Exhibit 99.4

Unaudited pro forma condensed combined balance sheet as of December 31, 2010, the unaudited pro forma condensed combined statements of income for the three months ended December 31, 2010, and the unaudited pro forma condensed combined statements of income for the fiscal year ended September 30, 2010 of RockTenn and Smurfit-Stone

UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

The following unaudited pro forma condensed combined financial information is designed to show how the merger of RockTenn and Smurfit-Stone might have affected historical financial statements if the merger and the related financing transactions had been completed at an earlier time. The following unaudited pro forma condensed combined financial information was prepared based on the historical financial results reported by RockTenn and Smurfit-Stone in their filings with the SEC.

The unaudited pro forma balance sheet assumes that the merger and the related financing transactions took place on December 31, 2010, and combines RockTenn’s December 31, 2010 unaudited condensed consolidated balance sheet with Smurfit-Stone’s December 31, 2010 audited condensed consolidated balance sheet. The unaudited pro forma condensed combined statement of income data for the year ended September 30, 2010 and for the three months ended December 31, 2010, have been prepared to give effect to the merger as if the merger and the related financing transactions had occurred on October 1, 2009 and October 1, 2010, respectively. The pro forma income statement information for the fiscal year ended September 30, 2010 combines RockTenn’s audited consolidated statement of income for the fiscal year ended September 30, 2010 with the audited consolidated statements of income of (a) Predecessor Smurfit-Stone for the six months ended June 30, 2010 and (b) Successor Smurfit-Stone for the six months ended December 31, 2010. The pro forma income statement information for the fiscal quarter ended December 31, 2010 combines RockTenn’s unaudited consolidated statement of income for the fiscal quarter ended December 31, 2010 with Smurfit-Stone’s unaudited consolidated statement of income for the quarter ended December 31, 2010.

We have made certain reclassifications to Smurfit-Stone’s presentation to conform to RockTenn’s presentation. The reclassifications primarily consisted of: (i) the aggregation of receivable for alternative energy tax credits, refundable income taxes, and prepaid expenses and other current assets into the line item other current assets, (ii) breaking out $55 million of investments in unconsolidated entities from the line item other assets, (iii) the aggregation of the line items interest payable and other current liabilities into the line item other current liabilities, (iv) the aggregation of the line items other operating income, (gain) loss on disposal of assets and foreign currency exchange gains (losses) into the line item cost of goods sold, and (v) breaking out $2 million of equity in income of unconsolidated entities from the line item other, net for each of the Smurfit-Stone’s six months ended June 30, 2010 and six months ended December 31, 2010.

The unaudited pro forma condensed combined financial statements were prepared using the acquisition method of accounting with RockTenn treated as the acquiring entity. Accordingly, consideration given by RockTenn to complete the merger with Smurfit-Stone will be allocated to assets and liabilities based upon their estimated fair values as of the date of completion of the merger. As of the date of this joint proxy statement/prospectus, RockTenn has not completed the detailed valuation studies necessary to arrive at final estimates of the fair value of the Smurfit-Stone assets to be acquired and the liabilities to be assumed and the related allocations of purchase price, nor has it identified all adjustments necessary to conform Smurfit-Stone’s accounting policies to RockTenn’s accounting policies. Additionally, a final determination of the fair value of Smurfit-Stone’s assets and liabilities, which cannot be made prior to the completion of the transaction, will be based on the actual net tangible and intangible assets and liabilities of Smurfit-Stone that exist as of the date of completion of the merger. Accordingly, the pro forma purchase price adjustments are preliminary, are subject to further adjustments as additional information becomes available and as additional analyses are performed and have been made solely for the purpose of providing the unaudited pro forma condensed combined financial statements presented below. RockTenn estimated the fair value of Smurfit-Stone’s assets and liabilities based on discussions with Smurfit-Stone’s management, due diligence and information presented in public filings. Until the merger is completed, both companies are limited in their ability to share information. Upon completion of the merger, final valuations will be performed. Increases or decreases in the fair value of relevant balance sheet amounts will result in adjustments to the balance sheet and/or statements of operations. There can be no assurance that such finalization will not result in material changes.

