The magic circle firm is advising Alcan on EU competition aspects out of its London and Brussels offices.
But it is Sullivan & Cromwell that will have to grapple with the mammoth US antitrust issues. Alcoa had to divest Alcan in 1950 after the US company was found to be an anticompetitive monopoly. Sullivan is historically one of Alcan's preferred advisers, representing the company in the 2003 acquisition of Pechiney for €3.4bn (£2.08bn).
As suspected, Alcan favourite Ogilvy Renault has been drafted in to advise on Canadian aspects.
The firms will be facing Alcoa's three-party counsel formed of Skadden Arps Slate Meagher & Flom, Canadian firm Stikeman Elliott, and Cleary Gottlieb Steen & Hamilton on the antitrust side, as first reported by The Lawyer (8 May).
If successful, the combination between Alcan and Alcoa would trump that of Rusal, which merged last year with Linklaters clients Sual and Glencore in a $30bn (£15.04bn) deal.
This week also saw Freshfields nab a role advising longstanding client Cerberus on the European aspects of its acquisition of an 80.1 per cent stake in Chrysler for £3.8bn. New York firm Schulte Roth & Zabel was US counsel to the private equity house, a marquee client.