File No. 70-9849

                United States Securities and Exchange Commission
                             Washington, D.C. 20549
                    ----------------------------------------
                                 Post-Effective
                               Amendment No. 4 to
                                    Form U-1
                             Application/Declaration
                                    Under the
                   Public Utility Holding Company Act of 1935
                    ----------------------------------------

      National Grid Transco plc            National Grid (Ireland) 1 Limited
      National Grid Holdings One plc       National Grid (Ireland) 2 Limited
      National Grid (US) Investments       6 Avenue Pasteur L 2310
      1-3 Strand                           Luxembourg
      London WC2N 5EH
      United Kingdom

                    (Names of companies filing this statement
                  and addresses of principal executive offices)
                  ---------------------------------------------
                            National Grid Transco plc
                    (Name of top registered holding company)
                  ---------------------------------------------

                            Kirk L. Ramsauer
                            Deputy General Counsel
                            National Grid USA
                            25 Research Drive
                            Westborough, Massachusetts 01582
                            Telephone: (508) 389-2972
                            Facsimile: (508) 389-3518

                   (Names and addresses of agents for service)

             The Commission is also requested to send copies of any
                communication in connection with this matter to:

                              Markian M. W. Melnyk
                     LeBoeuf, Lamb, Greene & MacRae, L.L.P.
                           1875 Connecticut Ave., N.W.
                           Washington, D.C. 20009-5728
                            Telephone: (202) 986-8000
                            Facsimile: (202) 986-8102



     This Post-effective Amendment No. 4 supplements the Form U-1
Application-Declaration in File No. 70-9849 subsequent to the issuance by the
Commission of an order in this matter/1 and Post-effective Amendment No. 2 filed
in this file on February 22, 2002. Post-effective Amendment No. 2 requested an
order deregistering National Grid Holdings One plc, National Grid (US)
Investments, National Grid (Ireland) 1 Limited, and National Grid (Ireland) 2
Limited under section 5(d) of the Public Utility Holding Company Act of 1935, as
amended (the "Act"). Post-effective Amendment No. 4 amends and restates
Post-effective Amendment No. 2 in its entirety. Post-effective Amendment No. 3
in this file, filed on January 10, 2003, relates to the Commission's retention
of jurisdiction over NM Properties, Inc. and its subsidiaries, and is a separate
and unrelated matter.

Item 1.  Description of the Proposed Transaction

     By order dated March 15, 2000, the Commission authorized National Grid
Group Holdings One plc ("National Grid One," formerly National Grid Group plc)
to acquire all of the issued and outstanding common stock of the New England
Electric System ("NEES"), a registered public-utility holding company. See
National Grid Group plc, et al, Holding Co. Act Release No. 27154 (March 15,
2000) ("March Order"). National Grid One acquired NEES through several
intermediate holding companies-- National Grid (US) Holdings Limited, National
Grid (US) Investments, National Grid (Ireland) 1 Limited, National Grid
(Ireland) 2 Limited and National Grid General Partnership (together, "Initial
Intermediate Holding Companies"). National Grid One and the Initial Intermediate
Holding Companies registered under section 5 of the Act after the NEES
acquisition, filing notice of their registration on Form U5A on March 22,
2000./2

     By order dated January 16, 2002, the Commission authorized National Grid
One and National Grid Group plc, or "New National Grid," to acquire Niagara
Mohawk

--------
1 National Grid Group plc, et al, Holding Co. Act Release No. 27490 (January 16,
2002).
2 Subsequent to the acquisition, NEES merged with NGG Holdings, LLC, which in
turn merged with NGG Holdings, Inc. That company filed notice of its
registration under section 5 of the Act on March 22, 2000, and was renamed
National Grid USA.


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Holdings, Inc. ("NiMo"). National Grid Group plc, et al, Holding Co. Act Release
No. 27490 (January 16, 2002) ("January Order"). The January Order also
authorized a reorganization whereby National Grid One's existing shares were
exchanged for shares of National Grid Group plc. (This exchange was carried out
through a "scheme of arrangement" implemented to protect the tax free nature of
the NiMo merger for NiMo shareholders who elected to exchange their shares in
NiMo for shares in National Grid Group plc, in case the shareholders in the
aggregate elected to receive more than one-fifth of the consideration for their
NiMo shares in cash.) After the reorganization, National Grid One, formerly
National Grid Group plc, was renamed and became a wholly owned subsidiary of New
National Grid. New National Grid was renamed National Grid Group plc.

