China's private automotive and battery manufacturer BYD announced on Wednesday in a financial statement that it earned 52.9 billion yuan ($8.5 billion) in sales in 2013, an increase of 13 percent year-on-year, as the world's biggest car market recovered.

Net profit of the company soared nearly 600 percent to 553 million yuan last year, according to the statement, but first-quarter profit is expected to fall about 87 percent or even 96 percent to 15 or 5 million yuan as China's subsidy policy shifts to electric cars.

The report said China's new electric cars subsidy policy in the second half of last year hit makers of low-end domestic vehicles hardest, as consumer demand changed in the automotive market.

The K9 model of the company's electric buses has been successfully marketed in Europe including the UK, France, Germany, Spain, Denmark and Austria.

US billionaire investor Warren Buffett-backed BYD also sold a fleet of 20 zero-emission, fully-electric e6 cars to London, and 35 electric buses to the Netherlands.

In China, BYD's electric buses are in operation in many cities, including Shenzhen, Changsha, Xi'an and Tianjin.