Director/PDMR Shareholding

National Grid PLC
08 September 2006

National Grid plc (NG)

8 September 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 39,199 NG ordinary shares under
the scheme was confirmed by the Trustee yesterday, the shares having been
purchased in the market on 7 September 2006, at a price of 638 pence per share,
on behalf of some 2,740 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



The Directors total interests after these events are:

Director                             Resulting total interest

Steven Holliday                      535,166 Ordinary Shares
                                     Nil- B shares - unchanged
Roger Urwin                          1,235,123 Ordinary Shares
                                     B Shares- 58,397



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


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