glaxoSlaughter and May has seized its most significant instruction this year from under the nose of arch rival Linklaters after emerging as principal corporate adviser in the long-running panel review of pharmaceuticals giant GlaxoSmithKline (GSK).

In a surprise move, GSK, the UK’s third-largest company with market capitalisation of more than £109bn, selected Slaughters as its primary corporate firm after a panel review lasting over 10 months.