The company will be supplied with bunkers for two vessels operating the Naantali to Kapellskar route.
Neste Oil will produce the fuel at its refinery in Naantali.
It is the second such deal for the refiner in a week, having signed up Estonian ro-ro group Tallink previously.
"Neste Oil has been our marine fuel supplier for a long time and we are looking forward to continue our successful cooperation," said Susanne Buhmann, manager of Finnlines' chartering and bunker department.
The
