EXHIBIT 10.3

AMENDMENT NO. 1

TO

CABOT CORPORATION

NON-EMPLOYEE DIRECTORS’ STOCK DEFERRAL PLAN

Cabot Corporation, a Delaware corporation (the “Company”), pursuant to
Section 7(b) of the Cabot Corporation Non-employee Directors’ Stock Deferral
Plan (the “Plan”), hereby amends the Plan, as follows, effective from July 14,
2006 (which was the date of adoption of the Plan by the Board of Directors):

Section 3(c) is amended by adding the following sentence at the end of such
Section:

“Notwithstanding the above, the Administrator may permit Non-employee Directors
to change an election regarding the time and form of distributions to be made
pursuant to Section 3(a) without meeting the requirements of this Section 3(c),
pursuant to such procedures as the Administrator may determine in its
discretion, to the extent permitted by transition guidance issued under
Section 409A.”

In Witness Whereof, the Company has caused this Amendment to be signed by its
duly authorized officer this 9th day of November, 2007.

 

CABOT CORPORATION By:  

/s/ Robby D. Sisco

Its:   Vice President-Human Resources