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                                    
                                                                               
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):                                              X         
                                                                               
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                                            
which the                                                                      
threshold is crossed or reached if                                             
different):                                                                    
                                                                               
6. Date on which issuer notified:        06.05.08                              
                                                                               
7. Threshold(s) that is/are crossed or   3%                                    
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
                                                                               
GB0007973794                                          18120294            3.73%
                                                                               

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            
                                                                               
18,120,294                              3.73%                                  

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 Nominiees Ltd (1,798,702 0.37%)                               
                                                                               
Vidacos Nominees Ltd (14,431,092 2.97%)                                        
                                                                               
Mellon Bank NA (1,085,350 0.22%)                                               
                                                                               
Nortrust Nominees Ltd (534,338 0.11%)                                          
                                                                               
State Street Nominees (270,812 0.06%)                                          

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 calcualtion based on Issued     
                                    Share Capital of 485,439,000               
                                                                               
14 Contact name:                    Deborah A Wagner                           
                                                                               
15. Contact telephone name:         0141 222 8000                              

For notes on how to complete form TR-1 please see the FSA website.

Note: Annex should only be submitted to the FSA not the issuer

Annex: Notification of major interests in shares                               

A: Identity of the persons or legal entity subject to the notification         
obligation                                                                     

Full name                                                                      
(including legal form of legal                                                 
entities)                                                                      
                                                                               
Contact address                                                                
(registered office for legal                                                   
entities)                                                                      
                                                                               
Phone number & email                                                           
                                                                               
Other useful information                                                       
(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