Brussels Airlines carried a total of 561,00 passengers in September.
Passenger traffic as measured in revenue seat kilometres increased 9.9% year-on-year, says the carrier.
ASK capacity grew by 9.7%, while passenger load factor was broadly flat at 72.9%.
The Belgian carrier's new route to New York posted an above-average passenger load factor of 88.8%.
On the cargo front, Brussels Airlines' freight tonne kilometres rose by 49.2%.
Overall load factor combining passenger and cargo levels rose to 66.4%.