For filings with the FSA include the annexFor filings with issuer exclude the annexTR-1: NOTIFICATION OF MAJOR INTEREST IN SHARESi1. Identity of the issuer or the underlying Oxford Instruments plcissuer of existing shares to which votingrights are attached: ii2. Reason for the notification (please tick the appropriate box or boxes):An acquisition or disposal of voting rights xAn acquisition or disposal of qualifying financial instruments whichmay result in the acquisition of shares already issued to which votingrights are attachedAn acquisition or disposal of instruments with similar economic effectto qualifying financial instrumentsAn event changing the breakdown of voting rightsOther (pleasespecify):3. Full name of person(s) subject to Henderson Global Investorsthe notification obligation: iii4. Full name of shareholder(s) (ifdifferent from 3.):iv5. Date of the transaction and date 11 November 2014on which the threshold is crossed orreached: v6. Date on which issuer notified: 12 November 20147. Threshold(s) that is/are crossed 5% (please refer to section 13)or reached: vi, vii8. Notified details:A: Voting rights attached to shares viii, ixClass/type of Situation previous Resulting situation aftershares to the triggering the triggering transaction transactionif possible Number Number % of votingusing Number of Number of rights xthe ISIN CODE of Voting of voting Shares Rights shares rightsORD GBP0.05 Direct Direct Indirect Direct Indirect xi xiiGB0006650450 2,861,804 2,861,804 2,876,804 5.02%B: Qualifying Financial InstrumentsResulting situation after the triggering transactionType 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, xviResulting situation after the triggering transactionType of Exercise Expiration Exercise/ Number of voting % of votingfinancial price date xvii Conversion rights instrument rights xix, xxinstrument period refers to xviii Nominal DeltaCFD 126,415 0.22%Total (A+B+C)Number of voting rights Percentage of voting rights3,003,219 5.24%9. Chain of controlled undertakings through which the voting rights and/or thefinancial instruments are effectively held, if applicable: xxiProxy 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 an increase in the ordinary share holding above the 5% threshold. The combined holding still remains within the 5% threshold level.14. Contact name: Susan Johnson-Brett15. Contact telephone number: 01865 393 200