TENARIS SA

On May 27, 2025, the Company’s board of directors approved a third share buyback program of up to $1.2 billion (excluding incidental transaction fees), to be executed within a year, with the intention to cancel the ordinary shares acquired through the program. The third share buyback program is carried out under the authority granted by the annual general meeting of shareholders held on May 6, 2025, which renewed the authorization to purchase, acquire or receive, from time to time, Company shares, including shares represented by ADRs, on such terms and conditions as may be approved by the board of directors up to a maximum of 10% of the Company’s shares.

For purposes of carrying out each tranche of the third share buyback program, the Company entered into a nondiscretionary buyback agreement with a primary financial institution, which makes trading decisions concerning the timing of the purchases of the Company’s shares independently of and uninfluenced by Tenaris and acts in compliance with applicable rules and regulations, including the Market Abuse Regulation 596/2014 and the Commission Delegated Regulation (EU) 2016/1052.

The third share buyback program was divided into two tranches. The first tranche of the program, which covered up to $600 million (excluding incidental transaction fees), ran from June 9, 2025, to (and including) September 30, 2025. Under the first tranche of the program, the Company repurchased 33,059,955 ordinary shares, representing 3.08% of the Company’s issued shares as measured at the beginning of the first tranche of the program, for a total consideration of approximately $584 million (excluding incidental transaction fees).

The second tranche of the third share buyback program, which covered up to $600 million (excluding incidental transaction fees), ran from November 3, 2025, and was originally scheduled to end no later than April 30, 2026. Under the second tranche of the program, the Company repurchased 29,295,219 ordinary shares, representing 2.73% of the Company's issued shares as measured at the beginning of the second tranche of the program, for an aggregate consideration of approximately $583.6 million (excluding incidental transaction fees), thereby substantially completing its targeted repurchases.

On February 23, 2026, the Company announced its decision to terminate, effective March 3, 2026, the second tranche of the third share buyback program. In a context of high volatility in the market, allowing the second tranche of the program to continue as initially scheduled would, by application of the customary mechanics in the existing buyback agreement, have resulted in a significant incremental pay-out to its counterparty. Accordingly, following the expiration of the blackout period corresponding to the Company’s annual earnings release on February 20, 2026, the Company exercised its right to terminate its existing buyback agreement on the first date it was allowed to do so under the terms of the agreement, and in March 2026, paid the incidental transaction fees.

During the six-month period ended June 30, 2026, the Company purchased 2,184,202 shares, for approximately $89.6 million (including a negative performance amount of $47.1 million). During the six-month period ended June 30, 2025, the Company purchased 12,277,261 shares, for approximately $235 million (including a positive performance amount of $1.1 million) under the second share buyback program and purchased 13,094,268 shares, for approximately $237 million under the third share buyback program.

Consolidated Condensed Interim Financial StatementsFor the six-month period ended June 30, 2026 - all amounts in thousands of U.S. dollars, unless otherwise stated

On May 12, 2026, the extraordinary shareholders meeting approved the cancellation of 62,355,174 ordinary shares held in treasury by the Company, which had been acquired during the third share buyback program, and resolved to approve the corresponding reduction of the issued share capital of the Company and the amendment of the first paragraph of article 5 of the Company’s articles of association. As a result, effective May 12, 2026, the issued share capital of the Company was reduced from $1,071,994,930 (represented by 1,071,994,930 shares with a par value of $1 per share) to $1,009,639,756 (represented by 1,009,639,756 shares with a par value of $1 per share). There were no ordinary shares held in treasury by the Company as of June 30, 2026.

Further information on the share buyback programs and share repurchases thereunder is available on Tenaris’s corporate website under the "Share Buyback Program Section".