Guilherme Posser Da Costa

São Tomé and Príncipe

He is the managing partner at DE JURIS Law Firm, since 1991.

He provides technical legal advice to national and foreign investors in the country, advising and supporting his clients in all fields of their activity and in the follow-up of corporate matters, namely in the setting ups, organization and development of business activities.

He provides technical-legal advice to existing companies for the implementation and development of successful businesses.

Practice Areas

Commercial and Corporate Law, M&A, Real Estate Law, Foreign Investment and Energy.

Experience Highlights

— Advice and legal assistance to several national and foreign companies;

— Advice the Chamber of Commerce and Industry of São Tomé and Príncipe on drafting the respective articles of association;

— Legal advice in negotiations with foreign companies in Angola;

— Legal advice to financial groups to offshore banks projects;

— Legal advice to foreign companies for several investment projects in São Tomé and Príncipe;

— Legal advice to the government in the creation of the framework law and licensing of Industrial activities, in the drafting of the law that creates the tourism fund and in the elaboration of the general labor law.

— Preparation of call for tenders files for foreign companies participating in public tenders in São Tomé and Príncipe;

— Constitution of several joint venture companies;

— Joint participation with professors of the Columbia University – New York, in the elaboration of the management petroleum resources Law;

— Participation in the delimitation of the maritime borders with Nigeria and Gabon.


Degree in Law and Juridical Sciences, by the School of Law of the University of Coimbra-Portugal (1978).


Portuguese, English and Spanish.