The U.S. Ambassador to Spain and Andorra has left the Biden administration to rejoin Winston & Strawn as a partner, the firm confirmed Tuesday.

Julissa Reynoso Pantaleón, the first woman to hold the ambassadorship, will join the Am Law 100 firm’s New York office in its litigation department. Reynoso previously worked at the firm as a litigation and international arbitration partner from June 2017 to December 2020.