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     BlackRock, Inc.                       
notification                                                                   
obligation:                                                                    
                                                                               
4. Full name of shareholder(s) (if                                             
different from 3):                                                             
                                                                               
5. Date of transaction (and date on      7 July 2011                           
which the                                                                      
threshold is crossed or reached if                                             
different):                                                                    
                                                                               
6. Date on which issuer notified:        11 July 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      Number of       Percentage of 
use              shares     voting      of      voting rights     voting rights 
ISIN code                   rights    shares                                    
                                                                                
                                              Direct   Indirect  Direct Indirect
                                                                                
GB0007973794   42,994,105 42,994,105      n/a     n/a 23,491,620    n/a    4.76%

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)                   
                                                                               
CFD                  -               -            2,077,177          0.42%     

Total (A+B)                                                                    

Number of voting rights                 Percentage of voting rights            
                                                                               
25,568,797                              5.18%                                  

9. Chain of controlled undertakings through which the voting rights and /or the
financial instruments are effectively held, if applicable:                     
                                                                               
BlackRock Investment Management (UK) Limited - 25,568,797 (5.18%)              

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:                    Sarah Howfield, Company Secretarial        
                                    Assistant                                  
                                                                               
15. Contact telephone name:         01256 744272