Chinese oil giant Sinopec, Asia's biggest refiner, net profits leapt sixfold in the third quarter, it said Friday, as low crude prices lowered its costs.

Net profit in the July to September period was 10.19 billion yuan ($1.5 billion), compared with 1.65 billion yuan in the same three months last year, it said in a statement to the Shanghai stock exchange.

The surge came after the Beijing-based firm saw its net profit drop 20 percent in the first half of the year, on top of a 30 percent fall last year.

International crude prices "hit bottom" in the third quarter, the firm said, and despite rebounding were "generally still at a low level".

Tian Miao, a Beijing-based analyst at North Square Blue Oak, told Bloomberg News: "Sinopec is a big beneficiary of low crude prices as it buys most of the oil it processes from overseas.

"The low comparison basis from a year ago also makes the quarterly numbers look good."

China's economic growth was stable at 6.7 percent in third quarter, according to official figures, the same as the previous two.

Investors gave Sinopec's profits surge a cautious welcome. On Friday afternoon its shares were up 0.60 percent in Shanghai and 0.18 percent higher in Hong Kong, where it is also listed.