Cheshire, UK--(Marketwire - June 4, 2007) -

                                 Protherics PLC

                    Notification of Major Interest in Shares

London, UK; Brentwood, TN, US; 4 June 2007 - Protherics PLC ("Protherics" or the
"Company"), the international biopharmaceutical company focused on critical care
and cancer, announces that, on 1 June 2007, a notification of interest in the
ordinary share capital of the Company was received from Aviva plc 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) (if different from Registered Holder:

                                                  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 31 May 2007
threshold is crossed or reached if different):

5. Date on which issuer notified:                 1 June 2007

6. Threshold(s) that is/are crossed or reached:   7% to 8% Change at Direct 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   23,774,294  23,774,294  28,134,889    28,134,889  12,252,231  8.29%       3.61%
                  (Direct)    (Direct)

                  16,634,944  16,634,944
                  (Indirect)  (Indirect)

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

40,387,120                                        11.90%

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

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