Xu's words were echoed by Liu Jieyin, president of Okay Airways Co, China's first private air carrier.

Okay, which launched its maiden flight in March, leases a Boeing 737 from Korean Airlines.

"Our company will save more than 100,000 yuan every month in leasing fees after the yuan move," Liu told China Daily.

Such benefits, Liu said, are bigger at China's leading airlines, given their larger fleets.

Meanwhile, maintenance and landing fees at foreign airports are also expected to see a "discount" of 2 per cent, said Liu Weimin, director and professor at the Aviation Laws Research Centre affiliated to the Civil Aviation Management Institute of China.

Investors' positive expectations pushed up the price of airline shares the day after China ended the yuan's decade-old peg to the US dollar, allowing the currency to strengthen 2 per cent from its previously fixed rate of about 8.28 yuan per one dollar.

"We have been anxiously waiting for the yuan appreciation," Zeng Zixiang, director of the policy research centre at China Southern airlines, was quoted as saying by China Business newspaper.

However, the small revaluation is not enough to pull some Chinese airlines back into the black, said analysts and air carriers. The key factor will be aviation oil prices in the second half of the year, they said.

Aviation oil accounts for more than 30 per cent of the total costs of Chinese airlines.