Holding in Company

Spirent PLC
26 March 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 FPE                      135,000
     MAGIM HSBC GIS NOM (UK) SALI                   140,000
     PRUCLT HSBC GIS NOM (UK) PAC AC             40,589,044
     PRUCLT HSBC GIS NOM (UK) PPL AC              3,436,250
     RBSTB NOMINEES LIMITED                          19,333
     ROY NOMS LTD 578052                            168,125
     ROY NOMS LTD 578141                            350,000
     ROY NOMS LTD 578192                          1,485,000

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

     26 MARCH 2001

12)  Total holding following this notification

     46,322,752
               
13)  Total percentage holding of issued class following this notification

     4.99%

14)  Any additional information

     NOTIFICATION IN ACCORDANCE WITH S.198 COMPANIES ACT 1985 (AS AMENDED)
     THAT SHAREHOLDER HAS A REDUCTION IN SHAREHOLDING FROM THE PREVIOUSLY
     NOTED 5.03%

15)  Name of contact and telephone number for queries

     LUKE THOMAS        01293 767676

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

     Date of Notification ....26 MARCH 2001....................