Director/PDMR Shareholding

Spirent PLC
15 March 2006

                               SPIRENT PLC  (the 'Company')

                           NOTIFICATION OF DEEMED INTERESTS

                      BY DIRECTORS, PERSONS DISCHARGING MANAGERIAL

                           RESPONSIBILITY OR CONNECTED PERSONS



The Company was notified on 14 March 2006 that Spirent Sharesave Trust Limited,
the trustee for the Spirent Sharesave Trust (the 'Trust') had transferred 80,434
Ordinary shares in the Company to satisfy the exercise of options under the
Company's Savings Related Share Option Scheme as follows:


                   No of Shares                   Option Price

                         47,586                       41 pence
                         32,848                       38 pence
                       --------
                         80,434
                       ========



Following this transfer the total number of Ordinary shares held by the Trust
is:



2,444,468 (representing 0.2523% of the issued share capital of the Company).



The Company's executive directors are potential beneficiaries of the Trust
(together with all other UK employee share option holders) and are, therefore,
treated under the Companies Act 1985 as having a deemed interest in the total
number of shares held by the Trust.  As a result, the directors' deemed interest
in the Trust has been reduced by the above number of shares transferred.



For the avoidance of doubt, the Company confirms that this notification does not
relate to an actual dealing in securities by the executive directors whose
interests in the Company's securities remain unchanged notwithstanding the above
events.





Michael Anscombe
Deputy Company Secretary
Spirent plc


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