FORM 6-K

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Report of Foreign Private Issuer

Pursuant to Rule 13a - 16 or 15d - 16 of

the Securities Exchange Act of 1934

For the month of June, 2004

Commission File Number: 1-10817

CELLTECH GROUP PLC

(Translation of registrant's name into English)

208 Bath Road, Slough, Berkshire SL1 3WE ENGLAND

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F X Form 40-F

Indicate by check mark whether the registrant by furnishing the information contained in this Form is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes No X

(If "Yes" is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b): 82-________).

Enclosure: Holding(s) in Company

SCHEDULE 10

NOTIFICATION OF MAJOR INTERESTS IN SHARES

1. Name of company

Celltech Group plc

2. Name of shareholder having a major interest

Credit Suisse First Boston group of companies

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

As 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


Credit Suisse First Boston Equities Limited		16,741,857
Credit Suisse First Boston International		25,154

5. Number of shares / amount of stock acquired

Unknown

6. Percentage of issued class

Unknown

7. Number of shares / amount of stock disposed

N/a

8. Percentage of issued class

N/a

9. Class of security

Ordinary 50p shares

10. Date of transaction

17 June 2004

11. Date company informed

21 June 2004

12. Total holding following this notification

16,767,011

13. Total percentage holding of issued class following this notification

6.02%

14. Any additional information

15. Name of contact and telephone number for queries

Anita Dowling Tel: 01753 777106

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

J A D Slater

Date of notification

21 June, 2004

The FSA does not give any express or implied warranty as to the accuracy of this document or material and does not accept any liability for error or omission. 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 any such material.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

CELLTECH GROUP PLC
(Registrant)

                                                                                                                                                           By: /s/ PETER ALLEN
                                                                                                                                                           Peter Allen
                                                                                                                                                           Chief Financial Officer

Dated: 21 June, 2004

CELLTECH GROUP PLC 6-K