Holding(s) in Company

16 November 2012

National Grid plc (National Grid)

Notification of Major Interest in National Grid Ordinary Shares

National Grid today received a notification on Form TR-1 from The Capital Group Companies, Inc. that its total interest in National Grid voting ordinary shares was, at 14 November 2012, at 11.964%, a total of 435,275,942 shares (its previous notification was at 12.14%).

This notice is given in fulfilment of National Grid's obligations under the FSA's Disclosure and Transparency Rules.

D C Forward

Assistant Secretary

0207 004 3226