Tenaris S.A.

Transaction in Own Shares • Nov 29, 2025

Giovanni Sardagna Tenaris 1-888-300-5432 www.tenaris.com

Weekly Report (November 24, 2025 – November 28, 2025) on the Second Tranche of Tenaris Share Buyback Program.

Luxembourg, November 28, 2025. - Tenaris S.A. (NYSE and Mexico: TS and EXM Italy: TEN) ("Tenaris") announced today that pursuant to its Second Tranche of the USD1.2 billion Share Buyback Program announced on November 2, 2025, covering up to USD600 million to be executed in the open market, it has repurchased the following ordinary shares from November 24, 2025 to (and including) November 28, 2025:

Date	Trading Venue	Shares Purchased	Weighted Average Price (EUR)	Purchases in EUR	Reference FX	Purchases in USD
24-nov-25	MTA	476,077	16.9520	8,070,457	1.1502	9,282,236
24-nov-25	CEUX	301,295	16.9527	5,107,764	1.1502	5,874,694
24-nov-25	TQEX	49,495	16.9515	839,014	1.1502	964,993
24-nov-25	AQXE	41,682	16.9528	706,627	1.1502	812,727
25-nov-25	MTA	519,225	16.9665	8,809,431	1.1530	10,156,833
25-nov-25	CEUX	318,499	16.9663	5,403,750	1.1530	6,230,253
25-nov-25	TQEX	50,305	16.9660	853,475	1.1530	984,014
25-nov-25	AQXE	42,084	16.9667	714,027	1.1530	823,237
26-nov-25	MTA	519,626	17.1688	8,921,355	1.1563	10,315,317
26-nov-25	CEUX	348,801	17.1688	5,988,495	1.1563	6,924,197
26-nov-25	TQEX	50,021	17.1695	858,836	1.1563	993,029
26-nov-25	AQXE	41,955	17.1706	720,393	1.1563	832,954
27-nov-25	MTA	516,354	17.2359	8,899,826	1.1590	10,314,898
27-nov-25	CEUX	348,225	17.2356	6,001,867	1.1590	6,956,164
27-nov-25	TQEX	51,750	17.2351	891,916	1.1590	1,033,731
27-nov-25	AQXE	40,717	17.2377	701,867	1.1590	813,464
28-nov-25	MTA	458,629	17.3069	7,937,446	1.1595	9,203,072
28-nov-25	CEUX	331,885	17.3076	5,744,133	1.1595	6,660,035
28-nov-25	TQEX	46,704	17.3052	808,222	1.1595	937,093
28-nov-25	AQXE	36,896	17.3072	638,566	1.1595	740,386
		4,590,225	17.1271	78,617,466		90,853,326

From November 24, 2025 to (and including) November 28, 2025, the Company has purchased a total of 4,590,225 ordinary shares for a total consideration of €78,617,466, equivalent to USD90,853,326.

As of November 28, 2025, the Company held in treasury 41,950,073 ordinary shares equal to 3.91% of the total issued share capital.

Tenaris intends to cancel treasury shares purchased under the Programs in due course.

Details of the above transactions, are available on Tenaris's corporate website under the Share Buyback Program Section https://ir.tenaris.com/share-buyback-program.

Some of the statements contained in this press release are "forward-looking statements". Forward-looking statements are based on management's current views and assumptions and involve known and unknown risks that could cause actual results, performance or events to differ materially from those expressed or implied by those statements. These risks include but are not limited to risks arising from uncertainties as to future oil and gas prices and their impact on investment programs by oil and gas companies.

Tenaris is a leading global supplier of steel tubes and related services for the world's energy industry and certain other industrial applications.