Exhibit 99.4

Michael Baker Corporation (“the Company”) acquired of 100% of the outstanding shares of RBF Consulting (“RBF”) on October 3, 2011, (“the Acquisition”). The following unaudited pro forma condensed consolidated financial statements of the Company include adjustments to the Company’s historical financial statements to reflect the Acquisition.

The historical financial information of the Company has been derived from the historical audited and consolidated financial statements of the Company included in the Annual Report on Form 10-K for the year ended December 31, 2010 and the unaudited condensed consolidated financial statements of the Company included in the Quarterly Report on Form 10-Q for the nine months ended September 30, 2011. The unaudited pro forma condensed consolidated statements of income for the year ended December 31, 2010 and the nine months ended September 30, 2011 were prepared as if the Acquisition occurred on January 1, 2010. The unaudited pro forma condensed consolidated balance sheet was prepared as if the Acquisition occurred as of September 30, 2011. The pro forma adjustments give effect to pro forma events that are (1) directly attributable to the Acquisition, (2) factually supportable and (3) with respect to the consolidated statements of income, expected to have a continuing impact on the combined results.

The unaudited pro forma condensed consolidated financial statements presented do not purport to represent what the results of operations or financial position of the Company would have been had the transaction occurred on the dates noted above, or to project the results of operations or financial position of the Company for any future periods. In the opinion of management, all necessary adjustments to the unaudited pro forma consolidated financial information have been made.

The unaudited pro forma condensed consolidated financial statements and accompanying notes should be read in conjunction with Management’s Discussion and Analysis of Financial Condition and Results of Operations and the historical financial statements in the Company’s 2010 Annual Report on Form 10-K and the September 30, 2011 Quarterly Report on Form 10-Q.

Michael Baker Corporation

Unaudited Pro Forma Condensed Consolidated Balance Sheet

As of September 30, 2011

Michael Baker Corporation

Unaudited Pro Forma Condensed Consolidated Statement of Income

For the nine months ended September 30, 2011

Michael Baker Corporation

Unaudited Pro Forma Condensed Consolidated Statement of Income

For the year ended December 31, 2010

Note 1. Basis of Presentation

The unaudited pro forma condensed consolidated balance sheet of Michael Baker Corporation (“The Company”) as of September 30, 2011 and the unaudited pro forma condensed consolidated statements of income for the year ended December 31, 2010, and for the nine months ended September 30, 2011 give effect to the acquisition of 100% of the outstanding shares of RBF on October 3, 2011 (“the Acquisition”). The Company paid approximately $49.3 million at closing for RBF, subject to a Net Working Capital adjustment provision. In addition, immediately prior to closing the Company received $1.2 million from RBF to fund professional liability tail insurance premiums and for bonus payments due in December 2011 that the Company is disbursing on RBF’s behalf. The Company paid approximately $45.7 million from existing cash and cash equivalents, and issued 203,218 shares of the Company’s common stock. The fair market value of the stock on the Acquisition date approximated $3.6 million based on the closing price of $17.65 per share on October 3, 2011. A portion of the Net Working Capital adjustment totaling $4.0 million was remitted to RBF in 2011 and the remaining preliminary estimated balance of approximately $1.0 million is expected to be settled in 2012. Of the total purchase price, the entire $3.6 million balance of the Michael Baker Corporation common shares and $1.7 million in cash was placed in escrow at closing in order to secure potential indemnification obligations of former owners of RBF to the Company for a period of 36 months subsequent to the closing.

The estimated consideration paid for RBF (in thousands):

The following table summarizes the preliminary allocation of the fair value of the purchase price for the Acquisition as of October 3, 2011:

Founded in 1944, RBF is an engineering, planning, surveying and environmental firm based in Irvine, California. RBF has a total of 17 offices located in California, Nevada and Arizona. RBF provides comprehensive planning, design and construction services for its clients including public and governmental agencies, the development community, private enterprise and non-profit agencies.

The unaudited pro forma condensed consolidated balance sheet assumes that the Acquisition occurred on September 30, 2011 and the unaudited pro forma condensed consolidated statements of income assume that the Acquisition occurred on January 1, 2010. The pro forma condensed consolidated statements of income do not include the costs related to the Acquisition. In the opinion of management, these statements include all material adjustments necessary to reflect, on a pro forma basis, the impact of the Acquisition on the historical financial information of the Company. The unaudited pro forma condensed consolidated financial statements are not necessarily indicative of what the Company’s financial position or results of operations would have been had the Acquisition been consummated on such dates or project the Company’s financial position or results of operations at or for any future date or period. The unaudited pro forma condensed consolidated financial statements should be read in conjunction with the historical consolidated financial statements of the Company included in its Quarterly Report on Form 10-Q for the quarter ended September 30, 2011 and its Annual Report on Form 10-K for the year ended December 31, 2010, as well as the audited financial statements for RBF for the year ended December 31, 2010, included as Exhibit 99.2 to this Form 8-K/A.

The Acquisition has been accounted for as a business combination under the acquisition method of accounting. Under the acquisition method of accounting, the purchase price was allocated to RBF’s underlying assets and liabilities based on preliminary estimates of their fair values at the date of the Acquisition. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The excess of the purchase price over the preliminary estimated fair value of the underlying assets acquired and liabilities assumed has been recorded as goodwill. Detailed information regarding the final purchase price allocation will be included in Michael Baker Corporation’s Annual Report on Form 10-K for the year ended December 31, 2011.

