President & CEO

Mr. John Kamin Marcxell is originally from France. Founder & CEO of Marcxell Group (USA) for many years. Competence and experience in the energy, investment, and real estate sectors. Various advisory and consultancy mandates and CEO positions.

Mr. Marcxell holds a degree in Civil Engineering from the Institut Supérieur des Technologies Appliquées (ISTA – Higher Institute of Applied Technologies) and an M.Sc. in Financial Engineering, an elite program in France in the field of business and financial management, that considered one of the best business degrees in the world.



Olaf Schmid is Vice President of Marcxell Investment, THI.Group, and has extensive experience and skills in corporate functions. He is an outstanding specialist in financial management and is well-versed in real estate investment banking in the European Union. Mr. Schmid is a German national and leads a team of multilingual employees, including locals and expatriates.

As Marcxell Investment‘s Chief Financial Officer, Mr. Olaf Schmid oversees and monitors all of the company’s budgetary procedures: budget forecasts, financing plans, general accounting (cash flow and receivables). He draws up the various balance sheets and ensures that the company’s expenses are in line with its performance objectives, and respect the financial balances essential to Marcxell Investment‘s good financial health.

He also validates the contracts issued by the company and keeps a constant watch on legislation. He represents Marcxell Investment during negotiations with banks. Within our group, which is made up of several subsidiaries.



Sladjan Petkovic is Vice President and general manager. Technical college graduate, active in General trade, finance, real estate and development, owner and General Manager of Crossroad doo, Specialist in domestic Public relations and various humanitarian projects. He supervises the studies, launches the consultations of companies and realization of the projects. Analysis of the conclusions of the consulting firms. Verification of conformity with the criteria and specifications of the group. Control of the drafting of contracts. Follows the orientations and relaunching of the BET studies and advice. Negotiation and conclusion of standard and EPC contracts and public relations.

Sladjan Petkovic organizes projects by managing teams and companies by monitoring work progress and compliance with the group’s schedule and specifications. He proposes economic variants and cost optimization. Sladjan Petkovic organizes and plans with the referenced suppliers to schedule supplies (following the Marcxell Investment Charter).



Jérôme Longelin is Vice President and CFO of Marcxell Investment. He is specialized in the coordination and supervision of the accounting and finance departments, personnel department, administration, and general services. He advises the management on strategic and financial choices.

Mr. Jérôme Longelin implements tools for real-time financial reporting and budget preparation. He optimizes capital management within Marcxell Group and Marcxell Investment, negotiates loans and MT and CT lines with banks.

His functions also include an essential legal dimension; internal financial and procedural audits in the different establishments of the Group; control and validation of the reliability and integrity of operating financial data; management of specific projects such as mergers and acquisitions.

Stavrinos XENI


Stavrinos Xeni is a graduate of the Navigation Academy, former owner and developer of ships and factories. He is active in sales, marketing and finance, public relations, and foreign affairs. Mr. Stavrinos Xeni is vice president and partner in Marcxell Investment. He holds the position of Marketing Director and Research Director.

He established the commercial and marketing strategy, modification of the visual identity of our company. Stavrinos Xeni defines and implements sales processes. Valuation of our know-how. Global manager of our image with the different prescribers (administrations, investors, communities).

Lykourgos TZAKIS


Lykourgos Tzakis is a graduate of a private music school, responsible for trade negotiations, the mandate of True Dominion Enterprises LTD, a specialist in Nigerian BLCO trading for the OFF OPEC quota. Active in oil and gas, general trading, and finance. Owner and Managing Director of Crossroad doo.

Lykourgos Tzakis is Vice President and Director of Marcxell Investment for Personnel Administration: payroll, employment contracts, relations with social organizations, and employee representatives. He follows all legal and fiscal files thanks to legal expertise allowing him to solve the most common problems and network of specialized advisers.

Lykourgos Tzakis develops and implements the strategy: to be a strong proposer, to accompany the general management, to be an intermediary and a facilitator, to control the implementation. Controls the proper functioning of the various departments: gathering and managing the company’s resources.

Cassandra SOTO


Cassandra Soto is a formidable professional within Marcxell Investment. She holds the position of General Secretary in Belgrade (Serbia) within our company. Cassandra Soto is currently in Mexico, and she is the general manager of the subsidiary THI.Group Mexico. She organizes the purchase of building lots for the realization and construction of resorts and luxury villas in Mexico.

Cassandra Soto ensures the continuity of our investments abroad. She manages trust missions (social plan, technology transfer, relations with foreign authorities), project management, implementation of information systems, structuring of an industrial group, initial audit, optimization of production lines.

Cassandra Soto also defines each center’s product range and specialization on its excellence, implementation of an information system, management of real estate projects, negotiations with suppliers, follow-up of a building site, and asset management.

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