Exhibit 99.3

UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL STATEMENTS

The following pro forma condensed combined financial information combines the historical consolidated financial position and results of operations of Huntington Bancshares Incorporated (“Huntington”) and its subsidiaries and FirstMerit Corporation (“FirstMerit”) and its subsidiaries, after giving effect to the acquisition by Huntington of FirstMerit using the acquisition method of accounting and giving effect to the related pro forma adjustments described in the accompanying notes. Under the acquisition method of accounting, the assets and liabilities of FirstMerit will be recorded by Huntington at their respective fair values as of the date the merger is completed. The pro forma condensed combined financial information should be read in conjunction with Huntington’s Quarterly Report on Form 10-Q for the period ended June 30, 2016, and Annual Report on Form 10-K for the year ended December 31, 2015, and FirstMerit’s Quarterly Report on Form 10-Q for the period ended June 30, 2016, and Annual Report on Form 10-K for the year ended December 31, 2015.

The pro forma condensed combined balance sheet gives effect to the merger as if the transaction had occurred on June 30, 2016. The pro forma condensed combined income statements for the six months ended June 30, 2016 and the year ended December 31, 2015, give effect to the merger as if the transaction had become effective on January 1, 2015.

The pro forma condensed combined financial information is presented for illustrative purposes only and does not indicate the financial results of the combined company had the companies actually been combined at the beginning of each period presented, nor the impact of possible business model changes. The pro forma condensed combined financial information also does not consider any potential effects of changes in market conditions on revenues, expense efficiencies, asset dispositions, and share repurchases, among other factors. In addition, as explained in more detail in the accompanying notes, the preliminary allocation of the pro forma purchase price reflected in the pro forma condensed combined financial information is subject to adjustment and may vary significantly from the actual purchase price allocation that will be recorded upon completion of the merger.

The pro forma condensed combined financial statements have been prepared to give effect to the following:

The pro forma condensed combined financial statements do not include certain non-recurring transaction costs that Huntington expects to incur in connection with the acquisition. Excluded are one-time expenditures estimated at $286 million pretax related to employee costs, costs to sell certain redundant locations, costs to merge information technology systems, and other one-time transaction related costs. Huntington expects to fund these costs through cash from operations. Due to the scope and complexity of these activities, the amount of these costs could increase or decrease materially and the timing of incurrence could change.

HUNTINGTON BANCSHARES INCORPORATED AND FIRSTMERIT CORPORATION

Unaudited Pro Forma Condensed Combined Consolidated Balance Sheet

As of June 30, 2016

See accompanying notes to unaudited pro forma combined condensed consolidated financial statements.

HUNTINGTON BANCSHARES INCORPORATED AND FIRSTMERIT CORPORATION

Unaudited Pro Forma Condensed Combined Consolidated Statement of Income

For the six months ended June 30, 2016

See accompanying notes to unaudited pro forma combined condensed consolidated financial statements.

HUNTINGTON BANCSHARES INCORPORATED AND FIRSTMERIT CORPORATION

Unaudited Pro Forma Condensed Combined Consolidated Statement of Income

For the year ended December 31, 2015

See accompanying notes to unaudited pro forma combined condensed consolidated financial statements.

Note 1 - Basis of Presentation

The pro forma condensed combined financial information and explanatory notes have been prepared to illustrate the effects of the merger involving Huntington and FirstMerit under the acquisition method of accounting with Huntington treated as the acquirer. The pro forma condensed combined financial information is presented for illustrative purposes only and does not necessarily indicate the financial results of the combined companies had the companies actually been combined at the beginning of each period presented, nor does it necessarily indicate the results of operations in future periods or the future financial position of the combined entities. Under the acquisition method of accounting, the assets and liabilities of FirstMerit, as of the effective date of the merger, will be recorded by Huntington at their respective fair values and the excess of the merger consideration over the fair value of FirstMerit’s net assets will be allocated to goodwill.

The merger, which is currently expected to be completed in the third quarter of 2016, provides for FirstMerit common shareholders to receive 1.72 shares of Huntington common stock and $5.00 in cash for each share of FirstMerit common stock they hold immediately prior to the merger. Based on the closing trading price of shares of Huntington common stock on the NASDAQ on January 25, 2016, the last trading day before the public announcement of the signing of the merger agreement, the value of the merger consideration per share of FirstMerit common stock was $20.14. Based on the closing trading price of shares of Huntington common stock on the NASDAQ on July 26, 2016, the last practicable trading day before the date of this filing on Form 8-K, the value of the merger consideration per share of FirstMerit common stock was $21.19. In addition, upon completion of the second step merger, as described in Huntington’s Current Report on Form 8-K filed on January 28, 2016, each share of FirstMerit’s 5.875% Non-Cumulative Perpetual Preferred Stock, Series A will be converted into the right to receive a share of Huntington’s 5.875% Series C Non-Cumulative Perpetual Preferred Stock.

