Exhibit 10.1 

May 13, 2016

By Hand

Patrick Prevost

[Address]

Dear Patrick:

This transition and separation agreement (the “Agreement”) is to confirm the terms of the remainder of your employment with Cabot Corporation (“Cabot” or the “Company”) and the termination of your employment with the Company. You may accept this offer only by signing a copy of this letter where indicated below and returning it to Brian A. Berube at Cabot Corporation, 2 Seaport Lane, Boston, MA 02210, so that Mr. Berube receives it not later than June 3, 2016, and by not thereafter revoking this agreement; otherwise this offer shall be null and void.

You resigned from your position as President and Chief Executive Officer of the Company on and effective as of March 11, 2016 (the “Transition Date”).  You acknowledge and agree that as of the Transition Date you resigned from any and all (i) officer positions you held with the Company or any of its Affiliates (as defined below), (ii) memberships you held on any boards of directors, boards of managers or other governing boards or bodies of the Company or any of its Affiliates, other than the Board of Directors of the Company, and (iii) memberships you held on any of the committees of any such boards or bodies (all such resignations, together with your resignation from your position as President and Chief Executive Officer, the “Resignations”).  The Company, on its own behalf and on behalf of its Affiliates has accepted the Resignations, as of the Transition Date.  You agree to execute such documents confirming the Resignations as the Company may reasonably request.

From Transition Date through the date that your employment terminates (the “Separation Date”), you will continue to be employed by the Company as an advisor to the Company.  Provided that you comply in full with your obligations hereunder, it is expected that the Separation Date will be July 15, 2016.  The period beginning on the Transition Date and concluding on the Separation Date is hereinafter referred to as the “Transition Period”.

During the Transition Period you will continue to receive your base salary, payable at the rate in effect as of the date hereof, and to participate in all employee benefit plans of the Company (including, but not limited to, the Company’s medical, dental, life insurance and supplemental life insurance plans) in accordance with the terms of those plans.  During the Transition Period, you will perform such duties as may be assigned to you from time to time by the Non-Executive Chairman of the Board of Directors of the Company or by the President and Chief Executive Officer of the Company (the “CEO”) or his designee, including but not limited to assisting with an orderly transition of your duties and responsibilities to the CEO, meeting with customers and other constituents of the Company to facilitate this transition and providing advice to the Company based on your knowledge of the Company and its business.  You agree to continue to devote your best professional efforts to the Company, and to abide by all Company policies and procedures as in effect from time to time.  

During the Transition Period you will remain an at-will employee of the Company.  If your employment terminates prior to July 15, 2016, the date of such termination of employment will be the “Separation Date” for purposes of this Agreement; it being understood that if the Company terminates your employment prior to July 15, 2016 for any reason other than “Cause”, as defined below, you shall be entitled, in addition to the Severance Benefits described below, to receive payment of your base salary through and including July 15, 2016, subject to your execution and non-revocation of the Release, as defined below, which payment shall be made within 30 days following the Separation Date.  Notwithstanding the foregoing, if the Company terminates your employment for Cause, you will not be eligible to receive the Severance Benefits (as defined below).  For purposes of this Agreement, “Cause”, as determined by the Company in its good faith, reasonable judgment, shall mean only  (i) your material breach of this Agreement, the Employee Agreement (as defined below) or any material written policy of the Company or its Affiliates which material breach, if susceptible to cure, remains uncured fourteen (14) days after the Company has provided written notice to you specifying in reasonable detail the nature of the alleged breach or (ii) your commission of a felony or other crime involving moral turpitude.  For purposes of this Agreement, “Affiliates” means all persons and entities directly or indirectly controlling, controlled by or under common control with the Company, where control may be by management authority, equity interest or otherwise.

You will receive, on the Separation Date, any base salary earned, but unpaid, as of the Separation Date, as well as pay, at your final base rate of pay, for any vacation days you earned but had not used as of the Separation Date, determined in accordance with Company policy and as reflected on the books of the Company (together, the “Final Compensation”). You will receive the payments described in this paragraph regardless of whether or not you decide to accept the additional payments and benefits offered by Cabot in this Agreement.

Except as otherwise stated herein, this Agreement does not modify or supersede any obligations that you have to Cabot by law or otherwise, and you understand that you must return all written and other materials belonging to Cabot (whether hardcopy, in electronic form or otherwise) and in your possession or control, together with all copies of such materials, upon termination of your employment, other than such materials provided to and utilized by you incident to your performance of services as a member of the Board of Directors of the Company.

