<PAGE>   1

                                                                   EXHIBIT 10.22

                                                                       #1(b)

KNOW ALL MEN BY THESE PRESENTS:

THIS AMENDMENT AGREEMENT is made and entered into this 30th day of March 1993,
by and among

         HOPEWELL ENERGY INTERNATIONAL LIMITED, a private corporation duly
         organized and existing under the laws of Hong Kong, with its principal
         address at the 64th Floor, Hopewell Centre, 183 Queen's Road East, Hong
         Kong, represented herein by its Director, Stewart WG Elliott, who is
         duly authorized to represent it in this Agreement, hereinafter referred
         to as HOPEWELL;

         NATIONAL POWER CORPORATION, a government owned and controlled
         corporation duly organized and existing under and by virtue
         of Republic Act No. 6395, as amended, with its principal
         office at the corner of Agham Road and Quezon Avenue,
         Diliman, Quezon City, Philippines, represented herein by its
         President, Pablo Malixi, who is duly authorized to represent
         it in this Agreement, hereinafter referred to as NAPOCOR; and

         HOPEWELL POWER (PHILIPPINES) CORP., a corporation duly organized and
         existing under the laws of the Philippines, with office address at
         Suite 202, C.T.C. Building, 2232 Roxas Boulevard, Pasay City,
         Philippines, represented herein by its Director, Edgardo Bautista, who
         is duly authorized to represent it in this Agreement, hereinafter
         referred to as HOPEWELL PHILIPPINES.

WHEREAS, HOPEWELL, NAPOCOR and HOPEWELL PHILIPPINES are parties to an energy
conversion agreement (the "Project Agreement") dated 9th November 1991, as
supplemented by an Accession Undertaking dated 28th January 1992 and amended by
a letter-agreement dated 9th December 1992, whereby HOPEWELL agreed to design,
build and operate a coal-fired thermal power station in the Philippines and
transfer the same to NAPOCOR on the Transfer Date (as defined therein).





<PAGE>   2
                                       2


WHEREAS, the parties desire to amend certain provisions of the Project Agreement
as hereinafter provided.

NOW, THEREFORE, the parties hereto agree as follows:

1.       Interpretation.

         Terms defined in the Project Agreement shall bear the same meanings
         herein. Section headings are inserted for ease of reference only and
         shall not be construed as interpretation of text. In this Amendment
         Agreement, words denoting the singular number includes the plural and
         vice-versa.

2.       Amendments.

2.1      Articles 2.4, 3.6(i) and (ii), 3.7, 28.2(iv) and 28.4 of the Project
         Agreement are hereby amended as follows:

                  2.4 THE SITE. NAPOCOR shall make full access available to and
                  from the Site to HOPEWELL, its employees, contractors,
                  sub-contractors and advisors along the Access Road (and for
                  such purpose construct on a timely basis and maintain at
                  NAPOCOR's cost the Access Road), for the purpose of
                  constructing and operating the Power Station, at no cost to
                  HOPEWELL, for the period from the Effective Date until the
                  Transfer Date and shall make available reasonable access to
                  and from the Site between the date hereof and the Effective
                  Date for the purpose of allowing preliminary contract works.
                  Subject to NAPOCOR providing the necessary and timely access
                  and land for the purpose, HOPEWELL shall be responsible for
                  the construction, maintenance and cost of the Bridge and the
                  construction, maintenance and operation of the water pipeline
                  from Palsabangan River to the Site, including the raw water
                  intake, pump station and all related structures and
                  facilities.

<PAGE>   3


                                       3


         3.6      ROADS AND ELECTRICITY. NAPOCOR shall at its own cost:

                  (i) ensure that there is provided to the Site by not
                  later than 31st December 1993 the Access Road capable of
                  taking traffic to and from the Site (and shall maintain and
                  repair the Access Road to ensure that it is so capable at all
                  times);

                  (ii) provide on a timely basis all land required by HOPEWELL
                  in connection with the construction of the Bridge and the
                  pipeline and related facilities referred to in Article 2.4 and
                  ensure that there is provided to and from the Site access
                  along the Access Road from the National Highway on the
                  mainland to the Bridge and from the Bridge to the Site, in
                  each case in accordance with the requirements of the
                  Seventeenth Schedule (Access Road and Bridge Specifications);

         3.7 SITE. NAPOCOR shall, at its own cost, give vacant possession of the
         Site to HOPEWELL by not later than the Effective Date and hereby
         warrants to HOPEWELL that the Site will be owned by NAPOCOR free from
         all liens and encumbrances and warrants and guarantees to HOPEWELL its
         peaceful and exclusive possession of the Site from the Effective Date
         to the Transfer Date. NAPOCOR shall, at its expense, take all steps
         necessary to ensure that it has registered legal title to the Site in
         its name and, when requested by HOPEWELL, shall execute such
         instruments as may be necessary to permit the annotation thereon of
         HOPEWELL's right to use the Site under this Agreement and the
         assignment of the same for the purpose of arranging financing for the
         Project. The Power Station will be located at the Site, which (a) shall
         be made available to HOPEWELL at no cost to HOPEWELL for the period
         from the Effective Date until the Transfer Date and (b) shall not be
         used for any purpose other than for power generation and support
         activities as contemplated herein without the prior consent of NAPOCOR.

