Additional Listing

Diagonal PLC
20 September 2001


Diagonal PLC (the 'Company')

Applications have been made to the UK Listing Authority and to the London
Stock Exchange for admission to i) the Official List and ii) trading on the
London Stock Exchange's markets for listed securities, in respect of 136,362
ordinary shares of 10p each in the Company. The shares are being issued as
additional consideration for the acquisition by the Company of Claritas
Information Security Limited. It is expected that admission will become
effective, and that dealings in these shares will commence on Friday 21
September 2001.