China may raise gasoline and diesel prices by 4 to 8 percent this week, to reflect international crude price hikes, said analysts.

If that happens, this would be the sixth price adjustment this year. China has raised fuel prices three times and reduced them twice under a new pricing mechanism this year.

This round of price hike is expected to be 300 yuan per tonne, they said. Some expected the adjustment to be around 500 yuan per tonne. The latest price adjustment on July 29 put domestic gasoline and diesel prices at 6,510 yuan per tonne and 5,770 yuan per tonne respectively.

China adopted a new oil pricing system this year, under which domestic fuel prices would be adjusted when the moving average of a basket of international crude (Brent, Dubai and Cinta) changes more than 4 percent over a period of 22 working days.

Analysts said Sinopec, the country's largest refiner will gain the most if the price spike is announced, as its profit margin largely depends on the volatility of international crude market.

Sinopec said on Sunday its net profit in the first half of 2009 rose by 332.8 percent year-on-year, due to adjusted refined oil prices on the domestic market.

Under international accounting rules, Sinopec's net profit stood at 33.25 billion yuan in the six-month period.

Domestic media reported that some executives from Sinopec said if domestic refined oil prices do not rise at the end of August, the company's refining sector would incur negative profits.

Analysts said currently Sinopec's refinery break-even price was near $60 a barrel. They said as an integrated oil giant, Petrochina has a much lower refinery break-even point than Sinopec.