Hainan Airlines' (SHA:600221, SHA:900945) available seat kilometers, which measures passenger capacity, slipped 1.2% year on year to 12.3 billion passengers in April, according to a Saturday filing on the Shanghai bourse.
The airline operator's B shares fell 2% during Monday's afternoon trade.
The revenue passenger kilometers slightly rose 0.1% from a year earlier to 10.4 billion yuan.
The company's cargo and mail volume jumped 6.5% year on year to 50,210 tons.