# EDGAR Filing Document

**Accession Number:** 0001333274
**File Stem:** 0001193125-26-290608
**Filing Date:** 2026-6
**Character Count:** 6902
**Document Hash:** e9818b9b1e4bc07fba9d1adc270f1363
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-290608.hdr.sgml**: 20260630

**ACCESSION NUMBER**: 0001193125-26-290608

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 13

**CONFORMED PERIOD OF REPORT**: 20260630

**ITEM INFORMATION**: Regulation FD Disclosure

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20260630

**DATE AS OF CHANGE**: 20260630

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MERCER INTERNATIONAL INC.
- **CENTRAL INDEX KEY:** 0001333274
- **STANDARD INDUSTRIAL CLASSIFICATION:** PULP MILLS [2611]
- **ORGANIZATION NAME:** 04 Manufacturing
- **EIN:** 470956945
- **STATE OF INCORPORATION:** WA
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 000-51826
- **FILM NUMBER:** 261140840

**BUSINESS ADDRESS:**
- **STREET 1:** 700 WEST PENDER STREET
- **STREET 2:** SUITE 1120
- **CITY:** VANCOUVER
- **STATE:** A1
- **ZIP:** V6C 1G8
- **BUSINESS PHONE:** 206-674-4639

**MAIL ADDRESS:**
- **STREET 1:** 14900 INTERURBAN AVENUE SOUTH
- **CITY:** SEATTLE
- **STATE:** WA
- **ZIP:** 98168

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MERCER INTERNATIONAL REGCO INC.
- **DATE OF NAME CHANGE:** 20050715

?xml version='1.0' encoding='ASCII'? 8-K

### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### WASHINGTON, D.C. 20549

### FORM 8-K

#### CURRENT REPORT

#### Pursuant to Section 13 or 15(d)

#### of the Securities Exchange Act of 1934

#### Date of Report (Date of earliest event reported): June 30, 2026

## MERCER INTERNATIONAL INC.

#### (Exact name of Registrant as Specified in Its Charter)

---

| | | |
|:---|:---|:---|
| **Washington** | **000-51826** | **47-0956945** |
| **(State or Other Jurisdiction**<br> **of Incorporation)** | **(Commission**<br> **File Number)** | **(IRS Employer**<br> **Identification No.)** |

---

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

#### (Address of Principal Executive Offices)

#### Registrant's Telephone Number, Including Area Code: (604) 684-1099

#### Not Applicable

#### (Former Name or Former Address, if Changed Since Last Report)
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instructions A.2. below):

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

---

| | | |
|:---|:---|:---|
| **Title of each class** | **Trading<br>Symbol(s)** | **Name of each exchange<br>on which registered** |
| Common Stock, par value $1.00 per share | MERC | NASDAQ Global Select Market |

---

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

------

#### Item 7.01. Regulation FD Disclosure.
The information furnished under Item 7.01 of this Current Report shall not be deemed to be "filed" for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), or otherwise subject to the liabilities of that section, nor shall it be incorporated by reference into any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing,

On June 30, 2026, Mercer International Inc. announced by press release that its German pulp mill, Mercer Rosenthal, will extend its maintenance shutdown, originally scheduled for two weeks, to cover the entire month of September 2026. A copy of such press release is furnished as Exhibit 99.1 to this Current Report.

#### Item 9.01. Financial Statements and Exhibits
(d) Exhibits.

---

| | |
|:---|:---|
| **Exhibit**<br> **Number** | **Description** |
| 99.1 | [Press Release dated June 30, 2026](d123506dex991.htm) |
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document) |

---

------

#### SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

---

| | | |
|:---|:---|:---|
|  | **MERCER INTERNATIONAL INC.** | **MERCER INTERNATIONAL INC.** |
| Date: June 30, 2026 | By: | */s/ Richard Short* |
|  |  | Richard Short |
|  |  | Chief Financial Officer |

---

## Exhibit 99.1

**Exhibit 99.1**![LOGO](g123506g0701001436611.jpg)

**NEWS RELEASE** 

**Maintenance mill shutdown at Mercer Rosenthal in September** 

Rosenthal am Rennsteig, June 30, 2026 – Mercer International Inc., a global forest products company with operations in Germany, the U.S., and Canada, announces that its German pulp mill, Mercer Rosenthal, will extend its maintenance shutdown, originally scheduled for two weeks, to cover the entire month of September 2026.

Mercer is working with production, wood procurement, logistics, and pulp sales to coordinate this undertaking with our customers and stakeholders.

**About Mercer International Inc.** 

Mercer International Inc. is a global forest products company with operations in Germany, the United States and Canada, with consolidated annual production capacity of 2.1 million tonnes of pulp, 960 million board feet of lumber, 210,000 cubic meters of cross-laminated timber, 45,000 cubic meters of glulam, 17 million pallets and 230,000 metric tonnes of biofuels. For further information, please visit www.mercerint.com.

**About Mercer Rosenthal** 

Mercer Rosenthal (MR) produces a variety of wood-based products such as kraft pulp, tall oil and lignin. Mercer Rosenthal also operates Thuringia's largest biomass power plant (413 MW thermal / 57 MW electrical). This allows the mill to be completely energy self-sufficient while also feeding electricity into the public grid. MR produces 360,000 tonnes of kraft pulp (NBSK) annually for paper and tissue production. With a focus on the European market, the site also serves international demand. Mercer Rosenthal employs approximately 400 people, including apprentices. For more information, please visit www.mercerint.com.