GlaxoSmithKline plc (the Company) announces that in accordance with the authority granted by shareholders at the Company's Annual General Meeting on 3 May 2012 it purchased 1,300,000 of its Ordinary shares of 25 pence each (shares) on 27 June 2012.

The highest price paid per share was 1485 pence per share.

The lowest price paid per share was 1462 pence per share.

The Company intends to hold these shares in Treasury.

The Company holds 473,157,927 of its shares in Treasury, representing 8.65% of the total issued share capital of the Company. 

Including shares which have been purchased but not yet settled, the Company holds 476,857,927 of its shares in Treasury, representing 9.55% of the current total voting rights in the Company.

The Company has 4,994,056,889 shares in issue (excluding shares held in Treasury). This number represents the total voting rights in the Company and may be used by shareholders as the denominator for the calculations by which they can determine if they are required to notify their interest in, or a change to their interest in, the Company under the Financial Services Authority's Disclosure and Transparency Rules.

This announcement does not constitute, or form part of, an offer or any solicitation of an offer to purchase or subscribe for securities in any jurisdiction and is in conformity with the Financial Services Authority's Disclosure and Transparency Rules.