<SEC-DOCUMENT>0001144204-17-048122.txt : 20170915
<SEC-HEADER>0001144204-17-048122.hdr.sgml : 20170915
<ACCEPTANCE-DATETIME>20170915061828
ACCESSION NUMBER:		0001144204-17-048122
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:			Givolon Ltd
		CENTRAL INDEX KEY:			0001716572
		STATE OF INCORPORATION:			Y9
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34474
		FILM NUMBER:		171086814

	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>v475135_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>0001716572</rptOwnerCik>
            <rptOwnerName>Givolon 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>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Total Return Swap (obligation to sell)</value>
                <footnoteId id="F1"/>
                <footnoteId id="F7"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>18.0308</value>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
                <footnoteId id="F4"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2017-09-14</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>1</equitySwapInvolved>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
                <footnoteId id="F4"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2022-12-31</value>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2022-12-31</value>
                <footnoteId id="F2"/>
                <footnoteId id="F3"/>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>27500000</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F8"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Call Option (obligation to sell)</value>
                <footnoteId id="F1"/>
                <footnoteId id="F7"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>2.7046</value>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2017-09-14</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.3261</value>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2017-09-14</value>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
            </exerciseDate>
            <expirationDate>
                <value>2022-12-31</value>
                <footnoteId id="F5"/>
                <footnoteId id="F6"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>27500000</value>
                    <footnoteId id="F5"/>
                    <footnoteId id="F6"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F8"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On September 14, 2017 (the &quot;Effective Date&quot;), Givolon Limited (&quot;Givolon&quot;), a wholly-owned subsidiary of Glencore AG at such time, purchased from Glencore AG 27,500,000 shares of common stock (&quot;Common Stock&quot;) of Century Aluminum Company (the &quot;Specified Shares&quot;) for the aggregate price of $495,845,625, or $18.03075 per share. Subsequently on the Effective Date, Glencore AG sold to Ryfold Limited (&quot;Ryfold&quot;) 100% of the equity interests in Givolon for the aggregate purchase price of $100 (the &quot;Givolon Sale&quot;).</footnote>
        <footnote id="F2">On the Effective Date, Glencore AG and Givolon entered into an ISDA Master Agreement in the form of the 1992 ISDA Master Agreement (Multi-currency - Cross Border) together with a related Schedule thereto (the &quot;Master Agreement&quot;) and a related Total Return Swap Confirmation, pursuant to which Glencore AG received economic exposure to a number of shares of Common Stock equal to the Specified Shares at a reference price equal to $18.03075 per share of Common Stock, under a stock-settled total return swap (the &quot;Century TRS&quot;).</footnote>
        <footnote id="F3">The Century TRS is scheduled to expire and settle on December 31, 2022 (following expiration of the Century Call Option (defined below)) (the &quot;Expiration Date&quot;).</footnote>
        <footnote id="F4">Under the Century TRS, (i) with respect to the period of time prior to the settlement of the Century TRS, (A) Glencore AG will be obligated to pay certain fees to Givolon, and (B) Givolon will be obligated to pay to Glencore AG an amount equal to any dividends and other distributions that would have been paid by Century Aluminum Company on a number of shares equal to the Specified Shares; and (ii) at settlement of the Century TRS, (A) Givolon will be obligated to deliver a number of shares equal to the Specified Shares to Glencore AG, and (B) Glencore AG will be obligated to pay to Givolon $18.03075 for each such share.</footnote>
        <footnote id="F5">On the Effective Date, Glencore AG and Givolon entered into a Century Call Option Confirmation pursuant to the Master Agreement, pursuant to which Glencore AG acquired an American-style call option that gives Glencore AG the right to purchase from Givolon, at any time prior to the expiration thereof, a number of shares of Common Stock equal to the Specified Shares at a price equal to $2.70462 per share of Common Stock (the &quot;Century Call Option&quot;). Glencore AG paid Givolon a premium of $15.32613 per share for the Century Call Option.</footnote>
        <footnote id="F6">The Century Call Option is scheduled to expire on the Expiration Date, prior to the time the Century TRS is scheduled to settle.</footnote>
        <footnote id="F7">Under the terms of the Century TRS and the Century Call Option, the Century TRS is scheduled to expire and settle after expiration of the Century Call Option, so that Glencore AG will acquire a number of shares equal to the Specified Shares under the Century TRS even if Glencore AG does not exercise the Century Call Option. In addition, the Century TRS will automatically terminate, with no remaining obligations on the part of either party, upon exercise of the Century Call Option. As a result, under the Century TRS and the Century Call Option, Glencore AG has the right to acquire and Givolon has the obligation to deliver to Glencore AG an aggregate number of shares equal to the Specified Shares. Givolon has granted to Glencore AG the irrevocable right to vote and to direct the voting of the Specified Shares.</footnote>
        <footnote id="F8">The Specified Shares and Givolon's interests in the Century TRS and the Century Call Option were held indirectly by each of Glencore AG (Givolon's sole shareholder), Glencore AG's parent, Glencore International AG and its parent, Glencore plc, prior to the Givolon Sale, and are held indirectly by each of Ryfold, Ryfold's parent, The Ryfold Trust, and Estera Trust (Jersey) Limited solely in its capacity as trustee of The Ryfold Trust, following the Givolon Sale.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>GIVOLON LIMITED By: /s/ Brendan Dowling, Director</signatureName>
        <signatureDate>2017-09-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
