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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0000864015-10-000001.txt : 20100720
<SEC-HEADER>0000864015-10-000001.hdr.sgml : 20100720
<ACCEPTANCE-DATETIME>20100720165310
ACCESSION NUMBER:		0000864015-10-000001
CONFORMED SUBMISSION TYPE:	D/A
PUBLIC DOCUMENT COUNT:		1
ITEM INFORMATION:		Rule 506
ITEM INFORMATION:		Investment Company Act Section 3(c)
ITEM INFORMATION:		Section 3(c)(1)
FILED AS OF DATE:		20100720
DATE AS OF CHANGE:		20100720
EFFECTIVENESS DATE:		20100720

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MARIN SECTOR INVESTORS L.P.
		CENTRAL INDEX KEY:			0000864015
		IRS NUMBER:				113002014
		STATE OF INCORPORATION:			DE

	FILING VALUES:
		FORM TYPE:		D/A
		SEC ACT:		1933 Act
		SEC FILE NUMBER:	021-86401-5N
		FILM NUMBER:		10960921

	BUSINESS ADDRESS:	
		STREET 1:		150 GREAT NECK RD
		STREET 2:		SUITE 301
		CITY:			GREAT NECK
		STATE:			NY
		ZIP:			11021
		BUSINESS PHONE:		(516) 829-6444

	MAIL ADDRESS:	
		STREET 1:		150 GREAT NECK RD
		STREET 2:		SUITE 301
		CITY:			GREAT NECK
		STATE:			NY
		ZIP:			11021

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MARIN SECTOR INVESTORS L P
		DATE OF NAME CHANGE:	19900530
</SEC-HEADER>
<DOCUMENT>
<TYPE>D/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<edgarSubmission>

    <schemaVersion>X0704</schemaVersion>

    <submissionType>D/A</submissionType>

    <testOrLive>LIVE</testOrLive>

    <primaryIssuer>
        <cik>0000864015</cik>
        <entityName>MARIN SECTOR INVESTORS L.P.</entityName>
        <issuerAddress>
            <street1>150 GREAT NECK RD</street1>
            <street2>SUITE 301</street2>
            <city>GREAT NECK</city>
            <stateOrCountry>NY</stateOrCountry>
            <stateOrCountryDescription>NEW YORK</stateOrCountryDescription>
            <zipCode>11021</zipCode>
        </issuerAddress>
        <issuerPhoneNumber>(516) 829-6444</issuerPhoneNumber>
        <jurisdictionOfInc>DELAWARE</jurisdictionOfInc>
        <edgarPreviousNameList>
            <previousName>MARIN SECTOR INVESTORS L P</previousName>
        </edgarPreviousNameList>
        <entityType>Limited Partnership</entityType>
        <yearOfInc>
            <overFiveYears>true</overFiveYears>
        </yearOfInc>
    </primaryIssuer>

    <relatedPersonsList>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Gerald</firstName>
                <lastName>Appel</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>150 Great Neck Rd</street1>
                <street2>Suite 301</street2>
                <city>Great Neck</city>
                <stateOrCountry>NY</stateOrCountry>
                <stateOrCountryDescription>NEW YORK</stateOrCountryDescription>
                <zipCode>11021</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>President of Signalert Corporation, the general partner of the Issuer</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Judith</firstName>
                <lastName>Appel</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>150 Great Neck Rd</street1>
                <street2>Suite 301</street2>
                <city>Great Neck</city>
                <stateOrCountry>NY</stateOrCountry>
                <stateOrCountryDescription>NEW YORK</stateOrCountryDescription>
                <zipCode>11021</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Secretary and Treasurer of Signalert Corporation, the general partner of the Issuer</relationshipClarification>
        </relatedPersonInfo>
        <relatedPersonInfo>
            <relatedPersonName>
                <firstName>Marvin</firstName>
                <lastName>Appel</lastName>
            </relatedPersonName>
            <relatedPersonAddress>
                <street1>150 Great Neck Rd</street1>
                <street2>Suite 301</street2>
                <city>Great Neck</city>
                <stateOrCountry>NY</stateOrCountry>
                <stateOrCountryDescription>NEW YORK</stateOrCountryDescription>
                <zipCode>11021</zipCode>
            </relatedPersonAddress>
            <relatedPersonRelationshipList>
                <relationship>Executive Officer</relationship>
            </relatedPersonRelationshipList>
            <relationshipClarification>Vice-president of Signalert Corporation, the general partner of the Issuer</relationshipClarification>
        </relatedPersonInfo>
    </relatedPersonsList>

