Chinese energy firm PetroChina said Thursday its net profit slumped 17 percent in 2014 from a year earlier as international crude oil prices plunged in the second half.

Net profit was 107.17 billion yuan ($17.25 billion) last year, down from 129.60 billion yuan in 2013, it said in a statement to the Hong Kong stock exchange.

"In 2014, the demand in the oil and gas market grew slowly due to the slowdown in (the) global economic recovery and the intensified downward pressure on the domestic economy," PetroChina said.

China's gross domestic product grew 7.4 percent last year, the slowest pace in nearly a quarter of a century.

"International crude oil prices fluctuated and went up slightly in the first half of the year and plummeted in the second half," PetroChina said.

The Chinese government cut its state-set prices for oil products 11 times in the second half of 2014, in line with international levels.

The turnover of PetroChina, the listed arm of China National Petroleum Corp. (CNPC), rose 1.1 percent year-on-year to 2.28 trillion yuan in 2014, according to the statement.

"In 2015, the global economy is expected to continue to recover at a low speed, subject to some unstableness and uncertainties. The energy sector is currently under substantive adjustment," PetroChina said.

Its shares closed up 5.83 percent in Shanghai, before the results were released, and rose 0.85 percent in Hong Kong.

Authorities said this month that PetroChina vice chairman and non-executive director, Liao Yongyuan, was being investigated by the ruling party's Central Commission for Discipline Inspection for "severe violations of discipline and law".

In the annual report, PetroChina confirmed Liao was under investigation and said he had resigned.

Wang Yongchun, a former vice president of parent company CNPC, will be tried for corruption, state media reported this week.