Cathay Pacific Airways on Wednesday warned of declining airfares, challenges at its budget carrier and uncertain cargo market conditions, sending its shares down more than 10% after it posted a slight rise in first-half profit.

Cathay Pacific Airways announced a US$8.1 billion order for 14 Boeing 777-9 jets, marking its first transaction with the U.S. manufacturer in 12 years.

Cathay Pacific Airways warned on Wednesday of declining airfares, challenges at its budget carrier and uncertain cargo market conditions, sending its shares down almost 10% to a one-month low. Hong Kong's flagship airline also said it had ordered 14 more Boeing 777-9 wide-body jets as it expands long-haul routes,