Holding(s) in Company

Cambridge Antibody Tech Group PLC
18 December 2003

                                  SCHEDULE 10

                   NOTIFICATION OF MAJOR INTERESTS IN SHARES


1)   Name of company
Cambridge Antibody Technology


2)   Name of shareholder having a major interest
Wellington Management Company


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
Non-beneficial


4)   Name of the registered holder(s) and, if more than one holder, the
     number of shares held by each of them
Investment Advisor - names of separate accounts not disclosed


5)   Number of shares/amount of stock acquired
Not disclosed


6)   Percentage of issued class
Not disclosed


7)   Number of shares/amount of stock disposed
Nil


8)   Percentage of issued class
Nil


9)   Class of security
Ordinary 10p shares


10)  Date of transaction
Not disclosed


11)  Date company informed
18 December 2003


12)  Total holding following this notification
3,847,815



13)  Total percentage holding of issued class following this notification
9.39%


14)  Any additional information
The accounts do not act as a group nor do they act in concert with respect to
the interests in shares


15)  Name of contact and telephone number for queries
Diane Mellett 01223 471471


16)  Name and signature of authorised company official responsible for
     making this notification
Diane Mellett, Company Secretary


     Date of notification 18 December 2003





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