Allen & Overy (A&O), Ashurst and Weil Gotshal & Manges have taken the lead roles on the £1.6bn auction for UK pharmaceuticals group Warner Chilcott.

Unusually, A&O and Ashurst are both advising the management and shareholders of the UK-based FTSE 250 company, which has its primary listing in London and secondary listings in New York and Dublin. The majority of the company’s operations are in the US.