FIRST AMENDMENT TO RIGHTS AGREEMENT

Exhibit 4.1

FIRST AMENDMENT TO RIGHTS AGREEMENT

This First Amendment to Rights Agreement (this “Amendment”), dated as of August 31, 2010, is by and between CF Industries Holdings, Inc., a Delaware corporation (the “Company”), and Mellon Investor Services LLC, a New Jersey limited liability company, as successor to The Bank of New York, a New York banking corporation (the “Rights Agent”).

W I T N E S S E T H

WHEREAS, the Company previously entered into a Rights Agreement, dated as of July 21, 2005 (the “Rights Agreement”), with The Bank of New York as Rights Agent;

WHEREAS, Mellon Investor Services LLC has become the successor Rights Agent under the Rights Agreement pursuant to Section 19 of the Rights Agreement;

WHEREAS, pursuant to Section 27 of the Rights Agreement, the Company and the Rights Agent may supplement or amend the Rights Agreement from time to time in accordance with the provisions of Section 27 thereof; and

WHEREAS, the Board of Directors of the Company has determined that an amendment to the Rights Agreement as set forth herein is in the best interest of the Company and its stockholders, and the Company and the Rights Agent desire to evidence such amendment in writing.

NOW, THEREFORE, in consideration of the premises and the mutual agreements herein set forth, the parties hereby agree as follows:

Section 1.  Amendment of Section 1 of Rights Agreement.   Paragraph (a) of Section 1 of the Rights Agreement is amended by deleting such paragraph (a) in its entirety and substituting a new paragraph (a) to read as follows:

(a)    “Acquiring Person” shall mean any Person who or which, together with all Affiliates and Associates of such Person, shall be the Beneficial Owner of 15% or more of the shares of Common Stock then outstanding, but shall not include (i) the Company, (ii) any Subsidiary of the Company, (iii) any employee benefit plan of the Company, or of any Subsidiary of the Company, or any Person or entity organized, appointed or established by the Company for or pursuant to the terms of any such plan, (iv) any Person who becomes the Beneficial Owner of fifteen percent (15%) or more (or, in the case of a Person that is not deemed to be an Acquiring Person as a result of the application of clause (v) of this Paragraph (a), twenty percent (20.0%) or more) of the shares of Common Stock then outstanding as a result of a reduction in the number of shares of Common Stock outstanding due to the repurchase of shares of Common Stock by the Company unless and until such Person, after becoming aware that such Person has become the Beneficial Owner of fifteen percent (15%) or more (or, in the case of a Person that is not deemed to be an Acquiring Person as a result of the application of

clause (v) of this Paragraph (a), twenty percent (20.0%) or more) of the then outstanding shares of Common Stock, acquires beneficial ownership of additional shares of Common Stock representing one percent (1%) or more of the shares of Common Stock then outstanding, or (v) any such Person who has reported or is required to report such ownership (but less than 20.0%) on Schedule 13G under the Exchange Act (or any comparable or successor report) or on Schedule 13D under the Exchange Act (or any comparable or successor report) which Schedule 13D does not state any intention to or reserve the right to control or influence the management or policies of the Company or engage in any of the actions specified in Item 4 of such schedule (other than the disposition of the Common Stock); provided, however, that if either (a) such Person referred to in this clause (v) becomes the Beneficial Owner of additional shares of Common Stock such that such person is the Beneficial Owner of twenty percent (20%) or more of the shares of Common Stock then outstanding, or (b) such Person is the Beneficial Owner of fifteen percent (15%) or more but less than twenty percent (20%) of the shares of Common Stock then outstanding and reports or is required to report such ownership of shares of Common Stock on Schedule 13D under the Exchange Act (or any comparable or successor report) which Schedule 13D reports the intention to or reserves the right to control or influence the management or policies of the Company or engage in any of the actions specified in Item 4 of such schedule (other than the disposition of the Common Stock), then such Person shall become an Acquiring Person immediately.

Section 2.  Amendment of Section 26 of the Rights Agreement.   Subsection (b) of Section 26 of the Rights Agreement is amended by deleting the Rights Agent’s address in its entirety and substituting it with the following new address for the Rights Agent:

Mellon Investor Services LLC

200 W. Monroe Street

Suite 1590

Chicago, IL 60606

Attention: Georg Drake

With a copy to:

Mellon Investor Services LLC

Newport Office Center VII

480 Washington Boulevard

Jersey City, NJ 07310

Attention: Legal Department

Section 3.  Amendment of Form of Summary of Rights.   The Form of Summary of Rights, attached as Exhibit C to the Rights Agreement is amended and restated in its entirety to read as provided in Exhibit C hereto.

