The firm's Hong Kong-traded shares fell 4.6 percent by midday and its mainland-listed shares declined 2.5 percent.

BYD has submitted an application for the plan to China's securities watchdog and could raise an estimated HK$7.61 billion through the share sale, the report said.

A BYD spokeswoman declined to comment when contacted by Reuters.

(Reporting by Samuel Shen and Kazunori Takada)