Holding(s) in Company

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARESi

1. Identity of the issuer or the underlying issuerof existing shares to which voting rights areattached: ii

Pennon Group plc

2 Reason for the notification (please tick the appropriate box or boxes):

An acquisition or disposal of voting rights

X

An acquisition or disposal of qualifying financial instruments which may result in the acquisition of shares already issued to which voting rights are attached

An acquisition or disposal of instruments with similar economic effect to qualifying financial instruments

An event changing the breakdown of voting rights

Other (please specify):

3. Full name of person(s) subject to thenotification obligation: iii

Lazard Asset Management LLC

4. Full name of shareholder(s)  (if different from 3.):iv

Bank of NY INC - Dir Personal

Bank of NY INC. - Global Custody

CIBC-Mellon Canadian office

Citibank NA Hong Kong - ETC

JP Morgan Chase - SWIFT

Mellon Trust

NOMURA

Northern Trust Co.

State Street Bank - Australia Ltd

State Street Bank - Custodian - ETC

State Street Master - Master Tr - ETC

State Street Master - Custody Master Trust

Sumitomo Trust & Banking Co.

5. Date of the transaction and date onwhich the threshold is crossed orreached: v

23 January 2017

6. Date on which issuer notified:

24 January 2017

7. Threshold(s) that is/are crossed orreached: vi, vii

Increase from 7% to 8%

8. Notified details:

A: Voting rights attached to shares viii, ix

Class/type ofshares

if possible usingthe ISIN CODE

Situation previousto the triggeringtransaction

Resulting situation after the triggering transaction

NumberofShares

NumberofVotingRights

Numberof shares

Number of votingrights

% of voting rights x

Direct

Direct xi

Indirect xii

Direct

Indirect

GB00B18V8630

32,141,152

33,187,671

8.019%

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate xiii

Exercise/Conversion Period xiv

Number of votingrights that may beacquired if theinstrument isexercised/ converted.

% of votingrights

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments xv, xvi

Resulting situation after the triggering transaction

Type of financialinstrument

Exercise price

Expiration date xvii

Exercise/Conversion period xviii

Number of voting rights instrument refers to

% of voting rights xix, xx

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

33,187,671

8.019%

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

Lazard Asset Management LLC controls all the voting rights held of this issuer.

Proxy Voting:

10. Name of the proxy holder:

N/A

11. Number of voting rights proxy holder will ceaseto hold:

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

13. Additional information:

14. Contact name:

Legal & Compliance Department

15. Contact telephone number:

0207 448 2085