Ontier was founded in 1959 in Madrid and operates offices across Spain, including Madrid, Oviedo, Santander and Seville. The firm also has an international presence across Europe and the Americas, supporting cross-border legal work.

Highlights: The firm advises on capital markets, corporate and M&A, restructuring and insolvency, project development and litigation. Its work spans multiple industries, including energy, real estate, maritime transport and technology.