Company | Country of Incorporation | Main activity | Percentage of ownership at December 31, (*) | ||
2017 | 2016 | 2015 | |||
ALGOMA TUBES INC. | Canada | Manufacturing of seamless steel pipes | 100% | 100% | 100% |
CONFAB INDUSTRIAL S.A. and subsidiaries | Brazil | Manufacturing of welded steel pipes and capital goods | 100% | 100% | 100% |
DALMINE S.p.A. | Italy | Manufacturing of seamless steel pipes | 100% | 100% | 99% |
HYDRIL COMPANY and subsidiaries (except detailed) (a) | USA | Manufacture and marketing of premium connections | 100% | 100% | 100% |
MAVERICK TUBE CORPORATION and subsidiaries | USA | Manufacturing of welded steel pipes | 100% | 100% | 100% |
NKKTUBES | Japan | Manufacturing of seamless steel pipes | 51% | 51% | 51% |
P.T. SEAMLESS PIPE INDONESIA JAYA | Indonesia | Manufacturing of seamless steel products | 89% | 77% | 77% |
PRUDENTIAL STEEL LTD. | Canada | Manufacturing of welded steel pipes | 100% | 100% | 100% |
S.C. SILCOTUB S.A. | Romania | Manufacturing of seamless steel pipes | 100% | 100% | 100% |
SIAT SOCIEDAD ANONIMA | Argentina | Manufacturing of welded and seamless steel pipes | 100% | 100% | 100% |
SIDERCA SOCIEDAD ANONIMA INDUSTRIAL Y COMERCIAL and subsidiaries | Argentina | Manufacturing of seamless steel pipes | 100% | 100% | 100% |
TALTA - TRADING E MARKETING SOCIEDADE UNIPESSOAL LDA. | Portugal | Holding Company | 100% | 100% | 100% |
TENARIS BAY CITY, INC. | USA | Manufacturing of seamless steel pipes | 100% | 100% | 100% |
TENARIS FINANCIAL SERVICES S.A. | Uruguay | Financial company | 100% | 100% | 100% |
TENARIS GLOBAL SERVICES (CANADA) INC. | Canada | Marketing of steel products | 100% | 100% | 100% |
TENARIS GLOBAL SERVICES (U.S.A.) CORPORATION | USA | Marketing of steel products | 100% | 100% | 100% |
TENARIS GLOBAL SERVICES (UK) LTD | United Kingdom | Holding company and marketing of steel products | 100% | 100% | 100% |
TENARIS GLOBAL SERVICES S.A. and subsidiaries (except detailed) (b) | Uruguay | Holding company and marketing of steel products | 100% | 100% | 100% |
TENARIS INVESTMENTS S.àr.l. | Luxembourg | Holding company | 100% | 100% | 100% |
TENARIS INVESTMENTS SWITZERLAND AG and subsidiaries | Switzerland | Holding company | 100% | 100% | 100% |
TENARIS CONNECTIONS BV | Netherlands | Development, management and licensing of intellectual property | 100% | 100% | 100% |
TENARIS TUBOCARIBE LTDA. | Colombia | Manufacturing of welded and seamless steel pipes | 100% | 100% | 100% |
TUBOS DE ACERO DE MEXICO, S.A. | Mexico | Manufacturing of seamless steel pipes | 100% | 100% | 100% |