****


**EXHIBIT
4.3**














**MIDAMERICAN
ENERGY COMPANY**





and








**THE
BANK OF NEW YORK** ,


as
Trustee





________________





6.750% ** Notes due
2031





________________








First
Supplemental Indenture





_________________








Dated as
of February 8, 2002



















FIRST
SUPPLEMENTAL INDENTURE, dated as of February 8, 2002 (herein called the First
Supplemental Indenture ”),
between MIDAMERICAN ENERGY COMPANY, a corporation duly organized and existing
under the laws of the State of Iowa (herein called the “ Company ”), and
THE BANK OF NEW YORK, a national banking association duly organized and existing
under the laws of the United States of America, as Trustee (herein called the
“ Trustee ”), under
the Original Indenture referred to below.





WITNESSETH:





WHEREAS,
the Company has heretofore executed and delivered to the Trustee an indenture
dated as of February 8, 2002 (herein called the “ Original
Indenture ” ) , to
provide for the issuance from time to time of its unsubordinated debentures,
notes or other evidences of indebtedness, the form and terms of which are to be
established as set forth in Sections 2.01 and 3.01 of the Original
Indenture;





WHEREAS,
Section 9.01 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, (i) the purpose of establishing the form and
terms of the Securities (as defined in the Original Indenture) of any series as
permitted by Sections 2.01 and 3.01 of the Original Indenture, and (ii) to add
to the covenants of the Company for the benefit of the Holders of all or any
series of Securities (as defined in the Original Indenture);





WHEREAS, the Company desires to create one series of securities in an aggregate
principal amount of four hundred million dollars ($400,000,000) to be designated
the *“* 6.750% ** Notes due
2031” (the “ Securities ”), and
all action on the part of the Company necessary to authorize the issuance of the
Securities under the Original Indenture and this First Supplemental Indenture
has been duly taken;





WHEREAS, the Company and the Trustee desire to make certain amendments to the
Original Indenture in conformance with the requirements described above;
and





WHEREAS, all acts and things necessary to make the Securities, when executed by
the Company and authenticated and delivered by the Trustee as provided in the
Original Indenture, 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.








1





NOW,
THEREFORE, THIS FIRST SUPPLEMENTAL INDENTURE





WITNESSETH:





That in
consideration of the premises and of the acceptance and purchase of the
Securities by the holders thereof and of the acceptance of this trust by the
Trustee, the Company covenants and agrees with the Trustee, for the equal
benefit of holders of the Securities, as follows:





ARTICLE
I


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 Security
attached hereto as Exhibit
A .





ARTICLE
II


TERMS AND
ISSUANCE OF THE SECURITIES





Section
2.01. *Issue
of Securities.* One
series of notes, which shall be designated the *“* 6.750% ** Notes due
2031”, 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 First Supplemental Indenture
(including the form of Security set forth in Exhibit
A) . The
aggregate principal amount of the 6.750% Notes due 2031 which may be
authenticated and delivered under this First Supplemental Indenture shall not
exceed $400,000,000.





Section
2.02. *Optional
Redemption.* The
Securities may be redeemed, in whole or in part, at the option of the Company
pursuant to the terms set forth in Annex
1 to the
Securities to be redeemed. The provisions of Article XI of the Original
Indenture shall also apply to any optional redemption of Securities by the
Company.





Section
2.03 *.
Defeasance and Discharge.* The
provisions of Section 14.02 of the Original Indenture shall be applicable to the
Securities.





Section
2.04. *Covenant
Defeasance.* The
provisions of Section 14.03 ** of the
Original Indenture shall be applicable to the Securities.





Section
2.05 *.
Place of Payment.* The Place
of Payment in respect of the Securities will be in The City of New York,
initially at the Corporate Trust Office of The Bank of New York (which as of the
date hereof is located at 101 Barclay Street, 21 West, New York, New York 10286,
Attention: Corporate Trust Administration).






2











Section
2.06. *Form
of Securities; Incorporation of Terms.* The form
of the Securities shall be substantially in the form of Exhibit
A , the
terms of which are herein incorporated by reference and which are part of this
First Supplemental Indenture. The Securities shall be issued as one or more
Global Securities in filly registered form, as determined in accordance with
Section 2.01 of the Original Indenture. The Global Securities shall be delivered
by the Trustee to the Depositary, as the Holder thereof, or a nominee or
custodian therefore, to be held by the Depositary in accordance with the


Original
Indenture.





