Herbert Smith has picked up the English law aspects of US biotech company Transkaryotic Therapies’ (TKT’s) $1.6bn (£840m) takeover by UK rival Shire Pharmaceuticals following a referral from Wall Street powerhouse Cravath Swaine & Moore.

The deal, which was mainly done under US law, sees Shire agree to pay $37 (£19) in cash for each share of TKT’s common stock, valuing the transaction, which is subject to regulatory and shareholder approval, at approximately $1.6bn.