BEIJING - China's largest oil refiner Sinopec saw net profits return to strong growth in the first quarter of 2013, while the country's top oil and gas producer PetroChina reported a decline in profits, company statements showed Thursday.

Analysts attributed the performances to a retail gasoline and diesel price hike and lower crude oil prices, which made the refinery business more profitable but weighed on prospecting and extracting operations.

Sinopec, or China Petroleum and Chemical Corporation, said in a statement its net profits surged 23.42 percent year-on-year to 15.83 billion yuan ($2.54 billion) in the first quarter by the Chinese financial reporting standards, compared with an 11.4-percent year-on-year drop in 2012.

By the international reporting standards, Sinopec's net profits rose 24.4 percent year-on-year to 16.68 billion yuan.

PetroChina Company Limited said its net profits fell 8 percent year-on-year to 36.02 billion yuan in the first quarter by the international reporting standards, bringing the basic earnings per share to 0.2 yuan.

An increase in retail gasoline and diesel prices in February helped both companies' refinery businesses, said Qiu Xiaofeng, an analyst with China Galaxy Securities.

The Chinese government controls fuel prices in the domestic market as policymakers are concerned about their impact on inflation in the world's most populous nation.

Authorities raised retail prices of gasoline by 300 yuan per ton and diesel by 290 yuan per ton in February.

Sinopec came out of the red in its refinery business in the first quarter, reaping 2.2 billion yuan of profits.

PetroChina lost 1.56 billion yuan in refinery operations, but the losses were down by 8.84 billion yuan from the first quarter of last year.

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