Note 2. Pro Forma Condensed Consolidated Balance Sheet Adjustments

Pro forma adjustments are necessary to reflect the preliminary allocation of the purchase price, including adjusting assets and liabilities to their estimated fair value and recognizing intangible assets, with related changes in amortization expense, and to reflect the effects of the issuance of Michael Baker Corporation equity necessary to consummate the Acquisition.

The unaudited pro forma condensed consolidated balance sheet assumes that the stock of RBF was acquired on September 30, 2011. The Company did not assume RBF’s debt totaling $3.0 million as part of the transaction. Consideration paid for RBF is based on the existing cash on hand disbursed at closing, the estimated payable derived from the preliminary net working capital adjustment, and the market value of the 203,218 shares of Michael Baker Corporation common stock transferred as of October 3, 2011, offset by the cash received from RBF to fund professional liability tail insurance premiums and for bonus payments due in December 2011 that the Company is disbursing on RBF’s behalf.

The Net Working Capital adjustment for the purposes of the pro forma condensed consolidated balance sheet is based on the balance sheet as of October 3, 2011. The Net Working Capital adjustment is expected to be settled in 2012, and the preliminary calculation resulted in the net working capital payable of approximately $5,021,000 payable to the former shareholders of RBF, $4.0 million of which has been paid to date. The preliminary Net Working Capital adjustment has been included as a pro-forma adjustment in the accompanying pro-forma balance sheet.

To reflect the purchase of RBF as of September 30, 2011, the same parameters of the transaction have been assumed, including the $49.3 million purchase price and the $1.2 million of cash received from RBF to fund professional liability tail insurance premiums and for bonus payments due in December 2011 that the Company is disbursing on RBF’s behalf. The excess of the purchase price, including the preliminary Net Working Capital adjustment, over the fair value of the assets acquired and liabilities assumed has been classified as goodwill. As the Company has not yet finalized the allocation of the purchase price, these amounts are subject to adjustment.

The following table sets forth the preliminary estimates of fair values of the identifiable intangible assets acquired with RBF on October 3, 2011 (in thousands):

Estimated future amortization expense related to the identifiable intangible assets acquired (in thousands):

Project backlog and customer contracts and related relationships represent the underlying relationships and agreements with RBF’s existing customers. Non-compete agreements represent the amount of lost business that could occur if the sellers, in the absence of non-compete agreements, were to compete with the Company. The trade name represents the value of the “RBF” brand. Project backlog, customer contracts and related relationships, non-compete agreements and the trade name intangible assets will be amortized on a basis approximating the economic value derived from those assets. The preliminary estimates of fair values and lives ascribed to these identifiable intangible assets are subject to change as the review and evaluation of these assets are finalized.

The adjustment to fair value RBF’s various real estate operating leases based upon current market rates resulted in an adjustment of approximately $1.4 million in the accompanying condensed consolidated pro-forma balance sheet.

As RBF was required to retire its line of credit borrowings with Wells Fargo Bank, N.A upon close of the transaction, $3.0 million has been included as a pro-forma adjustment for these borrowings.

The issuance of 203,218 common shares of Michael Baker Corporation is included as pro-forma adjustments in Shareholders’ Investment, reflecting an increase of approximately $0.2 million in Common Stock and approximately $3.4 million in Additional Paid-In Capital. These adjustments are offset by the pro-forma adjustments to reflect the elimination of RBF’s equity upon the purchase and consolidation with Michael Baker Corporation.

Note 3. Pro Forma Condensed Consolidated Statements of Income Adjustments

The pro forma condensed consolidated statements of income assume that the Acquisition occurred as of January 1, 2010. The pro-forma condensed consolidated statements of income do not include any costs related to the Acquisition. In addition, the pro-forma condensed consolidated statements of income do not assume any impacts from revenue, costs or other operating synergies that are expected to result from the Acquisition. Pro forma adjustments have been made to reflect amortization of the identifiable intangible assets for the related periods. Identifiable intangible assets are being amortized on a basis approximating the economic value derived from those assets.

Pro-forma adjustments to “Cost of work performed” have been made to reflect amortization of operating leases recorded at fair value and a portion of the intangible assets. Pro-forma adjustments to SG&A have been made to reflect the remaining portion of the intangible amortization expense, costs related to the Acquisition, the elimination of “key man” life insurance policies that RBF had maintained for its former primary shareholders, as well as the elimination of stock-based compensation expense related to RBF’s legacy equity incentive programs.

Pro-forma adjustments have also been made to reflect the elimination of interest expense related to RBF’s borrowings under their line of credit agreement with the Wells Fargo Bank, N.A, which was retired as of the closing date. Additionally, interest income earned on the cash balances held by RBF has also been eliminated as a pro-forma adjustment. An adjustment was also made to reflect a reduction in interest income earned by the Company due to the assumed disbursement of $45.7 million of cash and cash equivalents for the Acquisition as of January 1, 2010, net of the $1.2 million received by the Company from RBF to fund professional liability tail insurance premiums and for bonus payments due in December 2011 that the Company is disbursing on RBF’s behalf.

The pro forma adjustments for the income tax provisions were calculated based upon the statutory rates in effect during the respective periods for which pro forma condensed consolidated statements of income are presented. Actual amounts could vary from these pro forma estimates.