The tables below show our financial data for our segments for the periods indicated (in millions).



	Three Months Ended June 30, 2012
	West			Texas			North			Southeast			Consolidation and Elimination			Total
Revenues from external customers	$	258		$	188		$	269		$	164		$	—		$	879
Intersegment revenues	1			41			2			(6		)	(38		)	—
Total operating revenues	$	259		$	229		$	271		$	158		$	(38	)	$	879
Commodity Margin⁽¹⁾	$	210		$	145		$	181		$	73		$	—		$	609
Add: Mark-to-market commodity activity, net and other⁽²⁾⁽³⁾	(76		)	(217		)	(3		)	(42		)	(6		)	(344		)
Less:
Plant operating expense	112			72			58			36			(7		)	271
Depreciation and amortization expense	49			34			34			22			(1		)	138
Sales, general and other administrative expense	6			13			8			7			1			35
Other operating expenses⁽⁴⁾	9			1			6			2			1			19
(Income) from unconsolidated investments in power plants	—			—			(5		)	—			—			(5		)
Income (loss) from operations	(42		)	(192		)	77			(36		)	—			(193		)
Interest expense, net of interest income																182
Other (income) expense, net																6
Loss before income taxes																$	(381	)



	Three Months Ended June 30, 2011
	West		Texas		North			Southeast			Consolidation and Elimination			Total
Revenues from external customers	$	466	$	646	$	324		$	197		$	—		$	1,633
Intersegment revenues	1		5		5			40			(51		)	—
Total operating revenues	$	467	$	651	$	329		$	237		$	(51	)	$	1,633
Commodity Margin⁽¹⁾	$	236	$	128	$	184		$	59		$	—		$	607
Add: Mark-to-market commodity activity, net and other⁽²⁾⁽³⁾	11		27		(5		)	—			(9		)	24
Less:
Plant operating expense	116		63		47			41			(6		)	261
Depreciation and amortization expense	42		35		33			22			(1		)	131
Sales, general and other administrative expense	8		13		6			6			1			34
Other operating expenses⁽⁴⁾	11		3		9			2			(5		)	20
Loss from unconsolidated investments in power plants	—		—		2			—			—			2
Income (loss) from operations	70		41		82			(12		)	2			183
Interest expense, net of interest income														190
Loss on interest rate derivatives														37
Debt extinguishment costs and other (income) expense, net														8
Loss before income taxes														$	(52	)



	Six Months Ended June 30, 2012
	West			Texas			North			Southeast			Consolidation and Elimination			Total
Revenues from external customers	$	674		$	544		$	567		$	330		$	—		$	2,115
Intersegment revenues	5			61			5			16			(87		)	—
Total operating revenues	$	679		$	605		$	572		$	346		$	(87	)	$	2,115
Commodity Margin⁽¹⁾	$	418		$	254		$	325		$	129		$	—		$	1,126
Add: Mark-to-market commodity activity, net and other⁽²⁾⁽⁵⁾	(40		)	(183		)	9			(32		)	(14		)	(260		)
Less:
Plant operating expense	193			140			103			69			(13		)	492
Depreciation and amortization expense	99			69			67			45			(2		)	278
Sales, general and other administrative expense	14			24			14			15			1			68
Other operating expenses⁽⁴⁾	20			3			15			3			(1		)	40
(Income) from unconsolidated investments in power plants	—			—			(14		)	—			—			(14		)
Income (loss) from operations	52			(165		)	149			(35		)	1			2
Interest expense, net of interest income																364
Loss on interest rate derivatives																14
Debt extinguishment costs and other (income) expense, net																20
Loss before income taxes																$	(396	)



	Six Months Ended June 30, 2011
	West		Texas			North			Southeast			Consolidation and Elimination			Total
Revenues from external customers	$	1,065	$	1,096		$	595		$	376		$	—		$	3,132
Intersegment revenues	4		10			13			85			(112		)	—
Total operating revenues	$	1,069	$	1,106		$	608		$	461		$	(112	)	$	3,132
Commodity Margin⁽¹⁾	$	469	$	195		$	319		$	113		$	—		$	1,096
Add: Mark-to-market commodity activity, net and other⁽²⁾⁽⁵⁾	16		(33		)	(1		)	(4		)	(15		)	(37		)
Less:
Plant operating expense	203		143			92			74			(13		)	499
Depreciation and amortization expense	88		65			66			45			(2		)	262
Sales, general and other administrative expense	19		23			12			11			1			66
Other operating expenses⁽⁴⁾	19		3			16			3			(3		)	38
(Income) from unconsolidated investments in power plants	—		—			(7		)	—			—			(7		)
Income (loss) from operations	156		(72		)	139			(24		)	2			201
Interest expense, net of interest income															378
Loss on interest rate derivatives															146
Debt extinguishment costs and other (income) expense, net															108
Loss before income taxes															$	(431	)

_________


(1)	Our North segment includes Commodity Margin related to Riverside Energy Center, LLC of $24 million and $22 million for three months ended June 30, 2012 and 2011, respectively, and $32 million and $31 million for the six months ended June 30, 2012 and 2011, respectively.

(2)

Mark-to-market commodity activity represents the change in the unrealized portion of our mark-to-market activity, net, included in operating revenues and fuel and purchased energy expense on our Consolidated Condensed Statements of Operations. The increase in unrealized mark-to-market losses for the three and six months ended June 30, 2012, was primarily driven by the impact of a near term increase in forward power prices and corresponding Market Heat Rate expansion in the ERCOT region during the last several days of June 2012.


(3)	Includes $(1) million and $4 million of lease levelization and $3 million and $1 million of amortization expense for the three months ended June 30, 2012 and 2011, respectively.


(4)	Excludes $2 million of RGGI compliance and other environmental costs for both the three months ended June 30, 2012 and 2011, and $5 million and $4 million for the six months ended June 30, 2012 and 2011, respectively, which are components of Commodity Margin.


(5)	Includes $(9) million and $4 million of lease levelization and $7 million and $1 million of amortization expense for the six months ended June 30, 2012 and 2011, respectively.