<SEC-DOCUMENT>0001144204-19-033488.txt : 20190702
<SEC-HEADER>0001144204-19-033488.hdr.sgml : 20190702
<ACCEPTANCE-DATETIME>20190702100341
ACCESSION NUMBER:		0001144204-19-033488
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190630
FILED AS OF DATE:		20190702
DATE AS OF CHANGE:		20190702

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Glencore AG
		CENTRAL INDEX KEY:			0001449539
		STATE OF INCORPORATION:			V8
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34474
		FILM NUMBER:		19935531

	BUSINESS ADDRESS:	
		STREET 1:		BAARERMATTSTRASSE 3
		STREET 2:		P.O. BOX 1301
		CITY:			BAAR
		STATE:			V8
		ZIP:			CH-6341
		BUSINESS PHONE:		41 41 709 2512

	MAIL ADDRESS:	
		STREET 1:		BAARERMATTSTRASSE 3
		STREET 2:		P.O. BOX 1301
		CITY:			BAAR
		STATE:			V8
		ZIP:			CH-6341

REPORTING-OWNER:	

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

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34474
		FILM NUMBER:		19935532

	BUSINESS ADDRESS:	
		STREET 1:		BAARERMATTSTRASSE 3
		STREET 2:		P O BOX 555 CH 6341 BAAR
		CITY:			SWITZERLAND
		BUSINESS PHONE:		4142227722

	MAIL ADDRESS:	
		STREET 1:		BAARERMATTSTRASSE 3
		STREET 2:		P O BOX 555 CH 6341 BAAR
		CITY:			SWITZERLAND

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Glencore plc
		CENTRAL INDEX KEY:			0001521365
		STANDARD INDUSTRIAL CLASSIFICATION:	UNKNOWN SIC - 8880 [8880]
		STATE OF INCORPORATION:			Y9
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34474
		FILM NUMBER:		19935533

	BUSINESS ADDRESS:	
		STREET 1:		BAARERMATTSTRASSE 3
		CITY:			BAAR
		STATE:			V8
		ZIP:			CH-6341
		BUSINESS PHONE:		41 41 709 2000

	MAIL ADDRESS:	
		STREET 1:		BAARERMATTSTRASSE 3
		CITY:			BAAR
		STATE:			V8
		ZIP:			CH-6341

	FORMER NAME:	
		FORMER CONFORMED NAME:	Glencore Xstrata plc
		DATE OF NAME CHANGE:	20130606

	FORMER NAME:	
		FORMER CONFORMED NAME:	GLENCORE INTERNATIONAL PLC
		DATE OF NAME CHANGE:	20110520

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CENTURY ALUMINUM CO
		CENTRAL INDEX KEY:			0000949157
		STANDARD INDUSTRIAL CLASSIFICATION:	PRIMARY PRODUCTION OF ALUMINUM [3334]
		IRS NUMBER:				133070826
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	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
</SEC-HEADER>
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<TYPE>4
<SEQUENCE>1
<FILENAME>tv524707_from4.xml
<DESCRIPTION>OWNERSHIP DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-06-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000949157</issuerCik>
        <issuerName>CENTURY ALUMINUM CO</issuerName>
        <issuerTradingSymbol>CENX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001449539</rptOwnerCik>
            <rptOwnerName>Glencore AG</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BAARERMATTSTRASSE 3</rptOwnerStreet1>
            <rptOwnerStreet2>P.O. BOX 1301</rptOwnerStreet2>
            <rptOwnerCity>BAAR</rptOwnerCity>
            <rptOwnerState>V8</rptOwnerState>
            <rptOwnerZipCode>CH-6341</rptOwnerZipCode>
            <rptOwnerStateDescription>SWITZERLAND</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001032383</rptOwnerCik>
            <rptOwnerName>GLENCORE INTERNATIONAL AG</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BAARERMATTSTRASSE 3</rptOwnerStreet1>
            <rptOwnerStreet2>P.O. BOX 1363</rptOwnerStreet2>
            <rptOwnerCity>BAAR</rptOwnerCity>
            <rptOwnerState>V8</rptOwnerState>
            <rptOwnerZipCode>CH 6341</rptOwnerZipCode>
            <rptOwnerStateDescription>SWITZERLAND</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001521365</rptOwnerCik>
            <rptOwnerName>Glencore plc</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>BAARERMATTSTRASSE 3</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BAAR</rptOwnerCity>
            <rptOwnerState>V8</rptOwnerState>
            <rptOwnerZipCode>CH-6341</rptOwnerZipCode>
            <rptOwnerStateDescription>SWITZERLAND</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-06-30</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>36911</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10648427</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Series A Convertible Preferred Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-06-30</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>369.11</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>36911</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>68575.20</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares of Common Stock acquired upon conversion of 369.11 shares of Series A Convertible Preferred Stock on June 30, 2019.</footnote>
        <footnote id="F2">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.</footnote>
        <footnote id="F3">The shares of Common Stock reported in 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 indirectly by Glencore International AG and its parent, Glencore plc.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>GLENCORE AG By: /s/ Stephan Huber Name: Stephan Huber Title: Director</signatureName>
        <signatureDate>2019-07-02</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>GLENCORE AG By: /s/ Alicia Wright Name: Alicia Wright Title: Officer</signatureName>
        <signatureDate>2019-07-02</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>GLENCORE INTERNATIONAL AG By: /s/ Alicia Wright Name: Alicia Wright Title: Officer</signatureName>
        <signatureDate>2019-07-02</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>GLENCORE INTERNATIONAL AG By: /s/ Shaun Teichner Name: Shaun Teichner Title: Officer</signatureName>
        <signatureDate>2019-07-02</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>GLENCORE PLC By: /s/ Steven Kalmin Name: Steven Kalmin Title: CFO</signatureName>
        <signatureDate>2019-07-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
