	March 31, 2012		December 31, 2011

	(in millions)
Unsecured senior notes:
6.875% due 2018	$	800.0	$	800.0
7.125% due 2020		800.0		800.0
7.0% due 2017		13.0		13.0

	$	1,613.0	$	1,613.0
Less: Current portion		—		—

Net long-term debt	$	1,613.0	$	1,613.0

As of March 31, 2012, we maintained a senior secured revolving credit facility (the 2010 Revolving Credit Facility) under an agreement, dated April 5, 2010 and amended and restated August 3, 2011 (the 2010 Credit Agreement), that provided up to $500 million in borrowings, bore interest at a variable rate based on an applicable margin over LIBOR or a base rate, and was scheduled to expire in 2016. Borrowings under the Revolving Credit Facility could be used for working capital and general corporate purposes of the Company and its subsidiaries (subject to certain limitations). At March 31, 2012, there was $491.2 million of available credit under the 2010 Revolving Credit Facility (net of outstanding letters of credit), and there were no borrowings outstanding. The Credit Agreement required that the Company maintain a minimum interest coverage ratio and a maximum leverage ratio and included other customary terms and conditions, including negative covenants and events of default.

The obligations of CF Industries under the 2010 Credit Agreement were guaranteed by the Company and certain direct and indirect wholly-owned subsidiaries of the Company (collectively, the Guarantors). The obligations of CF Industries and the Guarantors under the 2010 Credit Agreement were secured by senior liens on substantially all of the assets of CF Industries and the Guarantors, subject to certain exceptions.

As described in Note 24—Subsequent Event, the 2010 Credit Agreement was terminated by us on May 1, 2012 and then the Company, as guarantor, and CF Industries, as borrower, entered into a new senior credit agreement. The new senior credit agreement is unsecured and the Company is currently the only guarantor of CF Industries' obligations under the new senior credit agreement.

On April 23, 2010, CF Industries issued $800 million aggregate principal amount of 6.875% senior notes due 2018 (the 2018 Notes) and $800 million aggregate principal amount of 7.125% senior notes due 2020 (the 2020 Notes and, together with the 2018 Notes, the Notes).

The 2018 Notes bear interest at a rate of 6.875% per annum, payable semiannually on May 1 and November 1, mature on May 1, 2018 and are redeemable at CF Industries' option, in whole at any time or in part from time to time, at a specified make-whole redemption price. The 2020 Notes bear interest at a rate of 7.125% per annum, payable semiannually on May 1 and November 1, mature on May 1, 2020 and are redeemable at CF Industries' option, in whole at any time or in part from time to time, at a specified make-whole redemption price.

The indentures governing the Notes contain customary events of default and covenants that limit, among other things, the ability of the Company and its subsidiaries, including CF Industries, to incur liens on certain properties to secure debt. In the event of specified changes of control involving the Company or CF Industries, they also require CF Industries to offer to repurchase the Notes at a price equal to 101% of the principal amount thereof, plus accrued and unpaid interest.

Under the supplemental indentures governing the Notes, the Notes are to be guaranteed by the Company and each of the Company's current and future subsidiaries (other than CF Industries) that from time to time is a borrower or guarantor under the 2010 Credit Agreement, or any renewal, replacement or refinancing thereof. Any such guarantees will be released with respect to a series of Notes upon satisfaction of the indenture requirements for legal defeasance with respect to the notes of such series or satisfaction and discharge of the indenture with respect to such series. In addition, under the supplemental indentures governing the Notes, the guarantee of a subsidiary guarantor will be automatically released with respect to a series of notes upon the release, discharge or termination of such guarantor's guarantee of the 2010 Credit Agreement, or any renewal, replacement or refinancing thereof. As described in Note 24, as a result of the termination of the 2010 Credit Agreement, the guarantees of the subsidiaries of the Company securing obligations under the 2010 Credit Agreement were released. As a result, the subsidiaries were automatically released from their guarantees of the Notes.

At March 31, 2012, the carrying value of the 2018 Notes and 2020 Notes was $1.6 billion and the fair value was approximately $1.9 billion.

In 2007, Terra issued $330 million of 7% Senior Notes due 2017 (2017 Notes). In 2009, Terra repurchased approximately $317.5 million aggregate principal amount of the 2017 Notes in a tender offer and consent solicitation, and as a result, substantially all of the restrictive covenants in the indenture governing the 2017 Notes were eliminated. At March 31, 2012, the carrying value of the 2017 Notes that remain outstanding was $13.0 million, which approximates fair value.

From time to time, CFL receives advances from CF Industries and from CFL's noncontrolling interest holder to finance major capital expenditures. The advances outstanding are evidenced by unsecured promissory notes due December 31, 2013 and bear interest at market rates. The amount shown as notes payable represents the advances payable to CFL's noncontrolling interest holder. The carrying value of notes payable approximates their fair value.