Holding(s) in Company

For filings with the FSA include the annex
For filings with issuer exclude the annex
 
TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARESi
 
1. Identity of the issuer or the underlying issuer   United Utilites Group PLC
of existing shares to which voting rights are
attached: ii

2 Reason for the notification (please tick the appropriate box or boxes):

An acquisition or disposal of voting rights                    X

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

An acquisition or disposal of instruments with similar economic effect to
qualifying financial instruments

An event changing the breakdown of voting rights
Other (please specify):

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

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

5. Date of the transaction and date on                 1st December 2009
which the threshold is crossed or
reached: v

6. Date on which issuer notified:                     29th December 2009

7. Threshold(s) that is/are crossed or             Holding has gone above 5%
reached: vi, vii
 
8. Notified details:

A: Voting rights attached to shares viii, ix
Class/type of             Situation previous                          Resulting situation after
shares                    to the triggering                          the triggering transaction
                             transaction
 
if possible
using
the ISIN CODE
                      Number            Number         Number         Number of              % of voting
                    of Shares          of Voting         of            voting                 rights x
                                        Rights         shares          rights

                                                       Direct    Direct    Indirect      Direct      Indirect
                                                                   xi         xii

GB00B39J2M42           N/A                N/A            N/A       N/A    34,674,396       N/A         5.09%
 

 
B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

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

 
C: Financial Instruments with similar economic effect to Qualifying Financial Instruments xv,
xvi
Resulting situation after the triggering transaction
  Type of financial     Exercise   Expiration      Exercise/     Number of voting rights       % of voting
      instrument         price      date xvii     Conversion       instrument refers to       rights xix, xx
                                                 period xviii
                                                                                              Nominal    Delta

         CFD              N/A          N/A            N/A                811,065               0.12%
 
Total (A+B+C)

Number of voting rights                                    Percentage of voting rights

35,485,461
 
9. Chain of controlled undertakings through which the voting rights and/or the
financial instruments are effectively held, if applicable: xxi
 
On 1 December 2009, the Barclays Global Investors (BGI) business was acquired
by BlackRock, Inc. The combined holdings of BlackRock, Inc. following this
acquisition triggered this disclosure requirement.
 
BlackRock Investment Management (UK) Limited - 35,485,461 (5.21%)
 
Proxy Voting:

10. Name of the proxy holder:

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

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

 
                                     BlackRock Compliance Disclosures Team
13. Additional information:

14. Contact name:                    Stuart Watchorn

15. Contact telephone number:        020 7743 5741;
                                     [e-mail]
 
Note: Annex should only be submitted to the FSA not the issuer
Annex: Notification of major interests in sharesxxii
 
A: Identity of the persons or legal entity subject to the notification obligation

Full name                                  BlackRock, Inc.
(including legal form of legal entities)
 
Contact address                            33 King William Street, London, EC4R 9AS
(registered office for legal entities)
 
Phone number & email                       020 7743 5741 [e-mail]
 
Other useful information                   Stuart Watchorn
 
(at least legal representative for legal
persons)
 
B: Identity of the notifier, if applicable

Full name
 
Contact address
 
Phone number & email
 
Other useful information
 
(e.g. functional relationship with the
person or legal entity subject to the
notification obligation)
 
C: Additional information
 
For notes on how to complete form TR-1 please see the FSA website.