MERC 10-Q Quarter ended Sept. 30, 2012

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

For the quarterly period ended September 30, 2012

OR

For the transition period from                    to

Commission File No.: 000-51826

MERCER INTERNATIONAL INC.

(Exact name of Registrant as specified in its charter)

Suite 1120, 700 West Pender Street, Vancouver, British Columbia, Canada, V6C 1G8

(Address of office)

(604) 684-1099

(Registrant’s telephone number, including area code)

Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    YES x NO ¨

Indicate by check mark whether the Registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T during the preceding 12 months or for such shorter period that the registrant was required to submit and post such files).    YES x NO ¨

Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer. See definition of “accelerated filer and large accelerated filer” in Rule 12b-2 of the Exchange Act. (Check one):

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    YES ¨ NO x

The Registrant had 55,815,704 shares of common stock outstanding as at November 1, 2012.

MERCER INTERNATIONAL INC.

INTERIM CONSOLIDATED FINANCIAL STATEMENTS

FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2012

(Unaudited)

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MERCER INTERNATIONAL INC.

(Unaudited)

(In thousands of Euros)

The accompanying notes are an integral part of these interim consolidated financial statements.

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MERCER INTERNATIONAL INC.

(Unaudited)

(In thousands of Euros, except per share data)

The accompanying notes are an integral part of these interim consolidated financial statements.

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MERCER INTERNATIONAL INC.

INTERIM CONSOLIDATED STATEMENTS OF RETAINED EARNINGS

(Unaudited)

(In thousands of Euros)

INTERIM CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS)

(Unaudited)

(In thousands of Euros)

The accompanying notes are an integral part of these interim consolidated financial statements.

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MERCER INTERNATIONAL INC.

(Unaudited)

(In thousands of Euros)

The accompanying notes are an integral part of these interim consolidated financial statements.

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MERCER INTERNATIONAL INC.

INTERIM CONSOLIDATED STATEMENTS OF CASH FLOWS (continued)

(Unaudited)

(In thousands of Euros)

The accompanying notes are an integral part of these interim consolidated financial statements.

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MERCER INTERNATIONAL INC.

NOTES TO INTERIM CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

(In thousands of Euros, except per share data)

Basis of Presentation

The interim consolidated financial statements contained herein include the accounts of Mercer International Inc. (“Mercer Inc.”) and its wholly-owned and majority-owned subsidiaries (collectively the “Company”). The Company’s shares of common stock are quoted and listed for trading on both the NASDAQ Global Market and the Toronto Stock Exchange.

The interim consolidated financial statements have been prepared by the Company pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”). The year-end Consolidated Balance Sheet data was derived from audited financial statements. The footnote disclosure included herein has been prepared in accordance with accounting principles generally accepted for interim financial statements in the United States (“GAAP”). The interim consolidated financial statements should be read together with the audited consolidated financial statements and accompanying notes included in the Company’s latest annual report on Form 10-K for the fiscal year ended December 31, 2011. In the opinion of the Company, the unaudited interim consolidated financial statements contained herein contain all adjustments necessary to fairly present the results of the interim periods included. The results for the periods included herein may not be indicative of the results for the entire year.

The Company has three pulp mills that are aggregated into one reportable business segment, market pulp. Accordingly, the results presented are those of the reportable business segment.

Certain prior year amounts in the interim consolidated financial statements have been reclassified to conform to the current year presentation. Beginning in the second quarter of 2012, the Company has presented revenue from the sale of chemicals within energy and chemicals revenue in the Interim Consolidated Statement of Operations. This revenue had previously been presented within operating costs. Chemical revenue for the three and nine month periods ended September 30, 2012 was €2,936 and €8,923, respectively (2011 – €2,287 and €7,762).

In these interim consolidated financial statements, unless otherwise indicated, all amounts are expressed in Euros (“€”). The term “U.S. dollars” and the symbol “$” refer to United States dollars. The symbol “C$” refers to Canadian dollars.

