CNOOC Ltd, China's biggest offshore oil producer, revealed first quarter results on Friday, that showed strong growth in output and sales, triggered partly by its acquisition of Nexen Inc, the Canadian oil and gas company.

Output jumped 17.3 percent year-on-year to 93.6 million barrels of oil equivalent, which helped deliver a 13.3 percent rise in oil and gas sales.

The company did not break down its profits, but analysts believe that the strong sales will translate into decent profit growth, even though the oil price was on a downward track.