Holding(s) in Company

Pennon Group PLC 14 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 PENNON GROUP PLC. 2. Reason for the notification A subsidiary of Prudential plc no longer has a notifiable 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) 9 February 2007 6. Date on which issuer notified: 13 February 2007 7. Threshold(s) that is/are crossed or reached: See item 13 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 17,952,776 17,952,776 GB00B18V8630 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 17,852,776 17,852,776 - 5.01% - 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 17,852,776 5.01% 9. Chain of controlled undertakings through which the voting rights and/or the financial instruments are effectively held, if applicable : Prudential plc (parent company) M&G Group Limited (wholly owned subsidiary of Prudential plc) M&G Limited (wholly owned subsidiary of M&G Group Limited) 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: M&G Investment Management Limited (wholly owned subsidiary of M&G Limited) no longer has a notifiable interest (now below 5%) 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 17,852,776 5.01 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 5,469,175 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 17,852,776 5.01 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 5,469,175 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 17,852,776 5.01 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 5,469,175 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 14 February 2007 www.pennon-group.co.uk End transmission This information is provided by RNS The company news service from the London Stock Exchange

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Pennon Group (PNN)
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