Transaction in Own Shares

RNS Number : 0319B

National Grid PLC

04 January 2018

4 January 2018

National Grid plc ("National Grid")

ISIN Code: GB00BDR05C01

Transaction in Own Shares

National Grid announces that it has purchased the following number of its ordinary shares of 12^204/473p each on the London Stock Exchange from Barclays Capital Securities Limited ("Barclays") as part of its buy-back programme announced on 9 October 2017. The sole purpose of the programme is, as previously announced, to reduce the share capital of National Grid as part of the return of proceeds to shareholders following the sale of a majority interest in National Grid's UK gas distribution business.

Date of purchase:	4 January 2018
Number of Ordinary shares of 12^204/473p each purchased:	2,000,000
Highest price paid per share (pence):	858.2793
Lowest price paid per share (pence):	858.2793
Volume weighted average price paid per share:	858.2793

National Grid intends to hold the purchased shares in treasury. Following the purchase of these shares, National Grid holds 247,254,036 of its ordinary shares in treasury and has 3,370,316,089 ordinary shares in issue (excluding treasury shares).

A schedule of individual trades carried out by Barclays (BARCGBN1) as principal in connection with the above purchases on 4 January 2018 is attached to this announcement.

Schedule of purchases - aggregate information

Trading venue	Volume weighted average price (pence per share)	Aggregated volume
BATS Europe	859.3054	46,889
Chi-X Europe	858.3968	924,273
Turquoise	858.7492	29,121
London Stock Exchange	858.4252	999,717