Patria is a Finnish defense company, with more than 70 percent of its stock owned by the government.
The company said the four boats -- the Rauma, Raahe, Porvoo and Naantali received life-cycle modernization under a contract signed in 2010.
Patria was the upgrade project's main supplier, responsible for overall renovation planning, sub-contractor delivery coordination, and general integration. Patria's subcontractors included Saab AB, Western Shipyard Oy, Kongsberg Maritime AS, Furuno Finland Oy, Ab Marinel Oy and Valmarine Oy.
The value of the upgrade project was about $97.4 million.
"The Rauma Class Fast Attack Craft life-cycle upgrade project succeeded according to plan," said Pasi Niinikoski, president of Patria's Systems Business Unit. "Special thanks are due to the project team, partners and the customer for their smooth and flexible cooperation.
"The project was challenging because it involved many different system upgrades. Its successful completion is excellent proof of Patria's ability to manage and implement large-scale system integration projects."
Finland obtained the vessels from Patria in from 1990 to 1992. The new upgrading, which included combat systems, will keep them in operation into the 2020s, Patria said.