Transaction in Own Shares

National Grid PLC
06 March 2007

National Grid plc announces that on 05 March 2007 it purchased for cancellation
350,000 of its ordinary shares at a price of 747.7303 pence per share.



Following the purchase and upon the cancellation of these shares, the number of
ordinary shares with voting rights in issue will be 2,706,632,769.
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