Holding(s) in Company

For filings with the FSA include the annex  
For filings with issuer exclude the annex   

TR-1: Notifications of Major Interests in Shares                               

1. Identity of the issuer or the underlying issuer of existing                 
shares to which voting rights are attached:                                    
                                                                               
Serco Group plc                                                                
                                                                               
2. Reason for notification                                        [Yes/No]     
                                                                               
An acquisition or disposal of voting rights                         Yes        
                                                                               
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):                                                        
                                                                               
3. Full name of person(s) subject to     UBS Investment Bank                   
notification                                                                   
obligation:                                                                    
                                                                               
4. Full name of shareholder(s) (if       UBS AG London Branch                  
different from 3):                                                             
                                                                               
5. Date of transaction (and date on      17 June 2011                          
which the                                                                      
threshold is crossed or reached if                                             
different):                                                                    
                                                                               
6. Date on which issuer notified:        21 June 2011                          
                                                                               
7. Threshold(s) that is/are crossed or   5%                                    
reached:                                                                       

8: Notified Details                                                            
                                                                               
A: Voting rights attached to shares                                            

Class/type of  Situation previous to           Resulting situation after           
shares            the triggering               the triggering transaction          
                    transaction                                                    
                                                                                   
If possible    Number of  Number of  Number of       Number of       Percentage of 
use              shares     voting     shares      voting rights     voting rights 
ISIN code                   rights                                                 
                                                                                   
                                                  Direct   Indirect Direct Indirect
                                                                                   
GB0007973794           No     No     29,125,494 29,125,494        -  5.90%        -
                 previous  previous                                                
               disclosure disclosure                                               

B: Financial Instruments                                                       
                                                                               
Resulting situation after the triggering transaction                           

Type of          Expiration      Exercise/      No. of voting    Percentage of 
financial           date        conversion    rights that may be voting rights 
instrument                      period/date    acquired (if the                
                                                  instrument                   
                                                  exercised/                   
                                                  converted)                   
                                                                               
-                    -               -                -                -       

Total (A+B)                                                                    

Number of voting rights                 Percentage of voting rights            
                                                                               
29,125,494                              5.90%                                  

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

Proxy Voting:                                                                  
                                                                               
10. Name of 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:         Serco Group plc is disclosing this         
                                    information in accordance with DTR 5.8.12  
                                                                               
14 Contact name:                    Chris Winters, Assistant Company Secretary 
                                                                               
15. Contact telephone name:         01256 744108