China will raise its heavily regulated retail gasoline and diesel prices Tuesday by 6.4 percent and 7 percent, respectively, marking the biggest increase in 33 months, the National Development and Reform Commission announced.

Benchmark domestic retail price ceilings will increase by 600 yuan ($95) a metric ton to 9,980 yuan a ton for gasoline and 9,130 yuan a ton for diesel. Analysts say the price hikes are largely in line with market expectations.

The increases still leave a wide gap between international and domestic crude oil prices, and can't protect the state-controlled refiners PetroChina Co. (NYSE: PTR) and China Petroleum & Chemical Corp. (NYSE: SNP) from recording more losses. China's cap on fuel prices makes it difficult for companies to pass on the full impact of rising crude oil costs to consumers.

In the first three quarters of 2011, PetroChina lost 23.1 billion yuan from rising international crude prices, while China Petroleum & Chemical, also known as Sinopec, booked 41.5 billion yuan in losses. The two largest Chinese refinery companies are expected to remain in the red this year.

The latest price hike -- the second in just over five weeks -- came on the heels of a more than 10 percent spike in global crude prices since Feb. 8, when the retail prices of both gasoline and diesel were raised by 300 yuan per metric ton.

Under China's fuel pricing system, domestic fuel prices may be adjusted when international crude oil prices change by more than 4 percent over 22 working days.

By March 8, average crude oil prices in the Brent, Dubai and Cinta markets had risen by 8.92 percent over 22 working days, but the NDRC did not announce the price hikes, as China's annual parliamentary session was being held, Hu Huichun, an oil market analyst from SCI, a leading commodity information portal, told China's official Xinhua news agency.

Chen Qing, another SCI analyst, told Xinhua that easing inflation and subsidy programs prepared in advance by the government were the two biggest factors in the NDRC's decision to raise prices.

China's consumer price index, a main gauge of inflation, rose 3.2 percent from a year earlier in February, well below a peak inflation rate of 6.5 percent in July of last year.

People working in the fishery, forestry and public transport sectors will continue to receive fuel subsidies from the government, the NDRC said.

PetroChina Co. Ltd. (NYSE:PTR) shed 46 cents to $147.38 a share in Monday's late-afternoon trading, while China Petroleum & Chemical Corp. (NYSE: SNP) gained $1.8 a share to $117.54.