# EDGAR Filing Document

**Accession Number:** 0000949157
**File Stem:** 0001104659-26-023524
**Filing Date:** 2026-3
**Character Count:** 20875
**Document Hash:** 2d1e7b58c52fd082f5354b5af8ba3802
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-26-023524.hdr.sgml**: 20260304

**ACCESSION NUMBER**: 0001104659-26-023524

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13D/A

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260304

**DATE AS OF CHANGE**: 20260304

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** CENTURY ALUMINUM CO
- **CENTRAL INDEX KEY:** 0000949157
- **STANDARD INDUSTRIAL CLASSIFICATION:** PRIMARY PRODUCTION OF ALUMINUM [3334]
- **ORGANIZATION NAME:** 04 Manufacturing
- **EIN:** 133070826
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-47307
- **FILM NUMBER:** 26722305

**BUSINESS ADDRESS:**
- **STREET 1:** 1 SOUTH WACKER DRIVE
- **STREET 2:** SUITE 1000
- **CITY:** CHICAGO
- **STATE:** IL
- **ZIP:** 60606
- **BUSINESS PHONE:** 3126963101

**MAIL ADDRESS:**
- **STREET 1:** 1 SOUTH WACKER DRIVE
- **STREET 2:** SUITE 1000
- **CITY:** CHICAGO
- **STATE:** IL
- **ZIP:** 60606
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** GLENCORE INTERNATIONAL AG
- **CENTRAL INDEX KEY:** 0001032383

**ORGANIZATION NAME:**
- **EIN:** 000000000

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A

**BUSINESS ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** BAARERMATTSTRASSE 3
- **STREET 2:** P O BOX 555 CH 6341 BAAR
- **CITY:** BAAR
- **PROVINCE COUNTRY:** V8
- **BUSINESS PHONE:** 4142227722

**MAIL ADDRESS:**
- **ADDRESS IS A NON US LOCATION:** YES
- **STREET 1:** BAARERMATTSTRASSE 3
- **STREET 2:** P O BOX 555 CH 6341 BAAR
- **CITY:** BAAR
- **PROVINCE COUNTRY:** V8

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**(Amendment No. 30)**

**CENTURY ALUMINUM CO**

*(Name of Issuer)*

**Common Stock, $0.01 Par Value**

*(Title of Class of Securities)*

**156431108**

*(CUSIP Number)*

**Steven Kalmin**<br>Baarermattstrasse 3<br>Baar V8 CH-6340<br>41 41 709 2000

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

**03/04/2026**

*(Date of Event Which Requires Filing of this Statement)*

| **CUSIP No.** | **156431108** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Glencore International AG** | Name of reporting person<br>**Glencore International AG** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[x] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[x] | |
| 6 | Citizenship or place of organization<br>**V8** | Citizenship or place of organization<br>**V8** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**29690702.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**29690702.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**29690702.00** | Aggregate amount beneficially owned by each reporting person<br>**29690702.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**29.99%** | Percent of class represented by amount in Row (11)<br>**29.99%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**CO** | Type of Reporting Person (See Instructions)<br>**CO** | |

---

| **CUSIP No.** | **156431108** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Glencore plc** | Name of reporting person<br>**Glencore plc** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[x] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[x] | |
| 6 | Citizenship or place of organization<br>**Y9** | Citizenship or place of organization<br>**Y9** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**29690702.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**29690702.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**29690702.00** | Aggregate amount beneficially owned by each reporting person<br>**29690702.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**29.99%** | Percent of class represented by amount in Row (11)<br>**29.99%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**CO** | Type of Reporting Person (See Instructions)<br>**CO** | |

---

| **CUSIP No.** | **156431108** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Glencore AG** | Name of reporting person<br>**Glencore AG** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[x] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[x] | |
| 6 | Citizenship or place of organization<br>**V8** | Citizenship or place of organization<br>**V8** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**17505947.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**17505947.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**17505947.00** | Aggregate amount beneficially owned by each reporting person<br>**17505947.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**17.68%** | Percent of class represented by amount in Row (11)<br>**17.68%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**CO** | Type of Reporting Person (See Instructions)<br>**CO** | |

---

**Item 1. Security and Issuer**

**(a) Title of Class of Securities:**
Common Stock, $0.01 Par Value

**(b) Name of Issuer:**
CENTURY ALUMINUM CO

**(c) Address of Issuer's Principal Executive Offices:**
One South Wacker Drive, Suite 1000, Chicago, IL, 60606

Century Aluminum Company is a Delaware Corporation

**Item 4. Purpose of Transaction**

The Reporting Persons remain confident in the management team and outlook of the Company, maintain a position in the Company and intend to continue to hold Common Stock for investment purposes.

On March 4, 2026, the Reporting Persons monetized a portion of their investment via a sale of 6,315,245 shares in a block trade pursuant to Rule 144 and subject to customary conditions (the "Subject Sale").

