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 voting

rights 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 which

may 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 BlackRock, Inc.the notification obligation: iii 4. Full name of shareholder(s) (ifdifferent from 3.):iv 5. Date of the transaction and date 25 April 2013on which the threshold is crossed orreached: v 6. Date on which issuer notified: 26 April 2013 7. Threshold(s) that is/are crossed Holding has gone above 15%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 Direct Direct Indirect Direct Indirect xi xii GB0006650450 7,428,906 7,428,906 n/a n/a 7,763,012 n/a 13.64% 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 FinancialInstruments xv, xvi

Resulting situation after the triggering transaction Type of Exercise Expiration Exercise/ Number of voting % of voting financial price date xvii Conversion rights instrument rights xix, xx instrument period refers to xviii Nominal Delta CFD 879,463 1.55% 1.55% Total (A+B+C) Number of voting rights Percentage of voting rights 8,642,475 15.18%

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

BlackRock Investment Management (UK) Limited - 8,642,475 (15.18%) 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: Oxford Instruments plc 14. Contact name: Susan Johnson-Brett 15. Contact telephone number: 01865 393 200