Holding(s) in Company

TR-1: Notifications of Major Interests in Shares                               

 1. Identity of the issuer or the                 Oxford Instruments PLC       
    underlying issuer of existing shares                                       
    to which voting rights are attached:                                       

2: Reason for notification (yes/no)                                            
                                                                               
An acquisition or disposal of voting rights                           Yes      
                                                                               
An acquisition or disposal of qualifying financial instruments which  No       
may result in the acquisition of shares already issued to which                
voting rights are attached                                                     
                                                                               
An acquisition or disposal of instruments with similar economic       Yes      
effect to qualifying financial instruments                                     
                                                                               
An event changing the breakdown of voting rights                      No       
                                                                               
Other (please specify):                                               No       

3. Full name of person(s) subject to the     BlackRock UK Emerging Companies   
notification                                            Hedge Fund             
                                                                               
obligation:                                                                    
                                                                               
4. Full name of shareholder(s) (if                                             
different from 3.):                                                            
                                                                               
5. Date of the transaction (and date on               27 April 2012            
which the threshold                                                            
                                                                               
is crossed or reached):                                                        
                                                                               
6. Date on which issuer notified:                     30 April 2012            
                                                                               
7. Threshold(s) that is/are crossed or          Holding has gone below 3%      
reached:                                                                       

8: Notified Details                                                            
                                                                               
 A. Voting rights attached to shares                                           
                                                                               
  * Class/type of share If possible                 GB0006650450               
    use ISIN code                                                              
                                                                               
Situation previous to the triggering transaction                               
                                                                               
  * Number of shares                    * Number of voting rights              
                                                                               
                 n/a                                     n/a                   
                                                                               
Resulting situation after the triggering transaction                           
                                                                               
  * Number of             Number of voting rights            Percentage of     
    shares                                                   voting rights     
                                                                               
  * Direct               Direct            Indirect       Direct     Indirect  
                                                                               
     208,097            208,097              n/a         Below 3%      n/a     

 B. Qualifying Financial Instruments                                           
                                                                               
Resulting situation after the triggering transaction                           
                                                                               
    Type of       Expiration      Exercise/     No. of voting   Percentage of  
   financial         date        conversion    rights that may  voting rights  
  instrument                     period/date     be acquired                   
                                                   (if the                     
                                                 instrument                    
                                                 exercised/                    
                                                 converted)                    
                                                                               

Delta

C: Financial Instruments with similar economic effect to Qualifying             
Financial Instruments                                                           
                                                                                
Resulting situation after the triggering transaction                            
                                                                                
Type of          Exercise Expiration Exercise/  Number of    % of voting        
financial        price    date       Conversion voting       rights             
instrument                           period     rights                          
                                                instrument                      
                                                refers to                       
                                                                                
      CFD                                        1,463,091     Nominal     Delta    
                                                                                
                                                               Below 3%    Below
                                                                                
                                                                            3%  
                                                                                

Total (A+B+C)                                                                  
                                                                               
Number of voting rights                      Percentage of voting rights       
                                                                               
1,671,188                                    Below 3%                          

9. Chain of controlled undertakings through which the voting rights and/or the 
financial instruments are effectively held, if applicable:                     
                                                                               

Proxy Voting:                                                                  
                                                                               
10. Name of the 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:                                                    
                                                                               
14. Contact name:                   Susan Johnson-Brett                        
                                                                               
                                    Company Secretary                          
                                                                               
15. Contact telephone number:       01865 393324