SIP Operation

National Grid PLC
10 April 2006


National Grid plc (NG)



Monday 10 April 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 44,703 NG ordinary shares under
the scheme was confirmed by the Trustee on Friday 7 April, the shares having
been purchased in the market on 7 April 2006, at a price of 571 pence per share,
on behalf of some 2,800 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            559,490 Ordinary Shares
Roger Urwin            22 Ordinary Shares            1,501,218 Ordinary Shares

                                                     281,977 B Shares- unchanged


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






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