Holding(s) in Company

Pennon Group PLC
26 January 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



PENNON GROUP PLC.



2. Reason for the notification



Initial notification due to change of thresholds for non-material interest



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



            Prudential plc group of companies



4. Full name of shareholder(s)



See schedule



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



20 January 2007



6. Date on which issuer notified:



24 January 2007



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



5%



8. Notified details:



See schedule



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
                                  18,383,601
GB00B18V8630                                                         18,383,601




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

                                                       18,383,601              -          5.16%          -
                                 18,383,601
 GB00B18V8630




B: Financial Instruments

Resulting situation after the triggering transaction (xii)


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


N/A             N/A                   N/A                       N/A                         N/A



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


18,383,601                     5.16%



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



See schedule



Proxy Voting:



10. Name of the proxy holder:



            N/A



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



N/A



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



N/A



13. Additional information:



       None





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






SCHEDULE


                         Registered Holder                                           Holding     %


Prudential plc                                                                   18,383,601      5.16
                         Nortrust Nominee Ltd A/C MHA01                           2,700,000
                         Nortrust Nominee Ltd A/C MHF01                              74,633
                         Nortrust Nominee Ltd A/C MKD01                           3,900,000
                         Nortrust Nominee Ltd A/C MKK01                           6,000,000
                         Nortrust Noms Ltd                                           10,000
                         Nortrust Noms Ltd A/C CRI01                              4,800,000
                         Nortrust Noms Ltd A/C MVA01                                270,000
                         Pruclt HSBC GIS nom (uk) ppl ac                            628,968

M&G Group Limited                                                                18,383,601      5.16
                         nortrust nominee ltd a/c mha01                           2,700,000
                         NORTRUST NOMINEE LTD A/C MHF01                              74,633
                         NORTRUST NOMINEE LTD A/C MKD01                           3,900,000
                         NORTRUST NOMINEE LTD A/C MKK01                           6,000,000
                         NORTRUST NOMS LTD                                           10,000
                         NORTRUST NOMS LTD A/C CRI01                              4,800,000
                         nortrust noms ltd a/c mva01                                270,000
                         pruclt hsbc gis nom (uk) ppl ac                            628,968

m&g Investment
Management Limited
                                                                                 18,308,968      5.14
                         Nortrust Nominee Ltd A/C MHA01                           2,700,000
                         Nortrust Nominee Ltd A/C mkd01                           3,900,000
                         Nortrust Nominee Ltd A/C MKK01                           6,000,000
                         NORTRUST NOMS LTD                                           10,000
                         NORTRUST NOMS LTD A/C CRI01                              4,800,000
                         NORTRUST NOMS LTD A/C MVA01                                270,000
                         PRUCLT HSBC GIS NOM (UK) PPL AC                            628,968

M&G Limited                                                                      18,383,601      5.16
                         Nortrust Nominee Ltd A/C MHA01                           2,700,000
                         Nortrust Nominee Ltd A/C mhf01                              74,633
                         Nortrust Nominee Ltd A/C mkd01                           3,900,000
                         Nortrust Nominee Ltd A/C mkk01                           6,000,000
                         NORTRUST NOMS LTD                                           10,000
                         NORTRUST NOMS LTD A/C CRI01                              4,800,000
                         NORTRUST NOMS LTD A/C MVA01                                270,000
                         PRUCLT HSBC GIS NOM (UK) PPL AC                            628,968







26 January 2007



www.pennon-group.co.uk



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