<PAGE>

                                                           Execution Copy
                                                                                





          ____________________________________________________________
          ____________________________________________________________




                              UTILICORP UNITED INC.


                                       and


                       THE FIRST NATIONAL BANK OF CHICAGO,
                                   as Trustee



                              ____________________


                          6.875% Senior Notes Due 2004

                              ____________________



                          NINTH SUPPLEMENTAL INDENTURE

                          Dated as of September 1, 1997



                              ____________________


          ____________________________________________________________
          ____________________________________________________________


                                    
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          NINTH SUPPLEMENTAL INDENTURE, dated as of September 1, 1997 (herein 
called the "Ninth Supplemental Indenture"), between UTILICORP UNITED INC., a 
corporation duly organized and existing under the laws of the State of 
Delaware (hereinafter called the "Company"), party of the first part, and THE 
FIRST NATIONAL BANK OF CHICAGO, a national banking association duly organized 
and existing under the laws of the United States, as Trustee under the 
Original Indenture referred to below (hereinafter called the "Trustee"), 
party of the second part.

                                   WITNESSETH:

          WHEREAS, the Company has heretofore executed and delivered to the 
Trustee an Indenture, dated as of November 1, 1990 (hereinafter called the 
"Original Indenture"), to provide for the issuance from time to time of 
certain of its unsecured senior notes (hereinafter called the "Securities"), 
the form and terms of which are to be established as set forth in Sections 
201 and 301 of the Original Indenture; and

          WHEREAS, Section 901 of the Original Indenture provides, among 
other things, that the Company and the Trustee may enter into indentures 
supplemental to the Original Indenture for, among other things, the purpose 
of establishing the form or terms of the Securities of any series as 
permitted in Sections 201 and 301 of the Original Indenture; and

          WHEREAS, the Company desires to create a series of the Securities 
in an aggregate principal amount of $150,000,000 to be

                                    
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designated the "6.875% Senior Notes Due 2004" (the "Senior Notes"), and all 
action on the part of the Company necessary to authorize the issuance of the 
Senior Notes under the Original Indenture and this Ninth Supplemental 
Indenture has been duly taken; and

          WHEREAS, all acts and things necessary to make the Senior Notes when
executed by the Company and completed, authenticated and delivered by the
Trustee as in the Original Indenture and this Ninth Supplemental Indenture
provided, the valid and binding obligations of the Company and to constitute
these presents a valid and binding supplemental indenture and agreement
according to its terms, have been done and performed; and

          WHEREAS, Section 901 of the Original Indenture provides, among other
things, that the Company and the Trustee may enter into indentures supplemental
to the Original Indenture to, among other things, add to the covenants of the
Company for the benefit of the Holders of all or any series of Securities; and

          WHEREAS, the Company desires to limit the issuance of Mortgage Bonds
under its General Mortgage (as hereinafter defined) as set forth in Section 204
of this Ninth Supplemental Indenture for the benefit of the Holders of the
Senior Notes;

                                    2
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          NOW, THEREFORE, THIS NINTH SUPPLEMENTAL INDENTURE WITNESSETH:

          That in consideration of the premises, the Company covenants and
agrees with the Trustee, for the equal benefit of holders of the Senior Notes,
as follows:

                                   ARTICLE ONE

                                   DEFINITIONS

          The use of the terms and expressions herein is in accordance with the
definitions, uses and constructions contained in the Original Indenture and the
form of Senior Note attached hereto as Exhibit A.

                                   ARTICLE TWO

                     TERMS AND ISSUANCE OF THE SENIOR NOTES

          Section 201.  ISSUE OF SENIOR NOTES.  A series of Securities which 
shall be designated the "6.875% Senior Notes Due 2004" shall be executed, 
authenticated and delivered in accordance with the provisions of, and shall 
in all respects be subject to, the terms, conditions and covenants of the 
Original Indenture and this Ninth Supplemental Indenture (including the form 
of Senior Note set forth as Exhibit A hereto).  The aggregate principal 
amount of Senior Notes of the series created hereby which may be 
authenticated and delivered under the Original Indenture shall not, except as 
permitted by the provisions of the Original Indenture, exceed $150,000,000.

                                    3
<PAGE>



          Section 202.  FORM OF SENIOR NOTES; INCORPORATION OF TERMS.  The 
form of the Senior Notes shall be substantially in the form of Exhibit A 
attached hereto.  The terms of such Senior Notse are herein incorporated by 
reference and are part of this Ninth Supplemental Indenture.

