Holding(s) in Company

Spirent PLC
26 April 2005

                                  SCHEDULE 10

                   NOTIFICATION OF MAJOR INTERESTS IN SHARES



1. Name of company


SPIRENT PLC


2. Name of shareholder having a major interest


UBS AG


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


SHAREHOLDER IN 2 ABOVE


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


UBS AG LONDON BRANCH                                            27,902,633
UBS GLOBAL ASSET MANAGEMENT LIFE LIMITED                         1,765,002
                                                  TOTAL         29,667,635


5. Number of shares / amount of stock acquired


UNKNOWN



6. Percentage of issued class


UNKNOWN


7. Number of shares / amount of stock disposed


-


8. Percentage of issued class


-


9. Class of security


ORDINARY SHARES OF 3.3333 PENCE EACH


10. Date of transaction


NOT NOTIFIED


11. Date company informed


26 APRIL 2005


12. Total holding following this notification


29,667,635



13. Total percentage holding of issued class following this notification


3.08%



14. Any additional information


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


26 APRIL 2005



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