Nexperia, the EU-based automotive chipmaker at the centre of a geopolitical dispute, has suspended supplies to its Chinese factory, stepping up a trade war that threatens to halt production at carmakers around the world. The company wrote to customers this week informing them all supplies to a Chinese plant had been suspended. In September, the Netherlands used national security laws to take control of the chipmaker, citing concerns that its Chinese owner, Wingtech Technologies, was planning to shift intellectual property to another company it owned.