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                                                                     EXHIBIT 4.3

                            SIERRA PACIFIC RESOURCES

                              OFFICERS' CERTIFICATE

         Pursuant to Sections 2.01, 13.04 and 13.05 of the Indenture, dated as
of May 1, 2000 (as supplemented and amended from time to time, the "Indenture"),
between Sierra Pacific Resources (the "Company") and The Bank of New York, as
trustee, the undersigned officers of the Company, William E. Peterson, Senior
Vice President, General Counsel and Corporate Secretary, and Mark A. Ruelle,
Senior Vice President and Chief Financial Officer, of the Company, do hereby
certify that:

                  (1) there is hereby established a series of Securities
                  under and pursuant to the terms of the Indenture to be
                  designated as the Company's "8 3/4 Notes due 2005" (the
                  "Notes"), which shall initially be limited to an aggregate
                  principal amount of $300,000,000;

                  (2) the Notes will bear interest at an annual rate of 8 3/4%
                  from May 9, 2000, payable semi-annually on May 15 and
                  November 15 of each year beginning November 15, 2000 to the
                  persons in whose name they are registered at the close of
                  business on May 1 or November 1 preceding the interest
                  payment date. Interest on the Notes will be calculated on
                  the basis of a 360-day year of twelve 30-day months;

                  (3) the Notes will mature on May 15, 2005 and may be
                  redeemed before their maturity as described in (4), but are
                  not entitled to the benefit of any sinking fund;

                  (4) the Notes may be redeemed, in whole or in part, at the
                  Company's option, at any time or from time to time, at a
                  redemption price set forth below together with accrued
                  interest thereon at the applicable rate payable to the date
                  of redemption, on written notice given not more than 60
                  days nor less than 30 days prior to such redemption date.
                  The redemption price shall be the greater of:

                      (a) 100% of the principal amount of the Notes to be
                  redeemed, and

                      (b) the sum of the present values of the remaining
                  scheduled payments of principal and interest on the Notes
                  to be redeemed discounted to the date of redemption on a
                  semi-annual basis (assuming a 360-day year consisting of
                  twelve 30-day months) at the applicable Treasury Rate, plus
                  25 basis points.

         The following are defined terms relating to the Notes:

                  (a) "Business Day" means any day that is not a Saturday, a
                  Sunday or a day on which banking institutions or trust
                  companies in New York City are authorized or obligated by
                  law to close;

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                  (b) "Comparable Treasury Issue" means the U.S. Treasury
                  security selected by an Independent Investment Banker as
                  having a maturity comparable to the remaining term of the
                  notes to be redeemed that would be utilized, at the time of
                  selection and in accordance with customary financial
                  practice, in pricing new issues of corporate debt
                  securities of comparable maturity to the remaining term of
                  such notes;

                  (c) "Comparable Treasury Price" means, with respect to any
                  redemption date, (1) the average of the Reference Treasury
                  Dealer Quotations for such redemption date, after excluding
                  the highest and lowest Reference Treasury Dealer
                  Quotations, or (2) if the Trustee obtains fewer than four
                  such Reference Treasury Dealer Quotations, the average of
                  all such quotations;

                  (d) "Independent Investment Banker" means one of the
                  Reference Treasury Dealers appointed by the Trustee after
                  consultation with the Company;

                  (e) "Reference Treasury Dealer" means each of Merrill
                  Lynch, Pierce, Fenner & Smith Incorporated, Credit Suisse
                  First Boston Corporation, Salomon Smith Barney Inc., and at
                  least two other entities chosen by the Company, or their
                  affiliates which are primary U.S. government securities
                  dealers, and their respective successors; provided,
                  however, that if that company ceases to be a primary U.S.
                  Government securities dealer in New York City (a "Primary
                  Treasury Dealer"), the Company will substitute another
                  Primary Treasury Dealer;

                  (f) "Reference Treasury Dealer Quotations" means, with
                  respect to each Reference Treasury Dealer and any
                  redemption date, the average, as determined by the Trustee,
                  of the bid and asked prices for the Comparable Treasury
                  Issue (expressed in each case as a percentage of its
                  principal amount) quoted in writing to the Independent
                  Investment Banker at 3:30 p.m., New York City time, on the
                  third Business Day preceding such redemption date;

                  (g) "Treasury Rate" means, with respect to any redemption
                  date, the rate per annum equal to the semiannual equivalent
                  yield to maturity of the Comparable Treasury Issue,
                  assuming a price for the Comparable Treasury Issue
                  (expressed as a percentage of its principal amount) equal
                  to the Comparable Treasury Price for such redemption date;

         In the event of redemption of the Notes in part only, new Notes for
the unredeemed portion thereof shall be issued in the name of the Holder
thereof upon the surrender thereof.

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                  (5) the Notes initially will be issued in book-entry form
                  only.  The Notes will be represented by one or more global
                  securities deposited with The Depository Trust Company
                  ("DTC") and registered in the name of DTC's nominee.  The
                  Company will not issue the Notes in definitive form unless
                  DTC at any time is unwilling or unable to continue as a
                  depository and the Company does not appoint a successor
                  depository within 90 days.  Under such circumstances, the
                  Company will issue Notes in definitive form in exchange for
                  the entire global security. In addition, the Company may at
                  any time determine not to have Notes represented by a
                  global security and, in such event, the Company will issue
                  Notes in definitive form in exchange for the entire global
                  security. Notes so issued in definitive form will be issued
                  as registered Notes in denominations of $1,000 and integral
                  multiples thereof, unless the Company specifies otherwise;

                  (6) the Notes shall be substantially in the form of the
                  specimen Note attached hereto as EXHIBIT A; and

                  (7) the Company covenants and agrees, for the benefit of
                  the holders of the Notes, that if at any time between the
                  date hereof and May 5, 2001, the Company issues any debt
                  securities which have the benefit of any covenant that is
                  more favorable to the holders of such securities than the
                  covenants applicable to the Notes, then the Company shall
                  amend the Indenture to make a similar covenant for the
                  benefit of the holders of the Notes.