          Section 203.  PLACE OF PAYMENT.  The Place of Payment will be 
initially the corporate trust offices of the Trustee which, at the date 
hereof, are located at The First National Bank of Chicago, One First National 
Plaza, Suite 0126, Chicago, Illinois 60670-0126 and The First National Bank 
of Chicago, 14 Wall Street, 8th Floor, New York, New York  10005.

          Section 204.  LIMITATION ON ISSUANCE OF MORTGAGE BONDS.  The 
Company will not issue any Mortgage Bonds under its General Mortgage 
Indenture and Deed of Trust, dated September 15, 1988, between the Company 
and Commerce Bank of Kansas City, N.A., as Trustee (the "General Mortgage"), 
without making effective provision, and the Company covenants that in any 
such case effective provisions will be made, whereby the Senior Notes shall 
be directly secured by the General Mortgage equally and ratably with any and 
all other obligations and indebtedness thereby secured.

                                    4
<PAGE>




                                  ARTICLE THREE

                                  MISCELLANEOUS

          Section 301.  EXECUTION OF SUPPLEMENTAL INDENTURE.  This Ninth
Supplemental Indenture is executed and shall be construed as an indenture
supplemental to the Original Indenture and, as provided in the Original
Indenture, this Ninth Supplemental Indenture forms a part thereof.

          Section 302.  CONFLICT WITH TRUST INDENTURE ACT.  If any provision
hereof limits, qualifies or conflicts with another provision hereof which is
required to be included in this Ninth Supplemental Indenture by any of the
provisions of the Trust Indenture Act, such required provision shall control.

          Section 303.  EFFECT OF HEADINGS.  The Article and Section headings
herein are for convenience only and shall not affect the construction hereof.

          Section 304.  SUCCESSORS AND ASSIGNS.  All covenants and agreements in
this Ninth Supplemental Indenture by the Company shall bind its successors and
assigns, whether so expressed or not.

          Section 305.  SEPARABILITY CLAUSE.  In case any provision in this
Ninth Supplemental Indenture or in the Senior Notes shall be invalid, illegal or
unenforceable, the validity, legality and enforceability of the remaining
provisions shall not in any way be affected or impaired thereby.

          Section 306.  BENEFITS OF NINTH SUPPLEMENTAL INDENTURE.  Nothing in
this Ninth Supplemental Indenture or in the Senior

                                    5
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Notes, express or implied, shall give to any person, other than the parties 
hereto and their successors hereunder and the holders, any benefit or any 
legal or equitable right, remedy or claim under this Ninth Supplemental 
Indenture.

          Section 307.  GOVERNING LAW.  This Ninth Supplemental Indenture and
each Senior Note shall be deemed to be a contract made under the laws of the
State of New York, and for all purposes shall be governed by and construed in
accordance with the laws of said State.

          Section 308.  EXECUTION AND COUNTERPARTS.  This Ninth Supplemental
Indenture may be executed in any number of counterparts, each of which shall be
deemed to be an original, but all such counterparts shall together constitute
but one and the same instrument.

                                    6
<PAGE>


          IN WITNESS WHEREOF, the parties hereto have caused this Ninth
Supplemental Indenture to be duly executed, and their respective corporate seals
to be hereunto affixed and attested, all as of the day and year first above
written.

                                   UTILICORP UNITED INC.


[Seal]                             By: /s/ Dale J. Wolf
                                       --------------------------
                                        Name: Dale J. Wolf       
                                        Title: Vice President,
                                               Finance





Attest:


/s/ Randy Miller
--------------------------------
     Title: Asst. Treasurer


                                   THE FIRST NATIONAL BANK
                                     OF CHICAGO, as Trustee


[Seal]                             By: /s/ Tony Estevez
                                       -------------------------------
                                        Name: Tony Estevez
                                        Title: Supervisor


Attest:


/s/ Francis Ballentino
----------------------------------
  Title: Trust Officer


                                    7
<PAGE>




STATE OF MISSOURI  )
                   )  ss.:
COUNTY OF JACKSON  )


          On the 1st day of September, 1997, before me personally came Dale 
J. Wolf, to me known, who, being by me duly sworn, did depose and say that he 
is Vice President-Finance of UtiliCorp United Inc., the corporation described 
in and which executed the foregoing instrument; that he knows the seal of 
said corporation; that the seal affixed to said instrument is such corporate 
seal; that it was so affixed by authority of the Board of Directors of said 
corporation, and that he signed his name thereto by like authority.

