Icelandair Group carried 145,000 international passengers in March - an increase of 22% year-on-year.
Capacity on international routes rose by 31%, while load factor fell by 1.7 percentage points to 79.3%.
Passenger numbers on regional services and flights to Greenland - which are served by group subsidiary Air Iceland - fell 11% to 26,000 against a capacity decline of 10%.
Regional load factor grew by 0.5 percentage points to 74.3%.
In the cargo business, FTK throughput for the group decreased by 2% against a capacity increase of 14%.