Edgar Filing: TERRA INDUSTRIES INC

Filed by CF Industries Holdings, Inc.

(Commission File No. 333-157462)

Pursuant to Rule 425 under the Securities Act of 1933

and deemed filed pursuant to Rule 14a-12 and Rule 14a-6(j)

of the Securities Exchange Act of 1934

Subject Company:

Terra Industries Inc.

On April 15, 2009, CF Industries Holdings, Inc. issued the following press release:

NEWS

CF INDUSTRIES ISSUES LETTER TO STOCKHOLDERS

DEERFIELD, IL, April 15, 2009 — CF Industries Holdings, Inc. (NYSE: CF) today released the following letter to its stockholders:

To Our Stockholders:

Your Board of Directors has rejected Agrium’s offer because of our commitment to stockholder value. We have shown that commitment and CF Industries stock has been the best performing stock in our peer group — Agrium is by far the worst performing stock. Agrium’s offer is grossly inadequate and nothing Agrium says changes that. We are confident that our stockholders agree that the offer is inadequate. RiskMetrics Group said in its recent report published on April 12, 2009: “We also note that the nearly unanimous opinion of CF shareholders with whom we spoke is that the current Agrium offer is not sufficient.”(1) RiskMetrics has recommended that our stockholders vote FOR our directors at our Annual Meeting.

We believe that Agrium is more interested in interfering with our business combination with Terra Industries, than in acquiring CF Industries at anything other than a bargain price. If Agrium were serious about acquiring CF Industries, it would have made a credible offer. If Agrium were serious about acquiring CF Industries, it would have at least tried to engage with us. The fact is that Agrium and its financial advisors have not contacted or attempted to contact CF Industries in well over a month. The CEO of Agrium called on March 6, 2009, to ask if we needed additional information and he has not called since then.

Your Board will continue to focus on doing what is right for our stockholders. We appreciate your continued support of our efforts to build stockholder value at CF Industries. If you have any questions or need assistance in voting your shares, please contact Innisfree M&A Incorporated toll-free at (877) 456-3507.

On behalf of your Board of Directors,

Stephen R. Wilson

Chairman, President and Chief Executive Officer

(1) Permission to use quotations from the RiskMetrics report was neither sought nor obtained.

Morgan Stanley and Rothschild are acting as financial advisors and Skadden, Arps, Slate, Meagher & Flom LLP is acting as legal counsel to CF Industries.

Contacts

Charles A. Nekvasil

Director, Public and Investor Relations

847-405-2515 — CNekvasil@cfindustries.com

Susan Stillings / Monika Driscoll, 212-333-3810

Brunswick Group LLC

Alan Miller, 212-750-5833

Innisfree M&A Incorporated

About CF Industries

CF Industries Holdings, Inc., headquartered in Deerfield, Illinois, is the holding company for the operations of CF Industries, Inc. CF Industries, Inc. is a major producer and distributor of nitrogen and phosphate fertilizer products. CF Industries operates world-scale nitrogen fertilizer plants in Donaldsonville, Louisiana and Medicine Hat, Alberta, Canada; conducts phosphate mining and manufacturing operations in Central Florida; and distributes fertilizer products through a system of terminals, warehouses, and associated transportation equipment located primarily in the Midwestern United States. The company also owns a 50 percent interest in KEYTRADE AG, a global fertilizer trading organization headquartered near Zurich, Switzerland. Additional information on CF Industries is found on the company’s website at www.cfindustries.com.

Additional Information

This press release relates to the offer (the “Offer”) by CF Industries Holdings, Inc. (“CF Industries”) through its direct wholly-owned subsidiary, Composite Acquisition Corporation (“Composite Acquisition”), to exchange each issued and outstanding share of common stock (the “Terra common stock”) of Terra Industries Inc. (“Terra”) for 0.4235 shares of CF Industries common stock. This press release is for informational purposes only and does not constitute an offer to exchange, or a solicitation of an offer to exchange, Terra common stock, nor is it a substitute for the Tender Offer Statement on Schedule TO or the preliminary Prospectus/Offer to Exchange included in the Registration Statement on Form S-4 (Reg. No. 333-157462) (including the Letter of Transmittal and related documents and as amended from time to time, the “Exchange Offer Documents”) previously filed by CF Industries and Composite Acquisition with the Securities and Exchange Commission (the “SEC”). The Registration Statement has not yet become effective. The Offer is made only through the Exchange Offer Documents. INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THESE DOCUMENTS AND OTHER RELEVANT MATERIALS AS THEY BECOME AVAILABLE, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION.

