Cheshire, UK--(Marketwire - September 25, 2007) -

                           Protherics PLC

                    Notification of Major Interest in Shares

London, UK; Brentwood, TN, US: 25 September 2007 - Protherics PLC ("Protherics"
or the "Company"), the international biopharmaceutical company focused on
critical care and cancer, announces that, on 24 September 2007, in accordance
with the Transparency Obligations Directive, a notification of interest in the
ordinary share capital of the Company was received from Aviva plc.  The
notification follows an increase in the combined direct and indirect voting
rights of Aviva plc and its subsidiaries to 12.05% of total voting rights.
Further details are as follows:

1. Reason for the notification     (please tick the appropriate box or boxes)
An acquisition or disposal of voting rights                                 X

An acquisition or disposal of financial instruments which may result in the 
acquisition of shares already issued to which voting rights are attached

An event changing the breakdown of voting rights

Other (please specify):___________________________________________

2. Full name of person(s) subject to the            Aviva plc & its subsidiaries
notification obligation:

3. Full name of shareholder(s)                  Registered Holder:
(if different from 2.):

                                           BNY Norwich Union Nominees Limited


                                           Chase GA Group Nominees Limited


                                           Chase Nominees Limited


                                           CUIM Nominee Limited


                                           Vidacos Nominees Limited


                                           BNP Paribas - London


                                           Chase Nominees Limited


                                           CUIM Nominee Limited


                                           State Street Nominees Limited


                                           Vidacos Nominees Limited


                                           *denotes direct interest

4. Date of the transaction (and date on which the 20 September 2007
threshold is crossed or reached if different):

5. Date on which issuer notified:                 24 September 2007

6. Threshold(s) that is/are crossed or reached:   11% to 12% Change at Combined Interest level

7. Notified details:

A: Voting rights attached to shares
Class/type of     Situation previous to   Resulting situation after the triggering transaction
shares            the Triggering
if possible using Number of   Number of   Number of     Number of voting rights % of voting rights
the ISIN CODE     Shares      Voting      shares
                              Rights      Direct        Direct      Indirect    Direct      Indirect

Ordinary Shares   40,387,120  40,387,120  28,134,889    28,134,889  12,775,990  8.29%       3.76%


B: Financial Instruments

Resulting situation after the triggering transaction
Type of financial   Expiration date Exercise/ Conversion      Number of voting rights    % of voting
instrument                          Period/ Date              that may be acquired if    rights
                                                              the instrument is
                                                              exercised/ converted.


Total (A+B)
Number of voting rights                           % of voting rights

40,890,879                                        12.05%

8. Chain of controlled undertakings through which the voting rights and/or the financial instruments are
effectively held, if applicable :
                                                  See Section 3

Proxy Voting:

9. Name of the proxy holder:                                           See Section 3

10. Number of voting rights proxy holder will cease to hold:

11. Date on which proxy holder will cease to hold voting rights:

12. Additional information:                Figures are based on a total number of voting rights  of

                                   |  Ends  |

For further information please contact:

Nick Staples, Director of Corporate Affairs      +44 (0) 7919  480510
Julie Vickers, Company Secretary                 +44 (0)1928 518010

Financial Dynamics - press enquiries
London: Ben Atwell, Anna Keeble                  +44 (0) 20 7831 3113
New York: John Capodanno, Jonathan Birt           +1 212 850 5600

Or visit

                      This information is provided by RNS
            The company news service from the London Stock Exchange