Tenaris S.A.

Transaction in Own Shares • Jun 21, 2025

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

Weekly Report (June 16, 2025 – June 20, 2025) on the First Tranche of Tenaris Share Buyback Program.

Luxembourg, June 20, 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 16, 2025 to (and including) June 20, 2025:

Date	Trading Venue	Shares Purchased	Weighted Average Price (EUR)	Purchases in EUR	Reference FX	Purchases in USD
16-jun-25	MTAA	541,326	15.6368	8,464,606	1.1593	9,813,018
16-jun-25	CEUX	294,363	15.6367	4,602,866	1.1593	5,336,102
16-jun-25	TQEX	50,000	15.6552	782,760	1.1593	907,454
16-jun-25	AQEU	31,059	15.6419	485,822	1.1593	563,213
17-jun-25	MTAA	648,000	15.8811	10,290,953	1.1526	11,861,352
17-jun-25	CEUX	318,000	15.8795	5,049,681	1.1526	5,820,262
17-jun-25	TQEX	25,000	15.8692	396,730	1.1526	457,271
17-jun-25	AQEU	9,000	15.8739	142,865	1.1526	164,666
18-jun-25	MTAA	663,000	15.8893	10,534,606	1.1509	12,124,278
18-jun-25	CEUX	324,000	15.8900	5,148,360	1.1509	5,925,248
18-jun-25	TQEX	55,000	15.9000	874,500	1.1509	1,006,462
18-jun-25	AQEU	46,000	15.9034	731,556	1.1509	841,948
19-jun-25	MTAA	381,379	15.7834	6,019,457	1.1468	6,903,114
19-jun-25	CEUX	198,353	15.7807	3,130,149	1.1468	3,589,655
19-jun-25	TQEX	35,000	15.7928	552,748	1.1468	633,891
19-jun-25	AQEU	34,501	15.7911	544,809	1.1468	624,787
20-jun-25	MTAA	685,000	15.7958	10,820,123	1.1514	12,458,290
20-jun-25	CEUX	265,000	15.7946	4,185,569	1.1514	4,819,264
		4,603,981	15.8033	72,758,161		83,850,276

From June 16, 2025 to (and including) June 20, 2025, the Company has purchased a total of 4,603,981 ordinary shares for a total consideration of €72,758,161, equivalent to USD83,850,276.

As of June 20, 2025, the Company held in treasury 8,759,170 ordinary shares equal to 0.82% 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.