Holding(s) in Company

21st Mar 2007 11:00

TR-1 (i) 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):

United Utilities PLC

2. Reason for the notification State

Yes/No

An acquisition or disposal of voting rights An acquisition or disposal of financial instruments which may result in the acquisition of shares already issued to which voting

rights are attached

An event changing the breakdown of voting rights Other (please specify): Disclosure triggered by the Yes implementation of the Transparency Directive with new 5% disclosure threshold. 3. Full name of person(s) subject to the notification Pictet Asset Management obligation (iii): SA

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

(iv):

5. Date of the transaction (and date on which the N/A

threshold is crossed or reached if different) (v):

6. Date on which issuer notified: 20 March 2007 7. Threshold(s) that is/are crossed or reached: 5%

8. Notified details: -

A: Voting rights attached to shares

Class/type of Situation Resulting situation after the triggering

shares previous to transaction (vii) if possible using the Triggering the ISIN CODE transaction (vi) Number Number Number Number of voting % of voting of of of rights (ix) rights Shares Voting shares Rights (viii) Direct Direct Indirect Direct Indirect (x) (xi) Ordinary shares N/A N/A 0 0 57,889,156 0 6.597 of ‚£1.00 ISIN Code:GB0006462336 B: Financial Instruments

Resulting situation after the triggering transaction (xii)

Type of Expiration Exercise/ Number of voting % of financial date (xiii) Conversion rights that may be voting instrument Period/ Date (xiv) acquired if the rights instrument is exercised/ converted N/A N/A N/A N/A N/A Total (A+B) Number of voting rights % of voting rights 57,889,156 6.597

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

N/A Proxy Voting:10. Name of the proxy holder: Pictet Asset Management SA

11. Number of voting rights proxy holder will cease to hold: 57,889,156 12. Date on which proxy holder will cease to hold voting -

rights: 13. Additional information: - 14. Contact name: David Crowthorne

15. Contact telephone number: ++44 20 7847

5040

Annex Notification Of Major Interests In Shares (xvi)

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

notification obligation

Full name (including legal form for legal entities) Contact address (registered office for legal entities)

Phone number

Other useful information (at least legal representative for

legal persons)

B: Identity of the notifier, if applicable (xvii)

Full name Contact address Phone number

Other useful information (e.g. functional relationship with the person or legal entity subject to the notification obligation)

C: Additional information

UNITED UTILITIES PLC

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Related Shares:

United Utilities