In consideration of your acceptance of this Agreement and subject to your meeting in full your obligations hereunder, including your obligation to execute a post-employment general release and waiver of claims in the form attached hereto as Exhibit A (the “Release”) on or after the Separation Date (and within the time period described therein), the Company will provide you with the following payments and benefits.  If you do not timely execute the Release, or if the Release does not become effective in accordance with its terms, you shall not receive any of the payments or benefits described in paragraphs (1) through (6) below (collectively, the “Severance Benefits”).  The Severance Benefits shall only be made, commence, or become effective, as applicable, on the expiration of the seven-day period provided for in the Release, and only if such revocation rights are not timely exercised by you (such date, the “Effective Date”).

-2-

A summary of the options and restricted stock units that will vest pursuant to these provisions is set forth in Exhibit B attached to this Agreement.  

Except as specifically modified by the preceding sentences and Paragraph 3 below, the equity awards granted to you shall continue to be administered in accordance with the terms of the LTIP and the terms of award agreements evidencing such awards. Awards of restricted stock units shall be settled in accordance with the terms of the LTIP and the award agreements under which they were granted. Upon the vesting or settlement of the restricted stock units described above, unless you instruct the Company otherwise, to satisfy any tax withholding requirements arising in connection with the vesting or settlement of such awards, the Company will withhold shares of Company common stock from the shares otherwise deliverable to you in accordance with the terms of the applicable award agreements evidencing such equity awards.

-3-

Notwithstanding the foregoing, this release does not include and will not preclude a claim for or with respect to: (a) base salary payable through the Separation Date, or accrued, unused vacation time as recorded on the Company’s books as of the Separation Date; (b) vested benefits under any Company employee benefit plan; (c) your COBRA rights; (d) payments and benefits under this Agreement; (e) any claim which, as a matter of law, cannot be released by private agreement; and (f) rights to be indemnified by Cabot under Cabot’s By-Laws and/or Cabot’s Restated Certificate of Incorporation or as an officer or former officer of Cabot to insurance coverage under Cabot’s directors’ and officers’ insurance program in accordance with its terms.

-4-

-5-

If the terms of this Agreement are acceptable to you, please sign and return a copy of this letter to Brian A. Berube at Cabot Corporation, 2 Seaport Lane, Boston, MA 02210, within 21 days, that is, by June 3, 2016. If you sign this Agreement prior to the end of this 21-day period, you certify that you knowingly and voluntarily decided to sign it after considering it for less than 21 days, and your decision to do so was not induced by the Company through fraud, misrepresentation, or a threat to withdraw or alter the offers herein.

If you accept the foregoing offer, you shall have the right to revoke this Agreement by delivering or sending to Mr. Berube at the address above written notice of revocation so that your notice of revocation is received by Mr. Berube within seven calendar days after the date that this letter is signed by you. If you revoke within this time period, this Agreement shall be null and void in its entirety and you will not be entitled to any additional payments and benefits set forth in this Agreement. Otherwise this Agreement shall be binding upon you, your heirs and representatives and shall inure to the benefit of, and be binding upon, Cabot and its successors and assigns.

This Agreement shall be treated as a contract under seal for purposes of Massachusetts law.  

-6-

Notwithstanding anything in this Agreement to the contrary, the Company shall have the right to terminate the Severance Benefits and require that you repay or forfeit, as applicable, any Severance Benefits previously paid or provided to you hereunder (or any gains in respect of LTIP awards the vesting of which accelerates as provided in paragraph 2 hereof) at any time if the Company determines that you have breached any of the terms and conditions of this Agreement or the Employee Agreement, but any such termination of Severance Benefits shall not relieve you of your obligations and undertakings under this Agreement (including without limitation your release of claims under this Agreement).

Having carefully read and fully understanding the provisions and effects of this Agreement, the foregoing offer by Cabot Corporation is knowingly and voluntarily accepted and agreed to this 17^th day of May, 2016.

