Exhibit 12

STATEMENT SETTING FORTH DETAIL FOR COMPUTATION OF

RATIO OF EARNINGS TO FIXED CHARGES

	Successor												Predecessor
	Three Months Ended			For the Year Ended			For the Year Ended			May 1 through			January 1 through			For the Year Ended			For the Year Ended
	March 31,			December 31,			December 31,			December 31,			April 30,			December 31,			December 31,
Millions of dollars, ratio data	2013			2012			2011			2010			2010			2009			2008
Income (loss) from continuing operations before income taxes	$	1,263		$	4,185		$	3,531		$	1,731		$	6,947		$	(4,096	)	$	(7,986	)
Deduct income (loss) from equity investments		59			143			216			86			84			(181	)		38
Add distributions of earnings from equity investments		9			147			206			34			18			26			98
Earnings adjusted for equity investments		1,213			4,189			3,521			1,679			6,881			(3,889	)		(7,926	)
Fixed charges:
Interest expense, gross		71			655			1,044			545			713			1,795			2,476
Portion of rentals representative of interest		23			93			95			56			35			104			183
Total fixed charges before capitalized interest		94			748			1,139			601			748			1,899			2,659
Capitalized interest		3			9			8			2			4			35			13
Total fixed charges including capitalized interest		97			757			1,147			603			752			1,934			2,672
Earnings before fixed charges	$	1,310		$	4,946		$	4,668		$	2,282		$	7,633		$	(1,955	)	$	(5,254	)
Ratio of earnings to fixed charges(a)		13.51	x		6.53	x		4.07	x		3.78	x		10.15	x		—			—

(a) For the years 2009 and 2008, earnings were insufficient to cover fixed charges by $3,889 million and $7,926 million, respectively.