Holding(s) in Company

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

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARESi                                

1. Identity of the issuer or the underlying       Oxford Instruements plc      
issuer of existing shares to which voting                                      
rights are attached: ii                                                        

2 Reason for the notification (please tick the appropriate box or boxes):      

An acquisition or disposal of voting rights                                    
                                                                               
An acquisition or disposal of qualifying financial instruments which           
may result in the acquisition of shares already issued to which voting         
rights are attached                                                            
                                                                               
An acquisition or disposal of instruments with similar economic effect         
to qualifying financial instruments                                            
                                                                               
An event changing the breakdown of voting rights                               
                                                                               
Other (please       On market transfer between indirect and direct        x    
specify):           funds                                                      

3. Full name of person(s) subject to        Aviva plc & its subsidiaries       
the notification obligation: iii                                               
                                                                               
4. Full name of shareholder(s) (if               Registered holder:            
different from 3.):iv                                                          
                                         BNY Norwich Union Nominees Limited    
                                                      181,341*                 
                                                                               
                                            BNY (Nominees) Limited 5,640*      
                                                                               
                                          Chase (GA Group) Nominees Limited    
                                                     1,152,493*                
                                                                               
                                           Chase Nominees Limited 86,239*      
                                                                               
                                            CUIM Nominee Limited 19,292*       
                                                                               
                                           Vidacos Nominee Limited 2,527*      
                                                                               
                                              * denotes direct interest        
                                                                               
5. Date of the transaction and date               19 November 2010             
on which the threshold is crossed or                                           
reached: v                                                                     
                                                                               
6. Date on which issuer notified:                 22 November 2010             
                                                                               
7. Threshold(s) that is/are crossed   3% to 3% change at direct interest level 
or reached: vi, vii                                                            

8. Notified details:
A: Voting rights attached to shares viii, ix

Class/type of   Situation previous               Resulting situation after              
shares          to the triggering                      the triggering                   
                   transaction                          transaction                     
                                                                                        
if possible     Number     Number    Number         Number of           % of voting     
using             of         of     of shares        voting               rights x      
the ISIN CODE   Shares     Voting                    rights                             
                           Rights                                                       
                                                                                        
                                     Direct   Direct xi  Indirect    Direct   Indirect  
                                                            xii                         
                                                                                        
GB0006650450   1,563,148 1,563,148  1,447,532 1,447,532     Not      2.90%       Not    
                                                        disclosable          disclosable
                                                                                        
B: Qualifying Financial Instruments                                                     
                                                                                        
Resulting situation after the triggering transaction                                    
                                                                                        
 Type of financial  Expiration      Exercise/         Number of voting     % of voting  
    instrument      date xiii   Conversion Period    rights that may be      rights     
                                       xiv            acquired if the                   
                                                       instrument is                    
                                                         exercised/                     
                                                         converted.                     
                                                                                        

C: Financial Instruments with similar economic effect to Qualifying Financial   
Instruments xv, xvi                                                             
                                                                                
Resulting situation after the triggering transaction                            
                                                                                
Type of financ Exercise Expiration Exercise/  Number of voting    % of voting   
     ial        price   date xvii  Conversion rights instrument  rights xix, xx 
  instrument                         period       refers to                     
                                     xviii                                      
                                                                                
                                                                Nominal   Delta 
                                                                                

Total (A+B+C)                                                                  
                                                                               
        Number of voting rights               Percentage of voting rights      
                                                                               
               1,447,532                                 2.90%                 

9. Chain of controlled undertakings through which the voting rights and/or the 
financial instruments are effectively held, if applicable: xxi                 
                                                                               
The voting rights are managed and controlled by Aviva Investors Global Services
Limited, with the following chain of controlled undertakings:-                 
                                                                               
Aviva Investors Global Services Limited:                                       
                                                                               
• Aviva plc (Parent Company)                                                   
                                                                               
• Aviva Group Holdings Limited (wholly owned subsidiary of Aviva plc)          
                                                                               
• Aviva Investors Holdings Limited (wholly owned subsidiary of Aviva Group     
Holdings Limited)                                                              
                                                                               
• Aviva Investors Global Services Limited (wholly owned subsidiary of Aviva    
Investors Holdings Limited)                                                    

Proxy Voting:                                                                  
                                                                               
10. Name of the proxy holder:                        See section 4             
                                                                               
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:             Figures are based on a total number of 
                                             voting rights of 49,843,907.      
                                                                               
14. Contact name:                       Susan Johnson-Brett (Compnay Secretary)
                                                                               
15. Contact telephone number:                        01865 393 324             

Note: Annex should only be submitted to the FSA not the issuer                 
                                                                               
Annex: Notification of major interests in sharesxxii                           

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                                                      
                                                                               

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