SIP operation

National Grid Transco PLC
11 July 2005


National Grid Transco plc (NGT)

11 July 2005


NGT SHARE INCENTIVE PLAN (the 'SIP')
(Notification of Directors' Interests, pursuant to Section 324(2)
of the Companies Act 1985)

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Under the SIP scheme, operated through Towers Perrin Share Plan Services Limited
as Trustee, employees may acquire NGT ordinary shares by regular monthly
contributions. The current monthly purchase of 48,625 NGT ordinary shares under
the scheme was confirmed by the Trustee, the shares having been purchased in the
market on Thursday 7 July 2005, at a price of 519.9 pence per share, on behalf
of some 2,810 participants.

The following executive Directors of NGT are beneficiaries of the number of
shares purchased on their behalf:

Director                 Shares purchased in SIP      Resulting total interest
Steven Holliday                    24                         563,176
Roger Urwin                        24                       1,535,543



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