EXHIBIT 10.31

Union Carbide Corporation Executives' Supplemental Retirement Plan

---

Effective as of March 1, 2004
(except as may be otherwise provided herein)

PREAMBLES

ESTABLISHMENT OF PLAN

The
Union Carbide Corporation maintained a non-qualified pension plan program comprising of the Equalization Benefit Plan, the Supplemental Retirement Income Plan and the Enhanced
Retirement Income Plan. As of March 1, 2004, this program and the aforementioned plans are amended and restated in their entirety as set forth herein and renamed the Union Carbide Corporation
Executives' Supplemental Retirement Plan (the "Plan"). This is an unfunded program of deferred compensation for executives, which includes Part A for Non-U.S. Service,
Non-Controlled Group Service and/or
Non-Covered Controlled Group Service and Part B for a Select Group of Management or Highly Compensated Employees, Board Members, and Employees whose Benefits are Statutorily
Limited. The terms of this Plan supersede the terms of the former Union Carbide non-qualified pension plan program in effect prior to the effective date of this Plan with regards to active
Participants and Participants who terminated employment prior to the effective date but have not commenced benefits prior to the effective date.

PURPOSE

The
Company desires (a) to provide certain of its executives and a select group of management employees with supplemental retirement benefits that might otherwise be provided by the Union
Carbide Employees' Pension Plan ("UCEPP"), but for (i) restrictions of the exclusive benefit rule under Section 401(a) of the Internal Revenue Code (the "Code"), (ii) the
inability to grant past service, under UCEPP, to highly compensated Employees without meeting the non-discrimination requirements of Section 401(a)(4) of the Code, and/or
(iii) the inability to credit service to Employees while employed by a controlled group member not covered by the UCEPP, and (b) to restore benefits which are reduced under UCEPP and The
Dow Chemical Company Employees' Savings Plan ("ESP") due to current and/or future statutory limitations and which are not otherwise provided by any other plan maintained by the Company.

INTERPRETATION AND GOVERNING LAW

This
Plan is intended to constitute an unfunded program maintained primarily for the purpose of providing deferred compensation for a select group of management or highly compensated Employees
consistent with the requirements of Sections 201(2), 301(a)(3) and 401(a)(1) of the Employee Retirement Income Security Act of 1974, as amended ("ERISA"). In the event ERISA does not preempt state
law, the state law of Michigan applies.

28

---



PART A

FOR NON-U.S. SERVICE,
NON-CONTROLLED GROUP SERVICE,
AND/OR NON-COVERED CONTROLLED
GROUP SERVICE

---

ARTICLE I
DEFINITIONS

Additional
definitions appear in the Preamble of the Plan.

ARTICLE II
PARTICIPATION





29

---





ARTICLE III
RESTRICTED BENEFITS

30

---





ARTICLE IV
DISTRIBUTION OF RESTRICTED BENEFITS



31

---











32

---











ARTICLE V
RESTRICTED BENEFITS FUND



33

---











ARTICLE VI
MISCELLANEOUS













34

---







ARTICLE VII
PLAN ADMINISTRATION





35

---



PART B

FOR A SELECT GROUP OF MANAGEMENT OR
HIGHLY COMPENSATED EMPLOYEES, BOARD MEMBERS,
AND EMPLOYEES WHOSE BENEFITS ARE STATUTORILY LIMITED

---

ARTICLE I
DEFINITIONS

36

---





Additional
definitions appear in the Preamble of the Plan.

ARTICLE II
PARTICIPATION







ARTICLE III
SUPPLEMENTAL RETIREMENT BENEFITS



37

---





ARTICLE IV
DISTRIBUTION AND FORM OF
SUPPLEMENTAL RETIREMENT BENEFITS







38

---





| | a. | the present value of the Supplemental Benefit if paid immediately using the G83U mortality table and an interest rate of eight percent (8%); or                                                                                                                                                                                                                                                                  
| | -- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | b. | the present value of the Restricted Benefit deferred to age sixty-five (65) using the mortality table specified by the Commissioner of the Internal Revenue Service in Revenue Ruling 2001-62 and an interest rate equal to the yield rate for thirty
(30) year Treasury constant maturity securities in the Federal Reserve Statistical Release effective for the August prior to the Plan Year of distribution.







39

---

















40

---









ARTICLE V
SUPPLEMENTAL RETIREMENT BENEFITS FUND





41

---







ARTICLE VI
MISCELLANEOUS















42

---



ARTICLE VII
PLAN ADMINISTRATION





43

---



QuickLinks