<SEC-DOCUMENT>0001144204-17-048124.txt : 20170915
<SEC-HEADER>0001144204-17-048124.hdr.sgml : 20170915
<ACCEPTANCE-DATETIME>20170915062030
ACCESSION NUMBER:		0001144204-17-048124
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170914
FILED AS OF DATE:		20170915
DATE AS OF CHANGE:		20170915

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Estera Trust (Jersey) Ltd
		CENTRAL INDEX KEY:			0001716591
		STATE OF INCORPORATION:			Y9
		FISCAL YEAR END:			0331

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34474
		FILM NUMBER:		171086817

	BUSINESS ADDRESS:	
		STREET 1:		ESPLANADE 13-14
		CITY:			ST HELIER
		STATE:			Y9
		ZIP:			JE1 1EE
		BUSINESS PHONE:		44 1534 844 844

	MAIL ADDRESS:	
		STREET 1:		ESPLANADE 13-14
		CITY:			ST HELIER
		STATE:			Y9
		ZIP:			JE1 1EE

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Ryfold Ltd
		CENTRAL INDEX KEY:			0001716574
		STATE OF INCORPORATION:			Y9
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34474
		FILM NUMBER:		171086818

	BUSINESS ADDRESS:	
		STREET 1:		ESPLANADE 13-14
		CITY:			ST HELIER
		STATE:			Y9
		ZIP:			JE1 1EE
		BUSINESS PHONE:		44 1534 844 844

	MAIL ADDRESS:	
		STREET 1:		ESPLANADE 13-14
		CITY:			ST HELIER
		STATE:			Y9
		ZIP:			JE1 1EE

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Ryfold Trust
		CENTRAL INDEX KEY:			0001716570
		STATE OF INCORPORATION:			Y9
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34474
		FILM NUMBER:		171086816

	BUSINESS ADDRESS:	
		STREET 1:		ESPLANADE 13-14
		CITY:			ST HELIER
		STATE:			Y9
		ZIP:			JE1 1EE
		BUSINESS PHONE:		44 1534 844 844

	MAIL ADDRESS:	
		STREET 1:		ESPLANADE 13-14
		CITY:			ST HELIER
		STATE:			Y9
		ZIP:			JE1 1EE

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>v475137_4.xml
<DESCRIPTION>OWNERSHIP DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-09-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001716574</rptOwnerCik>
            <rptOwnerName>Ryfold Ltd</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ESTERA TRUST (JERSEY) LIMITED,</rptOwnerStreet1>
            <rptOwnerStreet2>13-14 ESPLANADE</rptOwnerStreet2>
            <rptOwnerCity>ST HELIER</rptOwnerCity>
            <rptOwnerState>Y9</rptOwnerState>
            <rptOwnerZipCode>JE1 1EE</rptOwnerZipCode>
            <rptOwnerStateDescription>JERSEY</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001716591</rptOwnerCik>
            <rptOwnerName>Estera Trust (Jersey) Ltd</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ESTERA TRUST (JERSEY) LIMITED,</rptOwnerStreet1>
            <rptOwnerStreet2>13-14 ESPLANADE</rptOwnerStreet2>
            <rptOwnerCity>ST HELIER</rptOwnerCity>
            <rptOwnerState>Y9</rptOwnerState>
            <rptOwnerZipCode>JE1 1EE</rptOwnerZipCode>
            <rptOwnerStateDescription>JERSEY</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001716570</rptOwnerCik>
            <rptOwnerName>Ryfold Trust</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ESTERA TRUST (JERSEY) LIMITED,</rptOwnerStreet1>
            <rptOwnerStreet2>13-14 ESPLANADE</rptOwnerStreet2>
            <rptOwnerCity>ST HELIER</rptOwnerCity>
            <rptOwnerState>Y9</rptOwnerState>
            <rptOwnerZipCode>JE1 1EE</rptOwnerZipCode>
            <rptOwnerStateDescription>JERSEY</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>Call Option (obligation to sell)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>100</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2017-09-14</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>100</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2017-09-14</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2027-09-14</value>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>27500000</value>
                    <footnoteId id="F1"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On the September 14, 2017, Glencore AG and Ryfold Limited (&quot;Ryfold&quot;) entered into a Call Option Agreement (the &quot;Givolon Call Option Agreement&quot;) pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Ryfold, at any time prior to the expiration thereof, 100% of the equity interests in Givolon Limited, a wholly-owned subsidiary of Ryfold (&quot;Givolon&quot;), for an aggregate exercise price of $100 (the &quot;Givolon Call Option&quot;). The Givolon Call Option will expire on September 14, 2027. Glencore AG paid Ryfold an aggregate premium of $100 for the Givolon Call Option.</footnote>
        <footnote id="F2">Ryfold's interest in the Call Option is held indirectly by each of Ryfold's parent, The Ryfold Trust, and Estera Trust (Jersey) Limited (&quot;Estera&quot;) solely in its capacity as trustee of The Ryfold Trust. Givolon holds directly a number of shares of Common Stock equal to the number of shares reported on Table II, which shares are indirectly owned by each of Ryfold, Ryfold's parent, The Ryfold Trust, and Estera solely in its capacity as trustee of The Ryfold Trust. Estera does not have and disclaims any pecuniary interest in such Common Stock and in the Call Option reported on Table II.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>RYFOLD LIMITED By: /s/ Brendan Dowling, Director</signatureName>
        <signatureDate>2017-09-14</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>ESTERA TRUST (JERSEY) LIMITED By: /s/ Brendan Dowling, Director</signatureName>
        <signatureDate>2017-09-14</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>ESTERA TRUST (JERSEY) LIMITED, in its capacity as trustee of THE RYFOLD TRUST By: /s/ Brendan Dowling, Director</signatureName>
        <signatureDate>2017-09-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
