Holding(s) in Company

National Grid PLC
19 March 2007







19 March 2007

National Grid plc ('NG.')



Notification of Interest in NG. Ordinary Shares;

Pursuant to Sections 198-202 of The Companies Act 1985.



National Grid plc has today received notification from Fidelity (Fidelity
International Limited and various subsidiaries, with 71,002,588 shares,
representing 2.62% of NG's issued share capital; and FMR Corp, with 11,803,275
shares, representing a further 0.43%) of a total 3.06% interest as of 15 March
2007.



This is a First Notification under the DTR Sourcebook (Fidelity having
previously notified a total of 3.04% as at 18 October 2006).



This notice is given in fulfilment of National Grid plc's obligation under DTR
5.8.12.




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