Hong Kong (CNN Business) Shares in one of China's top electric carmakers plummeted Wednesday after the company reported a staggering 89% drop in net profit for the most recent quarter.

BYD BYDDF stock fell 5.8% in Hong Kong by mid-afternoon. The company's Shenzhen-listed shares were down 6.8%.

The Warren Buffett-backed carmaker reported late Tuesday that it brought in 119.7 million yuan ($17 million) for the third quarter, far less than the nearly $1.1 billion yuan ($156 million) it brought in during the same time period last year. BYD blamed the decline on fluctuating fuel prices — the company also makes gas-powered vehicles — and a reduction in subsidies for new energy vehicles.

And the pain may not be over yet. BYD warned that its full-year profit could drop as much as 43% compared to last year.

That could be bad news for the Oracle of Omaha. Buffett's Berkshire Hathaway is one of BYD's biggest shareholders, with a 8.25% stake in the company.