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The adjustments to the unaudited pro forma condensed combined statement of income are based upon available information and certain assumptions that we believe are reasonable and exclude the following non-recurring charges that will be incurred in connection with the transaction: the pre-tax write-off of approximately $43.5 million of deferred financing fees related to the refinancing of certain amounts outstanding under existing RockTenn and Smurfit-Stone credit facilities, transaction fees of approximately $50.0 million pre-tax expected to be incurred by RockTenn and Smurfit-Stone related to the merger, approximately $42.5 million pre-tax of Smurfit-Stone executive payments, the acceleration of approximately $33.0 million of pre-tax stock-based compensation which vests at closing and the payment of approximately $11.0 million pre-tax of original issue discount on existing Smurfit-Stone debt.

The following unaudited pro forma financial data is derived from the historical consolidated financial statements of each of RockTenn and Smurfit-Stone and are not indicative of the results of operations or financial position that would have resulted had the proposed merger been consummated on the dates indicated and should not be construed as being indicative of future performance. The information below should be read in conjunction with the financial statements and accompanying notes of RockTenn and Smurfit-Stone contained in RockTenn’s Annual Report on Form 10-K for the year ended September 30, 2010, RockTenn’s Quarterly Report on Form 10-Q for the quarterly period ended December 31, 2010, and Smurfit-Stone’s Annual Report on Form 10-K for the year ended December 31, 2010, which are incorporated by reference into this joint proxy statement/prospectus.

RockTenn expects to incur significant costs associated with integrating the operations of the two companies. The unaudited pro forma condensed combined financial statements do not reflect the costs of any integration activities or benefits that may result from realization of future cost savings from operating efficiencies or synergies expected to result from the merger.

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Rock-Tenn Company

Unaudited Pro Forma Condensed Combined Balance Sheets

As of December 31, 2010

(in millions)

See the accompanying notes to the unaudited pro forma condensed combined financial statements which are an integral part of these statements. The pro forma adjustments are explained in Note 2 — Condensed Combined Pro Forma Balance Sheet Adjustments.

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Rock-Tenn Company

Unaudited Pro Forma Condensed Combined Statements of Income

For the Three Months Ended December 31, 2010

(in millions, except per share data)

See the accompanying notes to the unaudited pro forma condensed combined financial statements which are an integral part of these statements. The pro forma adjustments are explained in Note 3 — Condensed Combined Pro Forma Income Statement Adjustments.

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Rock-Tenn Company

Unaudited Pro Forma Condensed Combined Statements of Income

For the Fiscal Year Ended September 30, 2010 ⁽¹⁾

(in millions, except per share data)

See the accompanying notes to the unaudited pro forma condensed combined financial statements which are an integral part of these statements. The pro forma adjustments are explained in Note 3 — Condensed Combined Pro Forma Income Statement Adjustments.

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NOTES TO THE UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

Note 1. Basis of Presentation

On January 23, 2011, RockTenn entered into the merger agreement whereby Smurfit-Stone will merge with and into Sam Acquisition, LLC, with Sam Acquisition, LLC surviving as a wholly-owned subsidiary of RockTenn. In connection with the merger, each outstanding share of Smurfit-Stone common stock will be converted into the right to receive the merger consideration (except for shares of Smurfit-Stone common stock owned by RockTenn, Sam Acquisition, LLC, Smurfit-Stone (other than in a fiduciary capacity) or such holders who properly demand an appraisal of their shares of Smurfit-Stone common stock). In addition, at the effective time of the merger, each outstanding option to purchase Smurfit-Stone common stock under Smurfit-Stone’s equity-based compensation plans will be assumed by RockTenn and be converted into an option to purchase a number of shares of RockTenn common stock equal to the product of (i) the number of shares of Smurfit-Stone common stock subject to the option and (ii) the equity award exchange ratio, rounded down to the nearest whole share. The per share exercise price for RockTenn common stock issuable upon the exercise of such assumed stock option will be equal to (i) the per share exercise price of Smurfit-Stone common stock at which the option was exercisable immediately prior to the effective time of the merger divided by (ii) the equity award exchange ratio, rounded up to the nearest whole cent. Except as set forth above, each assumed stock option will be subject to the same terms and conditions as were applicable to the corresponding option to purchase Smurfit-Stone common stock immediately prior to the effective time of the merger; provided, that each outstanding option granted prior to the date of the merger agreement will vest and become exercisable as of the effective time of the merger as contemplated by Smurfit-Stone’s stock plans and each outstanding option granted on or after the date of the merger agreement will continue to vest in accordance with its normal vesting schedule. The equity award exchange ratio is the sum of (x) 0.30605 and (y) the quotient of $17.50 divided by the average, rounded to the nearest one ten thousandth, of the closing sale prices of RockTenn common stock on the NYSE as reported by The Wall Street Journal for the five full trading days immediately preceding, but not including, the date on which the merger becomes effective.

