China's Sinopec, one of the largest companies of its kind, said weak global economic recovery was in part behind its 13 percent decline in operating profit.

The company reported a net operating profit of $5.2 billion for the first half of the year, a decline of 13 percent from the prior year. The company blamed weak growth in the global economy and lower oil prices for the decline.

Nevertheless, China's economy still outpaces the rest of the world and the company, Asia's largest refiner, said a floor had been set early in the year for crude oil prices.

"Looking ahead into the second half of 2016, China's economic growth is expected to remain steady, which will drive the growth of domestic demand for refined oil products and petrochemical products," Chairman Wang Yupu said in a statement.

Analysis from S&P Global Platts said Chinese oil demand declined by about a half percent from the first half of last year. That figure is significant when compared with the 8.5 percent year-on-year growth recorded during the first half of 2015.

China's economy, meanwhile, is moderating slowly, with Sinopec's year-on-year estimate of 6.7 percent growth in gross domestic product a slight decline from the fourth quarter. According to Platts, China imported nearly 4 percent more oil in June year-on-year, while net production fell 9 percent.

After dropping below $30 per barrel in early 2016, crude oil prices have moderated in the upper $40 range.

Sinopec said it produced about 154 million barrels of oil during the six months ending June 30, a 6 percent decline from the previous year.

Platts said China's official data may be skewed somewhat because its masks competition in a deregulating domestic energy market.