SHANGHAI: Chinese oil giant PetroChina has posted its lowest profit since 1999 with the company citing a struggling global economy and slump in international oil prices last year.

PetroChina’s net profit tumbled 66.7 percent year-on-year to 35.65 billion yuan ($5.50 billion) in 2015, the company said in a statement filed to the Shanghai stock exchange. The profit figure was the weakest since 1999, according to Bloomberg News.

Annual revenue dropped 24.4 percent on the year to 1.73 trillion yuan, the statement said, as benchmark crude oil prices slumped by nearly half.

“In 2015, the global economic recovery slowed down, the downward pressure on China’s economy continuously intensified, the overall supply in the oil and gas market was sufficient and the international oil prices kept dropping,” the statement said.