Chinese carmaker BYD Co Ltd, backed by US billionaire Warren Buffett, forecast 2013 profit may rise more than seven-fold from last year, after the company posted robust quarterly results that beat analyst estimates.

BYD is in the midst of a revival thanks to demand for its traditional gasoline-fuelled vehicles, which account for half of the company's revenues, and an improvement in its solar cell business. It also makes electric cars.

Net profit for the full year is likely to rise 570-619 percent, and will range between 545.1 million yuan ($89.57 million) to 585.1 million yuan, BYD said in an exchange filing on Tuesday, citing a continued recovery in its auto sales and a better performance by its solar business.

Shenzhen-based BYD said net profit in July-September jumped 727.5 percent to 38.2 million yuan from a year earlier. Two analysts polled by Reuters had forecast a 22.5 million yuan profit.

Shares of the company fell 3.44 percent to HK$37.90 in Hong Kong trading at the close on Tuesday, ahead of the earnings announcement. The benchmark Hang Seng rose 0.18 percent.