Tenaris S.A.

Transaction in Own Shares • Jun 28, 2025

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

Weekly Report (June 23, 2025 – June 27, 2025) on the First Tranche of Tenaris Share Buyback Program.

Luxembourg, June 27, 2025. - Tenaris S.A. (NYSE and Mexico: TS and EXM Italy: TEN) ("Tenaris") announced today that pursuant to its First Tranche of the USD1.2 billion Share Buyback Program announced on June 6, 2025, covering up to USD 600 million to be executed in the open market, it has repurchased the following ordinary shares from June 23, 2025 to (and including) June 27, 2025:

Date	Trading Venue	Shares Purchased	Weighted Average Price (EUR)	Purchases in EUR	Reference FX	Purchases in USD
23-jun-25	MTAA	644,504	15.8797	10,234,530	1.1534	11,804,507
23-jun-25	CEUX	250,000	15.8772	3,969,300	1.1534	4,578,191
24-jun-25	MTAA	741,831	15.4433	11,456,319	1.1615	13,306,514
24-jun-25	CEUX	349,000	15.4427	5,389,502	1.1615	6,259,907
24-jun-25	TQEX	61,000	15.4420	941,962	1.1615	1,094,089
24-jun-25	AQEU	58,000	15.4386	895,439	1.1615	1,040,052
25-jun-25	MTAA	736,763	15.4425	11,377,463	1.1621	13,221,180
25-jun-25	CEUX	370,000	15.4423	5,713,651	1.1621	6,639,548
25-jun-25	TQEX	64,000	15.4448	988,467	1.1621	1,148,648
25-jun-25	AQEU	60,000	15.4405	926,430	1.1621	1,076,558
26-jun-25	MTAA	730,000	15.4230	11,258,790	1.1708	13,181,791
26-jun-25	CEUX	200,000	15.4182	3,083,640	1.1708	3,610,326
26-jun-25	TQEX	35,000	15.4024	539,084	1.1708	631,160
26-jun-25	AQEU	35,000	15.4026	539,091	1.1708	631,168
27-jun-25	MTAA	400,000	15.7293	6,291,720	1.1717	7,371,694
27-jun-25	CEUX	200,000	15.7327	3,146,540	1.1717	3,686,644
		4,935,098	15.5523	76,751,928		89,281,976

From June 23, 2025 to (and including) June 27, 2025, the Company has purchased a total of 4,935,098 ordinary shares for a total consideration of €76,751,928, equivalent to USD89,281,976.

As of June 27, 2025, the Company held in treasury 13,694,268 ordinary shares equal to 1.28% 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.