NOTIFICATION OF SHARE REPURCHASE PROGRAMME

30 September 2021

Pennon Group plc

Share Repurchase Programme

As detailed in Pennon's Trading Update on 28 September 2021, and in line with the package of shareholder returns announced by Pennon in June 2021 which was approved by shareholders at the General Meeting in June, authority was granted for the proposed on-market share buy-back programme (the "Programme") in respect of its ordinary shares of 61.05 pence each, of up to c.£400 million.

The purpose of the Programme is to reduce share capital, and completion of the Programme is subject to to Pennon's continued review of value creating opportunities in the UK water sector. The maximum number of shares that can be repurchased in connection with the Programme is 42,183,689 (being the maximum authority granted by shareholders at Pennon's AGM on 22 July 2021).

The first phase of the Programme commenced on 23 July and concluded on 10 September 2021, with c.£60 million deployed. Following on from this, Pennon is announcing today that it is initiating the second phase of the Programme and has entered into a non-discretionary agreement with Morgan Stanley & Co. International plc ("Morgan Stanley") to enable Morgan Stanley, acting as principal, to purchase ordinary shares of 61.05 pence each in the share capital of Pennon for an aggregate purchase price of no greater than £60 million and the simultaneous on-sale of such shares by Morgan Stanley to Pennon. This agreement commences on 30 September 2021 and share purchase activity pursuant to the agreement is expected to end no later than 26 November 2021. Morgan Stanley will make trading decisions in relation to Pennon shares purchased under the Programme independently of, and uninfluenced by, Pennon. All shares repurchased will be cancelled.

Further phases are expected to commence over the period to 30 September 2022.

Any purchase of Pennon shares done in relation to this announcement will be carried out on the London Stock Exchange and Multilateral Trading Facilities, as defined by the Directive 2014/65/EU on markets in financial instruments (including the delegated and implementing acts adopted under it) as implemented, retained, amended, extended, re-enacted or otherwise given effect in the United Kingdom from 1 January 2021 and as amended or supplemented in the United Kingdom thereafter, and executed within the price and volume conditions set out in the Listing Rules, the provisions of Article 5(1) of Regulation (EU) No. 596/2014 (as incorporated into UK domestic law by the European Union (Withdrawal) Act 2018), the Commission Delegated Regulation (EU) 2016/1052 (as incorporated into UK domestic law by the European Union (Withdrawal) Act 2018) dealing with buyback programmes and the Company's general authority to make market purchases of Pennon shares granted at its AGM on 22 July 2021.

The Company will announce any market repurchase of shares no later than 7.30 a.m. on the business day following the calendar day on which the repurchase occurred.

This announcement does not constitute, or form part of, an offer or any solicitation of an offer for securities in any jurisdiction.

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