Inflationary wage pressures and the recruitment of new drivers contributed to pre-tax profits at private coach operator Aircoach falling by 24% to €4.7m last year.
However, the bus company's revenues increased by 5.6% to €26.59m in the 12 months to the end of March last.
The company said an increase in route services drove increases in revenues and passenger numbers.
Aircoach's services include a number of routes to and from Dublin Airport to different parts of the capital, as well as routes between Dublin and Belfast and Cork.
The company said "driver costs rose significantly, partly due to inflationary wage pressure but principally due to the necessity to restore driver numbers to cover additional routes provided”.
The company paid a dividend of €3.8m to its UK parent, First Group last year.