Section
2.07. *Exchange
of the Global Securities.* Each of
the Global Securities shall be exchangeable for definitive Securities only as
provided in Section 3.05 of the Original Indenture.





Section
2.08. Regular Record Date for the Securities. The Regular Record Date for the
Securities shall be the June 15 or December 15 immediately prior to each
Interest Payment Date.





Section
2.09. *Authorized
Denominations.* Beneficial
interests in Global Securities, as well as definitive Securities, may be held
only in denominations of $1,000 and integral multiples of $1,000 in excess
thereof.





ARTICLE
III


DEPOSITARY





Section
3.01. *Depositary.* The
Depositary Trust Company, its nominees and their respective successors are
hereby appointed Depositary with respect to the Global Securities.





ARTICLE
IV


AMENDMENTS
TO ORIGINAL INDENTURE





Section
4.01. *Amendments.* The
Original Indenture is hereby amended as follows:





(a) Section
1.01 of the Original Indenture is hereby amended to add or modify the following
definitions, as the case may be:





“Common
Shareholders Equity” means,
at any time, the total shareholders’ equity of the Company and its consolidated
subsidiaries, determined on a consolidated basis in accordance with generally
accepted accounting principles, as of the end of the most recently completed
fiscal quarter of the Company for which financial information is then
available.”





3








“ Iowa-Illinois
Indenture” means
the Indenture of Mortgage and Deed of Trust, dated as of March 1, 1947, from
Iowa-Illinois Gas and Electric Company to Harris Trust and Savings Bank and Lynn
Lloyd (C. Potter, successor individual trustee), as trustees, and indentures
supplemental thereto.”





“ Midwest
Power Indenture” means
the General Mortgage Indenture and Deed of Trust, dated as of January 1, 1993,
between Midwest Power Systems Inc. and Morgan Guaranty Trust Company of New
York, trustee (Harris Trust and Savings Bank, successor trustee), and indentures
supplemental thereto.”





“ Permitted
Encumbrances” means:





(a) (i) any
mortgage, pledge or other lien or encumbrance on any property hereafter acquired
or constructed by the Company or a Subsidiary, or on which property so
constructed is located, and created prior to, contemporaneously with or within
360 days after, such acquisition or construction or the commencement of
commercial operation of such property to secure or provide for the payment of
any part of the purchase or construction price of such property, or (ii) any
property subject to any mortgage, pledge, or other lien or encumbrance upon such
property existing at the time of acquisition thereof by the Company or any
Subsidiary, whether or not assumed by the Company or such Subsidiary, or (iii)
any mortgage, pledge or other lien or encumbrance existing on the property,
shares of stock, membership interests or indebtedness of a corporation or
limited liability company at the time such corporation or limited liability
company shall become a Subsidiary or any pledge of the shares of stock or
membership interests of such corporation or limited liability company prior to,
contemporaneously with or within 360 days after such corporation or limited
liability company shall become a Subsidiary to secure or provide for the payment
of any part of the purchase price of such stock or membership interests, or (iv)
any conditional sales agreement or other title retention agreement with respect
to any property hereafter acquired or constructed; *provided* that, in
the case of clauses (i) through (iv), the lien of any such mortgage, pledge or
other lien does not spread to property owned prior to such acquisition or
construction or to other property thereafter acquired or constructed other than
additions to such acquired or constructed property and other than property on
which property so constructed is located; and *provided,
further,* that if a
firm commitment from a bank, insurance company or other lender or investor (not
including the Company, a Subsidiary or an Affiliate of the Company) for the
financing of the acquisition or construction of property is made prior to
contemporaneously with or within the 360-day period hereinabove referred to, the
applicable mortgage, pledge, lien or encumbrance shall be deemed to be permitted
by this clause (a) whether or not created or assumed within such
period;




4








(b) any
mortgage, pledge or other lien or encumbrance created for the sole purpose of
extending, renewing or refunding any mortgage, pledge, lien or encumbrance
permitted by clause (a) of this definition; *provided,
however,* that the
principal amount of indebtedness secured thereby shall not exceed the principal
amount of indebtedness so secured at the time of such extension, renewal or
refunding and that such extension, renewal or refunding mortgage, pledge, lien
or encumbrance shall be limited to all or any part of the same property that
secured the mortgage, pledge or other lien or encumbrance extended, renewed or
refunded;





