US firms Skadden Arps Slate Meagher & Flom and Shearman & Sterling have secured major UK mandates on the £12bn bid for Sainsbury's by a Qatari investment group.

Skadden is advising Delta Two on its approach for the supermarket giant, which comes just months after Sainsbury's fought off an approach from a private equity consortium, comprising CVC Capital, Blackstone and Texas Pacific Group.

Corporate partner Adrian Knight is thought to be leading the Skadden team acting for Delta Two. Knight is advising alongside his previous firm, Shearman, with Shearman acting for Delta Two's financial adviser, Credit Suisse. London corporate chief Peter King is leading the team for Shearman, which includes James Comyn (corporate), Anthony Ward (finance) and Patrick Clancy (derivatives).

Shearman has a long-standing relationship with Credit Suisse and it was approached by the bank several months ago. It is the second high-profile transaction for Shearman's London office in recent months.

The firm also advised Borsa Italiana on the UK law issues associated with the London Stock Exchange's £1.1bn acquisition of the exchange last month. It is also acting as US counsel to Royal Bank of Scotland on its ongoing bid for ABN Amro.

Herbert Smith has landed a secondary role to Skadden, advising Delta Two on property, employment and share scheme issues. Cravath Swaine & Moore's London office is understood to be acting for some of the lenders to Delta Two.