Staff members unload parcels from a plane of China Southern Airlines at the Wuhan International Airport in Wuhan city, Central China's Hubei province, August 8, 2013. [Photo/IC]

BEIJING - China Southern Airlines, the country's largest carrier by fleet, said Thursday its net profits rose 117.2 percent to 3.85 billion yuan ($590 million) in 2015.

The company attributed the increase to dropping global fuel prices and rising numbers of tourists, according to an annual financial report filed to the Shanghai Stock Exchange.

The airline's fuel cost fell 30.4 percent and passenger trips increased 8.4 percent last year, according to the report.

However, foreign exchange losses rocketed from 276 million yuan in 2014 to 5.7 billion yuan in 2015 due to the US dollar's appreciation against the yuan, said the report.

"The company expects a rapid increase in passenger trips in 2016. But there are still uncertainties in global fuel prices and the yuan exchange rate," said the report.