Holding(s) in Company

Cambridge Antibody Tech Group PLC
01 June 2005

                                  SCHEDULE 10

                   NOTIFICATION OF MAJOR INTERESTS IN SHARES


1)   Name of company

Cambridge Antibody Technology Group plc

2)   Name of shareholder having a major interest

Wellington Management Company, LLP


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 (E) names of separate accounts not disclosed.  The shares are
registered in the name of the Accounts of the Accounts custodians or nominees
according to their respective holdings.

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

Not disclosed

8)   Percentage of issued class

N/A

9)   Class of security

Ordinary 10 pence shares

10)  Date of transaction


Not disclosed

11)  Date company informed

1 June 2005

12)  Total holding following this notification

4,128,494 ordinary 10 pence shares












13)  Total percentage holding of issued class following this notification

7.998%

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

Justin Hoskins 01223 898589

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


Justin Hoskins, Company Secretary



Date of notification: 1 June 2005





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