Henderson Group - Holding(s) in Company - AusSuper

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

Henderson Group plc

2. 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):

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

AustralianSuper Pty Ltd

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

5. Date of the transaction (and date on which the threshold is crossed or reached if different):

24 May 2013

6. Date on which issuer notified:

3 June 2013

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

Above 5%

8. Notified details:

A: Voting rights attached to shares

Class/type of shares

 if possible using the ISIN CODE

Situation previous to the Triggering transaction

Resulting situation after the triggering transaction

Number of Voting Rights

Number of shares

Number of voting rights

% of voting rights

Direct

Indirect

Direct

Indirect

Ordinary Shares

-

-

56,399,317

56,399,317

5.06%

B: Financial Instruments

Resulting situation after the triggering transaction

Type of financial instrument

Expiration date

Exercise/ Conversion Period/ Date

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

% of voting rights

Total (A+B)

Number of voting rights

% of voting rights

56,399,317

5.06%

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

·; AustralianSuper Pty Ltd: Voting Rights: 56,399,317; Percentage Held: 5.06%

Proxy Voting:

10. Name of the proxy holder:

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:

Australian Super Pty Ltd

Level 33, 50 Lonsdale Street

Melbourne

VIC 3000

14. Contact name:

Peter Curtis - Head of Investment Operations

15. Contact telephone number: