Panama's Copa Holdings will ground its six Boeing 737 Max 9 aircraft, the latest airline in the region to ground planes in the wake of Sunday's crash of an Ethiopian Airlines plane.

The decision follows an order by the US air regulator to ground Boeing 737 Max jets, joining government regulators in Europe, China and other countries.

As regulators around the world have ordered the planes grounded, Latin America has largely left it up to carriers to make their own decisions.

As of Wednesday night, regulators in Brazil, Argentina and Mexico, the largest air travel markets in the region, had not forced the grounding of planes.

Argentina's state-run news agency Telam reported on Tuesday that South American regulators were discussing potential groundings but no decision was "imminent" and would be made by the countries as a group.

Copa operates Boeing 737 MAX 9 planes, which are of the same family but not the same model as the one involved in the Ethiopian Airlines crash.

All three Latin American airlines that operate MAX 8 planes - Brazil's Gol Linhas Aereas Inteligentes, Aerolineas Argentinas and Aeromexico - grounded their planes following the crash.