Section 4.  Continued Effectiveness.   The parties hereto hereby acknowledge and agree that, except as specifically amended hereby, the Rights Agreement shall remain in full force and effect in accordance with its terms.

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Section 5.  Severability.   If any term, provision, covenant or restriction of this Amendment is held by a court of competent jurisdiction or other authority to be invalid, void or unenforceable, the remainder of the terms, provisions, covenants and restrictions of this Amendment shall remain in full force and effect and shall in no way be affected, impaired or invalidated; provided, however, that notwithstanding anything in this Amendment or the Rights Agreement to the contrary, if any such term, provision, covenant or restriction is held by such court or authority to be invalid, void or unenforceable and the Board of Directors of the Company determines in its good faith judgment that severing the invalid language from this Amendment would adversely affect the purpose or effect of the Rights Agreement, the right of redemption set forth in Section 23 of the Rights Agreement hereof shall be reinstated and shall not expire until the close of business on the tenth Business Day following the date of such determination by the Board of Directors.

Section 6.  Governing Law.   This Amendment shall be deemed to be a contract made under the laws of the State of Delaware and for all purposes shall be governed by and construed in accordance with the laws of such State applicable to contracts made and to be performed entirely within such State; provided, however, that the rights, obligations and duties of the Rights Agent shall be governed by and construed in accordance with the laws of the State of New York.

Section 7.  Execution in Counterparts.   This Amendment may be executed in any number of counterparts and each of such counterparts shall for all purposes be deemed to be an original, and all such counterparts shall together constitute one and the same instrument.

Section 8.  Descriptive Headings.   Descriptive headings of the several sections of this Amendment are inserted for convenience only and shall not control or affect the meaning or construction of any of the provisions hereof.

Section 9.  Defined Terms.   Except as otherwise expressly provided herein, or unless the context otherwise requires, all capitalized terms used herein have the meanings assigned to them in the Rights Agreement.

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IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed and effective as of the day and year above written.

Exhibit C

SUMMARY OF RIGHTS TO PURCHASE

PREFERRED STOCK

Effective July 21, 2005 (the “Effective Date”), the Board of Directors of CF Industries Holdings, Inc. (the “Company”) authorized the issuance of one Right for each share of Common Stock of the Company issued between the Effective Date and the Distribution Date (as defined below). Each Right entitles the registered holder to purchase from the Company a unit consisting of one one-thousandth of a share (a “Unit”) of Series A Junior Participating Preferred Stock, par value $0.01 per share (the “Series A Preferred Stock”) at a Purchase Price of $90.00 per Unit, subject to adjustment. The description and terms of the Rights are set forth in a Rights Agreement (as amended from time to time, the “Rights Agreement”) between the Company and Mellon Investor Services LLC, as successor to The Bank of New York, as Rights Agent.

Initially, the Rights will be attached to all Common Stock certificates or, in the case of uncertificated shares, the associated balance indicated in the book-entry account system of the transfer agent for the Common Stock, representing shares then outstanding, and no separate Rights Certificates will be distributed. Subject to certain exceptions specified in the Rights Agreement, the Rights will separate from the Common Stock and a Distribution Date will occur upon the earlier of (i) 10 business days following a public announcement that a person or group of affiliated or associated persons (an “Acquiring Person”) has acquired beneficial ownership of 15% or more (or, in the case of certain institutional and other investors 20% or more) of the outstanding shares of Common Stock (the “Stock Acquisition Date”), other than as a result of repurchases of stock by the Company or (ii) 10 business days (or such later date as the Board shall determine) following the commencement of a tender offer or exchange offer that would result in a person or group becoming an Acquiring Person. Until the Distribution Date, (i) the Rights will be evidenced by shares of Common Stock and will be transferred with and only with such Common Stock, (ii) new Common Stock certificates issued after the Effective Date will contain a notation incorporating the Rights Agreement by reference and (iii) the surrender for transfer of any certificates for Common Stock outstanding will also constitute the transfer of the Rights associated with the Common Stock represented by such certificate. Pursuant to the Rights Agreement, the Company reserves the right to require prior to the occurrence of a Triggering Event (as defined below) that, upon any exercise of Rights, a number of Rights be exercised so that only whole shares of Preferred Stock will be issued.

The Rights are not exercisable until the Distribution Date and will expire at 5:00 P.M. (New York City time) on July 21, 2015, unless such date is extended or the Rights are earlier redeemed or exchanged by the Company as described below.

