The profit warning issued on Monday has been attributed to weaker than anticipated development of unit revenue.
Unit revenue in airline business translates to the revenue accrued by a company from a passenger flown a kilometre.
Finnair’s previous estimates had projected that its turnover would remain close to last year’s level.
The airline is also expected this month to come up with details of the measures it is considering to cut costs. The company also has plans to partially outsource its cabin crew.
Finnair may give a new full year profit forecast after it completes the cost-saving negotiations.