WHO MAY ATTEND AND VOTE AT MEETINGS.  To be entitled to
vote at any meeting of Securityholders a person shall (a) be a holder of one or
more Securities with respect to which the meeting is being held, or (b) be a
person appointed by an instrument in writing as proxy by such holder of one or
more Securities.  The only persons who shall be entitled to be present or to
speak at any meeting of Securityholders shall be the persons entitled to vote at
such meeting and their counsel and any representatives of the Trustee and its
counsel and any representatives of the Company and its counsel.

          Section 9.05.  REGULATIONS MAY BE MADE BY TRUSTEE.  Notwithstanding
any other provisions of this Indenture, the Trustee may make such reasonable
regulations as it may deem advisable for any meeting of Securityholders, in
regard to proof of the holding of Securities and of the appointment of proxies,
and in regard to the appointment and duties of inspectors of votes, the
submission and examination of proxies, certificates and other evidence of the
right to vote, and such other matters concerning the conduct of the meeting as
it shall think fit.  Except as otherwise permitted or required by any such
regulations, the holding of Securities shall be proved in the manner specified
in Section 8.02 and the appointment of any proxy shall be proved in the manner
specified in said Section 8.02; provided, however, that such regulations may
provide that written instruments appointing proxies regular on their face, may
be presumed valid and genuine without the proof hereinabove or in said Section
8.02 specified.

          The Trustee shall, by an instrument in writing, appoint a temporary
chairman of the meeting, unless the meeting shall have been called by the
Company or by Securityholders as provided in Section 9.03, in which case the
Company or the Securityholders calling the meeting, as the case may be, shall in
like manner appoint a temporary chairman.  A permanent chairman and a permanent
secretary of the meeting shall be elected by majority vote of the meeting.

          Subject to the provisions of Section 8.04, at any meeting each
Securityholder or proxy shall be entitled to one vote for each $1,000 principal
amount of Securities held or represented by him, provided, however, that no vote
shall be cast or counted at any meeting in respect of any Security challenged as
not outstanding and ruled by the permanent chairman of the meeting to be not
outstanding; provided, further, that each holder of Original Issue Discount
Securities shall be entitled to one vote for each $1,000 amount which would be
due upon acceleration of his Original Issue Discount Security on the date of the
meeting.  Neither a temporary nor a permanent chairman of the meeting shall have
a right to vote other than by virtue of Securities held by him or instruments in
writing as aforesaid duly designating him as the person to vote on behalf of
other Securityholders.  Any meeting of Securityholders duly called pursuant to
the provisions of Section 9.02 or 9.03 may be adjourned from time to time, and
the meeting may be held so adjourned without further notice.

                                      -55-

 
          At any meeting of Securityholders, the presence of persons holding or
representing Securities in principal amount sufficient to take action on the
business for the transaction of which such meeting was called shall constitute a
quorum, but, if less than a quorum is present, the person or persons holding or
representing a majority in principal amount of the Securities represented at the
meeting may adjourn such meeting with the same effect for all intents and
purposes, as though a quorum had been present.

          Section 9.06.  MANNER OF VOTING AT MEETINGS AND RECORD TO BE KEPT.
The vote upon any resolution submitted to any meeting of Securityholders shall
be by written ballots on which shall be subscribed the signatures of the holders
of Securities or of their representatives by proxy and the principal amount or
principal amounts of the Securities held or represented by them. The permanent
chairman of the meeting shall appoint two inspectors of votes who shall count
all votes cast at the meeting for or against any resolution and who shall make
and file with the permanent secretary of the meeting their verified written
reports in duplicate of all votes cast at the meeting.  A record in duplicate of
the proceedings of each meeting of Securityholders shall be prepared by the
permanent secretary of the meeting and there shall be attached to said record
the original reports of the inspectors of votes on any vote by ballot taken
thereat and affidavits by one or more persons having knowledge of the facts
setting forth a copy of the notice of the meeting and showing that said notice
was mailed as provided in Section 9.02.  The record shall show the principal
amount or principal amounts of the Securities voting in favor of, against, or
abstaining from voting on, any resolution.  The record shall be signed and
verified by the affidavits of the permanent chairman and permanent secretary of
the meeting and one of the duplicates shall be delivered to the Company and the
other to the Trustee to be preserved by the Trustee.

          Any record so signed and verified shall be conclusive evidence of the
matters therein stated.

          Section 9.07.  EXERCISE OF RIGHTS OF TRUSTEE, SECURITYHOLDERS AND
HOLDERS OF PREFERRED SECURITIES NOT TO BE HINDERED OR DELAYED.  Nothing in this
Article contained shall be deemed or construed to authorize or permit, by reason
of any call of a meeting of Securityholders or any rights expressly or impliedly
conferred hereunder to make such call any hindrance or delay in the exercise of
any right or rights conferred upon or reserved to the Trustee, to the
Securityholders or the holders of Preferred Securities under any of the
provisions of this Indenture or of the Securities.


                                  ARTICLE TEN

                            SUPPLEMENTAL INDENTURES

          Section 10.01.      PURPOSES FOR WHICH SUPPLEMENTAL INDENTURES MAY BE
ENTERED INTO WITHOUT CONSENT OF SECURITYHOLDERS.  The Company, when authorized
by a Resolution of the Company, and the Trustee may from time to time, and at
any time enter into an indenture or indentures supplemental hereto, in form
satisfactory to such Trustee (which shall comply with the provisions of the
Trust Indenture Act of 1939 as then in effect), for one or more of the following
purposes:

          (a) To evidence the succession of another corporation to the Company,
     or successive successions, and the assumption by the successor corporation
     of the 

                                      -56-

 
     covenants, agreements and obligations of the Company pursuant to Article
     Eleven hereof;

