Holding(s) in Company

Spirent PLC
09 February 2006

                   NOTIFICATION OF MAJOR INTERESTS IN SHARES



1. Name of listed company


SPIRENT 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 (FPM)                                            3,743,793
NORTHERN TRUST LONDON (FPM)                                            2,851,100
MELLON BANK (FPM)                                                      1,483,900
BANK OF NEW YORK BRUSSELS (FPM)                                        1,232,100
STATE STR BK AND TR CO LNDN (FPM)                                      1,055,400
BANKERS TRUST LONDON (FPM)                                               823,500
MIDLAND SECURITIES SERVICES (FPM)                                        371,200
CLYDESDALE BANK PLC (FPM)                                                118,700
JP MORGAN BOURNEMOUTH (FISL)                                          27,491,787
BROWN BROS HARRIMN LTD LUX (FIL)                                      35,845,733
BANK OF NEW YORK BRUSSELS (FIL)                                          415,700
NORTHERN TRUST LONDON (FIL)                                              136,100
JP MORGAN, BOURNEMOUTH (FII)                                           1,395,500
BNP PARIBAS, PARIS (FIGEST)                                              521,500
TOTAL                                                                 77,486,013


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



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


09 FEBRUARY 2006





12. Total holding following this notification


77,486,013



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)


8.02%



14. Any additional information


ON 16 DECEMBER 2005 THE SHAREHOLDER REPORTED TO THE COMPANY THAT IT HAD REDUCED
ITS HOLDING IN THE COMPANY TO 75,458,913 SHARES (7.81%).


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


09 FEBRUARY 2006






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