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 issuerof existing shares to which voting rights are PipeHawk plcattached: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 which may resultin the acquisition of shares already issued to which voting rights are attachedAn acquisition or disposal of instruments with similar economic effect toqualifying financial instrumentsAn event changing the breakdown of voting rightsOther (please specify): Mrs Jacquiline H Creswell,3. Full name of person(s) subject to thenotification obligation:iii Miss Antonia P N Creswell and Mr Robin B B Creswell4. Full name of shareholder(s) (if different from 3.):iv5. Date of the transaction and date onwhich the threshold is crossed or 10 March 2014reached: v6. Date on which issuer notified: 24 March 20147. Threshold(s) that is/are crossed or 5%reached: vi, vii8. Notified details:A: Voting rights attached to shares viii, ixClass/type Situation previous Resulting situation after the triggering transactionof to the triggeringshares transactionif possible Number Number Number Number of voting % of voting rightsusing of of of shares rights xthe ISIN Shares VotingCODE Rights Direct Direct xi Indirect xii Direct IndirectORD 1,354,000 1,354,000 1,700,000 1,700,000 5.15%GB0003010609B: Qualifying Financial InstrumentsResulting situation after the triggering transactionType of Expiration Exercise/ Number of voting % of votingfinancial date xiii Conversion Period xiv rights that may be rightsinstrument 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 price Expiration Exercise/ Number of voting rights % of votingfinancial date xvii Conversion period instrument refers to rights xix, xxinstrument xviii Nominal DeltaTotal (A+B+C)Number of voting rights Percentage of voting rights1,700,000 5.159. 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: N/A11. Number of voting rights proxy holder will cease N/Ato hold:12. Date on which proxy holder will cease to hold N/Avoting rights:13. Additional information:14. Contact name: Robin Creswell15. Contact telephone number: 020 7621 3000