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

Avanti Communications 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 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

MAST Capital Management, LLC

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

Mast Credit Opportunities I Master Fund Limited; Mast OC I Master Fund, L.P.; Mast Select Opportunities Master Fund, L.P.; Mast Admiral Master Fund, L.P.; Polar Bear Fund LP; KKR TFO Partners LP

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

August 21, 2015

6. Date on which issuer notified:

August 21, 2015

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

From below 10% to above 10%, but less than 11%

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

Common Shares

11,891,924

11,891,924

15,083,192

15,083,192

10.37%

ISIN: GB00B1VCNQ84

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

15,083,192

10.37%

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

Each of the shareholders listed in Section 4 is an investment vehicle which is managed by MAST Capital Management, LLC, an investment adviser registered with the United States Securities and Exchange Commission. MAST Capital Management, LLC is consequently subject to the shareholder disclosure thresholds prescribed by DTR 5.1.5.

Proxy Voting:

10. Name of the proxy holder:

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

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

13. Additional information:

14. Contact name:

Adam Kleinman

15. Contact telephone number:

+1-617-375-3000