Holding(s) in Company

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     Baillie Gifford & Co                  
notification                                                                   
obligation:                                                                    
                                                                               
4. Full name of shareholder(s) (if                                             
different from 3):                                                             
                                                                               
5. Date of transaction (and date on      17-Jul-09                             
which the                                                                      
threshold is crossed or reached if                                             
different):                                                                    
                                                                               
6. Date on which issuer notified:        20-Jul-09                             
                                                                               
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     Number of      Percentage of  
use              shares     voting      of     voting rights    voting rights  
ISIN code                   rights    shares                                   
                                                                               
                                              Direct  Indirect Direct  Indirect
                                                                               
Ordinary         24657200       5.08 Below 5%         Below 5%         Below 5%
                                                                               
Share                                                                          
                                                                               
GB0007973794                                                                   
                                                                               

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            
                                                                               
Below 5%                                Below 5%                               

9. Chain of controlled undertakings through which the voting rights and /or the
financial instruments are effectively held, if applicable:                     
                                                                               
In the narrative below, the figures in [ ] indicate the amount of voting rights
and the percentage held by each controlled undertaking where relevant.         
                                                                               
Baillie Gifford & Co, a discretionary investment manager, is the parent        
undertaking of an investment management group.                                 
                                                                               
Its wholly-owned subsidiary undertaking Baillie Gifford Overseas Limited       
[259007; 0.1%] is also a discretionary investment manager.                     
                                                                               
Its wholly-owned subsidiary undertaking Baillie Gifford & Co Limited [1194356; 
0.2%] is an OEIC Authorised Corporate Director and Unit Trust Manager which has
delegated its discretionary investment management role to Baillie Gifford & Co.
                                                                               
Its wholly-owned subsidiary undertaking Baillie Gifford Life Limited [6141585; 
1.3%] is a life assurance company which procures discretionary investment      
management services from Baillie Gifford & Co in respect of its own account    
shareholdings.                                                                 

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,
                                    Serco Group plc                            
                                                                               
15. Contact telephone:              01256 744108