EXHIBIT 10.26

Revolving Loan Agreement

This REVOLVING LOAN AGREEMENT,dated as of February 6, 2001, (the"Effective Date") is between Union Carbide
Corporation, a New York corporation, (the"Borrower"), and The Dow Chemical Company, a Delaware corporation, (the "Lender").

1.    DEFINITIONS

1.1

"Advance(s)" has the meaning stated in Section 2. 1.1.2

"Agreement" means this Revolving Loan Agreement.1.3

"Borrower" has the meaning stated in the preamble.1.4

"Business Day" means a day of the year on which banks are open for business in Midland, Michigan, and not required or authorized to close in New York City, New York.1.5

"Commitment" has the meaning stated in Section 2. 1.1.6

"Control" has the meaning stated in Section 7.9.1.7

"Effective Date" has the meaning stated in the preamble.1.8

"Event(s) of Default" has the meaning stated in Section 6. 1.1.9

"Interest Period" means the period commencing on the first Business Day of each calendar month and ending on the day immediately preceding the first Business Day of the succeeding calendar month.1.10

"Interest Rate" has the meaning stated in section 2.3.1.11

"Lender" has the meaning stated in the preamble.1.12

"LIBOR" means the rate for deposits in U.S. Dollars for a period of one month which appears on the Telerate Page 3750 as of 11:00 a.m., London time, on the date that is two Business Days prior to the first day of the
applicable Interest Period.1.13

"Loan" has the meaning stated in Section 2. 1.1.14

"Maturity Date" means April 30, 2002.


2.    AMOUNTS AND TERMS OF THE ADVANCES



The
Lender agrees, on the terms and conditions stated in this Agreement, to make advances to the Borrower (the "Advance(s)") in an aggregate outstanding amount not to exceed
$1,500,000,000 (One Billion Five Hundred Million U.S. Dollars) (the "Commitment") during the period from the Effective Date of this Agreement to the Maturity Date. The amount of Advances outstanding
from time to time under this Agreement is refer-red to as the "Loan." The amount of Advances repaid pursuant to Section 2.4(d) below prior to the Maturity Date, may be reborrowed
subject to the limitations contained in this Agreement.



Each
Advance shall be made on at least two Business Days' notice from the Borrower to the Lender specifying the amount, the date of making (which shall be a Business Day), the term of
the Advance, and the account into which such Advance is to be paid. The Lender will make each Advance available to the Borrower at such place of payment as the Borrower shall request in its notice no
later than 11:00 A.M. Borrower's local time on the date the Advance is made.



43

---





Either
party may by prior written notice at any time and from time to time, wholly cancel or permanently reduce the Lender's unused Commitment under this Agreement.



The
Lender maintains in accordance with its usual practice an account or accounts evidencing the indebtedness of the Borrower resulting from each Advance made from time to time and the
amounts of principal and interest payable and paid from time to time under this Agreement. In any legal action or proceeding in respect of this Agreement, the entries made in such account or accounts
are, in the absence of manifest error, conclusive evidence of the existence and amounts of the obligations of the Borrower.

3.    CONDITIONS OF LENDING



The
obligation of the Lender to make any Advance under this Agreement is subject to the conditions precedent that on the date this Agreement is executed and the date of such Advance:



44

---



4.    REPRESENTATIONS AND WARRANTIES



The
Borrower represents and warrants as follows:



5.    COVENANTS OF THE BORROWER



So
long as any Advance remains unpaid or the Lender has any Commitment, the Borrower will, unless the Lender otherwise consents in writing, furnish to the Lender:



6.    EVENTS OF DEFAULT



If
any of the following events ("Event(s) of Default") occur and continue:



45

---





7.    MISCELLANEOUS



No
amendment or modification of any provision of this Agreement or any instrument delivered under this Agreement is effective unless the same is in writing and signed by an authorized
representative of the Lender.



All
written notices and other communications delivered by hand or sent by first class mail are effective when received, and when sent by Telex, e-mail or facsimile are
effective when sent:



No
failure or delay on the part of the Lender to exercise any right under this Agreement operates as a waiver of this Agreement. Nor does any single or partial exercise of any right
under this Agreement preclude any other or further exercise of any right under this Agreement or the exercise of any other right. The remedies provided in this Agreement are cumulative and not
exclusive of any remedies provided by law.



If
any time during the term of the Loan under this Agreement, any applicable tax law is changed in such a manner that it increases the Lender's cost of maintaining the Loan, the Borrower
agrees to reimburse the Lender for all such additional costs;provide however, that if the Borrower is prevented or unable for any reason to reimburse
the Lender for such additional costs of maintaining the Loan, then the unpaid principal amount of the Loan, together with interest on the Loan, shall be repaid.

46

---



The
Borrower agrees to pay on demand all losses and all costs and expenses, if any, in connection with the enforcement of this Agreement and any instruments or other documents delivered
under this Agreement, including, without limitation, losses, costs and expenses sustained as a result of a default by the Borrower in the performance of its obligations contained in this Agreement or
any instrument or document delivered under this Agreement.



This
Agreement is binding upon and inures to the benefit of the Borrower and the Lender. Neither the Borrower nor the Lender have the right to assign any of their respective rights under
this Agreement or any interest in this Agreement without the prior written consent of the other party to this Agreement.



This
Agreement is governed by and construed in accordance with the laws of the State of Michigan, U.S.A., without regard to its provisions concerning conflicts of law.



In
the event that a court of competent jurisdiction determines that any portion of this Agreement is in violation of any statute or public policy, then only the portions of this
Agreement that violate such statute or public policy are stricken. All portions of this Agreement that do not violate any statute or public policy continue in full force and effect. Any court order
striking any portion of this Agreement modifies the stricken terms as narrowly as possible to give as much effect as possible to the intentions of the parties pursuant to this Agreement.



After
any change of Control (as defined below) of the Borrower, or any proposal, either public or private, that the Lender believes, in good faith, to be a bona fide proposal to effect
any change of Control (as defined below) of the Borrower, the Lender may, at its option, upon notice to the Borrower declare the obligation of the Lender to make advances or loans under this Agreement
to be terminated and declare all principal, interest, and other amounts payable under this Agreement to be immediately due and payable, whereupon the same shall become immediately due and payable. For
purposes of this Agreement, "Control" means the possession, directly or indirectly, of the power to direct or cause the direction of the management and policies of any individual, corporation,
partnership, unincorporated association or other entity, whether through the ownership of voting stock, by contract or otherwise. A person or entity who is the owner of 20% or more of an entity's
outstanding voting stock shall be deemed to have Control of such corporation.

|BORROWER:                 |  | LENDER:                 
|------------------------- |  | ------------------------
|UNION CARBIDE CORPORATION |  | THE DOW CHEMICAL COMPANY
|By:                       |  |                         
|Name:                     |  |                         
|Title:                    |  |                         

47

---

QuickLinks