Holding(s) in Company

Spirent PLC
01 November 2005

                   NOTIFICATION OF MAJOR INTERESTS IN SHARES



1. Name of listed company


SPIRENT PLC



2. Name of shareholder with a major interest


UBS AG



3. Please state whether notification indicates that regarding the holding of the
shareholder named in 2 above; 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                                     29,030,031
UBS Global Asset Management Life Limited                  1,765,002
UBS Capital Markets LP                                        3,504
UBS Wealth Management USA                                   103,400
TOTAL                                                    30,901,937




5. Number of shares / amount of stock acquired


NOT KNOWN



6. Percentage of issued class (any treasury shares held by the listed company
should not be taken into account when calculating percentage)


NOT KNOWN



7. Number of shares / amount of stock disposed


-



8. Percentage of issued class (any treasury shares held by the listed company
should not be taken into account when calculating percentage)


-



9. Class of security


ORDINARY SHARES OF 3.3333 PENCE EACH



10. Date of transaction


NOT KNOWN



11. Date company informed


31 OCTOBER 2005





12. Total holding following this notification


30,901,937



13. Total percentage holding of issued class following this notification (any
treasury shares held by the listed company should not be taken into account when
calculating percentage)


3.20%



14. Any additional information






15. Name of contact and telephone number for queries


LUKE THOMAS - 01293 767658



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


LUKE THOMAS - DEPUTY COMPANY SECRETARY



Date of notification


01 NOVEMBER 2005






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