<PAGE>   4


                                       4


         28.2(iv) a copy of an absolute deed of sale conveying title to the Site
         to NAPOCOR in a manner satisfactory to HOPEWELL, certified by the
         corporate secretary of NAPOCOR in a manner satisfactory to HOPEWELL or
         in lieu thereof, evidence satisfactory to HOPEWELL that the appropriate
         trial court has issued a judicial order of condemnation and resolved
         any motion for reconsideration of such order in favor of NAPOCOR in
         expropriation proceedings for the Site, and evidence that NAPOCOR has
         taken steps to acquire the right of way for the Access Road;

         28.4 In the event that (i) NAPOCOR for any reason is unable by 31st
         December 1993 to obtain either registered legal title to the Site in
         its name or a final condemnation order in respect of the Site, or (ii)
         NAPOCOR is found by the courts to be not entitled to expropriate the
         Site or any portion thereof, or (iii) any of the owners of the Site or
         any other person (other than NAPOCOR) is restored in, or awarded, the
         possession of the Site or any portion thereof, or (iv) NAPOCOR for any
         reason fails to provide HOPEWELL with peaceful and exclusive possession
         of the Site at any time from the Effective Date to the Transfer Date,
         or (v) NAPOCOR fails to complete the Access Road by 31st December 1993,
         or (vi) fails on a timely basis to provide use or access to land or
         rights of way necessary for the construction, maintenance, and
         operation of the water pipeline and related facilities referred to in
         Article 2.4, or (vii) any of the approvals, consents, registrations,
         exemptions or other rights, laws or regulations referred to in Articles
         28.2 or 28.3 or the Ninth Schedule (Documentary Requirements for the
         Effective Date), is subsequently terminated, withdrawn, rescinded or
         amended or any new required extension, approval, consent or
         registration cannot be obtained and as a result thereof the interest of
         HOPEWELL in the Site, the Project or the Power Station and/or
         HOPEWELL's economic return (net of tax or other imposition) on its
         investment is materially reduced, prejudiced or otherwise adversely
         affected (including, without limitation, any restriction on the ability
         to remit funds in dollars outside of the Philippines), then the parties
         hereto shall meet and endeavour to agree on amendments to this
         Agreement and if after 60 days no such agreement has been reached the
         provisions of Article 8.5 shall apply.

<PAGE>   5


                                       5


2.2      The second paragraph of the Seventeenth Schedule to the Project
         Agreement is hereby amended as follows:

                  SPECIFICATIONS

                  The Access Road and Bridge shall be capable of taking,
                  carrying and handling the loads of all types of vehicles in
                  all weather conditions during the construction, operation and
                  maintenance of the Power Station and shall be completed not
                  later than 31st December 1993.

3.       References to the Project Agreement.

         Any reference in the Project Agreement, the Accession Undertaking or
         the Amendment Agreement to "this Agreement" and any other reference,
         whether express or implied to a clause or provision of the Project
         Agreement shall be deemed to be a reference to the Project Agreement
         and to a clause or provision thereof as hereby amended.

4.       Effectiveness.

         This Amendment Agreement shall take effect on the date hereof. Unless
         otherwise expressly provided herein, no provision hereof shall be
         deemed to amend the provisions of the Project Agreement, which
         provisions shall remain in full force and effect.

5.       Miscellaneous.

         The provisions of Clauses 20, 22 and 24 of the Project Agreement shall
         apply to this Amendment Agreement as if the same were herein repeated
         in full mutatis mutandis.

<PAGE>   6


                                       6


IN WITNESS WHEREOF, this Amendment Agreement has been executed by the parties
through their duly authorized representatives on the day and year first above
written at Quezon City.


                                        HOPEWELL ENERGY INTERNATIONAL LIMITED

                                        By: /s/ Stewart WG Elliott
                                           ----------------------------------
                                           Stewart WG Elliott
                                           Director

                                        NATIONAL POWER CORPORATION

                                        By: /s/ Pablo Malixi
                                           ----------------------------------
                                           Pablo Malixi
                                           President

                                        HOPEWELL POWER (PHILIPPINES) CORP.

                                        By: /s/ Edgardo Bautista
                                           ----------------------------------
                                           Edgardo Bautista
                                           Director

<PAGE>   7


                                       7


CONSENT

The foregoing Amendment Agreement has been executed with our acknowledgment and
consent.

REPUBLIC OF THE PHILIPPINES
(As Guarantor under the
Performance Undertaking
dated January 29, 1992)



By: /s/ illegible
    --------------------------
    Under Secretary of Finance