Holding(s) in Company

 TR-1: Notifications of Major Interests in Shares

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

Senior plc

2. Reason for notification (yes/no)

An acquisition or disposal of voting rights

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): Acquisition of Gartmore Investment Ltd

X

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

Henderson Global Investors Ltd

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

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

21 April 2011

6. Date on which issuer notified:

26 April 2011

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

Holding has gone below 10%

8: Notified Details

A: Voting rights attached to shares

Class/type of shares

If possible use 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

Percentage of voting rights

Direct

Indirect

Direct

Indirect

GB0007958233

40,266,238

40,266,238

40,181,238

9.99%

B: Financial Instruments

Resulting situation after the triggering transaction

Type of financial instrument

Expiration date

Exercise/ conversion period/date

No. of voting rights that may be acquired (if the instrument exercised/converted)

Percentage of voting rights

C: Financial Instruments with similar economic effect to Qualifying Financial Instruments

Resulting situation after the triggering transaction

Type of financialinstrument

Exercise price

Expiration date

Exercise /Conversion periodi

Number of voting rights instrument refers to

% of voting rights

Nominal

Delta

Total (A+B+C)

Number of voting rights

Percentage of voting rights

40,181,238

9.99%

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

The Lowland Investment Company, Henderson Smaller Companies, Henderson High Income Trust and Henderson Global Investors Limited

Proxy Voting:

10. Name of 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:

Notification using the total voting rights figure of 402,218,951

14. Contact name:

Andrew Bodenham, Company Secretary, Senior plc

15. Contact telephone number:

01923 775547