Major Interests in Shares

TR-1: Notifications of Major Interests in Shares                               

1. Identity of the issuer or the underlying           Serco Group plc                 
issuer of existing shares to which voting                                      
rights are attached:                                                           
                                                                               
2. Reason for notification (yes/no)                                            
                                                                               
An acquisition or disposal of voting rights                         x          
                                                                               
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    Resolution Investment Services Limited 
notification obligation:                                                       
                                                                               
4. Full name of shareholder(s) (if                                             
different from 3):                                                             
                                                                               
5. Date of transaction (and date on     22/8/2008                              
which the threshold is crossed or                                              
reached if different):                                                         
                                                                               
6. Date on which issuer notified:       26/8/2008                              
                                                                               
7. Threshold(s) that is/are crossed or  3%                                     
reached:                                                                       
                                                                               
8: Notified Details Nominee Holdings                                           
                                                                               
A: Voting rights attached to shares                                            
                                                                               
Class/    Situation         Resulting situation after the triggering           
type of   previous to the   transaction                                        
shares    triggering                                                           
          transaction                                                          
If                                                                             
possible                                                                       
use ISIN                                                                       
code                                                                           

Number   Number of Number   Number of voting     Percentage of                 
of       voting    of       rights               voting rights                 
shares   rights    shares                                                      
                                                                               
                            Direct      Indirect Direct    Indirect            
                                                                               
GB0007973794                          14,252,027              2.93%

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            
                                                                               
14,252,027                              2.93%                                  

9. Chain of controlled undertakings through which the voting rights and /or the
financial instruments are effectively held, if applicable:                     
                                                                               
Pearl Group Limited                                                            
                                                                               
Impala Holdings Limited                                                        
                                                                               
Resolution PLC                                                                 
                                                                               
Resolution Asset Management Limited                                            
                                                                               
Resolution Investment Services Limited (indirect)                              
                                                                               
Bank of New York Nominees Ltd (1,404,267 0.29%)                                
                                                                               
Vidacos Nominees Ltd (10,887,313 2.24%)                                        
                                                                               
Mellon Bank NA (1,106,781 0.23%)                                               
                                                                               
Nortrust Nominees Ltd (418,808 0.09%)                                          
                                                                               
State Street Nominees (434, 858 0.09%)                                         

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:             Percentage calculation based on Issued 
                                        Share Capital of 485,678,000           
                                                                               
14 Contact name:                        Deborah A Wagner                       
                                                                               
15. Contact telephone name:             0141 222 8000