Director/PDMR Shareholding

National Grid PLC
29 November 2007


29th November 2007

National Grid plc (National Grid )
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Notification of Directors' Interests

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I Performance Share Plan
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On 28 November 2007, the following directors were granted an award of shares in
National Grid plc (the 'Shares') under the National Grid Performance Share Plan,
calculated by reference to a share price of 800.9919p and an ADS share price of
$83.3121. 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 November 2010 and will be transferred to participants net of
deductions on 28 November 2011.

Director Number of Shares/ADSs*
      1.  Edward Astle                                                  41,198
      2.  Steve Holliday                                                77,247
      3.  Steve Lucas                                                   47,125
      4.  Mark Fairbairn                                                37,453
      5.  Nick Winser                                                   41,620
      6.  Bob Catell                                                    17,084*
      7.  Tom King                                                      24,006*


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II Special Retention Award Plan


On 29 November 2007, Tom King was granted an award of 35,487 ADSs in National
Grid (the 'Shares') under the National Grid Special Retention Award Plan,
calculated by reference to a share price of $84.5360 per ADR. The award will
vest in three equal parts (on 29 November in 2008, 2009 and 2010). The ADSs will
be transferred to the participant in accordance with the rules of the Plan
thereafter.





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

Director Number of Shares/ADSs*
      1.  Edward Astle                                                 743,821
      2.  Steve Holliday                                               794,301
      3.  Steve Lucas                                                  663,767
      4.  Mark Fairbairn                                               357,172
      5.  Nick Winser                                                  552,406
      6.  Bob Catell                                                    19,084*
      7.  Tom King                                                      59,493*


Contact: D C Forward, Assistant Secretary (020 7004 3226)




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