         The undersigned officers of the Company do hereby further certify,
pursuant to Sections 13.04 and 13.05 of the Indenture, as follows:

                  (1) We have read the covenants and conditions of the
                  Indenture, in respect of which this certificate is
                  furnished; and

                  (2) We have made such examination or investigation, either
                  personally or through appropriate officers or employees of
                  the Company, as is necessary to enable us to express an
                  informed opinion that such covenants and conditions have
                  been complied with.

                  (3) In our opinion, such covenants and conditions have been
                  complied with.

         Capitalized terms not otherwise defined herein have the meanings set
forth in the Indenture.

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         IN WITNESS WHEREOF, we have hereunto set our hands this 9th day of
May, 2000.

                                        /s/ William E. Peterson
                                        --------------------------------------
                                        William E. Peterson
                                        Senior Vice President, General Counsel
                                          and Corporate Secretary

                                        /s/ Mark A. Ruelle
                                        --------------------------------------
                                        Mark A. Ruelle
                                        Senior Vice President, Chief
                                          Financial Officer and Treasurer<PAGE>
                                                                EXHIBIT 10(b)(i)

                        AMENDMENT NO. 1 AND WAIVER NO. 1
                             UNDER CREDIT AGREEMENT

         AMENDMENT NO. 1 AND WAIVER NO. 1 (this "AMENDMENT"), dated as of August
18, 1999, under the Credit Agreement (the "CREDIT AGREEMENT"), dated as of June
30, 1997, by and among OGDEN CORPORATION, a Delaware corporation (the
"BORROWER"), the Signatory Lenders party thereto (the "LENDERS") and THE BANK OF
NEW YORK, as Agent (the "AGENT").

                                    RECITALS

         A. Capitalized terms used herein which are not herein defined shall
have the respective meanings ascribed thereto in the Credit Agreement.

         B. The Borrower has entered into an agreement to purchase the equity
interest of the PacifiCorp. in a entity that owns a power plant in the
Philippines.

         C. One of the conditions to the closing of such purchase is that the
Borrower procure a standby letter of credit in the amount of $31,883,000 (the
"Philippines Letter of Credit").

         D. The Borrower has requested that the L/C Issuing Bank issue the
Philippines Letter of Credit pursuant to the Credit Agreement.

         E. To facilitate the Borrower's request, the Borrower has requested
that the Agent and the Lenders agree to (i) amend the Credit Agreement to
increase the Letter of Credit Sub-Facility from $30,000,000 to $33,000,000 and
(ii) waive compliance by the Borrower with the notice provisions of Section
2.20(b) of the Credit Agreement for the purposes of the issuance of the
Philippines Letter of Credit.

         F. The Agent and the Lenders are willing to agree to the Borrower's
request subject to the terms and conditions set forth herein.

            Accordingly, in consideration of the covenants, conditions and
agreements hereinafter set forth, and for other good and valuable consideration,
the receipt and adequacy of which are hereby acknowledged, the parties hereto
agree as follows:

         1. Section 2.20(a) of the Credit Agreement is amended by deleting the
reference to "$30,000,000" contained in such section and replacing it with
"$33,000,000."

         2. The Agent and the Lenders waive, for the purpose and only for the
purpose of the issuance of the Philippines Letter of Credit, compliance with the
provisions of Section 2.20(b) of the Credit Agreement requiring Borrower to
provide at least three (3) Business Days notice prior to the requested date of
the issuance of a Letter of Credit.

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         3. The effectiveness of this Amendment and Waiver is subject to the
prior or simultaneous fulfillment of the following conditions:

            (a) The Agent shall have received (i) this Amendment executed by a
duly authorized officer or officers of the Borrower and (ii) consents to this
Amendment and Waiver from the Required Lenders; and

            (b) The Agent shall have received such other documents as it shall
have reasonably requested.

         4. The Borrower hereby (i) reaffirms and admits the validity and
enforceability of the Credit Agreement and the other Loan Documents and all of
its obligations thereunder, (ii) represents and warrants that there exists no
Default or Event of Default, and (iii) represents and warrants that the
representations and warranties contained in the Credit Agreement as amended by
this Amendment (other than the representations and warranties made as of a
specific date) are true and correct in all material respects on and as of the
date hereof.

         5. This Amendment and Waiver may be executed in any number of
counterparts, each of which shall be an original and all of which shall
constitute one agreement. It shall not be necessary in making proof of this
Amendment to produce or account for more than one counterpart signed by the
party to be charged.

         6. This Amendment and Waiver is being delivered in and is intended to
be performed in the State of New York and shall be construed and enforceable in
accordance with, and be governed by, the internal laws of the State of New York
without regard to principles of conflict of laws.

         7. Except as amended hereby, the Credit Agreement shall in all other
respects remain in full force and effect.

            IN WITNESS WHEREOF, the parties hereto have caused this Amendment
and Waiver to be duly executed and delivered by their proper and duly authorized
officers as of the day and year first above written.

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