Tenaris S.A.

Transaction in Own Shares • Jun 29, 2024

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

Weekly Report (June 24, 2024 – June 28, 2024) on the Fourth Tranche of Tenaris Share Buyback Program

Luxembourg, June 28, 2024. - Tenaris S.A. (NYSE and Mexico: TS and EXM Italy: TEN) ("Tenaris") announced today that pursuant to its Fourth Tranche of the Share Buyback Program announced on June 14, 2024, covering up to \$300 million to be executed in the open market, it has repurchased the following ordinary shares from June 24 to (and including) June 28, 2024:

Date	Trading Venue	Shares Purchased	Weighted Average Price (EUR)	Purchases in EUR	Reference FX	Purchases in USD
24-Jun-2024	CEUX	246,000	14.4769	3,561,317	1.0700	3,821,640
24-Jun-2024	MTAA	700,000	14.4778	10,134,460	1.0700	10,875,323
25-Jun-2024	CEUX	200,000	14.4624	2,892,480	1.0700	3,094,956
25-Jun-2024	MTAA	700,000	14.4694	10,128,580	1.0700	10,837,554
26-Jun-2024	CEUX	270,000	14.2164	3,838,428	1.0700	4,100,964
26-Jun-2024	MTAA	700,000	14.2521	9,976,470	1.0700	10,658,888
27-Jun-2024	CEUX	270,000	14.1241	3,813,507	1.0700	4,084,652
27-Jun-2024	MTAA	700,000	14.1239	9,886,730	1.0700	10,589,669
28-Jun-2024	CEUX	130,000	14.3152	1,860,976	1.0700	1,994,598
28-Jun-2024	MTAA	700,000	14.3218	10,025,260	1.0700	10,745,064
		4,616,000	14.3237	66,118,208		70,803,307

From June 24, 2024 to (and including) June 28, 2024, the Company has purchased a total of 4,616,000 ordinary shares for a total consideration of €66,118,208, equivalent to USD70,803,307.

As of June 28, 2024, the Company held in treasury 43,742,579 ordinary shares (including 16,367,003 ordinary shares bought in the second tranche and 18,080,524 ordinary shares bought in the third tranche), equal to 3.76% of the total issued share capital.

Tenaris intends to cancel all shares purchased under the Program 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.