Prospect union has served notice that air traffic controllers at Highlands and Islands Airports Ltd are set to strike again on 12 June.
This follows a day of strike action on 23 May which closed six airports across the Highlands and Islands.
Prospect negotiator David Avery said: “Since the initial strike action we have received no new offer from the employer, therefore our members have taken the decision to undertake a second day of strike action.
“The onus is now on HIAL and Scottish Government ministers to engage seriously with this dispute and come up with a proposal that will resolve this issue.
“We remain willing to negotiate in good faith and hope that an acceptable solution can be found.”