SIP/ B Shares- Update

National Grid PLC
09 August 2006





National Grid plc (NG)



9 August 2006



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



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                        National Grid 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 40,651 NG. ordinary shares under
the scheme was confirmed by the Trustee yesterday, the shares having been
purchased in the market on 7 August 2006, at a price of 612.66 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
Steven Holliday                20 Ordinary Shares
Roger Urwin                    20 Ordinary Shares



                  Directors Interests- Repurchase of B Shares

Two Directors elected to accept the Offer made by Deutsche Bank AG London on 8
August 2006 to repurchase outstanding B Shares for 65 pence per B Share. The B
share interests of Roger Urwin (by 223,580 B shares) and Nick Winser (by 20,787
B shares) are reduced accordingly.





The Directors total interests after these events are:




Director                             Resulting total interest
Steven Holliday                      535,146 Ordinary Shares

                                     Nil- B shares - unchanged
Roger Urwin                          1,235,103 Ordinary Shares

                                     B Shares- 58,397
Nick Winser                          415,958 Ordinary Shares- unchanged

                                     Nil- B shares





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


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