          (b) To add to the covenants of the Company such further covenants,
     restrictions or conditions as the Company and the Trustee shall consider to
     be for the protection of the holders of all or any series of Securities
     (and if such covenants, restrictions or conditions are to be for the
     benefit of less than all series of Securities, stating that such covenants,
     restrictions or conditions are expressly being included solely for the
     benefit of such series), and to make the occurrence, or the occurrence and
     continuance, of a default in any such additional covenants, restrictions or
     conditions a default or an Event of Default permitting the enforcement of
     all or any of the several remedies provided in this Indenture as herein set
     forth; provided, however, that in respect to any such additional covenant,
     restriction or condition such supplemental indenture may provide for a
     particular period of grace after default (which period may be shorter or
     longer than that allowed in the case of other defaults) or may provide for
     an immediate enforcement upon such default or may limit the remedies
     available to the Trustee upon such default;

          (c) To add or change any of the provisions of this Indenture to such
     extent as shall be necessary to permit or facilitate the issuance of
     Securities in bearer form, registrable or not registrable as to principal,
     and with or without interest coupons;

          (d) To change or eliminate any of the provisions of this Indenture;
     provided, however, that any such change or elimination shall become
     effective only when there is no Security of any series outstanding created
     prior to the execution of such supplemental indenture which is entitled to
     the benefit of such provision;

          (e) To establish the form or terms of Securities of any series as
     permitted by Section 2.01 and 2.02;

          (f) To cure any ambiguity or to correct or supplement any provision
     contained herein or in any supplemental indenture which may be defective or
     inconsistent with any other provisions contained herein or in any
     supplemental indenture, or to make such other provision in regard to
     matters or questions arising under this Indenture or any supplemental
     indenture which shall not adversely affect the interests of the holders of
     the Securities; provided, however, that such action shall not adversely
     affect the interest of the holders of Securities of any series in any
     material respect or, in the case of the Securities of a series issued to an
     Aon Trust and for so long as any of the corresponding series of Preferred
     Securities issued by such Aon Trust shall remain outstanding, the holders
     of such Preferred Securities;

          (g) To mortgage or pledge to the Trustee as security for the
     Securities any property or assets which the Company may desire to mortgage
     or pledge as security for the Securities; and

                                      -57-

 
          (h) To qualify, or maintain the qualification of, the Indenture under
     the Trust Indenture Act.
     
          The Trustee is hereby authorized to join with the Company in the
execution of any such supplemental indenture, to make any further appropriate
agreements and stipulations which may be therein contained and to accept the
conveyance, transfer, mortgage, pledge or assignment of any property thereunder,
but the Trustee shall not be obligated to enter into any such supplemental
indenture which affects the Trustee's own rights, duties or immunities under
this Indenture or otherwise.

          Any supplemental indenture authorized by the provisions of this
Section may be executed by the Company and the Trustee without the consent of
the holders of any of the Securities at the time outstanding, notwithstanding
any of the provisions of Section 10.02.

          Section 10.02.  MODIFICATION OF INDENTURE WITH CONSENT OF HOLDERS OF A
MAJORITY IN PRINCIPAL AMOUNT OF SECURITIES.  With the consent (evidenced as
provided in Section 8.01) of the holders of not less than a majority in
principal amount of the Securities of all series at the time outstanding
(determined as provided in Section 8.04) affected by such supplemental indenture
(voting as one class), the Company, when authorized by a Resolution of the
Company, and the Trustee may from time to time and at any time enter into an
indenture or indentures supplemental hereto (which shall be in conformity with
the provisions of the Trust Indenture Act of 1939 as then in effect) for the
purpose of adding any provisions to or changing in any manner or eliminating any
of the provisions of this Indenture or of any supplemental indenture or of
modifying in any manner the rights of the holders of the Securities of each such
series; provided, however, that no such supplemental indenture shall (i) change
the fixed Maturity of any Securities, or reduce the rate or extend the time of
payment of any interest thereon or on any overdue principal amount or reduce the
principal amount thereof, or change the provisions pursuant to which the rate of
interest on any Security is determined if such change could reduce the rate of
interest thereon, or reduce the minimum rate of interest thereon, or reduce any
amount payable upon any redemption thereof, or adversely affect any right to
convert the Securities in accordance herewith, or reduce the amount to be paid
at Maturity or upon redemption in Capital Stock or make the principal thereof or
any interest thereon or on any overdue principal amount payable in any coin or
currency other than that provided in the Security without the consent of the
holder of each Security so affected, (ii) reduce the aforesaid percentage of
Securities, the holders of which are required to consent to any such
supplemental indenture without the consent of the holders of all Securities then
outstanding, (iii) modify any of the provisions of this Section, Section 4.07 or
Section 6.06, except to increase any such percentage or to provide that certain
other provisions of this Indenture cannot be modified or waived without the
consent of the holders of all Securities then outstanding or (iv) modify the
provisions of Article Fourteen with respect to the subordination of outstanding
Securities of any series in a manner adverse to the holders thereof without the
consent of the holder of each Security so affected; provided, however, that, in
the case of the Securities of a series issued to an Aon Trust, so long as any of
the corresponding series of Preferred Securities issued by such Aon Trust
remains outstanding, (i) no such amendment shall be made that adversely affects
the holders of such Preferred Securities in any material respect, and no
termination of this Indenture shall occur, and no waiver of any Event of Default
with respect to such series or compliance with any covenant with respect to such
series under this Indenture shall be effective, without the prior consent of the
holders of at least a majority of the aggregate liquidation amount of such
Preferred Securities then outstanding unless and until the principal (and
premium, if any) of the Securities of such series and all accrued and unpaid
interest (including any 

                                      -58-

 
Additional Interest) thereon have been paid in full; and (ii) no amendment shall
be made to Section 6.05 of this Indenture that would impair the rights of the
holders of such Preferred Securities provided therein or to this Indenture that
requires the consent of each holder of the Securities of such series without the
prior consent of each holder of such Preferred Securities then outstanding
unless and until the principal (and premium, if any) of the Securities of such
series and all accrued and unpaid interest (including any Additional Interest)
thereon have been paid in full.

