Tenaris S.A.

Transaction in Own Shares • Dec 8, 2023

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

Weekly Report (December 4, 2023 – December 8, 2023) on the First Tranche of Tenaris Share Buyback Program

Luxembourg, December 8, 2023. - Tenaris S.A. (NYSE and Mexico: TS and EXM Italy: TEN) ("Tenaris") announced today that pursuant to its First Tranche of the Share Buyback Program announced on November 5, 2023, covering up to US\$300 million to be executed in the open market, it has repurchased the following ordinary shares from December 4 to (and including) December 8, 2023:

Date	Trading Venue	Shares Purchased	Weighted Average Price (EUR)	Purchases in EUR	Reference FX	Purchases in USD
07-dic-23	MTA	603,728	15.6413	9,443,091	1.0791	10,190,039
07-dic-23	CEUX	284,189	15.6423	4,445,370	1.0791	4,796,998
07-dic-23	TQEX	29,049	15.6440	454,443	1.0791	490,389
07-dic-23	AQXE	28,377	15.6448	443,952	1.0791	479,069
		945,343	15.6418	14,786,855		15,956,496

From November 6, 2023 to (and including) December 8, 2023, the Company has purchased a total of 9,886,198 ordinary shares for a total consideration of €155,520,225, equivalent to US\$168,648,459.

As of December 8, 2023, the Company held in treasury 9,886,198 ordinary shares equal to 0.84% 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.