Peter Kellogg boosts Mercer (NASDAQ: MERC) ownership to 37.9% stake

Rhea-AI Filing Summary

Mercer International Inc. received an amended Schedule 13D showing that investor Peter R. Kellogg now beneficially owns approximately 37.9% of the company’s common stock as of May 19, 2026. Item 5 reports beneficial ownership of 25,380,929 shares with sole voting and dispositive power over that amount.

During May 12–19, 2026, entities controlled by Mr. Kellogg bought an additional 1,000,000 shares of Mercer common stock through the Nasdaq Stock Market at prices between about $0.84 and $0.96 per share. These purchases were separately reported on Form 4 filings.

Key Figures

Beneficial ownership percentage: 37.9% Beneficially owned shares: 25,380,929 shares Shares purchased in May 2026: 1,000,000 shares +3 more

6 metrics

Beneficial ownership percentage 37.9% Reported stake in Mercer common stock as of May 19, 2026

Beneficially owned shares 25,380,929 shares Shares beneficially owned by Peter R. Kellogg as of May 19, 2026

Shares purchased in May 2026 1,000,000 shares Aggregate bought by entities controlled by Kellogg between May 12–19, 2026

Purchase price range $0.84–$0.96 per share Prices paid for Mercer shares on Nasdaq during May 12–19, 2026

Sole voting power 25,380,929 shares Shares over which Kellogg has sole voting power

Sole dispositive power 25,380,929 shares Shares over which Kellogg has sole dispositive power

Key Terms

beneficially owned, sole Voting Power, sole Dispositive Power, Schedule 13G

4 terms

beneficially owned financial

"As of the close of business on May 19, 2026, Mr. Kellogg beneficially owned an aggregate of 25,380,929 shares"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

sole Voting Power financial

"Number of Shares Beneficially Owned by Each Reporting Person With: 7 | Sole Voting Power 25,380,929.00"

Sole voting power is the exclusive right to cast votes attached to a shareholder’s stock without needing approval from anyone else. Like holding the only remote control for a TV, it lets that holder decide corporate matters such as board members, mergers, and policy changes, making it important to investors because it concentrates control and can strongly influence a company’s strategy and the value of its shares.

sole Dispositive Power financial

"9 | Sole Dispositive Power 25,380,929.00"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

Schedule 13G regulatory

"If the filing person has previously filed a statement on Schedule 13G to report the acquisition"

A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 11)

MERCER INTERNATIONAL INC.

(Name of Issuer)

Common Stock, par value $1.00

(Title of Class of Securities)

588056101

(CUSIP Number)

Peter R. Kellogg
48 Wall Street, 30th Floor,
New York, NY, 10005
(212) 389-5841

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

05/19/2026

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

schemaVersion:

SCHEDULE 13D

CUSIP Number(s): 588056101

1

Name of reporting person

Peter R. Kellogg

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

OO

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 25,380,929.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 25,380,929.00
10	Shared Dispositive Power 0.00

11

Aggregate amount beneficially owned by each reporting person

24,469,540.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

37.9 %

14

Type of Reporting Person (See Instructions)

IN

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, par value $1.00
(b)	Name of Issuer: MERCER INTERNATIONAL INC.
(c)	Address of Issuer's Principal Executive Offices: Suite 1120, 700 West Pender Street, Vancouver, BRITISH COLUMBIA, CANADA , V6C 1G8.
Item 5.	Interest in Securities of the Issuer
(a)	As of the close of business on May 19, 2026, Mr. Kellogg beneficially owned an aggregate of 25,380,929 shares, constituting approximately 37.9% of the shares outstanding.
(b)	As of the close of business on May 19, 2026, Mr. Kellogg beneficially owned an aggregate of 25,380,929 shares, constituting approximately 37.9% of the shares outstanding.
(c)	During May 12, 2026 through May 19, 2026, entities controlled by Mr. Kellogg purchased an aggregate of 1,000,000 shares at prices ranging from approximately $0.84 to $0.96 per share through the Nasdaq Stock Market. All such transactions have been reported on a Form 4 filed by Mr. Kellogg.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Peter R. Kellogg

Signature:	/s/ Marguerite Gorman
Name/Title:	Marguerite Gorman, attorney-in-fact
Date:	05/19/2026

FAQ

What ownership stake does Peter R. Kellogg report in Mercer (MERC)?

Peter R. Kellogg reports beneficial ownership of about 37.9% of Mercer’s common stock. Item 5 states he beneficially owned 25,380,929 shares as of May 19, 2026, with sole voting and dispositive power over that amount.

How many Mercer (MERC) shares did Kellogg-controlled entities buy in May 2026?

Entities controlled by Peter R. Kellogg purchased an aggregate 1,000,000 Mercer shares in May 2026. These acquisitions occurred between May 12 and May 19, 2026, and were executed through the Nasdaq Stock Market, according to the amended Schedule 13D disclosure.

At what prices were the newly purchased Mercer (MERC) shares acquired?

The 1,000,000 Mercer shares were bought at prices ranging from approximately $0.84 to $0.96 per share. All purchases were made through the Nasdaq Stock Market and have also been reported on separate Form 4 insider transaction filings by Mr. Kellogg.

As of what date is Kellogg’s 37.9% Mercer (MERC) ownership calculated?

Kellogg’s roughly 37.9% ownership in Mercer is calculated as of the close of business on May 19, 2026. On that date, the filing reports that he beneficially owned 25,380,929 shares of Mercer common stock with sole voting and dispositive power.

What security is covered in this Mercer (MERC) Schedule 13D/A amendment?

The amendment covers Mercer International Inc.’s common stock with a par value of $1.00 per share. The filing identifies this class of securities and confirms that the reported beneficial ownership and recent purchases relate specifically to this common stock.

Where is Mercer International Inc. (MERC) headquartered according to the filing?

Mercer International Inc. is headquartered at Suite 1120, 700 West Pender Street, Vancouver, British Columbia, Canada, V6C 1G8. This address is listed as the location of the issuer’s principal executive offices in the Schedule 13D/A amendment.