The Reporting Persons may purchase or sell additional shares of Common Stock and other securities of the Issuer. Such transactions could be in the open market and/or in privately negotiated or structured transactions, provided that any such transactions would be on terms deemed favorable by the Reporting Persons. In addition, the Reporting Persons may formulate plans or proposals for, hold discussions with the Company's management, the Company's Board of Directors, the Company's stockholders and other parties about, and reserve the right to explore, or make plans or proposals relating to, transactions, discussions or actions which relate to or would result in any of the matters specified in clauses (a) through (j) of Item 4 of Schedule 13D. The Reporting Persons' consideration or discussion of any action would be based on their own assessment of various relevant considerations and any subsequent developments affecting the Company and its prospects.

**Item 5. Interest in Securities of the Issuer**

**(a)**
Glencore AG beneficially owns 17,505,947 shares of Common Stock, or 17.68% of the outstanding Common Stock, which it holds directly, and each of Glencore plc and Glencore International beneficially owns an aggregate of 29,690,702 shares of Common Stock, or 29.99% of the outstanding Common Stock, consisting of 12,184,755 shares held directly by Glencore International and the 17,505,947 shares held directly by Glencore AG.

To the best knowledge of the Reporting Persons, none of the other persons identified in Item 2(c) beneficially owns any shares of Common Stock.

The beneficial ownership percentages reported herein are based upon 98,969,007 shares of Common Stock outstanding as of December 31, 2025, based on the Company's Current Report on Form 10-K filed with the Securities and Exchange Commission on March 3, 2026.

**(b)**
The Reporting Persons share the power to vote and direct the voting of and to dispose or to direct the disposition of the 29,690,702 shares of Common Stock reported as beneficially owned by them herein, except that Glencore AG shares the power to vote and direct the voting of and to dispose or to direct the disposition of only the 17,505,947 shares held directly by it.

**(c)**
Except for the Subject Sale referenced in Item 4 above, in which, on March 4, 2026 Glencore International sold 6,315,245 shares of Common Stock at a price per share of $51.75 in a block trade under Rule 144, none of the Reporting Persons nor, to the Reporting Persons' knowledge, any of the other persons identified in Item 2(c), has engaged in any transaction during the past 60 days in any Common Stock.

**Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.**

Series A Preferred Stock Purchase: On July 7, 2008 the Company entered into a Stock Purchase Agreement with Glencore Investment Pty Ltd. ("Glencore Investment Pty") pursuant to which Glencore Investment Pty purchased the Series A Preferred Shares.

On November 10, 2025, all 49,485.91 shares of Series A Preferred Shares held by Glencore AG, being all of the Series A Preferred Shares still owned by Glencore AG at that time, were automatically converted into 4,948,591 shares of Common Stock in accordance with the terms of the Series A Preferred Shares, in connection with a sale of shares of Common Stock by Glencore International.  As a result of this conversion, the Reporting Persons no longer own any shares of Series A Preferred Stock.

Standstill and Governance Agreement:  In connection with the Stock Purchase Agreement, on July 7, 2008 Glencore AG and the Company entered into a Standstill and Governance Agreement (the "Governance Agreement").  Certain standstill obligations of Glencore AG and its affiliates under the Governance Agreement expired on each of April 8, 2009 and January 7, 2010.  No standstill obligations under the Governance Agreement are currently binding on Glencore AG or any of its affiliates.  The following is a summary of the material terms of the Governance Agreement that remain in effect today:

Board Representation. The Reporting Persons will have the right to designate a nominee for election to the Board of Directors, subject to the consent of the nominating committee. This right will terminate if the Reporting Persons (and their affiliates) beneficially own (within the meaning of Rule13d-3) less than 10% of the Common Stock for a period of three continuous months.

Registration Rights Agreement:  On July 7, 2008, Glencore Investment Pty and the Company entered into a Registration Rights Agreement, containing customary terms and conditions (the "Registration Rights Agreement"), pursuant to which the Company has agreed to register the Series A Preferred Shares and Common Stock issued upon conversion thereof for resale by the Reporting Persons and their affiliates and any of their respective pledgees.  Sales under the Registration Rights Agreement must be made in open market transactions that comply with Rule 144 under the Securities Act of 1933, as amended, or in widely distributed public offerings.  The Reporting Persons, their affiliates and any of their respective pledgees are entitled to demand up to six registrations from and after November 5, 2008 and subject to certain customary restrictions, may at any time participate in registered offerings initiated by the Company for its own account or the account of other stockholders.    Subject to the restriction on the number of demand registrations, the registration rights will continue until the Common Stock issued upon conversion of the Series A Preferred Shares are sold under an effective registration statement or the Series A Preferred Shares are no longer outstanding.  The Company will be responsible for all fees and expenses relating to any registration of the Series A Preferred Shares, except that the Reporting Persons will be responsible for any underwriters commissions and any fees and expenses of their legal counsel and any other advisors retained by them (including underwriters' counsel in the case of demand registrations).

