SIP Purchase

National Grid PLC
09 September 2005


National Grid plc (NG)

Friday 9 September 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 43,911 NG ordinary shares under
the scheme has been confirmed by the Trustee, the shares having been purchased
in the market  on Wednesday,7 September 2005, at a price of 551 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     22 Ordinary Shares           559,332 Ordinary Shares
Roger Urwin         22 Ordinary Shares           1,501,060 Ordinary Shares

                                                 281,977 B Shares

Contact: Helen Richardson, Assistant Secretary (020 7004 3228)


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