    <offeringData>
        <industryGroup>
            <industryGroupType>Pooled Investment Fund</industryGroupType>
            <investmentFundInfo>
                <investmentFundType>Hedge Fund</investmentFundType>
                <is40Act>false</is40Act>
            </investmentFundInfo>
        </industryGroup>
        <issuerSize>
            <aggregateNetAssetValueRange>$5,000,001 - $25,000,000</aggregateNetAssetValueRange>
        </issuerSize>
        <federalExemptionsExclusions>
            <item>06</item>
            <item>3C</item>
            <item>3C.1</item>
        </federalExemptionsExclusions>
        <typeOfFiling>
            <newOrAmendment>
                <isAmendment>true</isAmendment>
                <previousAccessionNumber>0000864015-09-000004</previousAccessionNumber>
            </newOrAmendment>
            <dateOfFirstSale>
                <value>1990-04-01</value>
            </dateOfFirstSale>
        </typeOfFiling>
        <durationOfOffering>
            <moreThanOneYear>true</moreThanOneYear>
        </durationOfOffering>
        <typesOfSecuritiesOffered>
            <isPooledInvestmentFundType>true</isPooledInvestmentFundType>
        </typesOfSecuritiesOffered>
        <businessCombinationTransaction>
            <isBusinessCombinationTransaction>false</isBusinessCombinationTransaction>
            <clarificationOfResponse></clarificationOfResponse>
        </businessCombinationTransaction>
        <minimumInvestmentAccepted>62862</minimumInvestmentAccepted>
        <salesCompensationList></salesCompensationList>
        <offeringSalesAmounts>
            <totalOfferingAmount>Indefinite</totalOfferingAmount>
            <totalAmountSold>10542212</totalAmountSold>
            <totalRemaining>Indefinite</totalRemaining>
            <clarificationOfResponse></clarificationOfResponse>
        </offeringSalesAmounts>
        <investors>
            <hasNonAccreditedInvestors>true</hasNonAccreditedInvestors>
            <numberNonAccreditedInvestors>17</numberNonAccreditedInvestors>
            <totalNumberAlreadyInvested>33</totalNumberAlreadyInvested>
        </investors>
        <salesCommissionsFindersFees>
            <salesCommissions>
                <dollarAmount>0</dollarAmount>
            </salesCommissions>
            <findersFees>
                <dollarAmount>0</dollarAmount>
            </findersFees>
            <clarificationOfResponse></clarificationOfResponse>
        </salesCommissionsFindersFees>
        <useOfProceeds>
            <grossProceedsUsed>
                <dollarAmount>0</dollarAmount>
            </grossProceedsUsed>
            <clarificationOfResponse></clarificationOfResponse>
        </useOfProceeds>
        <signatureBlock>
            <authorizedRepresentative>false</authorizedRepresentative>
            <signature>
                <issuerName>MARIN SECTOR INVESTORS L.P.</issuerName>
                <signatureName>Marvin Appel</signatureName>
                <nameOfSigner>Marvin Appel</nameOfSigner>
                <signatureTitle>Vice president of general partner of Issuer</signatureTitle>
                <signatureDate>2010-07-20</signatureDate>
            </signature>
        </signatureBlock>
    </offeringData>
</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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