                                          /s/ Joyce Auer
                                          -----------------------
                                          Notary Public,
                                          State of Missouri



STATE OF NEW YORK  )
                   )  ss.:
COUNTY OF QUEENS   )


          On the 6th day of October, 1997, before me personally came Tony 
Estevez, to me known, who, being by me duly sworn, did depose and say that he 
is Supervisor of The First National Bank of Chicago, the national banking 
association described in and which executed the foregoing instrument; that he 
knows the seal of said association; that the seal affixed to said instrument 
is such association seal; that it was so affixed by authority of the Board of 
Directors of said association, and that he signed his name thereto by like 
authority.

                                          /s/ Bertrand A. Reynolds, Jr.
                                          -----------------------------
                                          Notary Public,
                                          State of New York

                                    
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                                                                   EXHIBIT A


                          [FORM OF FACE OF SENIOR NOTE]

THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING OF THE INDENTURE
HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF A DEPOSITARY OR A
NOMINEE OF A DEPOSITARY.  THIS GLOBAL SECURITY IS EXCHANGEABLE FOR SECURITIES
REGISTERED IN THE NAME OF A PERSON OTHER THAN THE DEPOSITARY OR ITS NOMINEE ONLY
IN THE LIMITED CIRCUMSTANCES HEREINAFTER DESCRIBED AND MAY NOT BE TRANSFERRED
EXCEPT AS A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY OR BY A
NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY
OR BY THE DEPOSITARY OR ANY NOMINEE TO A SUCCESSOR OF THE DEPOSITARY OR A
NOMINEE OF SUCH SUCCESSOR.
 

REGISTERED                                                          REGISTERED


                              UTILICORP UNITED INC.

                           6.875% SENIOR NOTE DUE 2004

No. 918005 AP4                                $        


          UTILICORP UNITED INC., a corporation duly organized and existing under
the laws of Delaware (herein called the "Company", which term includes any
successor corporation under the Indenture hereinafter referred to), for value
received, hereby promises to pay to ____________________,  or registered
assigns, the principal sum of __________________________________________ DOLLARS
on October 1, 2004, and to pay interest thereon from October 1, 1997, or from
the most recent Interest Payment Date to which interest has been paid or duly
provided for, semi-annually on April 1 and October 1 in each year, commencing
April 1, 1998, at the rate per annum provided in the title hereof, until the
principal hereof is paid or made available for payment, and, subject to the
terms of the Indenture, at the rate per annum provided in the title hereof on
any overdue principal and premium, if any, and (to the extent that the payment
of such interest shall be legally enforceable) on any overdue instalment of
interest.  The interest so payable, and punctually paid or duly provided for, on
any Interest Payment Date will, as provided in such Indenture, be paid to the
Holder in whose name this Security (or one or more Predecessor Securities) is
registered at the close of business on the Regular Record Date for such interest
payment, which shall be the March 15 or September 15 (whether or not a Business
Day), as the case may be, next preceding such Interest Payment Date.  Any such
interest not so punctually paid or duly provided for will forthwith cease to be
payable to the Holder on such Regular Record Date, and may either

                                    
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be paid to the Holder in whose name this Security (or one or more Predecessor 
Securities) is registered at the close of business on a Special Record Date 
for the payment of such Defaulted Interest to be fixed by the Trustee, in 
which event notice whereof shall be given to Holders of Securities of this 
series not less than 10 days prior to such Special Record Date, or may be 
paid at any time in any other lawful manner not inconsistent with the 
requirements of any securities exchange on which the Securities of this 
series may be listed, and upon such notice as may be required by such 
exchange, all as more fully provided in said Indenture.

          Payment of the principal of and premium, if any, and interest on 
this Security will be made at the office or agency of the Trustee maintained 
for that purpose in the Borough of Manhattan, The City of New York, in such 
coin or currency of the United States of America as at the time of payment is 
legal tender for payment of public and private debts.  The Company may pay 
principal by check payable in such money or by wire transfer to a dollar 
account maintained by the holder (if the holder of the Security holds an 
aggregate principal amount of Securities in excess of $5,000,000).  The 
Company may pay interest by mailing a dollar check to a holder's registered 
address or, upon application by the holder hereof to the Registrar, not later 
than the applicable record date, by wire transfer to a dollar account 
maintained by the holder (if the holder of the Security holds an aggregate 
principal amount of Securities in excess of $5,000,000).

          Reference is hereby made to the further provisions of this Security 
set forth on the reverse hereof, which further provisions shall for all 
purposes have the same effect as if set forth at this place.

