The airline said it expects around 14,000 customers to be impacted by the upcoming flight cancellations, News.Az reports, citing public broadcaster YLE.
It added that efforts are underway to rebook affected passengers on alternative flights.
Finnair's announcement follows the Finnish Aviation Union's (IAU) notice of a strike scheduled for Monday, 19 May. According to the airline, the strike will impact ground operations and catering services at Helsinki Airport, where baggage handling may also face disruptions on Monday.
The IAU, representing employees, has been engaged in collective bargaining negotiations with the employers' association, Palta, since late January. The talks have reached a deadlock.
In addition to Monday's strike action, the IAU said more walkouts could still be in store. If no deal is reached in their talks with Palta, additional strikes are planned for Friday, 30 May and Monday, 2 June.
Finnair has repeatedly had tocancel flights due to industrial action by the aviation union, with the most recent cancellations taking place on Friday.
