** Shares of iPhone supplier STMicroelectronics STM.PA fall 4.5%, leading a downturn in the European semiconductor space after U.S. President Donald Trump's tariff threat to Apple AAPL.O
** Other industry players are also affected, with Besi BESI.AS, Infineon IFXGn.DE and ams OSRAM AMS.S sliding between 4% and 4.5%
** ASML ASML.AS is down 3.1%, ASM International ASMI.AS falls 3.6%
** Trump threatens to impose a 25% tariff on Apple AAPL.O for iPhones sold, but not manufactured, in the U.S.; he is also recommending a 50% tariff on goods from the EU from June 1
(Reporting by Leo Marchandon)
((Leo.marchandon@thomsonreuters.com))