In Nicaragua the companies under Free Zone Regime have to fulfil a number of requisites imposed by givernmental agencies, have to obtain their approval at the moment of registration, and have to continuously update on the legislative changes in the country.

What institutions are the critical ones to get established and operating in Nicaragua?

The National Comission of Free Zones (CNZF-Comisión Nacional de Zonas Francas) is the regulating agency of the Free Zone Regime. Any project has to be approve dby it in order to start operating.
MIFIC - The Ministry of Economics (Ministerio de Fomento de Industria y Comercio) deals with the economic matter of the industry: negotiation of Free Trade Agreement, competition studies, developmental projects for small and medium businesses, etc.
ProNicaragua - the governmental institution in charge on promoting investment, is the welcoming and opening-doors agency to Nicaragua.
MARENA - The Ministry of Environment (Ministerio de Ambiente y Recursos Naturales) regulates the proper use of natural resources and the effects on the environment.
MITRAB - The Ministry of Labor (Ministerio de Trabajo) is in charge of labor issues of the industry: laboral obligations, syndicates and permissions for establishing a new Co.
MTI - The Ministry of Transport (Ministerio de Transporte e Industria) is necessary to deal with for the permission before getting established, is the critical agent in constructing new access roads, reparation of the old ones, etc.
Alcaldias - Mayers: depending on the city where your Co will establish, you have to obtain the permissions, review the taxes structure.