Already during the Nordek negotiations, Horn was recruited to a leading position in the multi industrial company
Oy Wärtsilä Ab. At first he worked as deputy director in 1969–1970, and moving of operations was on-going when Horn started his directorship. When Horn started as manager, a previously prepared plan of building a new shipyard in Turku was launched as a project. Construction of
Perno shipyard was started on 16 May 1974. The first stage of construction comprised
dry dock, 600-tonne
bridge crane,
workshops and other buildings. Operation were gradually moved from the
old Turku yard to the new facility and the yard reached full production ability in 1979. During Horn's era Wärtsilä started to internationalise increasingly. Wärtsilä-owned porcelain producer
Arabia merged with the
Swedish Rörstrand, after which Wärtsilä took control of the entire share capital. Wärtsilä also acquired the Swedish sanitary porcelain producer IDO and
diesel engine business from
NOHAB. The company built a diesel engine factory in Singapore and opened many branches in a number of countries. By gaining ownership of Appleton works in the United States in 1983, Wärtsilä got a foothold in the North American paper machine business. Wärtsilä became enlisted on
Stockholm and
London stock exchange markets. The company structure was changed in small steps during Horn's leadership. His previous experience in foreign affairs proved useful when Wärtsilä negotiated about
icebreaker deliveries to Soviet Union. In 1978 Wärtsilä changed to system of two managers; Horn focused high-level management and public relations, and the operative management was given to
Tor Stolpe. The arrangement worked well in Wärtsilä and was kept until Horn's retirement in 1987. Shortly before leaving his post, Horn participated in a large-scale ownership arrangement between Wärtsilä and
Valmet. Wärtsilä sold its paper machine production to Valmet, and shipyards of both companies were put under one company,
Wärtsilä Marine, from which Wärtsilä's share was 70%. Wärtsilä Marine fell in a scandalous bankruptcy in 1989. Horn was chairman of board in Wärtsilä until it merged with
Oy Lohja Ab. He continued still for a few years as board member of the succeeding
Metra company. During his Wärtsilä leadership Horn held positions of trust in employers' associations. His strength was a good relationship with president Urho Kekkonen, whom he consulted in trade political questions. Due to his statements regarding oil crisis, he went to disputes with the
Neste manager
Uolevi Raade. Horn took part in forming Finnish Business and Policy Forum EVA and in the 1980s he was member of board also in other Finnish industrial companies. == References ==