          A supplemental indenture which changes or eliminates any covenant or
other provision of this Indenture which has expressly been included solely for
the benefit of one or more particular series of Securities or Preferred
Securities, or which modifies the rights of holders of Securities or holders of
Preferred Securities of such series with respect to such covenant or other
provision, shall be deemed not to affect the rights under this Indenture of the
holders of Securities or holders of Preferred Securities of any other series.

          Upon the request of the Company, accompanied by a copy of a Resolution
of the Company 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.

          It shall not be necessary for the consent of the Securityholders under
this Section to approve the particular form of any proposed supplemental
indenture, but it shall be sufficient if such consent shall approve the
substance thereof.

          Promptly after the execution by the Company and the Trustee of any
supplemental indenture pursuant to the provisions of this Section, the Company
shall mail a notice to the holders of Securities of each series so affected,
setting forth in general terms the substance of such supplemental indenture.
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.

          Section 10.03.  EFFECT OF SUPPLEMENTAL INDENTURES.  Upon the
execution of any supplemental indenture pursuant to the provisions of this
Article, this Indenture shall be and be deemed to be modified and amended in
accordance therewith and the respective rights, limitations of rights,
obligations, duties and immunities under this Indenture of the Trustee, the
Company and the holders of Securities 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.

          The Trustee shall be entitled to receive, and subject to the
provisions of Section 7.01 shall be entitled to rely upon, an Opinion of Counsel
as conclusive evidence that any such supplemental indenture complies with the
provisions of this Article and stating that the Securities affected by the
supplemental indenture, when such Securities are authenticated and delivered by
the Trustee and executed and issued by the Company in the manner and subject to
any conditions specified in such Opinion of Counsel, will be valid and binding
obligations of the Company, except as any rights thereunder may be 

                                      -59-

 
limited by bankruptcy, insolvency and other similar laws affecting the
enforcement of creditors' rights generally and by general equity principles.

          Section 10.04.  SECURITIES MAY BEAR NOTATION OF CHANGES BY
SUPPLEMENTAL INDENTURES.  Securities authenticated and delivered after the
execution of any supplemental indenture pursuant to the provisions of this
Article, or after any action taken at a Securityholders' meeting pursuant to
Article Nine, may bear a notation in form approved by the Trustee as to any
matter provided for in such supplemental indenture or as to any action taken at
any such meeting.  If the Company or the Trustee shall so determine, new
Securities so modified as to conform, in the opinion of the Trustee and the
Board of Directors of the Company, to any modification of this Indenture
contained in any such supplemental indenture may be prepared by the Company,
authenticated by the Trustee and delivered in exchange for the Securities then
outstanding.

          Section 10.05.  REVOCATION AND EFFECT OF CONSENTS.  Subject to
Section 8.05, until an amendment, supplement, waiver or other action becomes
effective, a consent to it by a Securityholder of a Security is a continuing
consent conclusive and binding upon such Securityholder and every subsequent
Securityholder of the same Security or portion thereof, and of any Security
issued upon the registration of transfer thereof or in exchange therefor or in
place thereof, even if notation of the consent is not made on any such Security.

          The Company may, but shall not be obligated to, fix a record date for
the purpose of determining the Securityholders entitled to consent to any
amendment, supplement or waiver.  If a record date is fixed, then,
notwithstanding the preceding paragraph, those Persons who were Securityholders
at such record date (or their duly designated proxies), and only such Persons,
shall be entitled to consent or revoke such consent to such amendment,
supplement or waiver, whether or not such Persons continue to be Securityholders
after such record date.  No such consent shall be valid or effective for more
than 180 days after such record date.

          After an amendment, supplement, waiver or other action becomes
effective, it shall bind every Securityholder.


                                 ARTICLE ELEVEN

                   CONSOLIDATION, MERGER, SALE OR CONVEYANCE

          Section 11.01.      COMPANY MAY CONSOLIDATE, ETC., ON CERTAIN TERMS.
The Company covenants that it will not merge or consolidate with any other
corporation or sell or convey all or substantially all of its assets to any
Person unless (i) either the Company shall be the continuing corporation, or the
successor corporation (if other than the Company) shall be a corporation
organized and existing under the laws of the United States of America or a State
thereof or the District of Columbia and such corporation shall expressly assume
the due and punctual payment of the principal of and interest on all the
Securities, according to their tenor, and the due and punctual performance and
observance of all of the covenants and conditions of this Indenture to be
performed by the Company by supplemental indenture satisfactory to the Trustee,
executed and delivered to the Trustee by such corporation, (ii) the Company or
such successor corporation, as the case may be, shall not, immediately after
such merger 

                                      -60-

 
or consolidation, or such sale or conveyance, be in default in the performance
of any such covenant or condition, and (iii) in the case of Securities of a
series issued to an Aon Trust, such consolidation, merger, sale or conveyance is
permitted under the relevant Trust Agreement and Aon Guarantee and does not give
rise to any breach or violation of such Trust Agreement or Aon Guarantee.

          Section 11.02. SUCCESSOR CORPORATION SUBSTITUTED. In case of any such
consolidation, merger, sale or conveyance and upon any such assumption by the
successor corporation, such successor corporation shall succeed to and be
substituted for the Company, with the same effect as if it had been named herein
as the party of the first part. Such successor corporation thereupon may cause
to be signed, and may issue either in its own name or in the name of the
Company, any or all of the Securities issuable hereunder which theretofore shall
not have been delivered to the Trustee; and upon the order of such successor
corporation, instead of the Company, and subject to all the terms, conditions
and limitations in this Indenture prescribed, the Trustee shall authenticate and
shall deliver any Securities which previously shall have been signed and
delivered by the officers of the Company to the Trustee, and any Securities
which such successor corporation thereafter shall cause to be signed and
delivered to the Trustee. All the Securities so issued shall in all respects
have the same legal rank and benefit under this Indenture as the Securities
theretofore or thereafter issued in accordance with the terms of this Indenture
as though all of such Securities had been issued at the date of the execution
hereof.

