HGG.L Regulatory News (HGG)

Annual Information Update

8 April 2010

Pursuant to United Kingdom Prospectus Rule 5.2, Henderson Group plc sets out below a brief description of the information published throughout the previous twelve months ended 8 April 2010. Further details on the information may be obtained from the Company. All information was notified to a RIS in London and Australia. Some of the information referred to below was provided as at a specific date and may now be out of date.

06/04/2010 Director/PDMR Shareholding

06/04/2010 Director/PDMR Shareholding

01/04/2010 Henderson Group - Director/PDMR Shareholding

01/04/2010 Henderson Group - Update of Securities

29/03/2010 Annual Report at UKLA

29/03/2010 Notice of AGM

29/03/2010 Annual Report and Accounts

25/03/2010 Henderson Group - Holding in Company - BlackRock

24/03/2010 Holding(s) in Company - BlackRock

03/03/2010 Director/PDMR Shareholding

03/03/2010 Director/PDMR Shareholding

02/03/2010 Henderson Group - Blocklisting Application

02/03/2010 Henderson Group - Director/PDMR Shareholding

02/03/2010 Henderson Group - Director/PDMR Shareholding

02/03/2010 Henderson Group - Holding(s) in Company - AMP Ltd

01/03/2010 Henderson Group - Update of Securities

25/02/2010 Henderson Group - Key dates

24/02/2010 2009 Annual Results

18/02/2010 Henderson Group - Holding(s) in Company - AMP Ltd

02/02/2010 Henderson Group - Blocklisting Interim Review

02/02/2010 Henderson Group - Blocklisting Interim Review

02/02/2010 Henderson Group - Director/PDMR Shareholding

02/02/2010 Henderson Group - Director/PDMR Shareholding

02/02/2010 Holding(s) in Company

01/02/2010 Update of Securities

25/01/2010 Henderson Group - Holding(s) in Company - AMP Ltd

21/01/2010 Change in presentation of results

05/01/2010 Henderson Group - Director/PDMR Shareholding

05/01/2010 Henderson Group - Director/PDMR Shareholding

04/01/2010 Henderson Group - Update of Securities

30/12/2009 Holding(s) in Company - BlackRock

16/12/2009 Senior Independent Director

11/12/2009 Block Listing Application

09/12/2009 Holding(s) in Company - Barclays

01/12/2009 Henderson Group - Director/PDMR Shareholding

01/12/2009 Henderson Group - Director/PDMR Shareholding

01/12/2009 Henderson Group - Update of Securities

25/11/2009 Henderson Group - Key Dates

04/11/2009 Henderson Group - November Investor Presentation

02/11/2009 Update of Securities

02/11/2009 Director/PDMR Shareholding

02/11/2009 Director/PDMR Shareholding

29/10/2009 Interim Management Statement

23/10/2009 Change of Director Information

22/10/2009 Holding(s) in Company

01/10/2009 Director/PDMR Shareholding

01/10/2009 Director/PDMR Shareholding

01/10/2009 Update of Securities

29/09/2009 Director/PDMR Shareholding

29/09/2009 Director/PDMR Shareholding

29/09/2009 Henderson Group - Investor presentation

17/09/2009 Director/PDMR Shareholding

16/09/2009 Holding(s) in Company

16/09/2009 Notice of Interim Management Statement

16/09/2009 Directorate Change

08/09/2009 Change of Director information

04/09/2009 Dividend rates

03/09/2009 Conference and investor presentations

01/09/2009 Director/PDMR Shareholding

01/09/2009 Director/PDMR Shareholding

01/09/2009 Holding(s) in Company

01/09/2009 Update of Securities

27/08/2009 Record and payment dates

27/08/2009 Half Yearly Report

26/08/2009 Director/PDMR Shareholding

26/08/2009 Board of Directors appointment approved

25/08/2009 Holding(s) in Company

18/08/2009 Holding(s) in Company

03/08/2009 Director/PDMR Shareholding

03/08/2009 Blocklisting Interim Review

03/08/2009 Update of Securities

30/07/2009 Director/PDMR Shareholding

30/07/2009 Board of Directors appointment approved

16/07/2009 Business Update and Board Changes

02/07/2009 Director/PDMR Shareholding

01/07/2009 Director/PDMR Shareholding

01/07/2009 Update of Securities

30/06/2009 Details of integration update

03/06/2009 Director/PDMR Shareholding

02/06/2009 Director/PDMR Shareholding

01/06/2009 Update of Securities

11/05/2009 AGM Statement

11/05/2009 Interim Management Statement

11/05/2009 Result of AGM

08/05/2009 Dividend Rates

01/05/2009 Director/PDMR Shareholding

01/05/2009 Update of Securities

30/04/2009 Holding(s) in Company - Perpetual

30/04/2009 Holding(s) in Company - Perpetual

28/04/2009 Director/PDMR Shareholding

17/04/2009 Holding(s) in Company - AMP

09/04/2009 Completion of Acquisition

09/04/2009 Update of Securities

06/04/2009 Offer for New Star wholly unconditional

06/04/2009 Publication of Prospectus

02/04/2009 GM Statement

02/04/2009 Annual Report at UKLA

02/04/2009 Annual Information Update

Henderson Group plc (company number 101484) has submitted filings to the Jersey Financial Services Commission (JFSC), in compliance with its obligations under Jersey law. Copies of these documents can be found on the JFSC Companies Registry website at www.jerseyfsc.org/registry or by contacting the Jersey Financial Services Commission at PO Box 111, 14-18 Castle Street, St Helier, Jersey, JE4 9QD, Channel Islands.

Henderson Group plc has also submitted filings to the Companies Registration Office in Ireland, in compliance with its obligations under Irish Law. Copies of these documents can be found on the Companies Registration Office website at www.cro.ie or by contacting the Companies Registration Office at Parnell House, 14 Parnell Square, Dublin 1.

Henderson Group plc

47 Esplanade,

Jersey JE1 0BD

No. 101484

ABN 67 133 992 766

For further information:

www.henderson.com or

Matthew Purkis

Deputy Company Secretary

Telephone: 020 7818 2959

matthew.purkis@henderson.com