Central America;
Several years ago I nearly had a job lined up in Guatemala doing ag work with
Helicópteros de Guatemala, but chose a different hemisphere instead.
There's a tour operator in Belize,
Astrum Helicopters Belize - where do you want to go today? that was looking at that time as well.
More recently a company in St. Lucia was looking for an Astar pilot.
No these aren't South America, but good luck with your search.