Aer Lingus carried 958,000 passengers last month or 7.6 percent more than a year earlier thanks to a growing route network, but individual flights were not quite as full.
Ireland's former state airline said on Monday its load factor was 81.5 percent in June, down from 82.2 percent a year ago.
Passenger traffic, measured by revenue passenger kilometres (RPKs), rose 12.4 percent from the same period in 2007, Aer Lingus said in a statement.
On short-haul routes, the load factor dropped to 81.1 percent from 81.6 percent a year ago, while RPKs gained 13.1 percent.
On long-haul routes, the load factor slipped to 82.1 percent from 83.0 as RPKs rose 11.6 percent year-on-year.
