New York-based LeBoeuf Lamb Greene & MacRae has opened in Paris by taking on the 13-lawyer Paris practice of struggling New York rival Donovan Leisure Newton & Irvine.
At the same time, the 700-lawyer firm has announced that it has set up an affiliated office with SAo Paulo-based firm Tavares Guerreiro Advogados in Brazil.
Donovans' Paris office went on the market after US rival Orrick Herrington & Sutcliffe took on Donovans' 40-lawyer New York litigation practice in April.
The remaining 20 lawyers at Donovans in the US are understood to be preparing to dissolve the partnership.
LeBoeufs has made former Donovans partners Rene de Monseignat, Alain de Foucaud and Reid Feldman partners in the firm and added Laurent Moury and Olivier Laude as counsel.
US partner Douglas Hawes will move to Paris to help integrate the office into LeBoeufs' network.
The established French practice specialises in the pharmaceutical, biotechnology and medical industries.
In Brazil, US partner Robert Romano will set up the firm's SAo Paulo office with local partner Jose Guerreiro and two associates. The office will focus on LeBoeuf's traditional core areas of insurance and energy practice.
James Johnson, managing partner of LeBoeufs' 42-lawyer London office, said: "The firm is dedicated to continued growth and the opportunity to serve clients involved in European activities."
In London, LeBoeufs has recently recruited Middle East specialist Mitri Naijar from the London office of Los Angeles-based US firm Gibson Dunn & Crutcher and international corporate tax expert Anthony Concanon, from Cameron McKenna.