          In case of any such consolidation, merger, sale or conveyance such
changes in phraseology and form (but not in substance) may be made in the
Securities thereafter to be issued as may be appropriate.

          Section 11.03.  OPINION OF COUNSEL TO TRUSTEE.  The Trustee shall be
entitled to receive, and subject to the provisions of Section 7.01 shall be
entitled to rely upon, an Opinion of Counsel as conclusive evidence that any
such consolidation, merger, sale or conveyance and any such assumption, complies
with the provisions of this Article and that all conditions precedent herein
provided for relating to such transaction have been complied with.


                                 ARTICLE TWELVE

                    SATISFACTION AND DISCHARGE OF INDENTURE,
                                UNCLAIMED MONEYS

          Section 12.01.      SATISFACTION AND DISCHARGE OF INDENTURE.  If (a)
the Company shall deliver to the Trustee for cancellation all Securities of any
series theretofore authenticated (other than any Securities of such series which
shall have been destroyed, lost or stolen and which shall have been replaced or
paid as provided in Section 2.07) and not theretofore cancelled, or (b) all the
Securities of such series not theretofore cancelled or delivered to the Trustee
for cancellation shall have become due and payable, or are by their terms to
become due and payable within one year or are to be called for redemption within
one year under arrangements satisfactory to the Trustee for the giving of notice
of redemption, and the Company shall deposit with the Trustee as trust funds the
entire amount sufficient to pay at Maturity or upon redemption all of such
Securities not theretofore cancelled or delivered to the Trustee for
cancellation, including principal and any interest due or to become due to such
date of Maturity or redemption date, as the case may be, and if in either case
the Company shall also pay or 

                                      -61-

 
cause to be paid all other sums payable hereunder by the Company with respect to
Securities of such series, then this Indenture shall cease to be of further
effect with respect to Securities of such series, (except as to (i) remaining
rights of registration of transfer, conversion, substitution and exchange and
the Company's right of optional redemption of Securities of such series, (ii)
rights hereunder of holders to receive payments of principal of, and any
interest on, the Securities of such series, and other rights, duties and
obligations of the holders of Securities of such series as beneficiaries hereof
with respect to the amounts, if any, so deposited with the Trustee, and (iii)
the rights, obligations and immunities of the Trustee hereunder), and the
Trustee, on demand of the Company, and at the cost and expense of the Company,
shall execute proper instruments acknowledging satisfaction of and discharging
this Indenture. The Company hereby agrees to compensate the Trustee for any
services thereafter reasonably and properly rendered and to reimburse the
Trustee for any costs or expenses theretofore and thereafter reasonably and
properly incurred by the Trustee in connection with this Indenture or the
Securities of such series.

          Notwithstanding the satisfaction and discharge of this Indenture with
respect to the Securities of any or all series, the obligations of the Company
to the Trustee under Section 7.06 shall survive.

          Section 12.02.  APPLICATION BY TRUSTEE OF FUNDS DEPOSITED FOR PAYMENT
OF SECURITIES.  Subject to Section 12.04, all moneys deposited with the Trustee
pursuant to Section 12.01 shall be held in trust and applied by it to the
payment, either directly or through any Paying Agent (including the Company
acting as its own Paying Agent), to the holders of the particular Securities of
such series, for the payment or redemption of which such moneys have been
deposited with the Trustee, of all sums due and to become due thereon for
principal and interest.

          Section 12.03.  REPAYMENT OF MONEYS HELD BY PAYING AGENT.  In
connection with the satisfaction and discharge of this Indenture with respect to
Securities of any series, all moneys with respect to Securities of such series
then held by any Paying Agent under the provisions of this Indenture shall, upon
demand of the Company, be paid to the Trustee and thereupon such Paying Agent
shall be released from all further liability with respect to such moneys.

          Section 12.04.  REPAYMENT OF MONEYS HELD BY TRUSTEE.  Any moneys
deposited with the Trustee or any Paying Agent for the payment of the principal
of or any interest on any Securities of any series and not applied but remaining
unclaimed by the holders of Securities of such series for two years after the
date upon which such payment shall have become due and payable, shall, at the
request of the Company, be repaid to the Company by the Trustee or by such
Paying Agent; and the holder of any of the Securities of such series entitled to
receive such payment shall thereafter look only to the Company for the payment
thereof; provided, however, that the Trustee or such Paying Agent, before being
required to make any such repayment, may at the expense of the Company cause to
be published once a week for two successive weeks (in each case on any day of
the week) in an Authorized Newspaper, or mailed to the registered holders
thereof, a notice that said moneys have not been so applied and that after a
date named therein any unclaimed balance of said money then remaining will be
returned to the Company.

                                      -62-

 
                               ARTICLE THIRTEEN

              IMMUNITY OF INCORPORATORS, STOCKHOLDERS, OFFICERS,
                            DIRECTORS AND EMPLOYEES

          Section 13.01.  INCORPORATORS, STOCKHOLDERS, OFFICERS, DIRECTORS AND
EMPLOYEES OF COMPANY EXEMPT FROM INDIVIDUAL LIABILITY. No recourse under or upon
any obligation, covenant or agreement of this Indenture, or of any Security, or
for any claim based thereon or otherwise in respect thereof, shall be had
against any incorporator, stockholder, officer, director or employee, as such,
past, present or future, of the Company or of any successor corporation, either
directly or through the Company, whether by virtue of any constitution, statute
or rule of law, or by the enforcement of any assessment or penalty or otherwise,
it being expressly understood that this Indenture and the obligations issued
hereunder are solely corporate obligations, and that no personal liability
whatever shall attach to, or is or shall be incurred by, the incorporators,
stockholders, officers, directors or employees, as such, of the Company or any
successor corporation, or any of them, because of the creation of the
indebtedness hereby authorized, or under or by reason of the obligations,
covenants or agreements contained in this Indenture or in any of the Securities
or implied therefrom; and that any and all such personal liability of every name
and nature, either at common law or in equity or by constitution or statute, of,
and any and all such rights and claims against every such incorporator,
stockholder, officer, director or employee, as such, because of the creation of
the indebtedness hereby authorized, or under or by reason of the obligations,
covenants or agreements contained in this Indenture or in any of the Securities
or implied therefrom are hereby expressly waived and released as a condition of
and as a consideration for, the execution of this Indenture and the issue of
such Securities.


