Virgin Australia's (VAH) domestic capacity fell in April, although passenger numbers increased as Easter shifted from March in 2013 to April this year.
On domestic routes, available seat kilometres fell by 0.5% to 2.126 million in April, compared with 2.136 million in April 2013.
The airline's own measure of available seats fell by 1.5% to 1.81 million in the month, from 1.84 million a year earlier.
The decrease follows Qantas' announcement that it will add no new capacity in the first three months of fiscal 2015, with analysts predicting the end of the airline capacity war.
The number of passengers, using the revenue passenger kilometres measure, increased 7.6% to 1.64 million in the month, from 1.53 million.