STOCKHOLDERS' EQUITY: (Tables)

6 Months Ended

Jun. 30, 2019

STOCKHOLDERS' EQUITY:

Schedule of activity in treasury stock

Activity in treasury stock in the six-month period ended June 30, 2019 and 2018 is as follows (in millions):

	2019		2018
Southern Copper common shares
Balance as of January 1,	$	2,768.3	$	2,768.7
Purchase of shares		—		—
Used for corporate purposes		(0.4)		(0.4)
Balance as of June 30,		2,767.9		2,768.3
Parent Company (Grupo Mexico) common shares
Balance as of January 1,		251.3		232.4
Other activity, including dividend, interest and foreign currency transaction effect		13.2		8.4
Balance as of June 30,		264.5		240.8
Treasury stock balance as of June 30,	$	3,032.4	$	3,009.1

Schedule of common shares

	2019	2018
Southern Copper common shares
Directors’ Stock Award Plan	14,400	16,000
Parent Company (Grupo Mexico) common shares
Employee stock purchase plan (shares in millions)	0.4	1.3

Summary of non-controlling interest activity

The following table presents the non-controlling interest activity for the six months ended June 30, 2019 and 2018:

	2019		2018
Balance as of January 1,	$	45.4	$	41.7
Net earnings		3.0		2.6
Dividend paid		(0.1)		(0.9)
Balance as of June 30,	$	48.3	$	43.4

Employee Stock Purchase 2015 Plan

STOCKHOLDERS' EQUITY:

Schedule of stock based compensation expense and unrecognized compensation expense

The stock based compensation expense for the first six months 2019 and 2018 and the unrecognized compensation expense under this plan were as follows (in millions):

	2019		2018
Stock based compensation expense	$	0.3	$	0.3
Unrecognized compensation expense	$	2.3	$	2.9

Schedule of stock award activity

		Unit Weighted Average
	Shares	Grant Date Fair Value
Outstanding shares at January 1, 2019	1,840,336	$	2.63
Granted	—		—
Exercised	(425,076)	$	2.63
Forfeited	—		—
Outstanding shares at June 30, 2019	1,415,260	$	2.63
Outstanding shares at January 1, 2018	2,293,120	$	2.63
Granted	—		—
Exercised	(49,320)	$	2.63
Forfeited	—		—
Outstanding shares at June 30, 2018	2,243,800	$	2.63

Employee Stock Purchase 2018 Plan

STOCKHOLDERS' EQUITY:

Schedule of stock based compensation expense and unrecognized compensation expense

The stock based compensation expense for the first six months ended June 30, 2019 and the unrecognized compensation expense under this plan were as follows (in millions):

	2019
Stock based compensation expense	$	0.2
Unrecognized compensation expense	$	3.4

Schedule of stock award activity

The following table presents the stock award activity of this plan for the six months ended June 30, 2019:

		Unit Weighted Average
	Shares	Grant Date Fair Value
Outstanding shares at January 1, 2019	2,782,424	1.86
Granted	—	—
Exercised	—	1.86
Forfeited	—	—
Outstanding shares at June 30, 2019	2,782,424	1.86