-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 PXrLGUctT4wpQdljKscALVaBKbqYuBa/i4o3fqXaDQg49K9uFKjzgbLWs1uN1YlW
 4CPNDhTTHWhxNqdciKjSsQ==

<SEC-DOCUMENT>0000947871-10-001083.txt : 20101203
<SEC-HEADER>0000947871-10-001083.hdr.sgml : 20101203
<ACCEPTANCE-DATETIME>20101203163128
ACCESSION NUMBER:		0000947871-10-001083
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101202
FILED AS OF DATE:		20101203
DATE AS OF CHANGE:		20101203

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Carmany George W III
		CENTRAL INDEX KEY:			0001308237

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32384
		FILM NUMBER:		101231835

	MAIL ADDRESS:	
		STREET 1:		C/O MACQUARIE INFRASTRUCTURE COMPANY LLC
		STREET 2:		600 FIFTH AVENUE, 21ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10020

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Macquarie Infrastructure CO LLC
		CENTRAL INDEX KEY:			0001289790
		STANDARD INDUSTRIAL CLASSIFICATION:	WHOLESALE-PETROLEUM & PETROLEUM PRODUCTS (NO BULK STATIONS) [5172]
		IRS NUMBER:				206196808
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		125 WEST 55TH STREET, 22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019
		BUSINESS PHONE:		212-231-1000

	MAIL ADDRESS:	
		STREET 1:		125 WEST 55TH STREET, 22ND FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10019

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Macquarie Infrastructure Assets LLC
		DATE OF NAME CHANGE:	20040510
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>ss106749_4-carmany.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-12-02</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001289790</issuerCik>
        <issuerName>Macquarie Infrastructure CO LLC</issuerName>
        <issuerTradingSymbol>MIC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001308237</rptOwnerCik>
            <rptOwnerName>Carmany George W III</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MACQUARIE INFRASTRUCTURE COMPANY LLC</rptOwnerStreet1>
            <rptOwnerStreet2>125 WEST 55TH STREET</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK,</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Limited Liability Company Interests</value>
            </securityTitle>
            <transactionDate>
                <value>2010-12-02</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>12000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>19.86</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>62503</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $19.59 to $19.99, inclusive.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Michael Kernan, Authorized Signatory</signatureName>
        <signatureDate>2010-12-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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