-7-

Exhibit A

Post-Employment General Release and Waiver of Claims

For and in consideration of certain benefits to be provided to me under the Separation and Transition Agreement between me and Cabot Corporation (the “Company”), dated as of May 13, 2016 (the “Agreement”), which are conditioned on my signing this General Release and Waiver of Claims (this “Release of Claims”), and to which I am not otherwise entitled, and other good and valuable consideration, the receipt and sufficiency of which I hereby acknowledge, on my own behalf and on behalf of my heirs, executors, administrators, beneficiaries, representatives, successors and assigns, and any other person or entity claiming through or under me, I hereby release and forever discharge the Company and its subsidiaries and other affiliates, and all of their respective past, present and future directors, shareholders, officers, members, managers, general and limited partners, insurers, employees, agents, representatives, consultants, successors and assigns, any employee benefit plans maintained by or on behalf of the Company or its subsidiaries, affiliates, or successors, or any of the trustees or administrators thereof, and all others connected with any of the foregoing, in their official and individual capacities (collectively, the “Releasees”), from any and all causes of action, suits, rights and claims, demands, damages and compensation of any kind and nature whatsoever, whether at law or in equity, whether now known or unknown, suspected or unsuspected, contingent or otherwise, which I now have or ever have had against the Releasees, or any of them, in any way related to, connected with or arising out of my employment and/or other relationship with the Company or any of its affiliates, or pursuant to Title VII of the Civil Rights Act, the Americans With Disabilities Act, the Family and Medical Leave Act, the Age Discrimination in Employment Act (as amended by the Older Workers Benefit Protection Act), the Employee Retirement Income Security Act, the wage and hour, wage payment or fair employment practices laws of the Commonwealth of Massachusetts and any other state or states in which I have provided services to the Company or its affiliates (each as amended from time to time) and/or any other federal, state or local law, regulation, or other requirement (collectively, the “Claims”) through the date that I sign this Release of Claims, and I hereby waive all such Claims.

I understand that nothing contained in this Release of Claims shall be construed to prohibit me from filing a charge with or participating in any investigation or proceeding conducted by the federal Equal Employment Opportunity Commission or a comparable state or local agency, provided, however, that I hereby agree to waive my right to recover monetary damages or other individual relief in any charge, complaint or lawsuit filed by me or by anyone else on my behalf.  Further, this release does not include and will not preclude a claim for or with respect to: (a) base salary payable through the Separation Date; or accrued, unused vacation time as recorded on the Company’s books as of the Separation Date; (b) vested benefits under any Company employee benefit plan; (c) my COBRA rights; (d) payments and benefits under the Agreement; (e) any claim which, as a matter of law, cannot be released by private agreement; and (f) my rights to be indemnified by Cabot under Cabot’s By-Laws and/or Cabot’s Restated Certificate of Incorporation or as an officer or former officer of Cabot to insurance coverage under Cabot’s directors’ and officers’ insurance program in accordance with its terms.

I acknowledge that this Release of Claims creates legally binding obligations, and that the Company hereby advises me to consult an attorney before signing it.  I further acknowledge that I may not sign this Release of Claims prior to the Separation Date (as such term is defined in the Agreement), but must sign this Release of Claims by the later of (i) five (5) days following the Separation Date (as defined in the Agreement) and (ii) twenty-one (21) days following the date hereof.  In signing this Release of Claims, I give the Company assurance that I have signed it voluntarily and with a full understanding of its terms; that I have had sufficient opportunity of not less than twenty-one (21) days before signing this Release of Claims to consider its terms and to consult with an attorney, if I wished to do so, or to consult with any person of my choosing; and that I have not relied on any promises or representations, express or implied, that are not set forth expressly in this Release of Claims.  I understand that I will have seven (7) days after signing this Release of Claims to revoke my signature, and that, if I intend to revoke my signature, I must do so in writing addressed and delivered to Brian A. Berube at Cabot Corporation prior to the end of the seven (7)-day revocation period.  I understand that this Release of Claims will become effective upon

-8-

the eighth (8th) day following the date that I sign it, provided that I do not revoke my acceptance in accordance with the immediately preceding sentence.

I represent and warrant that I have (i) returned to the Company any and all non-public documents, materials and information (whether in hardcopy, on electronic media or otherwise) related to Company business (whether present or otherwise) and all keys, access cards, credit cards, computer hardware and software, telephones and telephone-related equipment and all other property of the Company or any of its affiliates in my possession or control, and (ii) not retained any copy of any non-public Company documents, materials or information (whether in hardcopy, on electronic media or otherwise), other than such materials provided to and utilized by me incident to my performance of services as a member of the Board of Directors of the Company. I agree that I will not, for any purpose, attempt to access or use any Company computer or computer network or system, including without limitation its electronic mail system. Further, I acknowledge that I have disclosed to the Company all passwords necessary or desirable to enable the Company to access all information which I have password-protected on any of its computer equipment or on its computer network or system.

Accepted and agreed:

-9-

-10-