Yard founded in 1865 and acquired by Wärtsilä in 1935. In 1984 the yards of Valmet Oy Helsingin Telakka, Valmet Oy Pansion Telakka and Valmetin Laivateollisuus were acquired and combined with the existing yards to form Wärtsilä Marine Industries which went bankrupt in 1989. Masa-Yards was formed to continue the work in progress, later acquired by Kværner to form Kværner Masa-Yards. Acquired by Aker Finnyards in 2005 (itself a merger of Rauma-Repola and Hollming Oy) the group was renamed Aker Yards in 2006 and became part of STX Europe in 2008. The Helsinki yard was sold to United Shipbuilding Corporation in 2014 as Arctech Helsinki Shipyard.