                                ARTICLE FOURTEEN

                          SUBORDINATION OF SECURITIES

          Section 14.01.  AGREEMENT TO SUBORDINATE.  The Company, for itself, is
successors and assigns, covenants and agrees, and each holder of a Security of
any series likewise covenants and agrees by his acceptance thereof, that the
obligation of the Company to make any payment on account of the principal of and
interest on each and all of the Securities of any series shall be subordinate
and junior in right of payment to the Company's obligations to the holders of
Senior Indebtedness of the Company, and that in the case of any insolvency,
receivership, conservatorship, reorganization, readjustment of debt, marshalling
of assets and liabilities or similar proceedings or any liquidation or winding-
up of or relating to the Company as a whole, whether voluntary or involuntary,
all obligations of the Company to holders of Senior Indebtedness of the Company
shall be entitled to be paid in full before any payment shall be made on account
of the principal of or interest on any of the Securities. In the event of any
such proceeding, after payment in full of all sums owing with respect to Senior
Indebtedness of the Company, the holders of the Securities of each series,
together with the holders of any obligations of the Company ranking on a parity
with the Securities, shall be entitled to be paid from the remaining assets of
the Company the amounts at the time due and owing on account of unpaid principal
of and interest on the Securities of any series before any payment or other
distribution, whether in cash, property or otherwise, shall be made on account
of any capital stock or any obligations of the Company ranking junior to the

                                      -63-

 
Securities. In addition, in the event of any such proceeding, if any payment or
distribution of assets of the Company of any kind or character whether in cash,
property or securities, including any such payment or distribution which may be
payable or deliverable by reason of the payment of any other indebtedness of the
Company being subordinated to the payment of the Securities of any series shall
be received by the Trustee or the holders of the Securities of any series before
all Senior Indebtedness of the Company is paid in full, such payment or
distribution shall be held in trust for the benefit of and shall be paid over to
the holders of such Senior Indebtedness of the Company or their representative
or representatives or to the trustee or trustees under any indenture under which
any instruments evidencing any of such Senior Indebtedness of the Company may
have been issued, ratably, for application to the payment of all Senior
Indebtedness of the Company remaining unpaid until all such Senior Indebtedness
of the Company shall have been paid in full, after giving effect to any
concurrent payment or distribution to the holders of such Senior Indebtedness of
the Company. The obligations of the Company in respect of the Securities of all
series shall rank on a parity with any obligations of the Company ranking on a
parity with the Securities. Nothing in this Section 14.01 shall apply to claims
of, or payments to, the Trustee under or pursuant to Section 7.06.

          The subordination provisions of the foregoing paragraph shall not be
applicable to amounts at the time due and owing on the Securities of any series
on account of the unpaid principal of or interest on the Securities of such
series for the payment of which funds have been deposited in trust with the
Trustee or any Paying Agent or have been set aside by the Company in trust in
accordance with the provisions of this Indenture; nor shall such provisions
impair any rights, interests, or powers of any secured creditor of the Company
in respect of any security the creation of which is not prohibited by the
provisions of this Indenture.

          The Company shall give prompt written notice to the Trustee of any
insolvency, receivership, conservatorship, reorganization, readjustment of debt,
marshalling of assets and liabilities or similar proceedings or any liquidation
or winding-up of or relating to the Company as a whole, whether voluntary or
involuntary.  The Trustee, subject to the provisions of Section 7.01, shall be
entitled to assume that, and may act as if, no such event has occurred unless a
Responsible Officer of the Trustee assigned to the Trustee's corporate trust
department has received at the principal corporate trust office of the Trustee
from the Company or any one or more holders of Senior Indebtedness of the
Company or any trustee therefor (who shall have been certified or otherwise
established to the satisfaction of the Trustee to be such a holder or trustee)
written notice thereof.  Upon any distribution of assets of the Company referred
to in this Article, the Trustee and holders of the Securities of each series
shall be entitled to rely upon any order or decree of a court of competent
jurisdiction in which proceedings relating to any event specified in the first
sentence of this paragraph are pending for the purpose of ascertaining the
persons entitled to participate in such distribution, the holders of the Senior
Indebtedness of the Company, the amount thereof or payable thereon, the amount
or amounts paid or distributed thereon, and all other facts pertinent thereto or
to this Article, and the Trustee, subject to the provisions of Article Seven,
and the holders of the Securities of each series shall be entitled to rely upon
a certificate of the liquidating trustee or agent or other person making any
distribution to the Trustee or to the holders of the Securities of each series
for the purpose of ascertaining the persons entitled to participate in such
distribution, the holders of the Senior Indebtedness of the Company, the amount
thereof or payable thereon, the amount or amounts paid or distributed thereon
and all other facts pertinent thereto or to this Article.  In the absence of any
such liquidating trustee, agent or other person, the Trustee shall be entitled
to rely upon a written notice by a Person representing himself to be a holder of

                                      -64-

 
Senior Indebtedness of the Company (or a trustee or representative on behalf of
such holder) as evidence that such Person is a holder of such Senior
Indebtedness (or is such a trustee or representative).  In the event that the
Trustee determines, in good faith, that further evidence is required with
respect to the right of any Person, as a holder of Senior Indebtedness of the
Company, to participate in any payment or distribution pursuant to this Section,
the Trustee may request such Person to furnish evidence to the reasonable
satisfaction of the Trustee as to the amount of such Senior Indebtedness held by
such Person, as to the extent to which such Person is entitled to participation
in such payment or distribution, and as to other facts pertinent to the rights
of such Person under this Section, and if such evidence is not furnished, the
Trustee may defer any payment to such Person pending judicial determination as
to the right of such Person to receive such payment.

