SIP Operation

National Grid Transco PLC
10 May 2004



National Grid Transco plc (NGT)

Monday, 10 May 2004

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 77,114 NGT ordinary shares under
the scheme has been confirmed by the Trustee, the shares having been purchased
in the market last Friday, at a price of 428 pence per share.

The undermentioned executive directors of NGT, together with some 3,800
employees, are potential beneficiaries and are therefore deemed to be interested
in those ordinary shares.

The following Directors of NGT participated:

Director            Shares purchased in SIP           Resulting total interest

Steven Holliday                          29                            482,664
Roger Urwin                              29                          1,128,286


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