Holding(s) in Company

Spirent PLC
22 June 2005


                                  SCHEDULE 10

                   NOTIFICATION OF MAJOR INTERESTS IN SHARES



1. Name of company


SPIRENT PLC



2. Name of shareholder having a major interest


FIDELITY INTERNATIONAL LIMITED



3. Please state whether notification indicates that it is in respect of holding
of the shareholder named in 2 above or in respect of a non-beneficial interest
or in the case of an individual holder if it is a holding of that person's
spouse or children under the age of 18


COMPANY NAMED IN BOX 2 ABOVE AND ITS DIRECT AND INDIRECT SUBSIDIARIES, BEING
NON-BENEFICIAL HOLDERS



4. Name of the registered holder(s) and, if more than one holder, the number of
shares held by each of them


JP MORGAN, BOURNEMOUTH (FII)                                             751,500
BANK OF NEW YORK BRUSSELS (FIL)                                          470,700
BROWN BROTHERS HARRIMN LTD LUX (FIL)                                  16,028,894
NORTHERN TRUST LONDON (FIL)                                               66,700
JP MORGAN BOURNEMOUTH (FISL)                                          13,595,476
BANK OF NEW YORK BRUSSELS (FPM)                                        1,865,200
BANKERS TRUST LONDON (FPM)                                               773,400
CLYDESDALE BANK PLC (FPM)                                                171,700
HSBC BANK PLC (FPM)                                                      118,400
JP MORGAN BOURNEMOUTH (FPM)                                            3,408,417
MELLON BANK (FPM)                                                      1,523,000
MIDLAND SECURITIES SERVICES (FPM)                                        415,500
NORTHERN TRUST LONDON (FPM)                                            2,964,900
STATE STR BK AND TR CO LNDN (FPM)                                      1,621,000
BROWN BROTHERS HARRIMAN AND CO (IN FORM OF 11,000 ADRS) (FMRCO)           44,000

TOTAL                                                                 43,818,787


FII = Fidelity Investments International

FIL = Fidelity International Limited

FISL = Fidelity Investment Services Limited

FPM = Fidelity Pension Management

FMRCO = Fidelity Management & Research Company



5. Number of shares / amount of stock acquired


NOT KNOWN



6. Percentage of issued class


NOT KNOWN





7. Number of shares / amount of stock disposed


N/A



8. Percentage of issued class


N/A



9. Class of security


ORDINARY SHARES OF 3.3333 PENCE EACH



10. Date of transaction


NOT KNOWN



11. Date company informed


22 JUNE 2005



12. Total holding following this notification


43,818,787



13. Total percentage holding of issued class following this notification


4.55%



14. Any additional information


SHAREHOLDER PREVIOUSLY REPORTED A SHAREHOLDING OF 37,344,687 SHARES (3.88%) ON
20 JUNE 2005.



15. Name of contact and telephone number for queries


MICHAEL ANSCOMBE - 01293 767672



16. Name and signature of authorised company official responsible for making
this notification


MICHAEL ANSCOMBE - ASSISTANT COMPANY SECRETARY



Date of notification


22 JUNE 2005



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