          Section 14.02.  OBLIGATION OF THE COMPANY UNCONDITIONAL.  Nothing
contained in this Article or elsewhere in this Indenture is intended to or shall
impair, as between the Company and the holders of the Securities of each series,
the obligation of the Company, which is absolute and unconditional, to pay to
such holders the principal of and interest on such Securities of each series
when, where and as the same shall become due and payable, all in accordance with
the terms of such Securities, or is intended to or shall affect the relative
rights of such holders and creditors of the Company other than the holders of
the Senior Indebtedness of the Company, nor shall anything herein or therein
prevent the Trustee or the holder of any Security from exercising all remedies
otherwise permitted by applicable law upon default under this Indenture, subject
to the rights, if any, under this Article of the holders of Senior Indebtedness
of the Company in respect of cash, property, or securities of the Company
received upon the exercise of any such remedy.

          Section 14.03.  LIMITATIONS ON DUTIES TO HOLDERS OF SENIOR
INDEBTEDNESS OF THE COMPANY. With respect to the holders of Senior Indebtedness
of the Company, the Trustee undertakes to perform or to observe only such of its
covenants and obligations as are specifically set forth in this Article, and no
implied covenants or obligations with respect to the holders of Senior
Indebtedness of the Company shall be read into this Indenture against the
Trustee. The Trustee shall not be deemed to owe any fiduciary duty to the
holders of Senior Indebtedness of the Company, except with respect to moneys
held in trust pursuant to the first paragraph of Section 14.01.

          Section 14.04.  NOTICE TO TRUSTEE OF FACTS PROHIBITING PAYMENT.
Notwithstanding any of the provisions of this Article or any other provisions of
this Indenture, the Trustee shall not at any time be charged with knowledge of
the existence of any facts which would prohibit the making of any payment of
moneys to or by the Trustee unless and until a Responsible Officer of the
Trustee assigned to its corporate trust department shall have received at the
principal corporate trust office of the Trustee written notice thereof from the
Company or from one or more holders of Senior Indebtedness of the Company or
from any trustee therefor who shall have been certified by the Company or
otherwise established to the reasonable satisfaction of the Trustee to be such a
holder or trustee; and, prior to the receipt of any such written notice, the
Trustee, subject to the provisions of Section 7.01, shall be entitled in all
respects to assume that no such facts exist; provided, however, that, if prior
to the fifth Business Day preceding the date upon which by the terms hereof any
such moneys may become payable for any purpose, or in the event of the execution
of an instrument pursuant to Section 12.01 acknowledging satisfaction and
discharge of this Indenture, then if prior to the second Business Day preceding
the date of such execution, the Trustee shall not have received with respect to
such moneys the notice provided for in this Section, then, anything herein
contained to the contrary notwithstanding, the Trustee shall have full 

                                      -65-

 
power and authority to receive such moneys and/or apply the same to the purpose
for which they were received, and shall not be affected by any notice to the
contrary which may be received by it on or after such date; provided, however,
no such application shall affect the obligations under this Article of the
Persons receiving such moneys from the Trustee.

          The Trustee shall be entitled to rely on the delivery to it of a
written notice by a Person representing himself to be a holder of Senior
Indebtedness (or a trustee therefor) to establish that such notice has been
given by a holder of Senior Indebtedness (or a trustee therefor).  In the event
that the Trustee determines in good faith that further evidence is required with
respect to the right of any Person as a holder of Senior Indebtedness to
participate in any payment or distribution pursuant to this Article, the Trustee
may request such Person to furnish evidence to the reasonable satisfaction of
the Trustee as to the amount of Senior Indebtedness held by such Person, to the
extent to which such Person is entitled to participate in such payment or
distribution and any other facts pertinent to the rights of such Person under
this Article, and if such evidence is not furnished, the Trustee may defer any
payment to such Person pending judicial determination as to the right of such
Person to receive such payment.

          Section 14.05.  APPLICATION BY TRUSTEE OF MONEYS DEPOSITED WITH IT.
Anything in this Indenture to the contrary notwithstanding, any deposit of
moneys by the Company with the Trustee or any agent (whether or not in trust)
for any payment of the principal of or interest on any Securities shall, except
as provided in Section 14.04, be subject to the provisions of Section 14.01.

          Section 14.06.  SUBROGATION.  Subject to the payment in full of all
Senior Indebtedness of the Company, the holders of the Securities of each series
shall be subrogated to the rights of the holders of such Senior Indebtedness to
receive payments or distributions of assets of the Company applicable to such
Senior Indebtedness until the Securities shall be paid in full, and none of the
payments or distributions to the holders of such Senior Indebtedness to which
the holders of the Securities of any series or the Trustee would be entitled
except for the provisions of this Article or of payments over pursuant to the
provisions of this Article to the holders of such Senior Indebtedness by the
holders of such Securities or the Trustee shall, as among the Company, its
creditors other than the holders of such Senior Indebtedness, and the holders of
such Securities, be deemed to be a payment by the Company to or on account of
such Senior Indebtedness; it being understood that the provisions of this
Article are and are intended solely for the purpose of defining the relative
rights of the holders of such Securities, on the one hand, and the holders of
the Senior Indebtedness of the Company, on the other hand.