Use of Estimates

Preparation of financial statements and related disclosures in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant management judgment is required in determining the accounting for, among other things, doubtful accounts and reserves, depreciation and amortization, future cash flows associated with impairment testing for long-lived assets, derivative financial instruments, environmental conservation and legal liabilities, asset retirement obligations, pensions and post-retirement benefit obligations, income taxes, contingencies, and inventory obsolescence and provisions. Actual results could differ from these estimates, and changes in these estimates are recorded when known.

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MERCER INTERNATIONAL INC.

NOTES TO INTERIM CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

(In thousands of Euros, except per share data)

Recently Implemented Accounting Standards

In May 2011, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update 2011-04, Fair Value Measurements (“ASU 2011-04”), which expands the existing disclosure requirements for fair value measurements (particularly for Level 3 inputs) defined under FASB’s Accounting Standards Codification No. 820, Fair Value Measurement (“ASC 820”), and makes other amendments. Many of the amendments to ASC 820 are being made to eliminate wording differences between GAAP and International Financial Reporting Standards and are not intended to result in a change in the application of the requirements of ASC 820. However, some of the amendments clarify the application of existing fair value measurement requirements and others change certain requirements for measuring fair value and could change how the fair value measurement guidance in ASC 820 is applied. The measurement and disclosure requirements of ASU 2011-04 were effective for reporting periods beginning after December 15, 2011 and were applied prospectively. The adoption of this new guidance did not have an impact on the interim consolidated financial statements or related note disclosures.

In June 2011, FASB issued Accounting Standards Update 2011-05, Presentation of Comprehensive Income (“ASU 2011-05”), which revises the manner in which entities present comprehensive income in their financial statements. The new guidance amends FASB’s Accounting Standards Codification No. 220, Comprehensive Income (“ASC 220”), and gives reporting entities the option to present the total of comprehensive income, the components of net income, and the components of other comprehensive income in either a continuous statement of comprehensive income or two separate but consecutive statements. Under the two-statement approach, which the Company currently uses, the first statement includes components of net income, and the second statement includes components of other comprehensive income. ASU 2011-05 does not change the items that must be reported in other comprehensive income. This new guidance was effective for reporting periods beginning after December 15, 2011 and was applied retrospectively. The adoption of this guidance did not have an impact on the interim consolidated financial statements or related note disclosures.

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MERCER INTERNATIONAL INC.

NOTES TO INTERIM CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

(In thousands of Euros, except per share data)

Debt consists of the following:

The Company made principal repayments under these facilities of €27,254 during the nine month period ended September 30, 2012 (2011 – €42,511). As of September 30, 2012, the principal maturities of debt are as follows:

Certain of the Company’s debt instruments were issued under an indenture which, among other things, restricts its ability and the ability of its restricted subsidiaries to make certain payments. These limitations are subject to other important qualifications and exceptions. As at September 30, 2012, the Company was in compliance with the terms of the indenture.

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MERCER INTERNATIONAL INC.

NOTES TO INTERIM CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

(In thousands of Euros, except per share data)

Note 3. Debt (continued)

On March 13, 2009, the Company finalized an agreement with its lenders to amend its Stendal Loan Facility. The amendment deferred approximately €164,000 of scheduled principal payments until the maturity date, September 30, 2017. The amendment also provided for a 100% cash sweep, referred to as the “Cash Sweep”, of any cash, in excess of a €15,000 working capital reserve and the Guarantee Amount, as discussed in Note 10(a) – Commitments and Contingencies, and other amounts as contemplated in the amendment, held by Stendal which will be used first to fund the DSRA to a level sufficient to service the amounts due and payable under the Stendal Loan Facility during the then following 12 months, which means the DSRA is “Fully Funded”, and second to prepay the deferred principal amounts. As at September 30, 2012, the DSRA balance was €31,821 and was not Fully Funded.

