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     United Utilities Group PLC     
issuer 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    x    
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               3rd February 2010            
on which the threshold is crossed or                                           
reached: v                                                                     
                                                                               
6. Date on which issuer notified:                 4th February 2010            
                                                                               
7. Threshold(s) that is/are crossed           Holding has gone below 5%        
or 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     Number     Number    Number       Number of         % of voting   
using             of         of        of          voting            rights x     
the ISIN CODE   Shares     Voting    shares        rights                         
                           Rights                                                 
                                                                                  
                                     Direct   Direct   Indirect   Direct  Indirect
                                                xi       xii                      
                                                                                  
GB00B39J2M42  33,650,655 33,650,655   N/A      N/A    33,837,432   N/A     4.96%  
                                                                                  
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  rights that may be     rights    
                                     xiv           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     Exercise Expiration Exercise/  Number of voting    % of voting   
  financial     price   date xvii  Conversion rights instrument  rights xix, xx 
  instrument                         period       refers to                     
                                     xviii                                      
                                                                                
                                                                Nominal   Delta 
                                                                                
     CFD         N/A       N/A        N/A          127,445       0.02%    0.02% 

Total (A+B+C)                                                                  
                                                                               
        Number of voting rights               Percentage of voting rights      
                                                                               
              33,964,877                                 4.98%                 

9. Chain of controlled undertakings through which the voting rights and/or the 
financial instruments are effectively held, if applicable: xxi                 
                                                                               
BlackRock Investment Management (UK) Limited - 33,964,877 (4.98%)              

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:                                                   

13. Additional information:              BlackRock Compliance Disclosures Team 
                                                                               
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  
(registered office for legal entities)                    9AS                  
                                                                               
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.