Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * GLENCORE INTERNATIONAL AG 2. Issuer Name and Ticker or Trading Symbol CENTURY ALUMINUM CO [CENX] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) BAARERMATTSTRASSE 3, P.O. BOX 1363 3. Date of Earliest Transaction (Month/Day/Year) 09/30/2025 (Street) BAAR, V8 CH-6341 4. If Amendment, Date Original Filed (Month/Day/Year) 6. Individual or Joint/Group Filing (Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 09/30/2025 C 2,848 A (1)(2) 12,557,356 I See Footnote(3) Common Stock 27,500,000 D

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Series A Convertible Preferred Stock

(2)

09/30/2025

C

28.48

(2)

(2)

Common Stock

2,848

(2)

49,485.91

I

See Footnote(3)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
GLENCORE INTERNATIONAL AG BAARERMATTSTRASSE 3 P.O. BOX 1363 BAAR, V8 CH-6341		X
Glencore AG BAARERMATTSTRASSE 3 P.O. BOX 1363 BAAR, V8 CH-6341		X
Glencore plc BAARERMATTSTRASSE 3 P.O. BOX 1363 BAAR, V8 CH-6341		X

Signatures

GLENCORE INTERNATIONAL AG By: /s/ John Burton Name: John Burton Title: Director By: /s/ Steven Kalmin Name: Steven Kalmin Title: Director		10/02/2025
**Signature of Reporting Person		Date
GLENCORE AG By: /s/ Martin Haering Name: Martin Haering Title: Director By: /s/ Carlos Perezagua Name: Carlos Perezagua Title: Director		10/02/2025
**Signature of Reporting Person		Date
GLENCORE PLC By: /s/ John Burton Name: John Burton Title: Company Secretary		10/02/2025
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Represents shares of Common Stock acquired upon conversion of 28.48 shares of Series A Convertible Preferred Stock on September 30, 2025.
(2)	Each share of Series A Convertible Preferred Stock is convertible into 100 shares of Common Stock at the times and under the circumstances described in the Certificate of Designation for the Series A Convertible Preferred Stock. The Series A Convertible Preferred Stock has no expiration date.
(3)	The shares of Common Stock reported in Line 1 of Table I and the shares of Series A Convertible Preferred Stock reported in Table II are held directly by Glencore AG, a direct wholly-owned subsidiary of Glencore International AG, and may be deemed to be indirectly beneficially owned by Glencore International AG. The Common Stock reported on Line 2 of Table I is held directly by Glencore International AG. Glencore International AG is wholly owned by Glencore plc, which may be deemed an indirect beneficial owner of the securities held by Glencore AG and Glencore International AG.

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