Holding(s) in Company

RNS Number:2109B
Cambridge Antibody Tech Group PLC
07 April 2006

                   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. 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

N/A

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

6 April 2006

12. Total holding following this notification

3,650,883

13. Total percentage holding of issued class following this notification

6.875%

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

7 April 2006

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The FSA is not liable for any damages (including, without limitation, damages
for loss of business or loss of profits) arising in contract, tort or otherwise
from the use of or inability to use this document, or any material contained in
it, or from any action or decision taken as a result of using this document or
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