Holding(s) in Company

Spirent PLC
06 May 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)                                             423,700
BANK OF NEW YORK BRUSSELS (FIL)                                         397,900
BROWN BROS HARRIMN LTD LUX (FIL)                                      9,946,307
NORTHERN TRUST LONDON (FIL)                                              38,000
JP MORGAN BOURNEMOUTH (FISL)                                          8,009,776
BANK OF NEW YORK BRUSSELS (FPM)                                       1,538,500
BANKERS TRUST LONDON (FPM)                                              653,500
CITIBANK LONDON (FPM)                                                   633,900
CLYDESDALE BANK PLC (FPM)                                               145,200
JP MORGAN BOURNEMOUTH (FPM)                                           2,137,917
MELLON BANK (FPM)                                                     1,286,200
MIDLAND SECURITIES SERVICES (FPM)                                       347,000
NORTHERN TRUST LONDON (FPM)                                           2,834,700
STATE STR BK AND TR CO LNDN (FPM)                                       837,800
BROWN BROTHERS HARRIMAN AND CO (IN FORM OF 11,000 ADRS)                  44,000
                                                                    
TOTAL                                                                29,274,400


FII = Fidelity Investments International
FIL = Fidelity International Limited
FISL = Fidelity Investment Services Limited
FPM = Fidelity Pension Management


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 NOTIFIED


11. Date company informed


05 MAY 2005


12. Total holding following this notification


29,274,400



13. Total percentage holding of issued class following this notification


3.04%



14. Any additional information


THE SHAREHOLDER HAD PREVIOUSLY REPORTED TO THE COMPANY ON 4 MARCH 2005 THAT IT
NO LONGER HELD A NOTIFIABLE INTEREST IN THE COMPANY.



15. Name of contact and telephone number for queries


LUKE THOMAS - 01293 767658



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


LUKE THOMAS - DEPUTY COMPANY SECRETARY



Date of notification


06 MAY 2005



The FSA does not give any express or implied warranty as to the accuracy of this
document or material and does not accept any liability for error or omission.
The FSA is not liable for any damages (including, without limitation, damages
for loss of business or loss of profits) arising in contract, tort or otherwise
from the use of or inability to use this document, or any material contained in
it, or from any action or decision taken as a result of using this document or
any such material.


                      This information is provided by RNS
            The company news service from the London Stock Exchange