Holding(s) in Company

IG Group Holdings plc
19 June 2007


IG Group Holdings plc
19 June 2007

Notification of substantial shareholding

TR-1: NOTIFICATION OF MAJOR INTERESTS IN SHARES

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

     IG Group Holdings Plc

2. Reason for the notification (please place an X inside the appropriate bracket
/s):

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:

JANUS CAPITAL MANAGEMENT, LLC

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):

15/06/07

6. Date on which issuer notified:

18/06/07

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

Above 5%

8. Notified details:

A: Voting rights attached to shares

Situation previous to the Triggering transaction

Number of shares:
14,699,357

Number of voting Rights:
14,699,357

Class/type of shares if possible using the ISIN CODE:
Ordinary Shares at 0.005p each

Resulting situation after the triggering transaction

Number of shares:
Direct: 32,430,008

Number of voting rights:
Direct: 32,430,008
Indirect: -

% of voting rights:
Direct: 9.90%
Indirect: -

Class/type of shares if possible using the ISIN CODE:
Ordinary Shares at 0.005p each

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:
32,430,008

% of voting rights:
9.90%

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

...............

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:

...............

14. Contact name:
Guy Abbi, Company Secretary, IG Group Holdings Plc

15. Contact telephone number:
020 7633 5463


                      This information is provided by RNS
            The company news service from the London Stock Exchange