STOCK

6 Months Ended

Jun. 30, 2012

STOCK

STOCK

16.STOCK

Changes in common shares and treasury stock were as follows:

(In millions)	Common Shares Issued	Treasury Stock	Cost of Treasury Stock
Balance as of January 1, 2012	205.1	1.4	$	89.7
Stock-based compensation	0.8	0.2	14.8
Treasury stock purchases	—	0.5	44.0
Balance as of June 30, 2012	205.9	2.1	$	148.5
Balance as of January 1, 2011	204.8	0.1	$	3.2
Stock-based compensation	0.1	—	0.1
Treasury stock purchases	—	0.8	54.1
Balance as of June 30, 2011	204.9	0.9	$	57.4

The Company may use either authorized and unissued shares or treasury shares to meet share requirements resulting from the exercise of stock options and vesting of performance share awards and restricted stock units. Treasury stock is recognized at the cost to reacquire the shares. Shares issued from treasury are recognized using the first-in first-out method.

The Company corrected the number of authorized shares of common stock as of December 31, 2011 to properly reflect shares authorized in its second amendment and restated certificate of incorporation.

On March 16, 2010, MJN’s board of directors authorized the repurchase of up to $300 million of the Company’s stock. From the date of such authorization through June 30, 2012, 1.8 million shares were repurchased at an average cost per share of $69.33. As of June 30, 2012, we have $174.4 million available under the authorization.