Transaction in Own Shares

National Grid PLC
22 August 2007




National Grid plc - Transaction in Own Shares

22 August 2007


National Grid plc announces that on 21 August 2007 it purchased for cancellation
700,000 of its ordinary shares at a price of 707.84 pence per share from
Deutsche Bank AG London Branch.

Following the purchase and upon cancellation of these shares, the number of
ordinary shares with voting rights in issue (excluding Treasury shares) will be
2,614,164,264 and the number of ordinary shares in Treasury will be 13,876,812.

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