<SEC-DOCUMENT>0001104659-20-110457.txt : 20200930
<SEC-HEADER>0001104659-20-110457.hdr.sgml : 20200930
<ACCEPTANCE-DATETIME>20200930170607
ACCESSION NUMBER:		0001104659-20-110457
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20200928
FILED AS OF DATE:		20200930
DATE AS OF CHANGE:		20200930

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:		201213050

	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:		201213051

	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>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>tm2032132d1_4.xml
<DESCRIPTION>OWNERSHIP DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-09-28</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <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>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>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Cash Settled Total Return Swap</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>9.7193</value>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2020-09-28</value>
                <footnoteId id="F4"/>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>1</equitySwapInvolved>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
                <footnoteId id="F4"/>
                <footnoteId id="F5"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1</value>
                    <footnoteId id="F4"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2020-12-29</value>
                <footnoteId id="F2"/>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2020-12-29</value>
                <footnoteId id="F2"/>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4729302</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F6"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On July 2, 2010, Glencore International AG (&quot;Glencore International&quot;), a direct wholly-owned subsidiary of Glencore plc, entered into a Master Terms and Conditions for Swap Transactions agreement (the &quot;Swap Agreement&quot;) with Citigroup Global Markets Inc. (together with its successors in interest under the Swap Agreement, &quot;Citi&quot;), pursuant to which Glencore International and Citi may, from time to time, enter into cash-settled total return swaps (the &quot;Swaps&quot;). On September 14, 2017 Glencore International transferred all of its rights and obligations under the Swap Agreement and all agreements and transactions thereunder to Glencore Canada Corporation, an indirect wholly-owned subsidiary of Glencore plc (&quot;Glencore Canada&quot;), which rights and obligations were transferred back to Glencore International on April 17, 2018.</footnote>
        <footnote id="F2">Pursuant to the Swap Agreement, on September 15, 2010, Glencore International received economic exposure pursuant to a Swap (the &quot;First Swap&quot;) entered into between Glencore International and Citi with an initial expiration date of September 17, 2012 (subsequently extended to April 17, 2021).</footnote>
        <footnote id="F3">Upon expiration of the First Swap, (i) Glencore International will be obligated to make a cash payment to Citi with respect to any depreciation in the volume weighted average price of the 4,729,302 shares of common stock referenced by the First Swap (the &quot;First Subject Shares&quot;) from the $9.719270 per share volume weighted average price calculated during the initial averaging period for the First Swap (which ended on September 15, 2010) to the volume weighted average price of the First Subject Shares during the final valuation period preceding the expiration of the term of the First Swap, or (ii) Citi will be obligated to make a cash payment to Glencore International with respect to any appreciation in such volume weighted average price based on the above period.</footnote>
        <footnote id="F4">On September 28, 2020 the parties terminated the September 15, 2010 swap. The final settlement payment is scheduled to be made on December 29, 2020, and will be based on a final reference price based on the volume weighted average price of the Common Stock during a final valuation period between the termination date and the settlement date.</footnote>
        <footnote id="F5">Under the terms of the Swap Agreement, generally, Glencore International will be obligated to pay to Citi certain fees and commissions and Citi will be obligated to pay to Glencore International an amount in cash equal to any dividends that would have been paid by the issuer on the First Subject Shares.</footnote>
        <footnote id="F6">The cash settled total return swaps under the Swap Agreement are held directly by Glencore International, and may be deemed to be beneficially owned indirectly by Glencore plc. The cash settled total return swaps do not give the reporting persons direct or indirect voting, investment or dispositive control over any securities of the issuer, and accordingly, the reporting persons disclaim any beneficial ownership in the shares of common stock referenced by the swaps.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>GLENCORE INTERNATIONAL AG: By: /s/ Martin Haering; Name: Martin Haering; Title: Officer</signatureName>
        <signatureDate>2020-09-30</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>GLENCORE INTERNATIONAL AG: By: /s/ Derrick Crowley; Name: Derrick Crowley; Title: Officer</signatureName>
        <signatureDate>2020-09-30</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>GLENCORE PLC: By: /s/ John Burton; Name: John Burton; Title: Company Secretary</signatureName>
        <signatureDate>2020-09-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
