China National Offshore Oil Corporation (CNOOC), the country's top offshore oil and gas producer, said its net profit for 2006 soared 22 percent, the smallest increase in the last four years, hurt by lower crude oil prices and a pared output growth in an initially productive field.

The third-largest oil company in China said its net earning for last year was 31 billion yuan, compared with 25.32 billion yuan a year earlier. Overall production rose 8 percent.

The result slightly beat the expectation of energy analysts, who predicted the company's net profit for 2006 would be 30.7 billion yuan.

The slowdown in oil prices hurt CNOOC more than the other two top oil companies, PetroChina Co and China Petroleum & Chemical Corp, which reap additional earnings from oil processing.

CNOOC's 2007 earnings are also expected to slide as oil prices hover around $60 a barrel.

The company said it paid 3.98 billion yuan in windfall taxes to the government, levied because of gains in crude prices.

CNOOC's Liuhua field, an otherwise productive project in the South China Sea, has been shut down since May, damaged by Typhoon Chanchu.

CNOOC Chairman Fu Chengyu said the company was not sure whether the closed field will be able to reopen. The field produced 22,000 barrels a day, about 5 percent of the group's output.

Shares in CNOOC rose 41 percent in 2006, outpacing a 34 percent gain in the benchmark Hang Seng Index.