Holding(s) in Company

Spirent Communications PLC
02 October 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


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): Decrease in the number of total voting rights in Spirent 
Communications plc resulting from the on-going share buy-back programme        X

3. Full name of person(s) subject to 
   notification obligation:              (i) Sherborne Investors GP, LLC;

                                        (ii) Sherborne Investors LP;

                                       (iii) Craig L. McKibben;

                                        (iv) Gerard L Eastman, Jr; and

                                         (v) Edward Bramson.

                                                                                      

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

Person named in     Shareholder                                     No of shares
3 above

(i) - (iv)          Hanover Nominees Limited         130,250,000 ordinary shares
                                                     (aggregate)

(v)             (a) Hanover Nominees Limited         130,250,000 ordinary shares
                                                     (aggregate)

                (b) Merrill Lynch, Pierce, Fenner &       20,000 ordinary shares
                    Smith, Inc

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

October 1, 2007 (being the date of the most recent TVR announcement)

                                                                                    
6. Date on which issuer notified:       October 2, 2007

                                                                 
7. Threshold(s) that is/are crossed or reached:                     


(i) Sherborne Investors GP, LLC - 15% (aggregate);

(ii) Sherborne Investors LP - 15% (aggregate);

(iii) Craig L. McKibben - 15% (aggregate);

(iv) Gerard L Eastman, Jr - 15% (aggregate); and

(v) Edward Bramson - 15% (aggregate).

Please note, for the purposes of this TR-1 notification
the only entities who have triggered a new notification
obligation under the Disclosure and Transparency Rules
are those entities noted in 3 above.  None of Hayden
Investors Partners, LLC; Hayden Investors Partners II,
LLC; Sherborne Strategic Fund A, LLC or Sherborne
Strategic Fund B, LLC have reached, exceeded or fallen
below a relevant threshold as a result of Spirent
Communications plc's recent buy-back programme.



8. Notified Details


A: Voting rights attached to shares


Class/type of      Situation previous to the   Resulting situation after the triggering transaction
shares             triggering transaction
                   Number of     Number of     Number of      Number of voting rights       Percentage of voting rights
If possible use    shares        voting rights shares
ISIN code

                                               Direct         Direct         Indirect       Direct         Indirect

 Ordinary shares    130,250,000   130,250,000   130,250,000        N/A        130,250,000        N/A          15.13%
 ISIN: GB0004726096


 Ordinary shares      20,000        20,000         20,000         20,000          N/A           0.002%         N/A
 ISIN: GB0004726096




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 is
                                                               exercised/converted)


        N/A                  N/A                  N/A                   N/A                  N/A



Total (A+B)

Number of voting rights                              Percentage of voting rights


130,270,000                                          15.13%


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



Edward Bramson is the managing member and Craig L. McKibben and Gerard L.
Eastman, Jr. are members of Sherborne Investors GP, LLC.  Sherborne Investors
GP, LLC is the general partner of Sherborne Investors LP, which is the managing
member of each of the following funds (all of which hold ordinary shares in the
issuer through Hanover Nominees Limited):


(i)   Hayden Investors Partners, LLC (45,685,845 ordinary shares - approximately 5.31% -no new individual notification  
      required, see response to 7 above);

(ii)  Hayden Investors Partners II, LLC (40,844,268 ordinary shares - approximately 4.74% - no new individual           
      notification required, see response to 7 above);

(iii) Sherborne Strategic Fund A, LLC (29,644,000 ordinary shares - approximately 3.44% -  no new individual            
      notification required, see response to 7 above); and

(iv)  Sherborne Strategic Fund B, LLC (14,075,887 ordinary shares - approximately 1.64% - no individual notification    
      obligation).

Edward Bramson holds 20,000 further shares through Merrill Lynch, Pierce, Fenner
& Smith, Inc.


Proxy Voting:


10. Name of proxy holder:                            N/A


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


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


13. Additional information:                          N/A


14 Contact name:                                     Craig L. McKibben


15. Contact telephone name:                          [phone]



Additional information


Contact at Issuer: 

Michael Anscombe, Company Secretary, 

Spirent Communications plc

Telephone: [phone]


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