O’Melveny & Myers, Willkie Farr & Gallagher, Walkers Global and Zhong Lun Law Firm are advising NYSE-listed Chinese clinical research organization WuXi PharmaTech on its agreement to be bought by a Chinese investor consortium for $3.3 billion.

The various buyers are being represented by Wilson Sonsini Goodrich & Rosati, P.C., Sullivan & Cromwell, Weil, Gotshal & Manges, Fangda Partners and Conyers, Dill and Pearman.

WuXi has become the latest Chinese company to exit the U.S. stock market, after announcing that it had agreed officially merge with New WuXi Life Science Limited and its subsidiary WuXi Merger Limited, which were created by a group of investors and executives including CEO Ge Li.

Kurt Berney, a partner in the firm’s Shanghai and San Francisco offices, led the O’Melveny team.