Notification of Major Interest in Shares

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

IG GROUP HOLDINGS PLC

2 Reason for the notification (please tick the appropriate box or boxes):

An acquisition or disposal of voting rights

Yes

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

Ameriprise Financial, Inc. and its group

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

See additional information under 13.

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

4 April 2011

6. Date on which issuer notified:

5 April 2011

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

Below the threshold of 5%

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 rights x

Direct

Direct xi

Indirect xii

Direct

Indirect

GB00B06QFB75

18,158,248

18,158,248

 860,624

860,624

16,913,564

0.237%

4.673%

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

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

17,774,188

4.910%

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

Ameriprise Financial, Inc., which through intermediate holding companies controls the voting rights of Columbia Management Investment Advisers, Columbia Wanger Asset Management, Threadneedle Management Luxembourg S.A. and Threadneedle Asset Management Holdings Ltd, which itself controls the voting rights of Threadneedle Asset Management Ltd, Threadneedle International Ltd and Threadneedle Pensions Ltd.

Proxy Voting:

10. Name of the proxy holder:

N/A

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

N/A

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

N/A

13. Additional information:

Registered Owner

14. Contact name:

Claire Whiteley

Assistant Company Secretary

IG Group Holdings plc

15. Contact telephone number:

+44 (0)20 7896 0011

A: Identity of the persons or legal entity subject to the notification obligation

Full name

(including legal form of legal entities)

Ameriprise Financial, Inc. (a company incorporated in the State of Delaware, USA) and its group.

Contact address

(registered office for legal entities)

c/o Data Management, Threadneedle Asset Management Holdings Ltd, 60 St Mary Axe, London EC3A 8JQ, UK

Phone number & email

+44 (0)20 7464 5000

Other useful information

(at least legal representative for legal persons)

B: Identity of the notifier, if applicable

Full name

IG Group Holdings plc

Contact address

Cannon Bridge House, 25 Dowgate Hill, London, EC4R 2YA

Phone number & email

+44 (0)20 7896 0011

Other useful information

(e.g. functional relationship with the person or legal entity subject to the notification obligation)

C: Additional information