Freshfields Bruckhaus Deringer has taken a lead role for global insurance broker Aon on the relocation of its head office from Chicago to London.

Financial institutions partner James Smethurst and corporate head Julian Long led the Freshfields team while a duo of US law firms also took key roles advising Aon on the move, with Sidley Austin advising on US law aspects and McDermott Will & Emery leading on tax issues.