Holding(s) in Company

Radstone Technology PLC
01 March 2005

The company has received the following notification:

                                            Wellington Management Company, LLP
                                            75 State Street
                                            Boston
                                            Massachusetts 02109

28 February 2005

Radstone Technology plc
Brian Shears
Company Secretary
Tove Valley Business Park
Towcester
Northants NN12 6PF
UK

Re: Notification concerning interests in shares of Radstone Technology plc (the
"Company")

Dear Mr. Shears:

1.

Wellington Management Company, LLP ("Wellington Management") is registered as an
investment adviser with the United States Securities and Exchange Commission and
acts as discretionary investment manager on behalf of various separate (the "
Accounts") that hold an interest in shares of the Company.  Wellington
Management's interest in the shares is as an investment manager, as is mentioned
in Section 205(5) of the Companies At 1985 (the "Act").  The Accounts do not act
as a group nor do they act in concert with respect to the interests in shares.
Wellington Management acquired the interests in shares for the Accounts in its
capacity as discretionary investment manager to, and solely for the benefit of,
the Accounts, and the interests were acquired solely for investment purposes.
The shares are registered in the name of the Accounts or the Accounts'
custodians or nominees according to their respective holdings.

2.

Wellington Management as discretionary investment manager on behalf of the
Accounts has purchased, in the aggregate, an interest, within the meaning of
Sections 203 and 208 of the Act, in 2,163,200 ordinary shares, or 7.14% of the
shares outstanding of the Company.  This is an increase of 1.14% since our
notification on December 20, 2004.  Therefore, Wellington Management hereby
gives notice to the Company of such interest in shares, pursuant to the
provisions of Sections 198(1) and 208(4)(B) of the Act.

3.

This notice is given in fulfilment of, and for the express purposes of
discharging the obligations imposed on us by, Sections 198(1) and 208(4)(B) of
the Act and arising out of the circumstances referred to in paragraph 2.

If you have any questions or commitments, please do not hesitate to contact
Christine Chandler at 617-790-7265.

Regards

Julie A. Jenkins
Vice President and Counsel
Wellington Management Company, LLP


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