-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 GmzcWLPJYnRweSM7qnKQB2CZ9MeW+CPBOJixA/NlTl2st1J/meHzNP7428FPiPUu
 FYq3nLfnB33XtCcWQIN6fQ==

<SEC-DOCUMENT>0001201087-03-000001.txt : 20030701
<SEC-HEADER>0001201087-03-000001.hdr.sgml : 20030701
<ACCEPTANCE-DATETIME>20030701151942
ACCESSION NUMBER:		0001201087-03-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20030627
FILED AS OF DATE:		20030701

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CABOT CORP
		CENTRAL INDEX KEY:			0000016040
		STANDARD INDUSTRIAL CLASSIFICATION:	MISCELLANEOUS CHEMICAL PRODUCTS [2890]
		IRS NUMBER:				042271897
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		TWO SEAPORT LANE SUITE 1300
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02109-1806
		BUSINESS PHONE:		6173450100

	MAIL ADDRESS:	
		STREET 1:		TWO SEAPORT LANE SUITE 1300
		CITY:			BOSTON
		STATE:			MA
		ZIP:			82109

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CABOT GODFREY L INC
		DATE OF NAME CHANGE:	19680418

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CORDEIRO EDUARDO E
		CENTRAL INDEX KEY:			0001201087

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-05667
		FILM NUMBER:		03767873

	BUSINESS ADDRESS:	
		STREET 1:		4 WINSLOW RD
		CITY:			WINCHESTER
		STATE:			MA
		ZIP:			01890
		BUSINESS PHONE:		7817293192

	MAIL ADDRESS:	
		STREET 1:		4 WINSLOW RD
		CITY:			WINCHESTER
		STATE:			MA
		ZIP:			01890
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0101</schemaVersion>

    <documentType>4</documentType><periodOfReport>2003-06-27</periodOfReport>
    <issuer>
        <issuerCik>0000016040</issuerCik>
        <issuerName>CABOT CORP</issuerName>
        <issuerTradingSymbol>CBT</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId>
            <rptOwnerCik>0001201087</rptOwnerCik>
            <rptOwnerName>CORDEIRO EDUARDO E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Vice President</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeSecurity><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-06-27</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>S</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>3000</value></transactionShares><transactionValue><value>28.44</value></transactionValue><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>28154</value><footnoteId id="F1"/><footnoteId id="F2"/></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnershi
p><value></value></natureOfOwnership></ownershipNature></nonDerivativeSecurity><footnotes><footnote id="F1">Mr. Cordeiro also beneficially owns 1231 shares of Common Stock indirectly through Cabot Corporation's RSP Trustee.  Moreover, Mr. Cordeiro beneficially owns shares of Series B ESOP Convertible Preferred Stock, which are convertible into 2441 shares of Common Stock, indirectly through the RSP Trustee.</footnote><footnote id="F2">Exhibit 24 -- Power of Attorney</footnote></footnotes><ownerSignature><signatureName>Michaela Allbee         **Pursuant to a power of attorney from Eduardo Cordeiro</signatureName><signatureDate>2003-07-01</signatureDate></ownerSignature></ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>3
<FILENAME>attach_1.txt
<DESCRIPTION>POWER OF ATTORNEY FOR EDUARDO CORDEIRO
<TEXT>
POWER OF ATTORNEY

	Know all by these presents, that the undersigned hereby
constitutes and appoints each of Jane A. Bell, Michaela
Allbee and Brian A. Berube, signing singly, the undersigned's
true and lawful attorney-in-fact to:

(1)	  execute for and on behalf of the undersigned, in the
undersigned's capacity as an officer and/or director of Cabot
Corporation (the "Company"), Forms 3, 4, and 5 in accordance
with Section 16(a) of the Securities Exchange Act of 1934 and
the rules thereunder;

(2)	  do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to complete
and execute any such Form 3, 4, or 5, complete and execute
any amendment or amendments thereto, and timely file such
form with the United States Securities and Exchange
Commission and any stock exchange or similar authority; and

(3)	  take any other action of any type whatsoever in
connection with the foregoing which, in the opinion of such
attorney-in-fact, may be of benefit to, in the best interest
of, or legally required by, the undersigned, it being
understood that the documents executed by such
attorney-in-fact on behalf of the undersigned pursuant to
this Power of Attorney shall be in such form and shall
contain such terms and conditions as such attorney-in-fact
may approve in such attorney-in-fact's discretion.

	The undersigned hereby grants to each such attorney-in-fact
full power and authority to do and perform any and every act
and thing whatsoever requisite, necessary, or proper to be
done in the exercise of any of the rights and powers herein
granted, as fully to all intents and purposes as the
undersigned might or could do if personally present, with
full power of substitution or revocation, hereby ratifying
and confirming all that such attorney-in-fact, or such
attorney-in-fact's substitute or substitutes, shall lawfully
do or cause to be done by virtue of this power of attorney
and the rights and powers herein granted.  The undersigned
acknowledges that the foregoing attorneys-in-fact, in serving
in such capacity at the request of the undersigned, are not
assuming, nor is the Company assuming, any of the
undersigned's responsibilities to comply with Section 16 of
the Securities Exchange Act of 1934.

	This Power of Attorney shall remain in full force and effect
until the undersigned is no longer required to file Forms 3,
4, and 5 with respect to the undersigned's holdings of and
transactions in securities issued by the Company, unless
earlier revoked by the undersigned in a signed writing
delivered to the foregoing attorneys-in-fact.  The
undersigned hereby revokes any previous powers of attorney
delivered to the Company concerning the subject matter
hereof.

	IN WITNESS WHEREOF, the undersigned has caused this Power of
Attorney to be executed as of this 12th day of June, 2003.


/s/ Eduardo E. Cordeiro
Signature





\\\DC - 57385/2 - #1301253 v1


\\\DC - 57385/2 - #1301253 v1


\\\DC - 57385/2 - #1301253 v1

</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
