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Note 33 - Principal subsidiaries | 12 Months Ended
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Dec. 31, 2025
Note 33 - Principal subsidiaries |
Note 33 - Principal subsidiaries | 33 Principal subsidiaries The following is a list of Tenaris’s principal subsidiaries and its direct and indirect percentage of ownership of each controlled company at December 31, 202 5, 202 4 and 202 3.
Company | Country of Incorporation | Main activity | Percentage of ownership at December 31, (*)
2025 | 2024 | 2023
ALGOMA TUBES INC. | Canada | Manufacturing of welded and seamless steel pipes | 100% | 100% | 100%
CONFAB INDUSTRIAL S.A. and subsidiaries | Brazil | Manufacturing of welded steel pipes | 100% | 100% | 100%
DALMINE S.p.A. and subsidiaries (a) | Italy | Manufacturing of seamless steel pipes | 100% | 100% | 100%
EXIROS B.V. and subsidiaries (b) | Netherlands | Procurement and trading services | 50% | 50% | 50%
HYDRIL COMPANY | USA | Manufacturing and marketing of premium connections | 100% | 100% | 100%
MAVERICK TUBE CORPORATION and subsidiaries | USA | Manufacturing of welded and seamless steel pipes | 100% | 100% | 100%
OILFIELD SERVICES SOCIEDAD ANONIMA | Argentina | Hydraulic fracturing and coiled tubing services | 100% | 100% | 100%
P.T. SEAMLESS PIPE INDONESIA JAYA | Indonesia | Manufacturing of seamless steel products | 89% | 89% | 89%
SILCOTUB S.A. | Romania | Manufacturing of seamless steel pipes | 100% | 100% | 100%
SAUDI STEEL PIPE CO. and subsidiaries (c) | Saudi Arabia | Manufacturing of welded steel pipes | 48% | 48% | 48%
SIAT SOCIEDAD ANONIMA | Argentina | Manufacturing of welded steel pipes | 100% | 100% | 100%
SIDERCA SOCIEDAD ANONIMA INDUSTRIAL Y COMERCIAL and subsidiaries (d) | 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 welded and seamless steel pipes | 100% | 100% | 100%
TENARIS CONNECTIONS BV | Netherlands | Development, management and licensing of intellectual property | 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 | Uruguay | Marketing, distribution of steel products and holding company | 100% | 100% | 100%
TENARIS INVESTMENTS (NL) B.V. and subsidiaries | Netherlands | Holding company | 100% | 100% | 100%
TENARIS GLOBAL SERVICES and INVESTMENTS S.àr.l. and subsidiaries | Luxembourg | Marketing and distribution of steel products, financial operations and holding company | 100% | 100% | 100%
TENARIS QINGDAO STEEL PIPES LTD. | China | Processing of premium joints, couplings and automotive components | 100% | 100% | 100%
TENARIS TUBOCARIBE LTDA. | Colombia | Manufacturing of welded and seamless steel pipes | 100% | 100% | 100%
TUBOS DE ACERO DE MEXICO, S.A. and subsidiaries | Mexico | Manufacturing of seamless steel pipes | 100% | 100% | 100%
(*) | All percentages rounded.
Tenaris holds 40% of Tubular Technical Services Ltd. and Pipe Coaters Nigeria Ltd., 49% of Tubulars Finishing Nigeria Limited and 60% of Tenaris Baogang Baotou Steel Pipes Ltd. Until its deconsolidation in June 2025, Tenaris held 49% of Amaja Tubular Services Limited.
(a) | Dalmine S.p.A holds 57% of Immobiliare Cultura Industriale S.R.L.
(b) | Tenaris holds 50% of the voting rights and Ternium owns the remaining 50%. Exiros provides purchase agency services and raw materials and other products to various companies controlled by or under the significant influence of San Faustin. Pursuant to the Exiros shareholders’ agreement, Tenaris recognizes Exiros’ assets, liabilities, revenue and expenses in relation to its interest in the joint operation.
(c) | Saudi Steel Pipe Company is a public company listed in the Saudi Arabian Stock Exchange (Tad ā wul), Tenaris holds 47.79% and has the right to nominate the majority of the members of the board of directors, therefore Tenaris has control over SSPC. Since May 2023, Saudi Steel Pipe Co. holds 57.3% of Global Pipe Company, therefore Tenaris has control over GPC.
(d) | Until its liquidation in April 2023 Siderca held 51% of NKKTubes.

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