          Unless the certificate of authentication hereon has been executed 
by the Trustee referred to on the reverse hereof, or an Authenticating Agent, 
by manual signature of one of its authorized officers, this Security shall 
not be entitled to any benefit under the Indenture or be valid or obligatory 
for any purpose.

                                    2
<PAGE>



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

                                   UTILICORP UNITED INC.


Dated:                             By:___________________________
                                         Title:
________________                   

                                   Attest:

                                   ______________________________
[Seal]                                  Title:


TRUSTEE'S CERTIFICATE OF
  AUTHENTICATION

This is one of the Senior
Notes of the series designated 
herein referred to in the 
within-mentioned Indenture


THE FIRST NATIONAL BANK OF CHICAGO,
  as Trustee


By:____________________________
   Authorized Officer


                                    3
<PAGE>



                        [FORM OF REVERSE OF SENIOR NOTE]

                              UTILICORP UNITED INC.

                           6.875% SENIOR NOTE DUE 2004


          This Senior Note is one of a duly authorized series of securities 
of the Company (herein called the "Securities"), issued and to be issued in 
one or more series under an Indenture, dated as of November 1, 1990, as 
amended and supplemented (as amended and supplemented, the "Indenture"), 
between the Company and The First National Bank of Chicago, as Trustee 
(herein called the "Trustee", which term includes any successor trustee under 
the Indenture), to which Indenture and all indentures supplemental thereto 
reference is hereby made for a statement of the respective rights, 
limitations of rights, duties and immunities thereunder of the Company, the 
Trustee and the Holders of the Securities and the terms upon which the 
Securities are, and are to be, authenticated and delivered. This Security is 
one of the series designated on the face hereof, limited in aggregate 
principal amount to $150,000,000.

          This Security is not subject to any sinking fund, nor may this
Security be redeemed at the option of the Company prior to the Maturity Date.  

          Interest payments for this Security will be computed and paid on 
the basis of a 360-day year of twelve 30-day months.  If an Interest Payment 
Date falls on a day that is not a Business Day, such Interest Payment Date 
will be the following day that is a Business Day.

          The Indenture contains provisions for defeasance of (a) the entire 
indebtedness of this Security and (b) certain restrictive covenants upon 
compliance by the Company with certain conditions set forth therein.

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

          The Indenture permits, with certain exceptions as therein provided,
the amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Holders of the Securities of each series to be
affected under the Indenture at any time by the Company and the Trustee with the
consent of the Holders of not less than 66 2/3% in principal amount of the
Securities at the time Outstanding of all series to

                                    
<PAGE>


be affected (voting as a class).  The Indenture also contains provisions 
permitting the Holders of specified percentages in principal amount of the 
Securities of each series at the time Outstanding, on behalf of the Holders 
of all Securities of such series, to waive compliance by the Company with 
certain provisions of the Indenture and certain past defaults under the 
Indenture and their consequences.  Any such consent or waiver by the Holder 
of this Security shall be conclusive and binding upon such Holder and upon 
all future Holders of this Security and of any Security issued upon the 
registration of transfer hereof or in exchange hereof or in lieu hereof, 
whether or not notation of such consent or waiver is made upon this Security.

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

          This Security shall be exchangeable for Securities registered in the
names of Persons other than the Depositary with respect to such series or its
nominee only as provided in this paragraph.  This Security shall be so
exchangeable if (x) the Depositary notifies the Company that it is unwilling or
unable to continue as Depositary for such series or at any time ceases to be a
clearing agency registered as such under the Securities Exchange Act of 1934,
(y) the Company executes and delivers to the Trustee an Officers' Certificate
providing that this Security shall be so exchangeable or (z) there shall have
occurred and be continuing an Event of Default with respect to the Securities of
such series.  Securities so issued in exchange for this Security shall be of the
same series, having the same interest rate, if any, and maturity and having the
same terms as this Security, in authorized denominations and in the aggregate
having the same principal amount as this Security and registered in such names
as the Depositary for such Global Security shall direct. 

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

                                   2
<PAGE>



          The Securities of the series of which this Security is a part are
issuable only in registered form without coupons in denominations of $1,000 and
in integral multiples thereof.  As provided in the Indenture and subject to
certain limitations therein set forth, Securities of this series are
exchangeable for a like aggregate principal amount of Securities of this series
and of like tenor of a different authorized denomination, as requested by the
Holder surrendering the same.

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

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

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

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

                                       3