          Section 14.07.  SUBORDINATION RIGHTS NOT IMPAIRED BY ACTS OR OMISSIONS
OF COMPANY OR HOLDERS OF SENIOR INDEBTEDNESS OF THE COMPANY.  No right of any
present or future holders of any Senior Indebtedness of the Company to enforce
subordination as herein provided shall at any time in any way be prejudiced or
impaired by any act or failure to act on the part of the Company or by any act
or failure to act, in good faith, by any such holder, or by any noncompliance by
the Company with the terms, provisions and covenants of this Indenture,
regardless of any knowledge thereof with which any such holder may have or be
otherwise charged. The holders of Senior Indebtedness of the Company may, at any
time or from time to time and in their absolute discretion, change the manner,
place or terms of payment, change or extend the time of payment of, or renew or
alter, any such Senior Indebtedness of the Company, or amend or supplement any
instrument pursuant to which any such Senior Indebtedness of the Company is
issued or by which it may be secured, or release any security therefor, or
exercise or refrain from exercising any other of their rights under the Senior
Indebtedness of the Company including,

                                      -66-

 
without limitation, the waiver of default thereunder, all without notice to or
assent from the holders of the Securities of each series or the Trustee and
without affecting the obligations of the Company, the Trustee or the holders of
such Securities under this Article.

          Section 14.08.  AUTHORIZATION OF TRUSTEE TO EFFECTUATE SUBORDINATION
OF SECURITIES.  Each holder of a Security of any series, by his acceptance
thereof, authorizes and expressly directs the Trustee on his behalf to take such
action as may be necessary or appropriate to effectuate, as between the holders
of such Securities and the holders of Senior Indebtedness of the Company, the
subordination provided in this Article. If, in the event of any proceeding or
other action relating to the Company referred to in the first sentence of
Section 14.01, a proper claim or proof of debt in the form required in such
proceeding or action is not filed by or on behalf of the holders of the
Securities of any series prior to fifteen days before the expiration of the time
to file such claim or claims, then the holder or holders of Senior Indebtedness
of the Company shall have the right to file and are hereby authorized to file an
appropriate claim for and on behalf of the holders of such Securities.

          Section 14.09.  NO PAYMENT WHEN SENIOR INDEBTEDNESS IN DEFAULT.  In
the event and during the continuation of any default in the payment of principal
of (or premium, if any) or interest on any Senior Indebtedness, or in the event
that any event of default with respect to any Senior Indebtedness shall have
occurred and be continuing and shall have resulted in such Senior Indebtedness
becoming or being declared due and payable prior to the date on which it would
otherwise have become due and payable, unless and until such event of default
shall have been cured, waived or remedied or shall have ceased to exist and such
acceleration shall have been rescinded or annulled, or in the event any judicial
proceeding shall be pending with respect to any such default in payment or such
event or default, then no payment or distribution of any kind or character,
whether in cash, properties or securities shall be made by the Company on
account of principal of (or premium, if any) or interest (including any
Additional Interest) if any, on the Securities or on account of the purchase or
other acquisition of Securities by the Company or any Subsidiary.

          In the event that, notwithstanding the foregoing, the Company shall
make any payment to the Trustee or the holder of any Security prohibited by the
foregoing provisions of this Section, and if such fact shall, at or prior to the
time of such payment, have been made known to the Trustee or, as the case may
be, such holder, then and in such event payment shall be paid over and delivered
forthwith to the Company.

          Section 14.10.  RIGHT OF TRUSTEE TO HOLD SENIOR INDEBTEDNESS OF THE
COMPANY.  The Trustee shall be entitled to all of the rights set forth in this
Article in respect of any Senior Indebtedness of the Company at any time held by
it in its individual capacity to the same extent as any other holder of such
Senior Indebtedness, and nothing in this Indenture shall be construed to deprive
the Trustee of any of its rights as such holder.

          Section 14.11.  ARTICLE FOURTEEN NOT TO PREVENT DEFAULTS.  The
failure to make a payment pursuant to the terms of Securities of any series by
reason of any provision in this Article shall not be construed as preventing the
occurrence of a default under this Indenture.

                                      -67-

 
                                ARTICLE FIFTEEN

                           MISCELLANEOUS PROVISIONS

          Section 15.01.  SUCCESSORS AND ASSIGNS OF COMPANY BOUND BY INDENTURE.
All the covenants, stipulations, promises and agreements in this Indenture
contained by or in behalf of the Company shall bind its successors and assigns,
whether so expressed or not.

          Section 15.02.  ACTS OF BOARD, COMMITTEE OR OFFICER OF SUCCESSOR
CORPORATION VALID.  Any act or proceeding by any provision of this Indenture
authorized or required to be done or performed by any board, committee or
officer or officers of the Company shall and may be done and performed with like
force and effect by the like board, committee or officer or officers of any
corporation that shall at the time be the lawful sole successor of the Company.

          Section 15.03.  REQUIRED NOTICES OR DEMANDS MAY BE SERVED BY MAIL.
Any notice or demand which by any provisions of this Indenture is required or
permitted to be given or served by the Trustee, by the holders of Securities or
by the holders of Preferred Securities to or on the Company may be given or
served by registered mail postage prepaid addressed (until another address is
filed by the Company with the Trustee for such purpose), as follows:  Aon
Corporation, 123 North Wacker Drive, Chicago, Illinois 60606, Attention:
Treasurer.  Any notice, direction, request, demand, consent or waiver by the
Company, by any Securityholder or by any holder of a Preferred Security to or
upon the Trustee shall be deemed to have been sufficiently given, made or filed,
for all purposes, if given, made or filed in writing at the principal corporate
trust office of the Trustee, 101 Barclay Street, Floor 21 West, New York, New
York 10286, Attention:  Corporate Trust Trustee Administration.

