FORM 6-K

                      SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                            Report of Foreign Issuer


                       Pursuant to Rule 13a-16 or 15d-16 of
                       the Securities Exchange Act of 1934


                          For the month of April 2006


                             COLT TELECOM GROUP plc
                 (Translation of Registrant's Name into English)


                                 Beaufort House
                              15 St. Botolph Street
                                     London
                                    EC3A 7QN
                                     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- ________)



This Form 6-K shall be deemed to be incorporated by reference in the
Registrant's Registration Statement on Form F-3 (Reg. No.333-05972), in the
Registrant's Registration Statement on Form S-8 (Reg. No.333-8362)




COLT Telecom Group plc (the 'Company')

Cancellation of Warrants and Issue of Ordinary Shares

The Company announces that following the cancellation of the Warrants the
Company has today (10 April) issued 364,684 Ordinary Shares to its former
Warrantholders. The Ordinary Shares issued on cancellation of the Warrants were
admitted to the Official List and to trading on the London Stock Exchange's
market for listed securities at 08.00 this morning.

Capitalised terms used in this announcement have the same meanings as set out in
the Scheme document dated 10 March 2006.

For further information please call Luke Glass at COLT on 020 7390 3681.



                                     SIGNATURES


Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this Current Report on Form-6K to be signed on its
behalf by undersigned, thereunto duly authorized.



Date: 10 April 2006                            COLT Telecom Group plc



                                               By: ___Caroline Griffin Pain___


                                               Caroline Griffin Pain
                                               Company Secretary