Chinese electric-car maker BYD Co. Ltd. (1211.HK), which is backed by investor Warren Buffett, Friday said Mr. Buffett's Berkshire Hathaway Inc. (BRKA) has no present intention to cut its stake in the company.

BYD also said it wasn't aware of a substantial share sale by Mr. Buffett, who holds 225 million H shares in the company.

The car maker's statement comes a day after its Hong Kong-traded shares plunged as much as 47%.

BYD said its business operations remain normal and that it hasn't incurred substantial foreign exchange losses despite the weaker Russian ruble. The value of the company's products exported to Russia is less than US$1 million, and those transactions are in U.S. dollars, the car maker said.

The company added that its electric-vehicle business was operating normally and customer orders for electric buses haven't substantially decreased.

BYD's Hong Kong-traded shares regained some ground later on Thursday to close down 29% at 25.05 Hong Kong dollars (US$3.23).

Write to Chester Yung at chester.yung@wsj.com

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