Holding(s) in Company

For filings with the FCA include the annex

For filings with issuer exclude the annex

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARESi

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

Horizon Discovery 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):

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

Aviva plc & its subsidiaries

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

Registered Holder:

Available Upon Request 13,467*

BNY Norwich Union Nominees Limited 120,092*

Chase (GA Group) Nominees Limited 2,983,635*

State Street Nominees Limited 748,144*

*denotes direct interest

Chase (GA Grouo) Nominees Limited  640,520

Chase Nominees Limited 151,518

5. Date of the transaction and date onwhich the threshold is crossed orreached: v

5 September 2016

6. Date on which issuer notified:

6 September 2016

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

5% to

8. Notified details:

A: Voting rights attached to shares viii, ix

Class/type ofshares

if possible usingthe ISIN CODE

Situation previousto the triggeringtransaction

Resulting situation after the triggering transaction

NumberofShares

NumberofVotingRights

Numberof shares

Number of votingrights

%of voting rightsx

Direct

Direct xi

Indirect xii

Direct

Indirect

Ordinary Shares

GB00BK8FL363

5,209,999*

5,209,999*

4,657,376

3,865,338

792,038

4.07%

0.83%

*Includes right to recall loaned shares (329,493)

B: Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Expirationdate xiii

Exercise/Conversion Period xiv

Number of votingrights that may beacquired if theinstrument isexercised/ converted.

% of votingrights

 RIGHT TO RECALL LOANED SHARES

N/A

N/A

329,493*

*Direct interest

0.35%

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

Resulting situation after the triggering transaction

Type of financialinstrument

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

4,986,869

5.25%

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

The voting rights are managed and controlled by Aviva Investors Global Services Limited & Friends Provident International Limited, with the following chains 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)

Friends Provident International Limited

· Aviva plc (Parent Company)

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

· Aviva Life Holdings UK Limited (wholly owned subsidiary of Aviva Group Holdings Limited)

· Friends Life FPG Limited (wholly owned subsidiary of Aviva Life Holdings UK Limited)

· Friends Life FPL Limited (wholly owned subsidiary of Friends Life FPG Limited)

· Friends Life Limited (wholly owned subsidiary of Friends Life FPL Limited)

· Friends Life and Pensions Limited (wholly owned subsidiary of Friends Life Limited)

· Friends Provident International Limited (wholly owned subsidiary of Friends Life and Pensions Limited)

Proxy Voting:

10. Name of the proxy holder:

See Section 4

11. Number of voting rights proxy holder will ceaseto hold:

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

13. Additional information:

Figures are based on a total number of voting rights of 95,029,695 as per the Company's Additional Listing Announcement of 18 August 2016.

14. Contact name:

Neil Whittaker, Aviva plc

15. Contact telephone number:

01603 684420