Grupo Empresarial Ence SA...halted the construction of a South American mill for 90 days while Argentina and Uruguay study the environmental effects to a river in both countries...Ence's decision to suspend construction of the $500 million plant in Uruguay follows the March 26 announcement by Finland's Metsae-Botnia Oy to halt its $1.1 billion pulp plant in the area...[a] member of the citizens assembly of Gualeguaychu [said]..."Those factories will not only ruin our town as a tourist attraction but also will ruin our economy as we won't be able to export meat, dairy products, fish and honey."