Holding in Company

Spirent PLC
23 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          1,234,744
MAGIM HSBC GIS NOM(UK) SALI        140,000
PRUCLT HSBC GIS NOM(UK) PAC AC  40,839,043
PRUCLT HSBC GIS NOM(UK) PPL AC   3,027,570
RBSTB NOMINEES LIMITED              19,333
M&G (LOMBARD ST) NOMS FPM          140,000


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

23 JANUARY 2001


12)  Total holding following this notification

45,782,481

               
              
13)  Total percentage holding of issued class following this notification

4.94%


14)  Any additional information

NOTIFICATION IN ACCORDANCE WITH S.198 COMPANIES ACT 1985 (as amended)


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 ... 23 JANUARY 2001 ...