Union of South American Nations, a regional organization of South American countries modelled on the European Union. Originally founded in 2004 as the South American Community of Nations and renamed in 2007, it includes 12 countries: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela, with Mexico and Panama as observers.

http://www.unasursg.org/en The official website of UNASUR (in English).