(18) Common stock

Changes in Berkshire’s issued and outstanding common stock during the three years ending December 31, 2012 are shown in the table below.


	Class A, $5 Par Value (1,650,000 shares authorized)									Class B, $0.0033 Par Value (3,225,000,000 shares authorized)
	Issued			Treasury			Outstanding			Issued		Treasury			Outstanding
Balance at December 31, 2009		1,055,281			—			1,055,281			744,701,300		—			744,701,300
Shares issued in the acquisition of BNSF		80,931			—			80,931			20,976,621		—			20,976,621
Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition		(188,752	)		—			(188,752	)		285,312,547		—			285,312,547

Balance at December 31, 2010		947,460			—			947,460			1,050,990,468		—			1,050,990,468
Shares issued to acquire noncontrolling interests of Wesco Financial Corporation		—			—			—			3,253,472		—			3,253,472
Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition		(9,118	)		—			(9,118	)		15,401,421		—			15,401,421
Treasury shares acquired		—			(98	)		(98	)		—		(801,985	)		(801,985	)

Balance at December 31, 2011		938,342			(98	)		938,244			1,069,645,361		(801,985	)		1,068,843,376
Conversions of Class A common stock to Class B common stock and exercises of replacement stock options issued in a business acquisition		(33,814	)		—			(33,814	)		53,748,595		—			53,748,595
Treasury shares acquired		—			(9,475	)		(9,475	)		—		(606,499	)		(606,499	)

Balance at December 31, 2012		904,528			(9,573	)		894,955			1,123,393,956		(1,408,484	)		1,121,985,472

Each Class A common share is entitled to one vote per share. Class B common stock possesses dividend and distribution rights equal to one-fifteen-hundredth (1/1,500) of such rights of Class A common stock. Each Class B common share possesses voting rights equivalent to one-ten-thousandth (1/10,000) of the voting rights of a Class A share. Unless otherwise required under Delaware General Corporation Law, Class A and Class B common shares vote as a single class. Each share of Class A common stock is convertible, at the option of the holder, into 1,500 shares of Class B common stock. Class B common stock is not convertible into Class A common stock. On an equivalent Class A common stock basis, there were 1,642,945 shares outstanding as of December 31, 2012 and 1,650,806 shares outstanding as of December 31, 2011. In addition to our common stock, 1,000,000 shares of preferred stock are authorized, but none are issued and outstanding.

In September 2011, Berkshire’s Board of Directors (“Berkshire’s Board”) approved a common stock repurchase program under which Berkshire may repurchase its Class A and Class B shares at prices no higher than a 10% premium over the book value of the shares. In December 2012, Berkshire’s Board amended the repurchase program by raising the price limit to no higher than a 20% premium over book value. Berkshire may repurchase shares in the open market or through privately negotiated transactions. Berkshire’s Board authorization does not specify a maximum number of shares to be repurchased. However, repurchases will not be made if they would reduce Berkshire’s consolidated cash equivalent holdings below $20 billion. The repurchase program is expected to continue indefinitely and the amount of repurchases will depend entirely upon the level of cash available, the attractiveness of investment and business opportunities either at hand or on the horizon, and the degree of discount of the market price relative to management’s estimate of intrinsic value. The repurchase program does not obligate Berkshire to repurchase any dollar amount or number of Class A or Class B shares. In December 2012, Berkshire repurchased 9,475 Class A shares and 606,499 Class B shares for approximately $1.3 billion through a privately negotiated transaction and market purchases.