Director/PDMR Shareholding

RNS Number : 0824L

National Grid PLC

26 July 2011

National Grid plc (National Grid)

Notification of Changes in Directors' Interests

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Performance Share Plan- Lapse of options

Today, National Grid received a notification from ACS HR Solutions Share Plan Services (Guernsey) Limited, as Trustee of the National Grid Employee Share Trust (the 'Trust') confirming that the 2008 awards made to Executive Directors under the Performance Share Plan had partially vested.

Awards were granted to directors under the National Grid Performance Share Plan on 25 June 2008 as follows:

Director	Number of shares/ADSs* over which awards granted	Number of shares/ADSs* over which awards lapse	Number of shares/ADSs* over which awards vest
Steven Holliday	316,472	159,819	156,653
Nick Winser	158,166	79,874	78,292
Tom King	36,680*	18,523*	18,157*

These awards were subject to performance conditions which were required to be met as a condition of vesting. These performance conditions required Total Shareholder Return, measured over a period of three years commencing from 1 July 2008, to be at least median compared to a comparator group of companies for 50% of the award to vest and 50% of the award was subject to Earnings Per Share ('EPS') subject to the extent in the growth of the Company's EPS exceeds the increase in RPI over three financial years.

For these awards granted in 2008, these performance conditions were partially satisfied at the end of the three year performance period. As a result 49.5% of awards have vested.

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The total share interests of the above directors, following these changes, are: