Profits at Singapore Airlines in the three months to the end of December fell by 65 per cent to $50 million, compared with the same three months the year before that.
This was mainly due to non-operating expenses, for example fines paid by SIA Cargo to foreign authorities for its alleged involvement in global price-fixing.
During the quarter, SIA also increased its stake in budget airline Tigerair.
Overall, the group recorded an operating profit of $151 million, or $20 million more than a year ago.
SIA said on Thursday that the outlook for the air transportation industry continues to be challenging with airlines offering aggressive fares to fill up planes.