          Section 15.04.  OFFICERS' CERTIFICATE AND OPINION OF COUNSEL TO BE
FURNISHED UPON APPLICATIONS OR DEMANDS BY THE COMPANY.  Upon any request or
application by the Company to the Trustee to take any action under any of the
provisions of this Indenture, the Company shall furnish to the Trustee an
Officers' Certificate stating that all conditions precedent, if any, provided
for in this Indenture 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 have been complied with, except that in the case of any
such application or demand as to which furnishing of such document is
specifically required by any provision of this Indenture relating to such
particular application or demand no additional certificate or opinion need be
furnished.

          Each certificate or opinion provided for in this Indenture and
delivered to the Trustee with respect to compliance with a condition or covenant
provided for in this Indenture, other than certificates provided pursuant to
Section 4.06, shall include (1) a statement that the person making such
certificate or opinion has read such covenant or condition; (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.

                                      -68-

 
          Any certificate, statement or opinion of an officer of the Company may
be based, insofar as it relates to legal matters, upon a certificate or opinion
of or representations by counsel, unless such officer knows that the certificate
or opinion or representations with respect to the matters upon which his
certificate, statement or opinion may be based as aforesaid are erroneous, or in
the exercise of reasonable care should know that the same are erroneous.  Any
certificate, statement or opinion of counsel may be based, insofar as it relates
to factual matters, upon the certificate, statement or opinion of or
representations by an officer or officers of the Company stating that the
information with respect to such factual matters is in the possession of the
Company, unless such counsel knows that the certificate, statement or opinion or
representations with respect to the matters upon which his certificate,
statement or opinion may be based as aforesaid are erroneous, or in the exercise
of reasonable care should know that the same are erroneous.

          Any certificate, statement or opinion of an officer of the Company or
of counsel may be based, insofar as it relates to accounting matters, upon a
certificate or opinion of or representations by an accountant or firm of
accountants, unless such officer or counsel, as the case may be, knows that the
certificate or opinion or representations with respect to the accounting matters
upon which his certificate, statement or opinion may be based as aforesaid are
erroneous, or in the exercise of reasonable care should know that the same are
erroneous.  Any certificate or opinion of any independent firm of public
accountants filed with the Trustee shall contain a statement that such firm is
independent.

          Section 15.05.  PAYMENTS DUE ON SATURDAYS, SUNDAYS, AND HOLIDAYS.  In
any case where the date of payment of interest on or principal of the Securities
of any series or the date fixed for any redemption of any Security of any series
shall not be a Business Day, then payment of interest or principal need not be
made on such date, but shall be made on the next succeeding Business Day with
the same force and effect as if made on the date fixed for the payment of
interest on or principal of the Security or the date fixed for any redemption of
any Security of such series, and no additional interest shall accrue for the
period after such date and before payment.

          Section 15.06.  PROVISIONS REQUIRED BY TRUST INDENTURE ACT OF 1939 TO
CONTROL.  If and to the extent that any provision of this Indenture limits,
qualifies or conflicts with another provision included in this Indenture which
is required to be included in this Indenture by any of Sections 310 to 317,
inclusive, of the Trust Indenture Act through operation of Section 318(c)
thereof, such required provision shall control.

          Section 15.07.  INDENTURE AND SECURITIES TO BE CONSTRUED IN ACCORDANCE
WITH THE LAWS OF THE STATE OF NEW YORK.  This Indenture and each Security shall
be deemed to be a contract made under the laws of the State of New York, and for
all purposes shall be construed in accordance with the laws of said State
(without regard to conflicts of laws principles thereof).

          Section 15.08.  PROVISIONS OF THE INDENTURE AND SECURITIES FOR THE
SOLE BENEFIT OF THE PARTIES AND THE SECURITYHOLDERS.  Nothing in this Indenture
or in the Securities, expressed or implied, shall give or be construed to give
any person, firm or corporation, other than the parties hereto and their
successors and assigns and the holders of the Securities, any legal or equitable
right, remedy or claim under or in respect of this Indenture, or under any
covenant, condition and provision herein contained; all its covenants,
conditions and provisions being for the sole benefit of the parties hereto and
their 

                                      -69-

 
successors and assigns and of the holders of the Securities and, to the extent
expressly provided in Sections 6.01, 6.05, 6.06, 9.07, 10.01 and 10.02, the
holders of Preferred Securities.

          Section 15.09.  INDENTURE MAY BE EXECUTED 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 and the
same instrument.

          Section 15.10.  SECURITIES IN FOREIGN CURRENCIES.  Whenever this
Indenture provides for any action by, or any distribution to, holders of
Securities denominated in United States dollars and in any other currency, in
the absence of any provision to the contrary in the form of Security of any
particular series, the relative amount in respect of any Security denominated in
a currency other than United States dollars shall be treated for any such action
or distribution as that amount of United States dollars that could be obtained
for such amount on such reasonable basis of exchange and as of such date as the
Company may specify in a written notice to the Trustee.

          The Bank of New York, the party of the second part, hereby accepts the
trusts in this Indenture declared and provided, upon the terms and conditions,
hereinabove set forth.

                                      -70-

 
          IN WITNESS WHEREOF, AON CORPORATION, the party of the first part, has
caused this Indenture to be signed and acknowledged by its ***************** and
                                                           -----------------    
one of its Vice Presidents; and THE BANK OF NEW YORK, the party of the second
part, has caused this Indenture to be signed and acknowledged by its
_____________________________________________________, all as of the day and
year first written above.

*one of its Executive Vice Presidents

                                    AON CORPORATION



                                    By:   /s/ Harvey N. Medvin
                                         --------------------------------------
                                         Name: Harvey N. Medvin
                                         Title: Executive Vice President, Chief
                                                Financial Officer and Treasurer


                                    By:   /s/ James D. White
                                         --------------------------------------
                                         Name: James D. White
                                         Title: Vice President and Controller



                                    THE BANK OF NEW YORK, as Trustee



                                    By:   /s/ Mary La Gumina
                                         --------------------------------------
                                         Name:  Mary La Gumina
                                         Title: Assistant Vice President

                                      -71-