SIP Operation

National Grid PLC
08 November 2006


National Grid plc (NG)

8 November 2006

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

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NG SHARE INCENTIVE PLAN (the 'SIP')



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 37,269 NG ordinary shares under
the scheme was confirmed by the Trustee yesterday, on the shares having been
purchased in the market, at a price of 671.8 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
Steven Holliday                      19 Ordinary Shares
Roger Urwin                          19 Ordinary Shares





The Directors total interests after these events are:




Director                             Resulting total interest
Steven Holliday                      535,203 Ordinary Shares

                                     Nil- B shares - unchanged
Roger Urwin                          1,235,160 Ordinary Shares
                                     B Shares- 58,397- unchanged





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








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