Holding(s) in Company

Northumbrian Water Group PLC
07 April 2008


                          NORTHUMBRIAN WATER GROUP PLC

TR-1 NOTIFICATION OF MAJOR INTERESTS IN SHARES

1. Identity of the issuer or the underlying issuer   Northumbrian Water
of existing shares to which voting rights are        Group plc
attached

2. Reason for the notification                       Disposal of voting rights

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

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

5. Date of the transaction (and date on which the    1 April 2008
threshold is crossed or reached if different)

6. Date on which issuer notified:                    7 April 2008

7. Threshold(s)that is/are crossed or
reached:                                             12%

8. Notified details:
A: Voting rights attached to shares
Class/type   Situation previous to the   Resulting situation after the
of shares if Triggering transaction      Triggering transaction
possible     Number of  Number of     Number of Number of voting % of voting
using the    Shares     Voting Rights shares    rights           rights
ISIN CODE
                                                Direct Indirect  Direct Indirect
ORD GBP 0.10 72,165,166 72,165,166    67,347,163       67,347,163       12.98%
GB0033029744

B: Financial Instruments
Resulting situation after the triggering transaction
Type of      Expiration Exercise/     Number of voting rights that may   % of
financial    Date       Conversion    be acquired if the instrument is   voting
instrument              Period/Date   exercised/converted                rights

Total (A+B)
Number of voting rights                      % of voting rights
    67,347,163                               12.98%

9. Chain of controlled undertakings through which the voting rights and/or the
financial instruments are effectively held, if applicable
Bank of Ireland (Dublin) - 297,225
Citibank - 57,486,067
HSBC Bank plc (London) - 675,000
State Street Trust & Banking Co (London) - 8,156,099
North Trust Company (London) - 729,233
Other - 3,539

Proxy Voting:

10. Name of the proxy holder:

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:

14. Contact information:           Kate Alsop, Assistant Company Secretary

15. Contact telephone number:      0191 301 6701




                      This information is provided by RNS
            The company news service from the London Stock Exchange