As soon as practicable after the Distribution Date, Rights Certificates will be mailed to holders of record of the Common Stock as of the close of business on the Distribution

Date and, thereafter, the separate Rights Certificates alone will represent the Rights. Except as otherwise determined by the Board of Directors, only shares of Common Stock issued prior to the Distribution Date will be issued with Rights.

In the event that a Person becomes an Acquiring Person, each holder of a Right will thereafter have the right to receive, upon exercise, Common Stock (or, in certain circumstances, cash, property or other securities of the Company) having a value equal to two times the exercise price of the Right. Notwithstanding any of the foregoing, after a Person becomes an Acquiring Person, all Rights that are, or (under certain circumstances specified in the Rights Agreement) were, beneficially owned by any Acquiring Person will be null and void. However, Rights are not exercisable following the occurrence of the event set forth above until such time as the Rights are no longer redeemable by the Company as set forth below.

In the event that, at any time following the Stock Acquisition Date, (i) the Company engages in a merger or other business combination transaction in which the Company is not the surviving corporation, (ii) the Company engages in a merger or other business combination transaction in which the Company is the surviving corporation and the Common Stock of the Company is changed or exchanged, or (iii) 50% or more of the Company’s assets, cash flow or earning power is sold or transferred, each holder of a Right (except Rights which have previously been voided as set forth above) shall thereafter have the right to receive, upon exercise, common stock of the acquiring company having a value equal to two times the exercise price of the Right. The events set forth in this paragraph and in the second preceding paragraph are referred to as the “Triggering Events.”

At any time after a person becomes an Acquiring Person and prior to the acquisition by such person or group of fifty percent (50%) or more of the outstanding Common Stock, the Board may exchange the Rights (other than Rights owned by such person or group which have become void), in whole or in part, at an exchange ratio of one share of Common Stock, or one one-thousandth of a share of Preferred Stock (or of a share of a class or series of the Company’s preferred stock having equivalent rights, preferences and privileges), per Right (subject to adjustment).

The Purchase Price payable, and the number of Units of Preferred Stock or other securities or property issuable, upon exercise of the Rights are subject to adjustment from time to time to prevent dilution (i) in the event of a stock dividend on, or a subdivision, combination or reclassification of, the Preferred Stock, (ii) if holders of the Preferred Stock are granted certain rights or warrants to subscribe for Preferred Stock or convertible securities at less than the current market price of the Preferred Stock, or (iii) upon the distribution to holders of the Preferred Stock of evidences of indebtedness or assets (excluding regular quarterly cash dividends) or of subscription rights or warrants (other than those referred to above).

With certain exceptions, no adjustment in the Purchase Price will be required until cumulative adjustments amount to at least 1% of the Purchase Price. No fractional Units will be

issued and, in lieu thereof, an adjustment in cash will be made based on the market price of the Preferred Stock on the last trading date prior to the date of exercise.

At any time until ten business days following the Stock Acquisition Date, the Company may redeem the Rights in whole, but not in part, at a price of $.001 per Right (payable in cash, Common Stock or other consideration deemed appropriate by the Board of Directors). Immediately upon the action of the Board of Directors ordering redemption of the Rights, the Rights will terminate and the only right of the holders of Rights will be to receive the $.001 redemption price.

Until a Right is exercised, the holder thereof, as such, will have no rights as a stockholder of the Company, including, without limitation, the right to vote or to receive dividends. While the distribution of the Rights will not be taxable to stockholders or to the Company, stockholders may, depending upon the circumstances, recognize taxable income in the event that the Rights become exercisable for Common Stock (or other consideration) of the Company or for common stock of the acquiring company or in the event of the redemption of the Rights as set forth above.

Any of the provisions of the Rights Agreement may be amended by the Board of Directors of the Company prior to the Distribution Date. After the Distribution Date, the provisions of the Rights Agreement may be amended by the Board in order to cure any ambiguity, to make changes which do not adversely affect the interests of holders of Rights, or to shorten or lengthen any time period under the Rights Agreement. The foregoing notwithstanding, no amendment may be made at such time as the Rights are not redeemable.

A copy of the Rights Agreement has been filed with the Securities and Exchange Commission as an Exhibit to a Registration Statement on Form 8-A/Current Report on Form 8-K. A copy of the Rights Agreement is available free of charge from the Rights Agent. This summary description of the Rights does not purport to be complete and is qualified in its entirety by reference to the Rights Agreement, which is incorporated herein by reference.