Interest in shares in OctoPlu

RNS Number : 9801N

GlaxoSmithKline PLC

26 February 2009

Notifiable Share Interest in Octoplus N.V.

GlaxoSmithKline plc (GSK) announces that on 25 February 2009, S.R. One, Limited, a wholly owned US-registered subsidiary of GSK ("S.R.One"), increased to 16.9% its interest in the issued ordinary share capital of OctoPlus N.V. ("OctoPlus"), a pharmaceuticals product and drug delivery company located in the Netherlands, and whose shares are traded on Euronext Amsterdam. GSK's interest, which is held entirely by S.R. One, now comprises 5,096,846 ordinary shares of OctoPlus.

This increased interest became disclosable under the rules of the Netherlands Authority for the Financial Markets ("AFM") upon reaching 15% of the issued share capital of OctoPlus, and an announcement regarding this increased holding is therefore due to be made to the AFM on 26 February 2009. The additional 3,115,012 ordinary shares in OctoPlus, which increased GSK's interest above the disclosable threshold and to its present holding, were acquired as a result of the conversion of an existing convertible loan between S.R. One and OctoPlus into ordinary shares of OctoPlus.