Holding(s) in Company

1. Identity of the issuer or the underlying issuerof existing shares to which voting rights areattached: ii

Inmarsat PLC

Sedol B09LSH6

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

An acquisition or disposal of voting rights

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):

Voluntary baseline disclosure upon implementation of amendments to the Transparency Directive

√

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

1Lansdowne Partners International Limited

2Lansdowne Partners Limited

3Lansdowne Partners (UK) LLP

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

HSBC Client Holdings Nominee (UK) Ltd

(Registered Shareholders)

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

26/11/2015

6. Date on which issuer notified:

30/11/2015

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

Voluntary baseline disclosure upon implementation of amendments to the Transparency Directive

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

Ordinary Shares

51,289,234

51,289,234

52,703,005

11.72%

GB00B09LSH68

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

CFD

N/A

N/A

N/A

2,486,281

Nominal

Delta

0.55%

Total (A+B+C)

Number of voting rights

Percentage of voting rights

55,189,286

12.28%

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

Lansdowne Partners International Limited is the parent undertaking of Lansdowne Partners Limited which is the First Corporate Member of Lansdowne Partners (UK) LLP.

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:

Based on ordinary shares in issue of 449,585,758.

14. Contact name:

Ruari Paton

15. Contact telephone number:

+44(0)20 7290 5500