Transaction in Own Shares

National Grid PLC
05 March 2007



National Grid plc announces that on 02 March 2007 it purchased for cancellation
100,000 of its ordinary shares at a price of 750.1316 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 2,706,982,769.
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