The Swiss foreign ministry said in a statement that the conduct of Pilatus in Saudi Arabia and UAE was “incompatible with the federal government's foreign policy objectives,” without specifying further.
The Saudi and UAE air forces have formed key parts of the Arab coalition that has bombed Iran-backed Huthi rebels in Yemen since 2015, a campaign that has partly triggered what the UN calls the world's worst humanitarian disaster.
The Saudi-led campaign suffered a blow last week when Britain temporarily suspended approving new arms export licenses to Riyadh that might be used in Yemen.
In 2017, Pilatus signed a five-year maintenance contract on a fleet of 55 jets it sold to the Saudi military, while the UAE has bought 25 jets from the company used to train pilots.
The company's work in the two countries amounts to “technical support, replacement parts management and rectifying faults affecting the Pilatus PC-21 aircraft,” the foreign ministry said in a statement.
“These services qualify as logistical support for armed forces” and must be “discontinued,” it added.
It gave the company 90 days to pull out of both countries.
Founded in 1939, Pilatus employs around 2,000 people in central Switzerland, with a focus on aircraft production and services.