Hawaiian Airlines pilots have sought federal mediation after 18 months of bargaining with management failed to produce a new contract.

Hawaiian's chapter of the Air Line Pilots Association filed the request Tuesday with the National Mediation Board. Hawaiian is a unit of Hawaiian Holdings Inc.

A contract agreement was "very close" during private mediation in June, but discussions have since "reached a standstill," the union said.

Sending an airline labor dispute to the mediation board is one requirement for unions before their members can walk off the job. Hawaiian's union chapter said it will seek support from ALPA's National Strategic Preparedness and Strike Committee.

Hawaiian Airlines disputed the union's claim that the company earned "significant profits."

"Excluding a one-time litigation settlement, Hawaiian has generated operating losses through the first six months of 2008 and will pay well over $100 million more for fuel this year compared to 2007," the company said in a statement.

Pilots said they're seeking "modest" pay increases. The carrier also should consider their willingness to fly new, longer-range jets at current rates and work extra hours to help passengers stranded when competitors Aloha Airgroup Inc. and ATA Airlines Inc. abruptly shut down earlier this year, the union said.

The airline said it "remains committed to negotiating in good faith with our pilots' union to reach a new contract."

"We would like to increase the pay of our employees to the extent that the company is able to and to the extent that it will not deepen our competitive disadvantage," the statement continued.

"We believe pay increases are possible provided that contract provisions limiting efficiency are fixed, but it will take a more constructive negotiating approach by the union for this to happen. Our objective is to secure an agreement recognizing the uncertainties of our business and moving Hawaiian forward to the benefit of all of our stakeholders, pilots included.

Hawaiian Holdings' shares fell 93 cents, or 8.6 percent, to $9.86 yesterday in Nasdaq trading. The shares have more than doubled this year to lead the 14 carriers in the Bloomberg U.S. Airlines Index.