Transaction in Own Shares

National Grid PLC
17 January 2007


National Grid plc

17 January 2007

National Grid plc announces that on 16 January 2007 it purchased for
cancellation 500,000 of its ordinary shares at a price of 738.41 pence per share
from Deutsche Bank AG London Branch.

Following the purchase and upon the cancellation of these shares, the number of
ordinary shares with voting rights in issue will be 2,715,210,074.


CONTACT DETAILS

Investors
David Rees         [phone]           [phone](m)
Richard Smith      [phone]           [phone](m)
James Waite        [phone]           [phone](m)

Media

Clive Hawkins      [phone]           [phone](m)


END




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