Exhibit 12.1

TRANSCONTINENTAL GAS PIPE LINE COMPANY, LLC

COMPUTATION OF EARNINGS TO FIXED CHARGES

Thousands of Dollars, except ratios

(UNAUDITED)

	Year Ended December 31,															For the Nine Months Ended September 30, 2011			For the Nine Months Ended September 30, 2012
	2007			2008			2009			2010			2011
Earnings Available for Fixed Charges:
Net Income	$	172,151		$	1,298,885		$	280,357		$	270,776		$	279,658		$	206,224		$	183,426
Adjustment for undistributed income of equity investees		(881	)		(182	)		(635	)		2,626			(851	)		(594	)		(3,426	)
Plus — Interest expense and portion of rents representative of the interest factor, net of interest capitalized, and amortization of debt expense, discount and premium		95,355			96,479			94,680			95,228			95,420			71,746			68,823
Federal income taxes		105,533			36,286			0			0			0			0			0
Deferred federal income taxes		(13,294	)		(867,400	)		0			0			0			0			0
State and Municipal income taxes		11,475			(129,592	)		(248	)		360			368			264			342
Total	$	370,339		$	434,476		$	374,154		$	368,990		$	374,595		$	277,640		$	249,165
Fixed Charges:
Interest on long-term debt	$	88,954		$	89,939		$	92,800		$	92,800		$	92,685		$	69,673		$	66,805
Other interest expense (includes intercompany)		3,046			3,613			(1,235	)		(732	)		(373	)		(292	)		(93	)
Portion of rents representative of the interest factor, including amounts capitalized		1,043			954			1,048			1,025			1,043			770			953
Amortization of debt expense, discount and premium		2,617			2,201			2,328			2,418			2,383			1,836			1,442
Total	$	95,660		$	96,707		$	94,941		$	95,511		$	95,738		$	71,987		$	69,107
Ratio of earnings to fixed charges		3.87			4.49			3.94			3.86			3.91			3.86			3.61

For purposes of calculating the ratio of earnings to fixed charges:

(a) Earnings represent the aggregate of pre-tax income, adjusted for undistributed income of equity investees, and fixed charges, net of interest capitalized.

(b) Fixed charges represent interest (whether expensed or capitalized), the amortization of total debt premium, discount and expense, and that portion of rentals considered to be representative of the interest factor.