The Shenzhen Stock Exchange said Thursday that it will suspend the IPO of BYD Semiconductor, the chip unit of the namesake automaker, as the period of validity for the company’s financial documents had expired during the application process. China’s biggest maker of automotive microcontroller chips filed a listing application with Shenzhen’s startup board ChiNext last May. The IPO plan was first halted by the exchange in August, as a law firm advising on the offering was investigated by local regulators, before the company later passed a hearing with the exchange in January of this year. [Shenzhen Stock Exchange, in Chinese]