Transaction in Own Shares

National Grid PLC
05 December 2007

National Grid plc - Transaction in Own Shares

5 December 2007

National Grid plc announces that on 4 December 2007 it purchased 1,250,000 of
its ordinary shares at a price of 813.2690 pence per share from Morgan Stanley
Securities Limited. The purchased shares will be held as Treasury shares.

Following the purchase of these shares, the number of ordinary shares with
voting rights in issue (excluding Treasury shares) will be 2,557,605,327 and the
number of ordinary shares in Treasury will be 24,308,189.

End






                      This information is provided by RNS
            The company news service from the London Stock Exchange