Holding(s) in Company

Pennon Group PLC
08 October 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



A disposal of voting rights



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



Legal & General Group Plc (L&G)



4. Full name of shareholder(s)



Legal & General Assurance (Pensions Management) Limited (PMC)



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



4 October 2007



6. Date on which issuer notified:



5 October 2007



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



From 4% - 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

ORD GBP 0.407                     14,018,291                               14,018,291




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


 ORD GBP 0.407               13,868,291               13,868,291                        3.97%



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

13,868,291                     3.97%



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




Legal & General Group Plc (Direct and Indirect) (Group)




Legal & General Investment Management (Holdings) Limited
(LGIMH) (Direct and Indirect)


Legal & General Investment Management Limited (Indirect)
(LGIM)


Legal & General Group Plc (Direct) (L&G) (13,868,291 - 3.97% = LGAS, LGPL & PMC)


Legal & General Investment Management (Holdings) Limited
(Direct) (LGIMHD) (12,145,479 - 3.47%  PMC)
                                                           Legal & General Insurance Holdings Limited
                                                           (Direct) (LGIH)
Legal & General Assurance (Pensions Management) Limited    Legal & General Assurance Society Limited
(PMC) (12,145,479 - 3.47% PMC)                             (LGAS & LGPL)
                                                           Legal & General Pensions Limited (Direct)
                                                           (LGPL)



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:

     Notification using the total voting rights figure of 349,176,902.

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    Christopher Paul Richards - Interim Assistant Company Secretary



Phone number   01392 443060











8 October 2007



www.pennon-group.co.uk



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