Holding(s) in Company

PENNON GROUP PLC

FOR IMMEDIATE RELEASE

HOLDING IN COMPANY

NOTIFICATION OF MAJOR INTERESTS IN SHARES

1. Identity of the issuer or the underlying issuer of existing shares to which voting rights are attached:

PENNON GROUP PLC / GB00B18V8630

2. Reason for the notification

Take-on New Funds.

3. Full name of person(s) subject to the notification obligation

Aviva plc & its subsidiaries.

4. Full name of shareholder(s)

Registered Holder:

BNY Norwich Union Nominees Limited 110,470*

Chase (GA Group) Nominees Limited 1,225,195*

State Street Nominees Limited 14,655,868*

Available on request 17,185*

* Denotes direct interest

5. Date of the transaction and date on which the threshold is crossed or reached:

19 November 2015

6. Date on which issuer notified:

20 November 2015

7. Threshold(s) that is crossed: < 3% to 3% Change at Direct Interest level.

8. Notified details:

A: Voting rights attached to shares

Resulting situation after the triggering transaction

B: Financial Instruments

Resulting situation after the triggering transaction

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments Resulting situation after the triggering transaction

Total (A+B+C)

9. Chain of controlled undertakings through which the voting rights and/or the financial instruments are effectively held, if applicable:

The voting rights are managed and controlled by Aviva Investors Global Services Limited and Friends Provident International Limited, with the following chains of controlled undertakings:

Aviva Investors Global Services Limited:

- Aviva plc (Parent Company)

- Aviva Group Holdings Limited (wholly owned subsidiary of Aviva plc)

- Aviva Investors Holdings Limited (wholly owned subsidiary of Aviva Group Holdings Limited)

- Aviva Investors Global Services Limited (wholly owned subsidiary of Aviva Investors Holdings Limited)

Friends Provident International Limited:

- Aviva plc (Parent Company)

- Aviva Group Holdings Limited (wholly owned subsidiary of Aviva plc)

- Aviva Life Holdings UK Limited (wholly owned subsidiary of Aviva Group Holdings Limited)

- Friends Life FPG Limited (wholly owned subsidiary of Aviva Life Holdings UK Limited)

- Friends Life FPL Limited (wholly owned subsidiary of Friends Life FPG Limited)

- Friends Life Limited (wholly owned subsidiary of Friends Life FPL Limited)

- Friends Life and Pensions Limited (wholly owned subsidiary of Friends Life Limited)

- Friends Provident International Limited (wholly owned subsidiary of Friends Life and Pensions Limited)

Proxy Voting:

10. Name of the proxy holder:

See Section 4.

11. Number of voting rights proxy holder will cease to hold:

-

12. Date on which proxy holder will cease to hold voting rights:

-

13. Additional information:

-

A: Identity of the person or legal entity subject to the notification obligation

14. Contact Name: Neil Whittaker, Aviva plc

15. Contact telephone number: 01603 684420

B: Identity of the notifier

Full name (including legal form for legal entities):

Pennon Group Plc

Contact address (registered office for legal entities):

Peninsula House, Rydon Lane, Exeter, Devon, EX2 7HR

Contact name Richard Zmuda - Assistant Company Secretary

Phone number 01392 443517

24 November 2015

www.pennon-group.co.uk