The Finnish Aviation Union (IAU) has issued a third work stoppage warning affecting airport ground staff on 7 July.
The National Conciliator's Office announced the development on Sunday in a post on social media site X. It said the work stoppage would affect several airport services companies.
Last week, the union announced two work stoppage warnings on 2 and 4 July.
The union has called a number of four-hour work stoppages for airport ground staff in recent times.
Finnair has cancelled hundreds of flights due to the situation, most recently last week when it called off 140 flights on Tuesday and 128 flights on Thursday.
The walkouts stem from a six month-long dispute between the IAU and the Service Sector Employers group Palta.
The central disagreement concerns salary increases that were not carried out during the years of the pandemic, for which the union has demanded compensation. Meanwhile, the employers' group contends that there was no such agreement.
According to the Conciliator's Office, negotiations are to resume on Monday morning and will continue throughout the week, if necessary.
IAU members work in baggage handling, technical services, catering, cargo as well as in air navigation jobs.
