Air China's (SHA:601111, HKG:0753) combined passenger traffic, which is measured by revenue passenger kilometers or RPK, rose 8.4% year on year to 24.7 billion in May, according to a June 13 filing with the Hong Kong Stock Exchange.

The Chinese airline's passenger capacity climbed 4.5% to 30.4 billion available seat kilometers or ASK from the prior year.

The company's cargo capacity during the same month rose 2.2% to 1.1 billion available freight tonne kilometers, while cargo and mail traffic increased 6.2% to 436.3 million revenue freight tonne kilometers.

Air China's Hong Kong shares were down about 4% in recent trade.