Virgin Australia will cut its flights to Albany and Esperance because numbers do not support the services.
The airline applied to the Transport Department yesterday to amend its flight schedule on the regulated Perth to Albany and Perth to Esperance routes to "safeguard the long-term viability of these services".
It wants to reduce its scheduled flights on the routes from three to two flights a day on weekdays.
The proposed changes would also affect some services to Busselton and Ravensthorpe, though it will continue to fly to both areas.
Merren McArthur, Virgin Australia's group executive of regional airlines, said that "despite our best efforts to stimulate the market through airfare pricing and promotional activity, the Albany and Esperance routes continue to sustain unacceptable losses".
She said that in the past four years the company had reduced average fares on the routes about 20 per cent but passenger numbers had risen only 1.1 per cent.