Holding(s) in Company

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

Northumbrian Water Group plc

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

An acquisition or disposal of voting rights

Yes

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

Credit Suisse Group AG

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

Credit Suisse Group AG

Credit Suisse AG

Credit Suisse Securities (Europe) Ltd

Credit Suisse Asset Management LLC

Credit Suisse Fund Management S.A.

Credit Suisse International

Credit Suisse Management Company (Ireland) Limited

Credit Suisse Securities (USA) LLC

Clariden Leu AG

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

10th August 2011

6. Date on which issuer notified:

12th August 2011

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

5%

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

Ordinary 10p Shares

Not reportable

Not reportable

N/A

N/A

27,540,833

N/A

5.31%

GB0033029744

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

N/A

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

N/A

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

27,540,833

5.31%

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

1. Credit Suisse Group AG

2. Credit Suisse AG

 2.1 Credit Suisse Securities (Europe) Ltd

2 2 Credit Suisse Asset Management LLC

2.3 Credit Suisse Fund Management S.A.

2.4 Credit Suisse International

2.5 Credit Suisse Management Company (Ireland) Limited

2.6 Credit Suisse Securities (USA) LLC

3. Clariden Leu AG

Proxy Voting:

10. Name of the proxy holder:

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:

Kate Alsop, Assistant Company Secretary

15. Contact telephone number:

0191 301 6701