Exhibit 10.4

AMENDMENT

TO

CABOT CORPORATION

SENIOR MANAGEMENT SEVERANCE PROTECTION PLAN

Cabot Corporation, a Delaware corporation (the “Company”), pursuant to
Section 8.2 of the Cabot Corporation Senior Management Protection Plan (the
“Plan”), hereby amends the Plan, effective as of January 13, 2012, as follows:

 

1. Section 2.12 is amended in its entirety to read as follows:

““Eligible Employee” means each employee of the Company who is a member of the
management Executive Committee or who is designated as an Eligible Employee by
the Compensation Committee.”

 

2. Section 4.2 (c) is amended in its entirety to read as follows:

“(c) the Company shall pay to the Participant, as severance pay and in lieu of
any further salary for periods subsequent to the Participant’s Termination Date,
in a single payment (without any discount for accelerated payment, but subject
to applicable withholding taxes) within thirty (30) days after the Participant’s
Termination Date, an amount in cash equal to: (i) if the Participant is the
Chief Executive Officer of the Company, three (3) times the sum of (A) the
Participant’s Base Salary and (B) the Participant’s Bonus Amount; (ii) if the
Participant reports directly to the Chief Executive Officer or is a member of
the management Executive Committee (other than the Chief Executive Officer) or
is otherwise designated by the Compensation Committee as being entitled to
receive the same benefit as a member of the management Executive Committee, two
(2) times the sum of (A) the Participant’s Base Salary and (B) the Participant’s
Bonus Amount; and (iii) if the Participant is not covered by subclause (i) or
(ii) above, one (1) times the sum of (A) the Participant’s Base Salary and
(B) the Participant’s Bonus Amount;”

 

3. Section 4.2(d) is amended in its entirety to read as follows:

(d) For (i) the three (3) year period in the case of a Participant who is the
Chief Executive Officer, (ii) the two (2) year period in the case of a
Participant who reports directly to the Chief Executive Officer or is a member
of the management Executive Committee (other than the Chief Executive Officer)
or is otherwise designated by the Compensation Committee as being entitled to
receive the same benefit as a member of the management Executive Committee, and
(iii) the one (1) year period in the case of any other Participant, in each case
commencing on the Participant’s Termination Date (the “Continuation Period”),
the Company shall at its expense (and without contribution by the Participant)
continue on behalf of the Participant and his or her dependents and
beneficiaries (i) medical, health, dental and prescription drug benefits, ii)
long-term disability coverage and (iii) life insurance and other death benefits
coverage. The coverages and benefits (including deductibles, if any) provided
under this Section 4.2(d)

--------------------------------------------------------------------------------

during the Continuation Period shall be no less favorable to the Participant and
his or her beneficiaries than the most favorable of such coverages and benefits
provided the Participant and his or her dependents during the 90-day period
immediately preceding the Change in Control or as of any date following the
Change in Control but preceding the Participant’s Termination Date. The
obligation under this Section 4.2(d) with respect to the foregoing benefits
shall be limited if the Participant obtains any such benefits pursuant to a
subsequent employer’s benefit plans, in which case the Company may reduce or
eliminate the coverage and benefits it is required to provide the Participant
hereunder as long as the aggregate coverages and benefits of the combined
benefit plans is no less favorable to the Participant than the coverages and
benefits required to be provided hereunder. Any period during which benefits are
continued pursuant to this Section 4.2(d) shall be considered to be in
satisfaction of the Company’s obligation to provide “continuation coverage”
pursuant to Section 4980B of the Internal Revenue Code of 1986, as amended, and
the period of coverage required under said Section 4980B shall be reduced by the
period during which benefits were provided pursuant to this Section 4.2(d);

 

4. Section 4.5, “Gross-up Payment”, is deleted in its entirety.

 

5. The following new Article VI is added:

“ARTICLE VI

LIMITATION ON SEVERANCE BENEFITS

 

  6. Excise Tax Limitation.

(a) Notwithstanding anything contained in the Plan to the contrary, to the
extent that the Severance Benefit, either alone or together with any other
payments or benefits that a Participant is entitled to receive or receives would
be subject to the excise tax (the “Excise Tax”) imposed under Section 4999 of
the Internal Revenue Code of 1986, as amended (the “Code”), the Severance
Benefit shall be reduced (but not below zero) if and to the extent that a
reduction in the Severance Benefit would result in the Participant retaining a
larger amount, on an after-tax basis) taking into account federal, state and
local income taxes and the Excise Tax), than if the Participant received the
entire amount of such Severance Benefit. The Company shall reduce or eliminate
the Severance Benefit by first reducing or eliminating the portion of the
Severance Benefit which is not payable in cash and then by reducing or
eliminating cash payments, in each case in reverse order beginning with payments
or benefits which are to be paid the farthest in time from the Determination (as
hereinafter defined).

(b) The initial determination of whether the Severance Benefit shall be reduced
as provided in Section 6(a) and the amount of such reduction shall be made at
the Company’s expense by an accounting firm selected by the Company from among
the largest accounting firms in the United States (the “Accounting Firm”). The
Accounting Firm shall provide its determination (the “Determination”), together
with detailed

 

2

--------------------------------------------------------------------------------

supporting calculations and documentation to the Company and the Participant
within ten (10) days of the Termination Date. If the Accounting Firm determines
that no Excise Tax is payable by the Participant with respect to a Severance
Benefit, it shall furnish the Participant with an opinion reasonably acceptable
to the Participant that no Excise Tax will be imposed with respect to any such
Severance Benefit, and such Determination shall be binding, final and conclusive
upon the Company and the Participant. If the Accounting Firm determines that an
Excise Tax would be payable, the Participant shall have the right to accept the
Determination of the Accounting Firm as to the extent of the reduction, if any,
pursuant to Section 6(a), or to have such Determination reviewed by an
accounting firm selected by the Participant, at the expense of the Company, in
which case the determination of such second accounting firm shall be binding,
final and conclusive upon the Company and Participant.”

In Witness Whereof, the Company has caused this Amendment to be signed by its
duly authorized officer this 13th day of January 2012 and the undersigned
officer certifies that the amendment has been approved by a resolution adopted
by at least two-thirds of the Company’s Board of Directors.

 

CABOT CORPORATION By:  

/s/ Robby D. Sisco

  Name:   Robby D. Sisco   Title:   Vice President,     Human Resources

 

3