Freshfields Bruckhaus Deringer and Slaughter and May have taken lead roles on a $13bn (£9bn) deal which has seen GlaxoSmithKline (GSK) purchase a 36.5% stake in its consumer health joint venture with pharma giant Novartis.

Novartis announced today (27 March) that is selling its stake in the joint venture to focus on its core business. The announcement comes days after GSK pulled out of bidding for US pharma giant Pfizer's consumer unit.

The JV produces products such as Panadol painkillers and Nicotinell patches, among other pharmaceuticals. In a statement, GSK said it would begin "a strategic review of Horlicks and its other consumer healthcare nutrition products to support funding of the transaction".

Slaughters is advising GSK with a team led by corporate partners Simon Nicholls and David Johnson, alongside financing partner Guy O'Keefe and tax partner Dominic Robertson.

Freshfields, meanwhile, is advising Novartis, with a team led by led by corporate partners Julian Long and Jennifer Bethlehem, alongside tax partner Paul Davison and antitrust partner Rod Carlton.

Novartis CEO Vas Narasimhan said: "While our consumer healthcare joint venture with GSK is progressing well, the time is right for Novartis to divest a non-core asset at an attractive price."

Freshfields and Linklaters advised Novartis on the formation of the JV in 2014, with Slaughters acting for GSK. Hogan Lovells also advised Novartis on US aspects of the deal, while Cleary Gottlieb Steen & Hamilton advised GSK on antitrust matters.

GSK had majority control of the JV with an equity interest of 63.5%.