Director/PDMR Shareholding

National Grid PLC
28 June 2006

28th  June 2006

National Grid plc (National Grid)

Notification of Changes in Directors' Interests

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Performance Share Plan

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On 27 June 2006, the following directors were granted an award of Ordinary
shares in National Grid plc (the 'Shares') under the National Grid Performance
Share Plan, calculated by reference to a share price of 591.5382p (or, in the
case of Mr M Jesanis, an ADS price of $53.8284). The extent to which awards will
vest will depend upon the company's performance against the relevant conditions.
Subject to performance, the shares will vest in June 2009 and will be
transferred to participants net of deductions on 27 June 2010.

            Director                                            Number of Shares
1.        Mr E M Astle                                                    88,751
2.        Mr S J Holliday                                                126,788
3.        Mr S C B Lucas                                                 101,430
4.        Mr M Jesanis                                     102,175 (20,435 ADSs)
5.        Mr N P Winser                                                   88,751



The total share interests of the above directors, following these changes, are:



            Director                                            Number of Shares
1.        Mr E M Astle                                                   708,405
2.        Mr S J Holliday                                                650,774
3.        Mr S C B Lucas                                                 693,276
4.        Mr M Jesanis                                                   530,407
5.        Mr N P Winser                                                  508,493

The directors' holdings in B Shares in National Grid plc remain unchanged.


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