Monarch recorded 17% growth in scheduled service passenger numbers in May over the same month last year.
The proportion of online bookings dropped from 87% to 85%.
The rise is passenger numbers was helped by the start of flights to Ibiza from Birmingham, Gatwick, Luton and Manchester as well as services to Murcia from Gatwick and Almeria from Luton.
The airline carried 375,467 scheduled passengers last month, up from 320,748 the same month a year earlier.
by Phil Davies
