Cuba on Tuesday unveiled rules for its first free trade manufacturing zone, a vast $900 million project being paid for mostly by Brazil in the port of Mariel near Havana. The Mariel Special Development Zone, a major trial balloon being floated by President Raul Castro\'s communist government, is slated to feature manufacturing operations both for export and for the Cuban market, as well as a megaport that would take over shipping now done in Havana. The government on Tuesday published a legal decree in the Official Gazette detailing rules for the area and its operations. Brazilian multinational Odebrecht is handling the infrastructure on the project, and Brazil is providing $640 million in financing, with Cuba handling the rest. Castro, 81, has taken steps to modernize some elements of the economy, such as trimming state payrolls and allowing more types of self-employment, but the state remains firmly in control of most economic activity. It was not immediately clear when manufacturing in the new free trade zone would begin, but some port operations will start this month.