     Under the March Order, National Grid One was authorized to make
non-material changes to its corporate structure. Accordingly, prior to the
acquisition of NiMo, the Initial Intermediate Holding Companies were
restructured to remove National Grid (US) Investments, National Grid (Ireland) 1
Limited and National Grid (Ireland) 2 Limited (collectively, "Former
Intermediate Holding Companies") as intermediate holding companies. National
Grid (US) Investments 4, National Grid US Partner 1 Limited, National Grid US
Partner 2 Limited, and National Grid Holdings Inc. were added as new
intermediate holding companies. National Grid (US) Holdings Limited and National
Grid General Partnership were not changed in the restructuring, remaining
intermediate holding companies. The restructuring was implemented in response to
prior occurring and anticipated changes in tax law./3

     On January 25, 2002, National Grid Group plc, National Grid (US)
Investments 4, National Grid US Partner 1 Limited, National Grid US Partner 2
Limited and National Grid Holdings Inc. registered under ss.5 of the Act by
filing a notification of registration on Form U5A. The reorganization and
intermediate holding company restructuring processes discussed above removed
both National Grid One and the Former Intermediate

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

3 See Exhibit R-1, providing supplemental information on the restructuring,
filed under a request for confidential treatment.


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Holding Companies from the direct or indirect ownership of voting securities in
National Grid USA and its public utility subsidiary companies./4

     Section 2(a)(8) of the Act defines a holding company as:

     (A) Any company which directly or indirectly owns, controls, or holds with
         power to vote, 10 per centum or more of the outstanding voting
         securities of a public-utility company or of a company which is a
         holding company by virtue of this clause or clause (B), unless the
         Commission, as hereinafter provided, by order declares such company not
         to be a holding company; and

     (B) any person which the Commission determines, after notice and
         opportunity for hearing, directly or indirectly to exercise (either
         alone or pursuant to an arrangement or understanding with one or more
         persons) such a controlling influence over the management or policies
         of any public-utility or holding company as to make it necessary or
         appropriate in the public interest or for the protection of investors
         or consumers that such person be subject to the obligations, duties,
         and liabilities imposed in this title upon holding companies.

     Neither National Grid One nor any of the Former Intermediate Holding
Companies directly or indirectly own, control, or hold with power to vote 10
percent or more of the outstanding voting securities of a public utility company
or a company which is a holding company by virtue of clause (A) or (B) of
section 2(a)(8) of the Act; nor do they exercise any controlling influence over
the management or policies of any public utility or holding company.
Consequently, National Grid One and the Former Intermediate Holding Companies
seek an order declaring their deregistration under section 5(d) of the Act.

     National Grid One is currently the parent of National Grid Holdings
Limited, a FUCO under section 33 of the Act. National Grid One may submit a
notification on Form U-57 to obtain FUCO status after deregistration.

Item 2.  Fees, Commissions and Expenses

------------
4 National Grid USA holds directly all of the issued and outstanding ownership
interests of New England Power Company, Massachusetts Electric Company, The
Narragansett Electric Company, Granite State Electric Company, Nantucket
Electric Company and New England Electric Transmission Corporation. It also owns
directly 53.97% of the common stock of both New England Hydro-Transmission
Corporation and New England Hydro-Transmission Electric Co., Inc.


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     Applicants expect to pay or incur approximately $15,000 in aggregate fees,
commissions, and expenses in connection with the transactions proposed herein.

Item 3.  Applicable Statutory Provisions

     The proposed transaction is subject to Section 5(d) of the Act.

Item 4.  Regulatory Approvals

     The proposed transaction does not require the approval of any state
regulatory agencies or the approval of any federal regulatory agencies other
than this Commission.

Item 5. Procedure

     Applicants respectfully request that the Commission issue an order granting
the deregistration as soon as possible. It is submitted that a recommended
decision by a hearing or other responsible officer of the Commission is not
needed for approval of the deregistration. The Division of Investment Management
may assist in the preparation of the Commission's decision. There should be no
waiting period between the issuance of the Commission's order and the date on
which it is to become effective.

Item 6.  Exhibits and Financial Statements

Exhibits
--------

E-3         Opinion of Counsel (filed herewith).
N-4         Chart of the Registered Holding Company Corporate Structure (filed
            under cover of Form SE).
R-1         Initial Intermediate Holding Company Restructuring
            Supplemental Information (confidential treatment requested).

Financial Statements
--------------------

Not applicable.


Item 7.  Information as to Environmental Effects

     The proposed transaction involves neither a "major federal action" nor
"significantly affects the quality of the human environment" as those terms are
used in


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Section 102(2)(C) of the National Environmental Policy Act, 42 U.S.C. Sec 4321
et seq. No federal agency is preparing an environmental impact statement with
respect to this matter.


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                                    SIGNATURE

          Pursuant to the requirements of the Public Utility Holding Company Act
of 1935, Applicants have duly caused this Application-Declaration to be signed
on their behalf by the undersigned thereunto duly authorized.

Date:  July 31, 2003            National Grid Transco plc
                                National Grid Holdings One plc
                                National Grid (US) Investments

                                By: /s/ Fiona Smith
                                    -------------------
                                Fiona Smith
                                Group General Counsel


Date:  August 1, 2003           National Grid (Ireland) 1 Limited
                                National Grid (Ireland) 2 Limited


                                By: /s/ John Cochrane
                                   ---------------------
                                John Cochrane
                                Director


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                                  Exhibit Index
                                  -------------


E-3         Opinion of Counsel.


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