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 Instruments plcissuer of existing shares to which votingrights are attached: ii 2 Reason for the notification (please tick the appropriate box or boxes): An acquisition or disposal of voting rights x An acquisition or disposal of qualifying financial instruments whichmay result in the acquisition of shares already issued to which votingrights are attached An acquisition or disposal of instruments with similar economic effectto qualifying financial instruments An event changing the breakdown of voting rights Other (pleasespecify): 3. Full name of person(s) subject to Henderson Global Investorsthe notification obligation: iii 4. Full name of shareholder(s) (ifdifferent from 3.):iv 5. Date of the transaction and date 19 December 2014on which the threshold is crossed orreached: v 6. Date on which issuer notified: 22 December 2014 7. Threshold(s) that is/are crossed Below 5% (please refer to section 13)or reached: vi, vii 8. Notified details:A: Voting rights attached to shares viii, ix Class/type of Situation previous Resulting situation aftershares to the triggering the triggering transaction transaction if possible Number Number % of votingusing Number of Number of rights xthe ISIN CODE of Voting of voting Shares Rights shares rights ORD GBP0.05 Direct Direct Indirect Direct Indirect xi xii GB0006650450 2,876,804 2,876,804 2,857,222 4.98% B: Qualifying Financial Instruments Resulting situation after the triggering transaction Type of financial Expiration Exercise/ Number of voting % of votinginstrument 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 FinancialInstruments xv, xvi Resulting situation after the triggering transaction Type of Exercise Expiration Exercise/ Number of voting % of votingfinancial price date xvii Conversion rights instrument rights xix, xxinstrument period refers to xviii Nominal Delta CFD 113,591 0.19% Total (A+B+C) Number of voting rights Percentage of voting rights 2,970,813 5.18% 9. Chain of controlled undertakings through which the voting rights and/or thefinancial instruments are effectively held, if applicable: xxi Proxy Voting: 10. Name of the proxy holder: 11. Number of voting rights proxyholder will cease to hold: 12. Date on which proxy holder willcease to hold voting rights: 13. Additional information: This disclosure is due to a decrease in ordinary share holding below the 5% threshold. The combined holding still remains within the 5% threshold level. 14. Contact name: Susan Johnson-Brett 15. Contact telephone number: 01865 393 200