1. Identity of the issuer or the underlying issuer
of existing shares to which voting rights are
attached: ii

Hydrodec Group plc   

2 Reason for the notification (please tick the appropriate box or boxes):

An acquisition or disposal of voting rights

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

An acquisition or disposal of instruments with similar economic effect to qualifying financial instruments

An event changing the breakdown of voting rights 

Other (please specify):

On market transfer between direct and indirect funds 

X

3. Full name of person(s) subject to the
notification obligation: iii

Aviva plc & its subsidiaries   

4. Full name of shareholder(s) 
 (if different from 3.):iv

Registered Holder:

BNY Norwich Union Nominees Limited 
                                               2,466,277*

Chase (GA Group) Nominees Limited 
                                              17,969,822*

CUIM Nominee Limited             2,467,081*

*denotes direct interest   

BNP Paribas - London             1,816,642   

Chase Nominees Limited         5,645,222

State Street Nominees Limited       18,621,871 

5. Date of the transaction and date on
which the threshold is crossed or
reached: v

07 December 2009

6. Date on which issuer notified:

09 December 2009

7. Threshold(s) that is/are crossed or
reached: vi, vii

9% to 8% Change at Direct Interest Level

8. Notified details:

A: Voting rights attached to shares viii, ix

Class/type of
shares

if possible using
the ISIN CODE

Situation previous
to the triggering
transaction

Resulting situation after the triggering transaction

Number
of
Shares              

Number
of
Voting
  Rights               

Number
of shares

Number of voting
rights

% of voting rights x

Direct               

Direct xi            

Indirect xii

Direct        

Indirect

Ordinary Shares


GB00B02FJF09

44,877,053

44,877,053

48,986,915

22,903,180

26,083,735

8.56%

9.76%

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financial
instrument

Expiration
date xiii

Exercise/  
Conversion Period xiv

Number of voting
rights that may be
acquired if the
instrument is
exercised/ converted.

% of voting
rights

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments xv, xvi

Resulting situation after the triggering transaction

Type of         financial
instrument

Exercise        price

Expiration date xvii

Exercise/
Conversion period xviii

Number of voting rights instrument        refers to

% of voting rights xix, xx

Nominal

Delta

Total (A+B+C)

Number of voting rights                               

Percentage of voting rights

48,986,915

18.32%

9. Chain of controlled undertakings through which the voting rights and/or the
financial instruments are effectively held, if applicable: xxi

The voting rights are managed and controlled by Aviva Investors Global Services Limited, with the following chain of controlled undertakings:-

Aviva Investors Global Services Limited:

• Aviva plc (Parent Company)

• Aviva Group Holdings Limited (wholly owned subsidiary of Aviva plc)

• Aviva Investors Holdings Limited (wholly owned subsidiary of Aviva Group Holdings Limited)

• Aviva Investors Global Services Limited (wholly owned subsidiary of Aviva Investors Holdings Limited)

Proxy Voting:

10. Name of the proxy holder:

See Section 4

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

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

13. Additional information:

Figures are based on a total number of voting rights of  267,421,339.

14. Contact name:

   Neil Whittaker

15. Contact telephone number:

   01603 684420