In August 2011, the Company’s Board of Directors authorized the purchase of up to $25.0 million in aggregate principal amount of the Company’s Senior Notes from time to time, over a period ending August 2012. In June 2012, the Company’s Board of Directors authorized the purchase of up to €50,000 in aggregate principal amount of the Company’s Senior Notes from time to time, over a period ending June 2013. During the nine month period ended September 30, 2012, the Company purchased $2.0 million of its outstanding Senior Notes. During the twelve month period ended December 31, 2011, the Company purchased $13.6 million of its outstanding Senior Notes.

The Senior Notes are general unsecured senior obligations of the Company. The Senior Notes rank equal in right of payment with all existing and future senior unsecured indebtedness of the Company and senior in right of payment to any current or future subordinated indebtedness of the Company. The Senior Notes are effectively junior in right of payment to all borrowings of the Company’s restricted subsidiaries, including borrowings under the Company’s credit agreements which are secured by certain assets of its restricted subsidiaries.

The Company may redeem all or a part of the Senior Notes, upon not less than 30 days’ or more than 60 days’ notice, at the redemption prices (expressed as percentages of principal amount) equal to 104.75% for the twelve month period beginning on December 1, 2014, 102.38% for the twelve month period beginning on December 1, 2015, and 100.00% beginning on December 1, 2016 and at any time thereafter, plus accrued and unpaid interest.

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MERCER INTERNATIONAL INC.

NOTES TO INTERIM CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

(In thousands of Euros, except per share data)

In January 2012, the Stendal mill entered into two additional loans payable by the Stendal mill to its noncontrolling shareholder as part of the financing for Project Blue Mill. The first loan has a principal amount of €1,192 and the second loan has a principal amount of €440. Both loans bear interest at 7.00% per annum and are due in 2017, provided that the Project Blue Mill facility (Note 3(d)) and the Stendal Loan Facility (Note 3(a)) have been fully repaid on such date. The second loan may be repaid prior to October 1, 2017 if the DSRA has been Fully Funded for the first time. The first loan is subordinated to all liabilities of the Stendal mill and the second loan is subordinated to all liabilities of the Stendal mill only until such time as the DSRA is Fully Funded for the first time.

As at September 30, 2012, accrued interest on these loans was €9,392. As at December 31, 2011, accrued interest on the loan was €7,996.

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MERCER INTERNATIONAL INC.

NOTES TO INTERIM CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

(In thousands of Euros, except per share data)

Included in pension and other post-retirement benefit obligations are amounts related to the Company’s Celgar and Rosenthal mills. The largest component of this obligation is with respect to the Celgar mill which maintains a defined benefit pension plan and post-retirement benefit plans for certain employees (“Celgar Plans”).

Pension benefits are based on employees’ earnings and years of service. The Celgar Plans are funded by contributions from the Company based on actuarial estimates and statutory requirements. Pension contributions during the three and nine month periods ended September 30, 2012 totaled €481 and €1,493, respectively (2011 – €534 and €1,429).

Effective December 31, 2008, the defined benefit plan was closed to new members. In addition, the defined benefit service accrual ceased on December 31, 2008, and members began to receive pension benefits, at a fixed contractual rate, under a new defined contribution plan effective January 1, 2009. During the three and nine month periods ended September 30, 2012, the Company made contributions of €142 and €462, respectively (2011 – €141 and €426) to this plan.

Information about the Celgar Plans, in aggregate for the three and nine month periods ended September 30, 2012 and September 30, 2011 is as follows:

The Company participates in a multiemployer plan for hourly-paid employees at the Celgar mill. The contributions to this plan are determined based on an amount per hour worked pursuant to a collective bargaining agreement. The Company has no current or future contribution obligations in excess of the contractual contributions. During the three and nine month periods ended September 30, 2012, the Company made contributions of €632 and €1,572, respectively (2011 – €455 and €1,429) to this plan.

