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Exhibit 10.1

UBS Financial Services Inc.

Please complete and sign this form.
We must receive it by November 14, 2008.

ACCEPTANCE OF UBS’S OFFER RELATING TO AUCTION RATE SECURITIES

By signing below and returning this form, I accept UBS’s offer of Rights
relating to my Eligible ARS in the account listed below.  I understand and
acknowledge the following:

·  
All eligible ARS must remain in my UBS account listed below until I exercise my
Rights to sell my Eligible ARS to UBS or they are redeemed by the issuer or
purchased or sold on my behalf by UBS;

·  
I will instruct my UBS Financial Advisor or Branch Manager if and when I want to
exercise my Rights and sell my Eligible ARS to UBS during the period of June 30,
2010, through July 2, 2012;

·  
The acceptance of UBS’s offer constitutes consent (to the extent legally
required) for UBS, acting as principal, to purchase my Eligible ARS or to sell
them on my behalf at any time in its sole discretion and without other prior
notice to me, from the date that I accept this offer through July 2, 2012;

·  
If UBS purchases, sells or otherwise disposes of my Eligible ARS, it will
deposit the par value in my account within one business day of settlement of the
transaction;

·  
I release UBS and its employees/agents from all claims except claims for
consequential damages directly or indirectly relating to its marketing and sale
of ARS and expressly agree that I will not seek any damages or costs (punitive
damages, attorney fees, etc.) other than consequential damages.  I also will not
serve as a class representative or receive benefits under any class action
settlement or investor fund;

·  
If the account named below is in the name of a corporation, partnership, trust
or other equity, I represent and warrant that I have the power and authority to
accept this offer on behalf of that entity.

Clean Diesel Technologies, Inc.
Please complete and sign this form.
Attn:  Ann Ruple
We must receive it by November 14, 2008.
300 Atlantic Street
   
Suite 702
Mail
UBS Financial Services, Inc.
Stamford CT  06901-3522
 
ATTN:  ARS Group
   
1000 Harbor Boulevard
   
Weehawken, NJ  07086
       
Fax
+1-201-442-7766

Account Number:  CP 06577
                 
Account Owner Signature
/s/  Ann B. Ruple    Vice President
 
Date
11/5/08
         
Additional Party Signature
/s/  C. W. Grinnell   Vice President
 
Date
11/5/08
         
Daytime Telephone Number
(203) 327-7050
     

If you have questions, please contact your UBS Financial Advisor or Branch
Manager at +1-312-525-4500.
Clients outside the U.S. may call +1-201-352-0105 collect.

We kindly request that you do not include comments or questions on this form as
it could delay processing of your instructions.

UBS AG has filed a registration statement (including a prospectus) with the SEC
for the offering to which this communication relates.  Before you make an
investment decision, you should read the prospectus in that registration
statement and other documents that UBS has filed with the SEC for more complete
information about UBS and this offering.  You may get these documents for free
by visiting EDGAR on the SEC Web site at www.sec.gov or by calling UBS’s ARS
Client Service Center at +1-800-253-1974.

UBS Financial Services Inc. serves as the clearing firm for UBS International
Inc.  Accordingly, the information and terms contained in this letter and the
accompanying materials are directed to clients of both UBS Financial Services
Inc and UBS International Inc.
 
 

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