The pro forma allocation of the purchase price reflected in the pro forma condensed combined financial information is subject to adjustment and may vary from the actual purchase price allocation that will be recorded at the time the merger is completed. Adjustments may include, but not be limited to, changes in (i) FirstMerit’s balance sheet through the effective time of the merger; (ii) the aggregate value of merger consideration paid if the price of shares of Huntington common stock varies from the assumed $9.41 per share, which represents the closing share price of Huntington common stock on July 26, 2016; (iii) total merger related expenses if consummation and/or implementation costs vary from currently estimated amounts; and (iv) the underlying values of assets and liabilities if market conditions differ from current assumptions.

The accounting policies of both Huntington and FirstMerit are in the process of being reviewed in detail. Upon completion of such review, conforming adjustments or financial statement reclassification may be determined.

Note 2 - Preliminary Purchase Price Allocation

The pro forma adjustments include the estimated purchase accounting entries to record the merger transaction. The excess of the purchase price over the fair value of net assets acquired, net of deferred taxes, is allocated to goodwill. Estimated fair value adjustments included in the pro forma financial statements are based upon available information and certain assumptions considered reasonable, and may be revised as additional information becomes available.

Core deposit intangible assets of $350 million are included in the pro forma adjustments separate from goodwill and amortized using the straight-line method over ten years. Purchased credit card relationship and Trust relationship intangible assets of $15 and $40 million are also included in the pro forma adjustments separate from goodwill and amortized using the sum-of-the-years-digits method over eight and twelve years, respectively. When the actual amortization is recorded for periods following the completion of the merger, the straight line or sum-of-the-years-digits method will be used. Goodwill totaling $1.2 billion is included in the pro forma adjustments and is not subject to amortization. The purchase price is contingent on Huntington’s price per common share at the closing date of the merger, which has not yet occurred. Accordingly, a 10% increase or decrease in Huntington’s most recently used price per share of common stock would result in a corresponding goodwill adjustment of approximately $269 million.

The preliminary purchase price allocation is as follows:

HUNTINGTON BANCSHARES INCORPORATED AND FIRSTMERIT CORPORATION

Unaudited Pro Forma Purchase Price

As of June 30, 2016

Note 3 - Pro Forma Adjustments

The following pro forma adjustments have been reflected in the pro forma condensed combined financial information. All taxable adjustments were calculated using a 35.0% tax rate to arrive at deferred tax asset or liability adjustments. All adjustments are based on current assumptions and valuations, which are subject to change.

The adjustment also reflects $615 million of cash paid to First Commonwealth Bank related to the branch divestiture, offset by an increase in short-term borrowings of $615 million to fund the divestiture. See Note 5 for more information.

The adjustment also reflects incremental interest expense of $7 million for the six months ended June 30, 2016, and $14 million for the year ended December 31, 2015, related to the issuance of acquisition debt totaling $500 million, bearing interest at an interest rate of 2.85%, in connection with the FirstMerit acquisition transaction. The interest expense adjustment assumes amortization of estimated total debt issuance costs of $1 million for the six months ended June 30, 2016 and year ended December 31, 2015.

Note 4 - Merger Integration Costs

Merger- and integration-related costs are not included in the pro forma condensed combined statements of income since they will be recorded in the combined results of income as they are incurred prior to, or after completion of, the merger and are not indicative of what the historical results of the combined company would have been had the companies been actually combined during the periods presented. Merger- and integration-related costs are estimated to be $431 million pretax; $145 million is estimated to be incurred at closing. The $145 million of contractually obligated pre-tax merger costs are reflected in the pro forma adjustments as a $123 million reduction to cash and due from banks (reference A) and a $22 million increase to accrued expenses and other liabilities (reference M).

Note 5 - Divestiture of FirstMerit and/or Huntington Branches

On July 27, 2016, Huntington and FirstMerit announced that, in connection with their proposed merger, 13 branches within Stark and Ashtabula counties, with approximately $735 million in total deposits and $115 million in total loans as of May 31, 2016, will be sold to First Commonwealth Bank, the banking subsidiary of First Commonwealth Financial Corporation. The sale is in connection with an agreement reached with the U.S. Department of Justice in order to resolve its competitive concerns about Huntington’s proposed acquisition of FirstMerit. The divestiture transaction is subject to the completion of the merger of Huntington and FirstMerit, which remains subject to OCC approval.