Support Agreement: The Company disclosed in its notice of Annual Meeting of Stockholders held on May 27, 2009 and related proxy statement a management proposal to amend the Company's Restated Certificate of Incorporation to increase the number of authorized shares of Common Stock.  Following filing of the proxy statement, Glencore AG and the Company engaged in discussions relating to the proposed increase in the Company's authorized capital.  The Company determined to amend the proposal to provide for an increase in the number of authorized shares of Common Stock from 100,000,000 to 195,000,000, and on May 4, 2009, the Company and Glencore AG entered into a Support Agreement (the "Support Agreement") whereby (a) Glencore AG agreed to vote for the amended proposal to increase authorized capital and the other matters being proposed by the Company for approval at the May 27, 2009 stockholders meeting, and (b) except for certain limited and strategic transactions and other customary exceptions, the Company agreed to give the Reporting Persons the right to maintain their equity percentage ownership in the Company by purchasing (i) their pro rata portion of additional shares of Common Stock and other securities or interests convertible into or exchangeable or exercisable for Common Stock (including cash settled derivatives) issued by the Company and its affiliates in cash offerings and (ii) additional shares of Common Stock and other securities or interests convertible into or exchangeable or exercisable for Common Stock (including cash settled derivatives) issued by the Company and its affiliates in any debt exchange offers if and to the extent the aggregate cumulative number of shares of Common Stock or their equivalent issued in debt exchanges in any twelve month period prior to November 4, 2010 would equal or exceed 30 million shares.  The right to acquire securities will terminate if the Reporting Persons beneficially own (within the meaning of Rule13d-3) less than 10% of the Common Stock for a period of three continuous months.

Irrevocable Proxies: On September 14, 2017, Glencore AG granted to the Chief Accounting Officer and the Treasurer of the Company a five-year irrevocable proxy (the "2017 Glencore Irrevocable Proxy") to vote, as directed by Glencore AG, all shares of Common Stock that Glencore AG owns of record from time to time, provided that the proxies must limit the number of such shares they vote on each matter submitted to the stockholders such that the number of such shares they vote, when added to other shares that Glencore AG and its affiliates have the right to vote (including the Specified Shares), do not equal or exceed 50% of the total number of shares voted by all stockholders. The Glencore Irrevocable Proxy expired in accordance with its terms on September 14, 2022. On March 23, 2023, the Reporting Persons granted to the Chief Accounting Officer and the Treasurer of the Company a five-year irrevocable proxy (the "2023 Glencore Irrevocable Proxy") on the same terms as the 2017 Glencore Irrevocable Proxy.

Security Deeds: On December 1, 2023, Glencore International and Glencore AG together pledged 39,655,115 shares of Common Stock in aggregate (the "Pledged Shares") to HSBC Bank PLC as lender, to secure a revolving loan facility made available to Glencore International (the "2023 Credit Facility"). The 2023 Credit Facility remains available until terminated by the lender. The 2023 Credit Facility and the related deeds of security pursuant to which each of the pledgors granted the pledge of the Pledged Shares owned by it (the "2023 Security Deeds") contain covenants, events of default and other terms and conditions customary for facilities of this type. Glencore International's obligations under the 2023 Credit Facility are guaranteed by Glencore plc.  The number of Pledged Shares was reduced as a result of the sale of the Subject Shares.

The foregoing descriptions of the Governance Agreement, Registration Rights Agreement, Support Agreement, 2017 Glencore Irrevocable Proxy, 2023 Glencore Irrevocable Proxy and 2023 Security Deeds do not purport to be complete and are subject to, and qualified in their entirety by reference to, the full text of such instruments and agreements, which are filed herewith or were previously filed with the Securities and Exchange Commission as exhibits to this Statement, and are hereby incorporated herein by reference. Except for terms of such instruments and agreements, to the best knowledge of the Reporting Persons, there exists no contracts, arrangements, understandings or relationships (legal or otherwise) among the persons named in Item 2 and between such persons and any person with respect to any securities of the Company, including but not limited to the transfer or voting of any securities of the Company, finder's fees, joint ventures, loan or option arrangements, puts or calls, guarantees of profits, division of profits or loss, or the giving or withholding of proxies.

### 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.

**Reporting Person:** Glencore International AG

**Signature:** /s/ John Burton

**Name/Title:** John Burton/Authorised Signatory

**Date:** 03/04/2026

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.

**Reporting Person:** Glencore plc

**Signature:** /s/ John Burton

**Name/Title:** John Burton/Authorised Signatory

**Date:** 03/04/2026

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.

**Reporting Person:** Glencore AG

**Signature:** /s/ John Burton

**Name/Title:** John Burton/Authorised Signatory

**Date:** 03/04/2026