(c)  liens for
taxes or assessments or governmental charges or levies not then due and
delinquent or the validity of which is being contested in good faith, and
against which an adequate reserve has been established; liens on any property
created in connection with pledges or deposits to secure public or statutory
obligations or to secure performance in connection with bids or contracts;
materialmen’s, mechanics’, carrier’s, workmen’s, repairmen’s or other like
liens; or liens on any property created in connection with deposits to obtain
the release of such liens; liens on any property created in connection with
deposits to secure surety, stay, appeal or customs bonds; liens created by or
resulting from any litigation or legal proceeding which is currently being
contested in good faith by appropriate proceedings; leases and liens, rights of
reverter and other possessory rights of the lessor thereunder; zoning
restrictions, easements, rights-of-way or other restrictions on the use of real
property or minor irregularities in the title thereto; and any other liens and
encumbrances similar to those described in this clause (c), the existence of
which, in the opinion of the board of directors of the Company, does not
materially impair the use by the Company or a Subsidiary of the affected
property in the operation of the business of the Company or a Subsidiary, or the
value of such property for the purposes of such business;





(d) any
mortgage, pledge or other lien or encumbrance created after February 8, 2002 on
any property leased to or purchased by the Company or a Subsidiary after that
date and securing, directly or indirectly, obligations issued by a State, a
territory or a possession of the United States, or any political subdivision of
any of the foregoing, or the District of Columbia, to finance the cost of
acquisition or cost of construction of such property; *provided* that the
interest paid on such obligations is entitled to be excluded from gross income
of the recipient pursuant to Section 103(a)(l) of the Internal Revenue Code of
1986, as amended (or any successor to such provision), as in effect at the time
of the issuance of such obligations;




5


(e) any
mortgage, pledge or other lien or encumbrance on any property now owned or
hereafter acquired or constructed by the Company or a Subsidiary, or on which
property so owned, acquired or constructed is located, to secure or provide for
the payment of any part of the construction price or cost of improvements of
such property, and created prior to, contemporaneously with or within 360 days
after, such construction or improvement; *provided* that if a
firm commitment from a bank, insurance company or other lender or investor (not
including the Company, a Subsidiary or an Affiliate of the Company) for the
financing of the acquisition or construction of property is made prior to,
contemporaneously with or within the 360-day period hereinabove referred to, the
applicable mortgage, pledge, lien or encumbrance shall be deemed to be permitted
by this clause (e) whether or not created or assumed within such period;
and





(f) any
mortgage, pledge or other lien or encumbrance not otherwise described in clauses
(a) through (e); *provided* that the
aggregate amount of indebtedness secured by all such mortgages, pledges, liens
or encumbrances does not exceed the greater of $100,000,000 or 10% of Common
Shareholders’ Equity.”





“ Principal
Facility” means
the real property, fixtures, machinery and equipment relating to any facility
owned by the Company or any Subsidiary, except any facility that is not of
material importance to the business conducted by the Company and its
Subsidiaries, taken as a whole.”





“ Regulated
Subsidiary” means
any Subsidiary which owns or operates facilities used for the generation,
transmission or distribution of electric energy and is subject to the
jurisdiction of any governmental authority of the United States or any state or
political subdivision thereof, as to any of its: rates; services; accounts;
issuances of securities; affiliate transactions; or construction, acquisition or
sale of any such facilities, except that any “exempt wholesale generator”, as
defined in 15 USC 79z-5a(a)(l), “qualifying facility”, as defined in 18 CFR
29z,l0l(b)(l), “foreign utility company”, as defined in 15 USC 79z-5b(a)(3), and
“power marketer”, as defined in NORTHWEST POWER MARKETING COMPANY, LL.C., *75* FERC PARA
61,281, shall not be a Regulated Subsidiary.”




6








“ Subsidiary” means a
corporation or limited liability company more than 50% of the outstanding voting
stock or voting membership interests of which is or are 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,
(1) “voting 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 and (2) “voting
membership interests” means membership interests which ordinarily have voting
power for the election of directors (or the equivalent thereof), whether at all
times or only so long as no senior class of membership interests have such
voting power by reason of any contingency.





“ Wholly-Owned
Subsidiary” means a
Subsidiary of which all of the outstanding voting stock or voting membership
interests (other than directors’ qualifying shares) is or are at the time,
directly or indirectly, owned by the Company, or by one or more Wholly-Owned
Subsidiaries of the Company or by the Company and one or more Wholly-Owned
Subsidiaries.”





