The Emanuele Grimaldi-led company claimed Finland's regulations are discriminatory under European Union law.
As a result, the company had been charged excessive dues between 2001 and 2004.
The Helsinki District Court has asked the state of Finland to pay Finnlines EUR 17m ($19.1m) as a refund.
The company said if the judgement becomes final, it will affect its financial statements for 2015 positively to the tune of EUR 16.5m.
