Island Air is once again selling return flights for $12 to customers who buy roundtrip interisland tickets.

The state's third-largest airline said customers can purchase $12 return tickets until tomorrow for travel through March 15.

Hawaiian Airlines said yesterday it will not match the fare, and Aloha Airlines and go! declined to match when Island Air first offered the $12 return fares earlier this month.

Island Air chief executive officer Rob Mauracher said the response to the first $12 sale was "overwhelming."

Founded in 1980 as Princeville Airways, Island Air is a niche-player in the interisland market. The company, owned by San Francisco-based Gavarnie Holdings LLC, operates 75 daily interisland flights.

On Dec. 1, Island Air announced it was laying off 65 of its 415 employees as a result of the new low-fare environment. The company also eliminated five of its 17 interisland routes and said it will take two of its 37-seat De Havilland Dash-8 aircraft out of service.

At the time of the layoffs, Mauracher said go!'s launch this year destabilized the interisland fare structure, forcing Island Air to reduce its expenses. The new airline go!, a unit of Phoenix-based Mesa Air Group, triggered a fare war when it opened for business on June 9 with an introductory $39 one-way fare.

Reach Rick Daysog at rdaysog@honoluluadvertiser.com.