IMO, blok perdagangan Amerika Selatan = definisi, bukan padanan nama untuk Mercosur. Di luar Mercosur masih ada blok perdagangan Amerika Selatan lain:
"The biggest Trade Block in South America is Mercosur (or Mercosul in Portuguese), comprising Argentina, Brazil, Paraguay, Uruguay and Venezuela. Associate states include Bolivia, Chile, Colombia, Ecuador and Peru. The second-biggest trade bloc is the Andean Community of Nations comprising Bolivia, Colombia, Ecuador, Peru, Venezuela and as of 2006 Chile. The Union of South American Nations is expected to merge both trade blocs."
http://en.wikipedia.org/wiki/Economy_of_South_America
The translation workplace 
peer agreement (net): +2
