SOURCE: Spirent Communications PLC

May 29, 2007 06:58 ET

Spirent Communications PLC - Holding(s) in Company

Crawley, UK--(Marketwire - May 29, 2007) -



Form TR-1 with annex. FSA Version 2.1 updated April 2007


TR-1: Notification of Major Interests in Shares


                                                              
1. Identity of the issuer or the underlying issuer of
existing shares to which voting rights are attached:          Spirent Communications plc


2. Reason for notification (yes/no) 

                                    
An acquisition or disposal of voting rights                   X


An acquisition or disposal of financial instruments which may result in the acquisition
of shares already issued to which voting rights are attached


An event changing the breakdown of voting rights


Other (please specify):______________
                                                                     

3. Full name of person(s) subject to notification                     BlackRock, Inc
obligation:


4. Full name of shareholder(s) (if different from
3):
                                                                     

5. Date of transaction (and date on which the
threshold is crossed or reached if different):                        22nd May 2007
                                                                      

6. Date on which issuer notified:                                     25th May 2007
                                                                      

7. Threshold(s) that is/are crossed or reached:                       Gone above 5%




8: Notified Details

A: Voting rights attached to shares


Class/type of    Situation previous to    Resulting situation after the triggering transaction
shares           the triggering
                 transaction

If possible use  Number of   Number of    Number of   Number of voting rights   Percentage of voting
ISIN code        shares      voting       shares                                rights
                             rights

                                                      Direct       Indirect     Direct       Indirect


  GB0004726096       N/A          N/A         N/A          N/A      44,428,430      N/A         5.04%




B: Financial Instruments


Resulting situation after the triggering transaction


Type of financial    Expiration date      Exercise/ conversion No. of voting rights  Percentage of voting
instrument                                period/date          that may be acquired  rights
                                                               (if the instrument
                                                               exercised/converted)





Total (A+B)


Number of voting rights                              Percentage of voting rights

     44,428,430                                             5.04%




9. Chain of controlled undertakings through which the voting rights and /or the financial instruments are 
effectively held, if applicable:


BlackRock Investment Management (UK) Limited - 44,428,430 (5.04%)


Proxy Voting:


10. Name of proxy holder:


11. Number of voting rights proxy holder will cease
to hold:


12. Date on which proxy holder will cease to hold
voting rights:




13. Additional information:


14 Contact name:                                       Thomas Hone


15. Contact telephone name:                            020 7743 2098



C:        Additional information


Contact at Issuer: Michael Anscombe, Deputy Company Secretary, Spirent Communications plc

Telephone: 01293 767672


                      This information is provided by RNS
            The company news service from the London Stock Exchange