(Yicai Global) Aug. 23 -- Chinese carmaker BYD has halted the planned listing of its chip manufacturing arm on the Shenzhen stock exchange's Nasdaq-style ChiNext board after the law firm hired to guide the process came under investigation by China’s securities regulators.

All initial public offering applications by companies served by Beijing Tian Yuan Law Firm, including BYD Semiconductor, are no longer under review, the Shenzhen bourse said on Aug. 18. Around 30 companies have been affected.

Hualong Securities, Carea Assets Appraisal and Zhongxingcai Guanghua Certified Public Accountants are also being probed, according to the China Securities Regulatory Commission website. No details were given about the alleged infringements.

BYD Semiconductor has made no comment.

The suspension will be a blow to BYD, whose stock price has doubled since the Shenzhen-based automaker first announced it will take its semiconductor arm public in mid-May. Car chip makers have become the darling of investors as a global chip shortage hampers vehicle production.

BYD Semiconductor makes automotive-grade insulated gate bipolar transistor semiconductor modules, or the central processing unit of new energy vehicles. It is known as the ‘Mount Everest’ of electric car core technology due to its high design threshold, advanced manufacturing technology and large investment.

BYD Semiconductor completed two funding rounds worth CNY2.7 billion (USD415.8 million) last year, boosting its valuation to CNY10.2 billion (USD1.6 billion). BYD holds a 72.3 percent stake in the unit.

BYD’s share price [SHE:002954] closed up 1.65 percent at CNY289.80 (USD44.64) today.

Editors: Tang Shihua, Kim Taylor