Transaction in Own Shares

National Grid PLC
29 October 2007

National Grid plc - Transaction in Own Shares

29 October 2007

National Grid plc announces that on 26 October 2007 it purchased for
cancellation 620,000 of its ordinary shares at a price of 799.3166 pence per
share from Morgan Stanley Securities Limited.

Following the purchase and upon cancellation of these shares, the number of
ordinary shares with voting rights in issue (excluding Treasury shares) will be
2,582,040,617 and the number of ordinary shares in Treasury will be 13,133,370.

End

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