Holding(s) in Company

Pennon Group PLC
06 February 2007

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 (ii):



PENNON GROUP PLC



2. Reason for the notification



An acquisition or disposal of voting rights



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



(1)   Lansdowne Partners Limited being the General Partners of Lansdowne


      Partners Limited Partnership

    (2) Lansdowne UK Equity Fund Limited

    (3) Lansdowne Partners International Limited



4. Full name of shareholder(s)



Morstan Nominees Ltd (Registered Shareholder)



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



2 February 2007



6. Date on which issuer notified:



5 February 2007



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



Less than 3%



8. Notified details:









A: Voting rights attached to shares


Class/type of shares if possible              Situation previous to the Triggering transaction
using the ISIN CODE
                                  Number of shares                   Number of voting Rights


Ordinary Shares                   11,501,676                         11,501,676





Resulting situation after the triggering transaction


Class/type of shares if      Number of shares         Number of voting rights (ix)      % of voting rights
possible using the ISIN CODE
                             Direct                   Direct (x)   Indirect (xi)        Direct      Indirect


 Ordinary Shares                                                    Less than 3%                     Less than
                                                                                                    3%



B: Financial Instruments

Resulting situation after the triggering transaction


Type of         Expiration Date       Exercise/Conversion       Number of voting rights     % of voting rights
financial       (xiii)                Period/ Date              that may be acquired if the
instrument                                                      instrument is exercised/
                                                                converted.








Total (A+B)
Number of voting rights        % of voting rights


Less than 3%                   Less than 3%





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



Lansdowne Partners International Limited is the parent undertaking of Lansdowne
Partners Limited











Proxy Voting:



10. Name of the proxy holder:



Lansdowne Partners Limited



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:



     (1) Lansdowne Partners Limited being the General Partner of Lansdowne

         Limited Partnership ('LPLP') controls less than 3% of voting rights



     (2) Lansdowne UK Equity Fund Limited owns less than 3% of voting rights



Annex to Notification of Major Interests In Shares



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



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  Margaret Lilian Heeley

              Assistant Company Secretary



 Phone number 01392 443060







6 February 2007





www.pennon-group.co.uk





End transmission




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