FisherBroyles Expands Cross-Border Capabilities with Three Key Hires

Paul McCulloch, Guillermo Massieu and Leopoldo Olavarría Strengthen Firm’s Bench in Trade, Energy, Technology and Regulatory Law Across the Americas.

ATLANTA—(August 25, 2025)—FisherBroyles, LLP, the world’s first and one of the largest distributed law firms, has bolstered its cross-border and regulatory practices with the addition of three seasoned attorneys: Paul McCulloch in New York, and Guillermo Massieu and Leopoldo Olvarría in Mexico City. Their combined experience deepens the firm’s capabilities in international trade, tax, energy, technology, cybersecurity and compliance.

McCulloch joins the firm’s New York office with more than two decades of experience at the intersection of law, finance, health care, cybersecurity and emerging technology. A former managing partner of NYC CyberLaw Group, PLLC, and veteran legal architect of digital banks, fintech programs and AI compliance programs, McCulloch brings expansive experience in navigating complex technology and regulatory environments. His clients have included global financial institutions, startups, government agencies and nonprofit entities. He is a Certified Information Privacy Manager and serves as chair of the Puerto Rico KnowledgeNet Chapter of the IAPP.

Massieu, based in Mexico City, is a nationally recognized leader in international trade and tax law with more than 30 years of experience advising both multinational and domestic companies. A former director in the Central Administration of Foreign Trade Audit at Mexico’s Tax Administration Service (SAT), Massieu played a key role in implementing free trade agreements such as USMCA. His practice focuses on foreign trade litigation, constitutional tax challenges and compliance counseling, especially in audits and origin verification procedures.

Olavarría brings more than 35 years of legal experience advising on high-value international business transactions and cross-border energy projects. Having served as a partner at global firms including Baker McKenzie, Norton Rose Fulbright and CMS, he has led over 30 major due diligence efforts and M&A transactions across Central and South America — spanning oil and gas, power generation, infrastructure and renewable energy. Licensed to practice in Mexico, Colombia and Venezuela, Olavarría’s work also includes regulatory law, compliance programs and corporate governance. He is a key member of the Mexican Steering Committee of the Association of International Energy Negotiators.

“Paul, Guillermo and Leopoldo each bring distinct strengths to our global platform — Paul’s depth in privacy and technology law, Guillermo’s command of cross-border tax and trade disputes, and Leopoldo’s unmatched experience in energy and infrastructure transactions,” said Kevin Broyles, cofounder and managing partner of FisherBroyles. “Their entrepreneurial approach and commitment to client service are a perfect fit for our model, and we’re excited to welcome them to the firm.”

FisherBroyles continues to grow strategically across the Americas by bringing on accomplished attorneys with a track record of excellence and innovation. The firm remains committed to delivering partner-level counsel through an innovative, distributed model that redefines how sophisticated legal services are delivered.

FisherBroyles was founded in 2002 by Broyles and James Fisher II.