SIP Operation

National Grid PLC
11 October 2005

National Grid plc (NG)



11 October 2005



NG SHARE INCENTIVE PLAN (the 'SIP')



(Notification of Directors' Interests, pursuant to Section 324(2) of the
Companies Act 1985)



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Under the SIP scheme, operated through Towers Perrin Share Plan Services Limited
as Trustee, employees may acquire NG ordinary shares by regular monthly
contributions. The current monthly purchase of 46,578 NG ordinary shares under
the scheme was confirmed by the Trustee yesterday, the shares having been
purchased in the market on Friday, 7 October 2005, at a price of 529.5 pence per
share, on behalf of some 2,750 participants.



The following executive Directors of NG are beneficiaries of the number of
shares purchased on their behalf:


Director               Shares purchased in SIP       Resulting total interest
Steven Holliday        24 Ordinary Shares            559,356 Ordinary Shares
Roger Urwin            24 Ordinary Shares            1,501,084 Ordinary Shares
                                                     281,977 B Shares- unchanged



Contact: D C Forward, Assistant Secretary (020 7004 3226)


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