Holding in Company

Spirent PLC
3 January 2001


                  DEALINGS BY SUBSTANTIAL SHAREHOLDERS


1)   NAME OF COMPANY

     SPIRENT PLC

2)   NAME OF SHAREHOLDER HAVING A MAJOR INTEREST

     PRUDENTIAL PLC

3)   Please state whether notification indicates that it is in respect of 
     holding of the Shareholder named in 2 above or 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

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

     M&G (LOMBARD ST) NOMS AA                      218,666
     M&G (LOMBARD ST) NOMS G                       163,125
     M&G (LOMBARD ST) NOMS K                       934,744
     MAGIM HSBC GIS NOM (UK) SALl                  253,750
     PRUCLT HSBC GIS NOM (UK) PAC AC            41,519,043
     PRUCLT HSBC GIS NOM (UK) PPL AC             3,013,910
     RBSTB NOMINEES LIMITED                         19,333
     

5)   Number of shares/amount of stock acquired.

     NOT KNOWN

6)   ( NOT KNOWN %) of issued Class

7)   Number of shares/amount of stock disposed

     NOT KNOWN

8)   ( NOT KNOWN %) of issued Class

9)   Class of security

     ORDINARY SHARES OF 3 1/3P EACH

10)  Date of transaction

     NOT KNOWN

11)  Date company informed

     3 JANUARY 2001

12)  Total holding following this notification

     46,122,571
          
13)  Total percentage holding of issued class following this notification

     4.97%

14)  Any additional information

     NOTIFICATION IN ACCORDANCE WITH S.198 COMPANIES ACT 1985 (AS AMENDED)
     OF ADJUSTMENT TO HOLDING FOLLOWING RIGHTS ISSUE AND ISSUE OF ADDITIONAL
     SHARES AS CONSIDERATION FOR COMPANY ACQUISITION.

15)  Name of contact and telephone number for queries

     MARK YOUNG    01293 767710

16)  Name and signature of authorised company official responsible for 
     making this notification

     Date of Notification .....3 JANUARY 2001...................