Holding(s) in Company

Spirent Communications PLC
04 July 2006

                   NOTIFICATION OF MAJOR INTERESTS IN SHARES



1. Name of listed company


SPIRENT COMMUNICATIONS PLC



2. Name of shareholder with a major interest


FIDELITY INTERNATIONAL LIMITED



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 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 (FISL)                                 36,698,765
BROWN BROS HARRIMN LTD LUX (FIL)                             14,141,429
JP MORGAN, BOURNEMOUTH (FII)                                  2,287,420
BNP PARIBAS, PARIS (FIGEST)                                   2,948,500
TOTAL                                                        56,076,114


FISL = Fidelity Investment Services Limited
FIL = Fidelity International Limited
FII = Fidelity Investments International
FIGEST = Fidelity Gestion



5. Number of shares / amount of stock acquired


-



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


-



7. Number of shares / amount of stock disposed


NOT KNOWN



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


NOT KNOWN



9. Class of security


ORDINARY SHARES OF 3.3333 PENCE EACH



10. Date of transaction


NOT KNOWN



11. Date company informed


04 JULY 2006





12. Total holding following this notification


56,076,114



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)


5.90%



14. Any additional information


ON 11 APRIL 2006 THE SHAREHOLDER REPORTED TO THE COMPANY THAT IT HAD INCREASED
ITS HOLDING IN THE COMPANY TO 58,320,794 SHARES (6.02%).



15. Name of contact and telephone number for queries


MICHAEL ANSCOMBE - 01293 767672



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


MICHAEL ANSCOMBE - DEPUTY COMPANY SECRETARY



Date of notification


04 JULY 2006






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