His experience spans complex domestic and cross-border corporate and financing transactions across Europe, the Americas and Asia. He has been involved in privatisation and market liberalisation processes, capital markets transactions, corporate and acquisition finance, and corporate and debt restructurings.

He has also advised on transactions involving international private equity funds and management buyouts, as well as the negotiation and structuring of joint ventures and collaboration arrangements for project development, both in Spain and internationally. His practice also encompasses distressed situations and insolvency proceedings, bringing together the legal, strategic and financial dimensions of each matter.

A significant part of his practice involves working closely with the boards of directors and governing bodies of listed and privately held companies, advising on corporate governance, board organisation and procedures, shareholder relations and major corporate decisions. He has served, and continues to serve, as secretary and deputy secretary to boards of directors, and regularly advises on directors’ duties and liabilities and dealings with regulatory authorities.

His career combines extensive experience as a partner in law firms with senior executive and legal leadership roles at major corporate groups and listed companies. This dual perspective enables him to advise businesses not only on individual transactions but also on their broader growth, international expansion and business development strategies, bringing together the strategic, financial and regulatory dimensions of each matter.

Before founding Belagua, Guillermo spent a significant part of his career as a partner at several law firms.

He served as General Secretary and General Counsel of Ence, a publicly listed company, and was a member of its Executive Committee. During this period, he was involved in major corporate and financing transactions, the development of the company’s renewable energy business and international divestments.

Earlier in his career, he held senior legal positions within the Telefónica Group, serving as Deputy Head of Legal at Telefónica Internacional and Deputy General Secretary of Unisource in Zurich. In these roles, he was involved in international expansion projects, acquisitions and strategic alliances across Europe and the Americas. He began his professional career at Commerzbank in Frankfurt and Madrid.

Guillermo has combined his professional practice with university teaching and participation in legal and business education programmes. He has served as an Associate Professor at IE University and has taught at several academic institutions and business schools, including ICADE, Centro de Estudios Garrigues, Instituto de Estudios Bursátiles and Fundación Repsol.

He founded and chaired the Corporate Law and Corporate Governance Section of the Madrid Bar Association. He is the author of several specialist publications and a regular speaker at legal conferences and professional forums.

• Law Degree and Diploma in Business Administration, Universidad Pontificia Comillas (ICADE).
• Master’s Degree in Financial Economics, Universidad Pontificia Comillas (ICADE).
• Master’s Degree in Institutional and Political Communication, Universidad Carlos III de Madrid.
• Diploma of Advanced Studies in Law, Universidad CEU San Pablo.
• Executive and specialist programmes at Harvard University (Negotiation and Program of Instruction for Lawyers) and the University of Amsterdam (Competition Law).

Spanish and English. Knowledge of German, French and Italian.