(b) Section
1.12 of the Indenture is amended by replacing the words “without regard to
conflicts of laws and rules of said state” with the words “without regard to
conflicts of laws rules of said state”.





(c) Section
10.06 of the Original Indenture is hereby amended by replacing the reference to
Section 10.04 therein with a reference to Section 10.08.





(d) Article X
of the Original Indenture is amended by adding a new Section 10.08 thereto
immediately following Section 10.07 thereof, such Section 10.08 to read as
follows:





“Section
10.08.  Limitation
upon Mortgages and Liens .





The
Company will not at any time directly or indirectly create or assume and will
not cause or permit a Subsidiary directly or indirectly to create or assume,
except in favor of the Company or a Wholly-Owned Subsidiary, any mortgage,
pledge or other lien or encumbrance upon any Principal Facility or any interest
it may have therein or upon any stock of any Regulated Subsidiary or any
indebtedness of any Subsidiary to the Company or any other Subsidiary, whether
now owned or hereafter acquired, without making effective provision (and the
Company covenants that in such case it will make or cause to be made, effective
provision) whereby the outstanding Securities and any other indebtedness of the
Company then entitled thereto shall be secured by such mortgage, pledge, lien or
encumbrance equally and ratably with any and all other obligations and
indebtedness thereby secured, so long as any such other obligations and
indebtedness shall be so secured (provided,




7





that for
the purpose of providing such equal and ratable security, the principal amount
of outstanding Original Issue Discount Securities 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 *5.02);
provided, however,* that the
foregoing covenant shall not be applicable to (I) the lien of the Iowa-Illinois
Indenture, (2) the lien of the Midwest Power Indenture, (3) Permitted
Encumbrances or (4) any transfer, lease, use or other encumbrance of or on the
Company’s or any Subsidiary’s transmission assets (a) substantially in
accordance with the filings made with the Federal Energy Regulatory Commission
on September 28. 2001 and given docket numbers ECO I - 156-000 and ERO
1-3154-000 and/or (b) as otherwise required by applicable state or federal
order, regulation, rule or statute.”





(e) The first
sentence of Section 14.03 of the Original Indenture is hereby amended by
replacing the references to Section 10.04 therein with references to Section
10.08 in each place where such references appear in such sentence.





Section
4.02. *Application
of Amendments.* The
amendments to the Original Indenture set forth in Section 4.01 hereof shall be
applicable only to the Securities, and shall not be applicable to any other
series of securities issued under the Indenture.





ARTICLE
V


MISCELLANEOUS





Section
5.01. *Execution
as Supplemental Indenture.* This
First Supplemental Indenture is executed and shall be construed as an indenture
supplemental to the Original Indenture and, as provided in the Original
Indenture, this First Supplemental Indenture forms a part thereof.





Section
5.02. *Effect
of Headings.* The
Article and Section headings herein are for convenience only and shall not
affect the construction hereof.





Section
5.03. *Successors and Assigns.* All
covenants and agreements contained in this First Supplemental Indenture made by
the Company shall bind its successors and assigns, whether so expressed or
not.





Section
5.04. *Separability
Clause.* In case
any provision in this First Supplemental Indenture or in the Securities 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.




8








Section
5.05 *.
Benefits of First Supplemental Indenture.* Nothing
in this First Supplemental Indenture or in the Securities, express or implied,
shall give to any person, other than the parties hereto and their successors
hereunder and the Holders of the Securities, any benefit or any legal or
equitable right, remedy or claim under this First Supplemental
Indenture.





Section
5.06. *Execution
and Counterparts.* This
First 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.





Section
5.07. *Trustee Not Responsible/or Recitals.* The
recitals herein contained are made by the Company and not by the Trustee, and
the Trustee assumes no responsibility for the correctness thereof. The Trustee
makes no representation as to the validity or sufficiency of this First
Supplemental Indenture or of the Securities. The Trustee shall not be
accountable for the use or application by the Company of the Securities or the
proceeds thereof.





(SIGNATURE
PAGE FOLLOWS)




9








IN
WITNESS WHEREOF, the parties hereof have caused this First Supplemental
Indenture to be duly executed by their respective officers or directors duly
authorized thereto, all as of the day and year first above written.





MIDAMERICAN
      ENERGY COMPANYBy:/s/
      Brian K. HankelName:Brian
      K. HankelTitle:THE
      BANK OF NEW YORK,as
      TrusteeBy:/s/
      Robert A. MassimilloName:Robert
      A. MassimilloTitle:Vice
      President