A China Eastern Airlines plane takes off at an airport in Taiyuan, Shanxi province, April 5, 2013.

Hong Kong - Two of China's major state-owned airlines have posted lower quarterly profits because of the weaker yuan.

Air China and China Eastern Airlines said late Tuesday that earnings were hit by the depreciating currency.

The yuan has weakened this year after a long period of gradually rising.

Profitability at Chinese airlines is highly vulnerable to exchange rate fluctuations.

While the airlines earn most of their revenue in yuan, major expenses such as fuel and new airplanes are priced in dollars.

Beijing-based Air China reported net profit in the January-March period of 92.7 million yuan, down 63 percent from the same period last year.

The net loss at China Eastern, based in Shanghai, widened to 205 million yuan. - Sapa-AP