SIP Operation

National Grid PLC
11 January 2006

National Grid plc (NG)



11 January 2006

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 42,949 NG ordinary shares under
the scheme was confirmed by the Trustee yesterday, the shares having been
purchased in the market on 9 January 2006, at a price of 557.5 pence per share,
on behalf of some 2,700 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                     559,425 Ordinary Shares
Roger Urwin            22 Ordinary Shares                     1,501,153 Ordinary Shares

                                                              281,977 B Shares- unchanged



Contact: D C Forward, Assistant Secretary (0207 004 3226)


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