The threat of a potentially lengthy strike hung over Iceland’s national airline, Icelandair, on Friday after the company’s mechanics announced plans for industrial action.

The Icelandic Aircraft Mechanics Association (FVFI) said it would strike for 24 hours June 16, followed by an indefinite strike June 19. The mechanics are seeking higher salaries.

Icelandair has been seeking to settle a series of negotiations with various sectors of its workforce and has recently negotiated a short-term deal with the pilots’ union that runs until the end of September. It also received an agreement with cabin crew, which will be sustained until Aug. 30, 2015.

The FVFI is the last union with which the national carrier has to reach a settlement, CFO Bogi Nils Bogason said Friday.

If the strike goes ahead, “it will affect the schedule a lot,” but not necessarily lead to a complete shutdown of the airline’s operations, Bogason said.

Icelandair would not lease in aircraft to deal with the initial 24-hour strike, he added. However, he declined to comment on whether that course of action is a possibility if the longer strike goes ahead.

Discussions with the mechanics are still ongoing, he said, and the company hopes to be able to resolve the dispute.

Icelandair said it is unable to calculate the potential financial effects of the strike. However, the threat of industrial action at an airline tends to lead to a sharp drop in advance bookings as passengers seek certainty of their travel arrangements with other carriers.