Related party transactions

As of

December 31, 2017:

San Faustin S.A., a Luxembourg société anonyme (“San Faustin”), owned

713,605,187

shares in the Company, representing

60.45%

of the Company’s capital and voting rights.

San Faustin owned all of its shares in the Company through its wholly-owned subsidiary Techint Holdings S.à r.l., a Luxembourg société à responsabilité limitée (“Techint”), who is the holder of record of the above-mentioned Tenaris shares.

Rocca & Partners Stichting Administratiekantoor Aandelen San Faustin, a Dutch private foundation (Stichting) (“RP STAK”) held voting shares in San Faustin sufficient in number to control San Faustin.

person or group of persons controls RP STAK.

Based on the information most recently available to the Company, Tenaris’s directors and senior management as a group owned

0.08%

of the Company’s outstanding shares.

Transactions and balances disclosed as with “non-consolidated parties” are those with companies over which Tenaris exerts significant influence or joint control in accordance with IFRS, but does

not

have control. All other transactions and balances with related parties which are

not

non-consolidated parties and which are

not

consolidated are disclosed as “Other”. The following transactions were carried out with related parties:

(all amounts in thousands of U.S. dollars)	Year ended December 31,
	2017		2016		2015
(i) Transactions
(a) Sales of goods and services
Sales of goods to non-consolidated parties		32,362		21,174		24,019
Sales of goods to other related parties		94,624		32,613		87,663
Sales of services to non-consolidated parties		11,637		9,542		10,154
Sales of services to other related parties		3,751		2,948		4,010
		142,374		66,277		125,846
(b) Purchases of goods and services
Purchases of goods to non-consolidated parties		234,361		67,048		260,280
Purchases of goods to other related parties		17,711		20,150		35,153
Purchases of services to non-consolidated parties		12,077		11,528		16,153
Purchases of services to other related parties		50,794		53,530		78,805
		314,943		152,256		390,391

(all amounts in thousands of U.S. dollars)	At December 31,
	2017			2016
(ii) Period-end balances
(a) Arising from sales / purchases of goods / services
Receivables from non-consolidated parties		117,853			117,187
Receivables from other related parties		50,815			13,357
Payables to non-consolidated parties		(49,354	)		(21,314	)
Payables to other related parties		(14,475	)		(12,708	)
		104,839			96,522

Directors’ and senior management compensation

During the years ended

December 31, 2017,

2016

and

2015,

the cash compensation of Directors and Senior managers amounted to

$45.8

million,

$38.6

million and

$28.8

million respectively. These amounts include cash benefits paid to certain senior managers in connection with the vesting of pre-existing retirement plans. In addition, Directors and Senior managers received

484,

500

and

540

thousand units for a total amount of

$4.7

million,

$4.8

million and

$5.4

million respectively in connection with the Employee retention and long term incentive program mentioned in Note O

Employee benefits –Other long term benefits