B share conversion

National Grid PLC
18 September 2007

National Grid plc
('National Grid', the 'Company')


B Share Conversion


18 September 2007


Following the announcement on 21 August 2007, and in accordance with the rights
and restrictions attached to the B shares, National Grid yesterday converted all
outstanding B shares into ordinary shares on the basis of 1 ordinary share for
every (736.6p / 65p) B shares, fractional entitlements being disregarded.

Share certificates will be sent to shareholders and CREST accounts will be
credited on or about 1 October 2007.


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