Chinese state-owned energy giant CNOOC on Friday said profit climbed over six percent last year as it started a spate of new projects, despite taking a "serious blow" from falling oil prices.

The forecast-beating profit rise came after rivals Sinopec and PetroChina both said their profits dived last year as crude prices more than halved between June and January.

China's largest offshore oil and gas producer reported net profit of 60.20 billion yuan ($9.68 billion) in 2014, 6.6 percent more than 56.46 billion yuan in 2013.

The results beat the 52.3 billion yuan predicted by 24 analysts polled by Bloomberg News.

"2014 was an important year for the company's new oil and gas projects, with 13 projects commencing production," chief executive officer Li Fanrong said in a filing to the Hong Kong stock exchange.

But chairman Wang Yilin warned the slump in oil prices and slow global economic recovery had hit sales and threatened the company's long-term strategy.

Revenue fell almost four percent to 274.63 billion yuan compared to 2013.

"This plummet strongly affected the oil industry all over the world, bringing with it a 'cold winter'," Wang said in the filing.

"The 'cold winter' struck a serious blow against the company's development (and) investment strategy, as well as its operational management."

CNOOC said it had achieved its annual production target with a net output of 432.5 million barrels of oil equivalent, up 5.1 percent from a year earlier.

The energy giant acquired Canada's Nexen energy company in 2013 for $15.1 billion. CNOOC said Nexen is the focus of its overseas development.

Energy firm PetroChina saw its 2014 net profit slump 17 percent while Sinopec said income dived 29.7 percent due to the drop in global crude oil prices.

The Chinese government cut its state-set prices for oil products 11 times in the second half of 2014 as international crude prices plummeted and prices are expected to remain weak this year.