This press release is neither an offer to purchase nor the solicitation of an offer to sell any securities. On March 23, 2009, CF Industries filed a Solicitation/Recommendation Statement on Schedule 14D-9 with the SEC with respect to the exchange offer commenced by Agrium Inc. INVESTORS AND SECURITY HOLDERS OF CF INDUSTRIES ARE URGED TO READ THE SOLICITATION/RECOMMENDATION STATEMENT AND OTHER RELEVANT MATERIALS AS THEY BECOME AVAILABLE, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION.

In connection with the solicitation of proxies for the 2009 annual meeting of stockholders of Terra, CF Industries and its wholly-owned subsidiary CF Composite, Inc. (“CF Composite”) filed a revised preliminary proxy statement with the SEC on April 7, 2009 and intend to file a definitive proxy statement. When completed, the definitive proxy statement of CF Industries and CF Composite and accompanying proxy card will be mailed to stockholders of Terra. INVESTORS AND SECURITY HOLDERS OF TERRA ARE URGED TO READ THE PROXY STATEMENT AND OTHER RELEVANT MATERIALS CAREFULLY IN THEIR ENTIRETY AS THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION.

Investors and security holders will be able to obtain free copies of any documents filed by CF Industries with the SEC through the web site maintained by the SEC at www.sec.gov. Free copies of any such documents can also be obtained by calling Innisfree M&A Incorporated toll-free at (877) 456-3507.

CF Industries, CF Composite, their respective directors and executive officers and the individuals nominated by CF Composite for election to Terra’s board of directors are participants in the solicitation of proxies from Terra stockholders for Terra’s 2009 annual meeting of stockholders. Information regarding such participants and a description of their direct and indirect interests in such solicitation, by securities holdings or otherwise, is contained in the revised preliminary proxy statement filed by CF Industries with the SEC on April 7, 2009. CF Industries and its directors and executive officers will be participants in any solicitation of proxies from Terra stockholders or CF Industries stockholders in respect of the proposed transaction with Terra. Information regarding CF Industries’ directors and executive officers is available in the supplement to its proxy statement for its 2009 annual meeting of stockholders, which was filed with the SEC on April 7, 2009, and a description of their direct and indirect interests in such solicitation, by security holdings or otherwise, will be contained in the proxy statement/prospectus filed in connection with the proposed transaction with Terra.

All information in this press release concerning Terra and Agrium, including their respective businesses, operations and financial results was obtained from public sources. While CF Industries has no knowledge that any such information is inaccurate or incomplete, CF Industries has not had the opportunity to verify any of that information.

Safe Harbor Statement

Certain statements contained in this press release may constitute “forward-looking statements.” All statements in this press release, other than those relating to historical information or current condition, are forward-looking statements. These forward-looking statements are subject to a number of risks and uncertainties, many of which are beyond our control, which could cause actual results to differ materially from such statements. Risks and uncertainties relating to the proposed transaction include: Terra’s failure to accept CF Industries’ proposal and enter into definitive agreements to effect the transaction; our ability to obtain shareholder, antitrust, regulatory and other approvals on the proposed terms and schedule; uncertainty of the expected financial performance of CF Industries following completion of the proposed transaction; CF Industries’ ability to achieve the cost-savings and synergies contemplated by the proposed transaction within the expected time frame; CF Industries’ ability to promptly and effectively integrate the businesses of Terra and CF Industries; and disruption from the proposed transaction making it more difficult to maintain relationships with customers, employees or suppliers. Additional risks and uncertainties include: the relatively expensive and volatile cost of North American natural gas; the cyclical nature of our business and the agricultural sector; changes in global fertilizer supply and demand and its impact on the selling price of our products; the nature

of our products as global commodities; intense global competition in the consolidating markets in which we operate; conditions in the U.S. agricultural industry; weather conditions; our inability to accurately predict seasonal demand for our products; the concentration of our sales with certain large customers; the impact of changing market conditions on our forward pricing program; the reliance of our operations on a limited number of key facilities; the significant risks and hazards against which we may not be fully insured; reliance on third party transportation providers; unanticipated adverse consequences related to the expansion of our business; our inability to expand our business, including the significant resources that could be required; potential liabilities and expenditures related to environmental and health and safety laws and regulations; our inability to obtain or maintain required permits and governmental approvals or to meet financial assurance requirements; acts of terrorism; difficulties in securing the supply and delivery of raw materials we use and increases in their costs; losses on our investments in securities; loss of key members of management and professional staff; recent global market and economic conditions, including credit markets; and the other risks and uncertainties included from time to time in our filings with the SEC. Except as required by law, we undertake no obligation to update or revise any forward-looking statements.

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