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MERCER INTERNATIONAL INC.

NOTES TO INTERIM CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

(In thousands of Euros, except per share data)

Common shares

The Company has authorized 200,000,000 common shares with a par value of $1 per share.

As at September 30, 2012, the Company had 55,815,704 common shares issued and outstanding. As at December 31, 2011, the Company had 55,779,204 common shares issued and outstanding. During the nine months ended September 30, 2012, the Company issued 36,500 restricted shares to directors of the Company.

Share Repurchase Program

In August 2011, the Company’s Board of Directors authorized a share repurchase program (the “Program”) to repurchase up to $25.0 million worth of the Company’s outstanding common shares from time to time over a period ending August 2012. In July 2012, the Company’s Board of Directors re-authorized the Program to allow for the repurchase of up to approximately $14.4 million of the Company’s outstanding shares of common stock over a period ending August 2013. During the nine month period ended September 30, 2012, the Company did not repurchase any of its common shares. During the twelve month period ended December 31, 2011, the Company repurchased 1,263,401 of its common shares at an aggregate cost of $10.6 million.

Preferred shares

The Company has authorized 50,000,000 preferred shares with $1 par value issuable in series, of which 2,000,000 shares have been designated as Series A. The preferred shares may be issued in one or more series and with such designations and preferences for each series as shall be stated in the resolutions providing for the designation and issue of each such series adopted by the Board of Directors of the Company. The Board of Directors is authorized by the Company’s articles of incorporation to determine the voting, dividend, redemption and liquidation preferences pertaining to each such series. As at September 30, 2012, no preferred shares had been issued by the Company.

In June 2010, the Company adopted a new stock incentive plan (the “2010 Plan”) which provides for options, restricted stock rights, restricted shares, performance shares, performance share units (“PSUs”) and stock appreciation rights to be awarded to employees, consultants and non-employee directors. As at September 30, 2012, after factoring in all allocated shares, there remain approximately 1.1 million common shares available for grant pursuant to the 2010 Plan.

Performance Shares and PSUs

Performance shares are common shares granted to an employee which have restrictive conditions, such as the ability to sell the shares, until the Company and the grantee achieve certain performance objectives. PSUs comprise rights to receive common shares at a future date that are contingent on the Company and the grantee achieving certain performance objectives.

The fair value of the performance shares and PSUs is recorded as compensation expense over the vesting period. The fair value is determined based upon the targeted number of shares awarded and the quoted price of the Company’s shares at the reporting date. The target number of shares is determined using management’s best estimate. The final determination of the number of shares to be granted or unrestricted will be made by the Company’s Board of Directors. For the three and nine month periods ended September 30, 2012 the Company recognized an expense of €714 and €1,091, respectively, related to the PSUs (2011 expense – €13 and €771).

As at September 30, 2012, there are no performance shares outstanding.

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MERCER INTERNATIONAL INC.

NOTES TO INTERIM CONSOLIDATED FINANCIAL STATEMENTS

(Unaudited)

(In thousands of Euros, except per share data)

Note 6. Stock-Based Compensation (continued)

The following table summarizes PSU activity during the period:

Restricted Shares

The fair value of restricted shares is determined based upon the number of shares granted and the quoted price of the Company’s shares on the date of grant. Restricted shares generally vest over one year; however, 200,000 restricted shares granted during the year ended December 31, 2011 vest in equal amounts over a five-year period commencing in 2012. The fair value of the restricted shares is recorded as compensation expense on a straight-line basis over the vesting period.

For the three and nine month periods ended September 30, 2012, the Company recognized an expense of €177 and €662, respectively (2011 – €295 and €691) related to the restricted shares. As at September 30, 2012, the total remaining unrecognized compensation cost related to restricted shares amounted to approximately €901 (2011 – €1,642), which will be amortized over the remaining vesting periods.

The following table summarizes restricted share activity during the period:

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MERCER INTERNATIONAL INC.