FWIW, PTY is Central, not South America.

Although unless I'm mistaken, there are also flights to continental South America which are operated as only United Business and not Polaris, like IAH-LIM and IAH-BOG. Even EWR-LIM is operated as United Business, I believe, despite being on an internationally-configured 752.

ETA: I see United747 beat me to the latter point... Polaris isn't operated on Central American and even several South American markets.