Cleary Gottlieb Steen & Hamilton is losing a senior Paris partner in a rare departure from the New York firm's top tier French arm.

Laurent Cohen-Tanugi, a corporate partner in the firm's Paris office for 12 years, is leaving on 2 January 2004 to become senior vice president and general counsel of Clearys' client Sanofi-Synthelabo.

At Sanofi-Synthelabo, the sixth largest pharmaceutical company in Europe, Cohen-Tanugi will take responsibility for its global legal team of 100 lawyers and is also to launch a review of the company's legal counsel.

"I have been with Clearys for over 20 years and at this point in my career I wanted to have a broader role. I have found my practice getting narrower and more technical and this will let me work more broadly," Cohen-Tanugi told Legal Week Global.

The company is a long-term client of Clearys and Cohen-Tanugi has acted as one of its corporate advisers for a number of years. He succeeds Jean-Pierre Kerjouan, who will become a special adviser.

Cohen-Tanugi's move is a blow to what is seen as the best Paris practice yet built by a foreign firm.