Mexico's Energy Minister Fernando Canales said on Thursday that the country had invited Spain and Bolivia to join the Mesoamerican Energy Integration Program (PIEM).
Speaking one day before the PIEM summit, Canales said the United States and Canada might also be invited to join the project in the future.
The PIEM project, dubbed the region's biggest one since the Panama canal, is a scheme to build a large refinery in a Central American nation, pipe natural gas down the Pacific coast and join up power grids.
Canales added that Mexico did not conceive PIEM to be a "counterweight" to the regional energy integration plans promoted by Venezuelan President, Hugo Chavez, describing the project as being "complementary."
Presidents and foreign ministers of the PIEM nations -- Belize, Colombia, Costa Rica, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama and the Dominican Republic -- will meet on Friday and Saturday in Santo Domingo, the Dominican capital, to decide on the site of the refinery.
The proposed plant would probably be in a Pacific Ocean port, said the minister. Guatemala, Honduras and Panama have offered to host the plant.
The Pacific Ocean is a better option than the Atlantic because it makes it easier for the refinery to import natural gas or crude oil from Peru or Bolivia, he added. It would also allow the plant to export gasoline to the West Coast of the United States or elsewhere in the world, he said.
He estimated such a plant would supply gasoline to Central America up to eight U.S. dollars cheaper than the price on the international market, adding that the new Mexican government, which is set to be sworn in on Dec. 1 after the July 2 elections, will continue the PIEM project, "to give Mexico's professionalism an international value."