The restrictions on each Smurfit-Stone restricted stock unit award with respect to shares of Smurfit-Stone common stock that is outstanding at the effective time of the merger and that was granted prior to the date of the merger agreement will lapse at the effective time of the merger and each such restricted stock unit award will be converted into the right to receive, with respect to each share of Smurfit-Stone common stock underlying such restricted stock unit award, the merger consideration on the same terms as other shares of Smurfit-Stone common stock, subject to certain specified tax withholdings. In addition, at the effective time of the merger, each Smurfit-Stone restricted stock unit award that is outstanding immediately prior to the effective time of the merger and that was granted on or after the date of the merger agreement will be converted into a restricted stock unit award, on the same terms and conditions applicable to such Smurfit-Stone restricted stock unit award immediately prior to the effective time of the merger (including applicable vesting requirements), with respect to a number of shares of RockTenn common stock that is equal to the number of shares of Smurfit-Stone common stock subject to the award prior to the effective time of the merger multiplied by the equity award exchange ratio, rounded to the nearest whole share.

In addition, at the effective time of the merger, with respect to shares of Smurfit-Stone common stock that have been reserved in accordance with Smurfit-Stone’s plan of reorganization, RockTenn must have reserved a sufficient number of shares of common stock to deliver the common stock component of the merger consideration, with respect to such shares.

In connection with the merger, RockTenn has entered into a commitment letter with the lenders. Pursuant to the commitment letter, the lenders have committed to provide new senior secured credit facilities in an aggregate principal amount of $3.7 billion, consisting of a $1.20 billion, 5-year term revolving credit facility; a Term A $1.25 billion, 5-year term loan facility; and a Term B $1.25 billion, 6-year term loan facility. The borrowings under the new credit facilities will be used to finance the merger in part, to repay outstanding

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indebtedness of Smurfit-Stone and to refinance RockTenn’s existing credit facilities, and to pay for fees and expenses incurred in connection with the merger and related transactions and provide for additional liquidity.

The joint lead arrangers and joint lead bookrunners are currently in the process of syndicating the $3.7 billion senior secured credit facilities to a number of other financial institutions and other prospective lenders. At the request of RockTenn, these credit facilities would be allocated in amounts different from those set forth in the commitment letter described above, with the revolving credit facility and the Term A term loan facility each being increased to $1.475 billion, and the Term B term loan facility being reduced to $750 million. In addition, the maturity of the Term B term loan facility would be extended to the seventh anniversary of the completion of the merger, while the maturities of the revolving credit facility and Term A term loan facility would continue to be on the fifth anniversary of the completion of the merger.

For a more complete description of the financing for the merger, including expected changes in the terms of such financing, see the section entitled “Description of Debt Financing” beginning on page 118 of this joint proxy statement/prospectus.

