Hong Leong Asia's stock plummeted 6.22% during midday trading on Friday.
The decline came after the company's NYSE-listed unit, China Yuchai International, unveiled an internal combustion engine powered entirely by ammonia and designed for heavy-duty commercial vehicles. The engine, developed by operating subsidiary Guangxi Yuchai Machinery, aims to provide a zero-carbon power solution for heavy-duty, long-haul commercial transport.