Glaxosmithkline Regulatory News (GSK)

NOTIFICATION OF MAJOR HOLDINGS (to be sent to the relevant issuer and to the FCA in Microsoft Word format if possible)i

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

GlaxoSmithKline plc

1b. Please indicate if the issuer is a non-UK issuer (please mark with an "X" if appropriate)

Non-UK issuer

2. Reason for the notification (please mark the appropriate box or boxes with an "X")

An acquisition or disposal of voting rights

X

An acquisition or disposal of financial instruments

An event changing the breakdown of voting rights

Other (please specify)iii:

3. Details of person subject to the notification obligationiv

Name

The Capital Group Companies, Inc. ("CGC")

City and country of registered office (if applicable)

Los Angeles, CA 90071, USA

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

Name

City and country of registered office (if applicable)

5. Date on which the threshold was crossed or reachedvi:

13 May 2020

6. Date on which issuer notified (DD/MM/YYYY):

15 May 2020

7. Total positions of person(s) subject to the notification obligation

% of voting rights attached to shares (total of 8. A)

% of voting rights through financial instruments(total of 8.B 1 + 8.B 2)

Total of both in % (8.A + 8.B)

Total number of voting rights of issuervii

Resulting situation on the date on which threshold was crossed or reached

5.0803%

0.0000%

5.0803%

5,017,091,542

Position of previous notification (if

applicable)

N/A

N/A

N/A

8. Notified details of the resulting situation on the date on which the threshold was crossed or reachedviii

A: Voting rights attached to shares

Class/type ofshares

ISIN code (if possible)

Number of voting rightsix

% of voting rights

Direct

(Art 9 of Directive 2004/109/EC) (DTR5.1)

Indirect

(Art 10 of Directive 2004/109/EC) (DTR5.2.1)

Direct

(Art 9 of Directive 2004/109/EC) (DTR5.1)

Indirect

(Art 10 of Directive 2004/109/EC) (DTR5.2.1)

Ordinary Shares (GB0009252882)

208,357,778

4.1530%

ADRs (US37733W1053)

46,524,658

0.9273%

SUBTOTAL 8. A

254,882,436

5.0803%

B 1: Financial Instruments according to Art. 13(1)(a) of Directive 2004/109/EC (DTR5.3.1.1 (a))

Type of financial instrument

Expirationdatex

Exercise/Conversion Periodxi

Number of voting rights that may be acquired if the instrument is

exercised/converted.

% of voting rights

N/A

SUBTOTAL 8. B 1

B 2: Financial Instruments with similar economic effect according to Art. 13(1)(b) of Directive 2004/109/EC (DTR5.3.1.1 (b))

Type of financial instrument

Expirationdatex

Exercise/Conversion Period xi

Physical or cash

settlementxii

Number of voting rights

% of voting rights

N/A

SUBTOTAL 8.B.2

9. Information in relation to the person subject to the notification obligation (please mark the

applicable box with an "X")

Person subject to the notification obligation is not controlled by any natural person or legal entity and does not control any other undertaking(s) holding directly or indirectly an interest in the (underlying) issuerxiii

Full chain of controlled undertakings through which the voting rights and/or thefinancial instruments are effectively held starting with the ultimate controlling natural person or legal entityxiv (please add additional rows as necessary)

X

Namexv

% of voting rights if it equals or is higher than the notifiable threshold

% of voting rights through financial instruments if it equals or is higher than the notifiable threshold

Total of both if it equals or is higher than the notifiable threshold

The Capital Group Companies, Inc.

Holdings by CG Management companies are set out below:

5.0803%

0.0000%

5.0803%

• Capital Bank & Trust Company2

• Capital International, Inc.1

• Capital International Limited1

• Capital International Sàrl1

• Capital Research and Management Company2

5.0551%

0.0000%

5.0551%

1Indirect subsidiaries of Capital Research and Management Company.

2Subsidiary of The Capital Group Companies, Inc.

10. In case of proxy voting, please identify:

Name of the proxy holder

The number and % of voting rights held

The date until which the voting rights will be held

11. Additional informationxvi

The Capital Group Companies, Inc. ("CGC") is the parent company of Capital Research and Management Company ("CRMC") and Capital Bank & Trust Company ("CB&T"). CRMC is a U.S.-based investment management company that serves as investment manager to the American Funds family of mutual funds, other pooled investment vehicles, as well as individual and institutional clients. CRMC and its investment manager affiliates manage equity assets for various investment companies through three divisions, Capital Research Global Investors, Capital International Investors and Capital World Investors. CRMC is the parent company of Capital Group International, Inc. ("CGII"), which in turn is the parent company of four investment management companies ("CGII management companies"): Capital International, Inc., Capital International Limited, Capital International Sàrl and Capital International K.K. CGII management companies and CB&T primarily serve as investment managers to institutional and high net worth clients. CB&T is a U.S.-based investment management company that is a registered investment adviser and an affiliated federally chartered bank.

Neither CGC nor any of its affiliates own shares of your company for its own account. Rather, the shares reported on this Notification are owned by accounts under the discretionary investment management of one or more of the investment management companies described above.

Place of completion

Los Angeles, CA, USA

Date of completion

14 May 2020