Linklaters has been called in to act for Sanofi-Sythnelabo for the first time on its high-profile E48bn (£33bn) hostile bid for Aventis, after the French giant's regular counsel was conflicted out.

The bid, which could create the world's third largest pharmaceutical company, is regarded as a landmark for the French market since hostile bids are extremely rare on the Continent.

As exclusively revealed on legalweek.com (27 January) Sanofi's preferred counsel, Cleary Gottlieb Steen & Hamilton, rejected the instruction because of previous advice it had given to Aventis, leaving Sanofi to instruct Linklaters' Thierry Vassogne.

One lawyer close to the deal said: "Sanofi did not so much approach Linklaters as Vassogne personally because he is one of the best lawyers in France."

Sanofi also sought advice from Jean-Michel Darrois, name partner of Darrois Villey Maillot & Brochier, and Jean-Pierre Martel of Rambaud Martel.

Wachtell Lipton Rosen & Katz founding partner David Katz is advising Sanofi on US aspects of the deal alongside Washington DC's Arnold & Porter.

Brendin Prat is advising Aventis.