The accompanying unaudited pro forma condensed combined financial statements were prepared in accordance with Article 11 of SEC Regulation S-X. The accompanying unaudited pro forma condensed combined financial statements present the pro forma consolidated financial position and results of operations of the combined company based upon the historical financial statements of RockTenn and Smurfit-Stone, after giving effect to the merger, the related financing and adjustments described in these notes, and are intended to reflect the impact of the merger on RockTenn’s consolidated financial statements. The unaudited pro forma condensed combined balance sheet gives effect to the merger as if it had been consummated on December 31, 2010 and includes estimated pro forma adjustments for the preliminary valuations of tangible and intangible assets acquired and liabilities assumed and for the estimated impact of the financing transactions associated with the merger. The allocation of the estimated purchase price is preliminary, pending finalization of various estimates and analyses, including a complete purchase price allocation study. Since these unaudited pro forma condensed combined financial statements have been prepared based on preliminary estimates of purchase consideration and fair values attributable to the merger, the actual amounts eventually recorded for the merger may differ materially from the information presented. The unaudited pro forma condensed combined statements of income give effect to the merger as if it had occurred at the beginning of the periods presented. The accompanying unaudited pro forma condensed combined financial statements are presented for illustrative purposes only and do not reflect any transaction costs, restructuring costs, compensation expenses or other one-time charges that may be incurred with integrating the operations of Smurfit-Stone nor do they include synergies, or other cost reductions that may result from the transaction.

The unaudited pro forma condensed combined balance sheet has been adjusted to reflect the preliminary allocation of the purchase price to identifiable net assets acquired and the excess purchase price to goodwill. While a final determination of the fair value of assets acquired and liabilities assumed and therefore the amount of goodwill cannot be completed prior to the transaction closing, we do not anticipate any material additional identifiable assets acquired that would meet the separability criterion or the contractual-legal criterion under Accounting Standards Codification 805, “Business Combinations”. The estimated fair value assigned to goodwill in the accompanying pro forma balance sheet is primarily attributable to (i) buyer-specific synergies expected to arise after the acquisition (e.g., enhanced geographic reach of the combined organization, increased vertical integration opportunities and diversification of fiber sourcing) and (ii) the assembled work force of Smurfit-Stone. The purchase price allocation in these unaudited pro forma condensed combined financial statements is based upon an estimated purchase price of approximately $5.2 billion. At the time of completion of the merger, outstanding shares of Smurfit-Stone common stock (including those shares issuable pursuant to Smurfit-Stone’s plan of reorganization under Chapter 11) will be converted into the right to receive $17.50 in cash and 0.30605 of a share of RockTenn common stock, subject to adjustment as described in “The Merger Agreement—Consideration to be Received in the Merger” on page 99. We expect to issue approximately 31.0 million shares of RockTenn common stock in connection with the merger based on the number of shares of Smurfit-Stone

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common stock outstanding as of April 25, 2011, the number of shares of Smurfit-Stone common stock subject to restricted stock unit awards and granted prior to January 23, 2011, and the number of shares reserved for issuance under Smurfit-Stone’s plan of reorganization as of April 25, 2011. The pro forma purchase price has been prepared based on the closing price of RockTenn common stock of $70.03 on April 25, 2011. A one dollar movement in stock price would result in a change in purchase price of approximately $31 million. The actual number of shares of RockTenn common stock issued in the merger will be based upon the actual number of Smurfit-Stone shares outstanding when the merger closes. The purchase price also includes the estimated fair value of stock options and other stock-based awards to be issued as of the closing date of the merger. The treatment of Smurfit-Stone equity awards is as described above. Vested stock options held by employees of Smurfit-Stone are considered part of the purchase price. Accordingly, the purchase price includes an estimated fair value of stock options and other stock-based awards.

The preliminary purchase price is calculated as follows:

The table below represents a preliminary allocation of the total purchase price to Smurfit-Stone’s tangible and intangible assets acquired and liabilities assumed based on RockTenn management’s preliminary estimate of their respective fair values as of December 31, 2010:

Note 2. Condensed Combined Pro Forma Balance Sheet Adjustments

The following represents an explanation of the various pro forma adjustments to the unaudited Condensed Pro Forma Combined Balance Sheet.

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Note 3. Condensed Combined Pro Forma Income Statement Adjustments

The following represents an explanation of the various pro forma adjustments to the unaudited Pro Forma Condensed Combined Income Statements.

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