Marian Portero Collado is a Director in Econ One’s International Arbitration Group, based in Florida USA, as an economic-financial expert, leading research studies in determining economic, financial, socioeconomic and environmental damages analyses.  Marian has experience authoring expert forensic reports and testifying in international arbitration tribunals. International experience in leading and conducting complex investigations, due diligence, and developing case investigation frameworks and strategies supporting international arbitration cases. Based on her experience acquired in Accenture, Spain and the United States, in the sectors of FMCG, Infrastructure, Pharmaceutical, Telecom, Automotive, Construction, Financial Services and Insurance, Marian has participated in international projects in Eastern Europe, Africa and the Americas, providing economic, financial, socioeconomic and environmental forensic support services, including presentations as an expert witness in international arbitration tribunals.

Key expertise:

• International experience in leading research studies and due diligence developing case frameworks and strategies.
• Management and coordination of research processes and outcomes with Counsel and Experts.
• Economic and financial disputes determining loss of profits in economic, socioeconomic and environmental damages and valuations.
• Experienced author of expert forensic reports and testimony in international arbitration cases.
• Sectors – FMCG, Infrastructure, Construction, Pharmaceutical, Telecom, Automotive and Financial Services.

Expert/Testimony Experience:

Marian is an expert on economic issues, specialized in leading research studies, valuations and determination of economic, socioeconomic & environmental damages, in the sectors of transport, infrastructure, construction, financial services and insurance. Marian has presented written and oral testimony as an expert in international arbitration tribunals, including the ICC, ICSID and PCA.

Selected Speaking Engagements

MASIN Masterclass Webinar | August 26, 2026
Panelist, “Called to the Stand: The Rise of Female Expert Witnesses in International Arbitration”
Discussion on the evolving role of experts in increasingly complex international disputes, including independence, clear communication, multidisciplinary expertise, technology, and opportunities for the next generation of female expert witnesses.
View related news

Africa Moot Arbitration Conference | Nairobi, Kenya | February 19, 2026
Panelist, “Managing Complex Arbitrations: Procedural Innovations, Third-Party Funding and ESG”
Discussion on procedural innovation, evolving third-party funding models, and ESG considerations in complex arbitrations. Marian contributed a quantum perspective, including the assessment and quantification of socioeconomic and environmental impacts in infrastructure, mining, and energy disputes.
View related news

International Arbitration Congress | San José, Costa Rica | 2025
Panelist, “Prueba pericial en arbitrajes de construcción”
Discussion on expert evidence in construction arbitration, including documenting claims, selecting experts, and presenting clear, well-supported analysis. Marian contributed an economic and damages perspective, with a focus on connecting technical evidence, causation, and damages quantification.

Bracewell / Econ One / Navantia | New York, New York | 2024
Panelist, Financial Impact of ESG and Dispute Resolution
Discussion on the interaction between sustainability and governance issues, financial impacts, and dispute resolution. Marian contributed perspectives reflecting Econ One’s work at the intersection of ESG, economic impact, valuation, and damages assessment in complex disputes.

Econ One / CAMESCOM | Mexico City, Mexico | 2024
Panelist, “ESG y Resolución de Disputas: Retos y Soluciones”
Discussion on the growing impact of ESG requirements on businesses and dispute resolution in Mexico. Marian shared her experience with claims involving socioeconomic and environmental impacts, including the challenges of establishing causation and developing robust methodologies to assess and quantify those impacts.
View related news

Econ One / CCHD | Madrid, Spain | 2023
Panelist, “ESG, Sustainability and Dispute Resolution: Emerging Challenges and Needs”
Discussion on how ESG and sustainability requirements are changing corporate decision-making and dispute resolution. Marian contributed the expert and quantum perspective, addressing the challenges of identifying and quantifying socioeconomic and environmental impacts and their increasing relevance in international disputes.

Languages: English, Español, Frances

International Experience: United States, South and Central America, Europe, Africa, Eastern Europe.