Holding(s) in Company

Spirent Communications PLC
08 August 2006



                   NOTIFICATION OF MAJOR INTERESTS IN SHARES



1. Name of listed company

SPIRENT COMMUNICATIONS PLC


2. Name of shareholder with a major interest

SHERBORNE INVESTORS GP, LLC


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

AS IN 2 ABOVE, SEE ADDITIONAL INFORMATION


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

SHERBORNE INVESTORS GP, LLC


5. Number of shares / amount of stock acquired

89,671,780


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

9.63%


7. Number of shares / amount of stock disposed

N/A


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

N/A


9. Class of security

ORDINARY SHARES OF 3&1/3RD PENCE EACH


10. Date of transaction

NOT KNOWN


11. Date company informed

08 AUGUST 2006


12. Total holding following this notification

89,671,780


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)

9.63%


14. Any additional information

SHERBORNE INVESTORS GP, LLC, SHERBORNE INVESTORS CO., LP & EDWARD BRAMSON (THE
MANAGING MEMBER OF SHERBORNE INVESTORS GP, LLC) ARE ALL NAMED AS INTERESTED
PARTIES IN THE NOTIFICATION RECEIVED BY THE COMPANY.


15. Name of contact and telephone number for queries

PAUL EARDLEY - 01293 767676


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

WARREN NASH


Date of notification

08 AUGUST 2006




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