BEIJING - The net profits of PetroChina, China's largest oil and gas producer, slumped 68.1 percent year on year to 30.6 billion yuan ($4.8 billion) in the first three quarters of 2015, the company reported on Thursday.

During the first nine months, business revenue dropped 25.6 percent to 1.31 trillion yuan, according to the company's quarterly report filed with the Shanghai Stock Exchange.

The company suffered a particularly weak third quarter, when international oil prices declined. At 5.19 billion yuan, its profits in these three months were 81.4 percent lower than in the same period of 2014.