SecProbe.io

Mail Stop 3010
          September 23, 2009
Mr. John Cryan Group Chief Financial Officer UBS AG  Bahnhofstrasse 45 CH-8001 Zurich,  Switzerland

Re: UBS AG
 Form 20-F for the fiscal year ended December 31, 2008
 Filed March 11, 2009
File No. 001-15060

Dear Mr. Cryan:
We have reviewed your filing and have the following comments.  Please be as
detailed as necessary in your explanations.  In our comments, we may ask you to provide
us with information so we may better unders tand your disclosure.  After reviewing this
information, we may raise additional comments.
 Please understand that the purpose of our re view process is to assist you in your
compliance with the applicable disclosure  requirements and to  enhance the overall
disclosure in your filing.  We look forward to  working with you in these respects.  We
welcome any questions you may have about our  comments or any other aspect of our
review.  Feel free to call us at the telephone numbers listed at the end of this letter.
 Form 20-F for the year ended December 31, 2008

 Off-Balance Sheet, page 47

 Support to non-consolidated investment funds, page 50

 1. You disclose that in 2008, as a result of  the financial markets crisis which caused
declining asset values, market illiquidity and de-leveraging by investors, you supported several non-consolidated invest ment funds that you manage in your
wealth and asset management businesses.  Please tell us if your reassessed your
treatment of these funds for consolidation as a result of  the additional support and
provide us with the results of your  reassessments, if applicable.

Mr. John Cryan
UBS AG September 23, 2009 Page 2   Credit Risk, page 134

 Past due but not impaired loans, page 145

 2. We note that past due but not impaired loans that are 61-90 days old and over 90
days old increased significantly from year to year.  Please discuss this trend and
tell us in more detail how you determined that these loans were not impaired.
 Note 23 Derivative instrument s and hedge accounting, page 312

 3. We note your disclosure regarding your cr edit derivatives in Note 23.  Concerning
your involvement as a seller of credit deri vatives, please tell us, and disclose the
following information in future filings fo r your credit default swaps and total rate
of return swaps:

• Discuss the types of credit events or circumstances that would require you
to perform under the credit derivativ es and the current status of the
payment/performance risk of the credit derivatives;
• Discuss the nature of (1) any recourse  provisions that would enable you to
recover from third parties any of  the amounts paid under the credit
derivatives and (2) any assets held ei ther as collateral or by third parties
that, upon the occurrence of any speci fied triggering event or condition
under the credit derivative, you can obtain and liquidate  to recover all or a
portion of the amounts paid under the cred it derivative.  Plea se indicate, if
estimable, the approximate extent to which the proceeds from liquidation of those assets would be expected to cover the maximum potential amount
of future payments under the credit derivative.  In your estimate of
possible recoveries, please tell us the effect of purchase d credit protection
with identical underlying(s).
 4. For credit protection sold and credit protection purchased, please tell us and
consider disclosing in future filings the extent to which the derivative activity was for the following purposes:

• Providing default risk protection to o ffset credit exposure to your holdings
of the related reference entity’s debt  in your loan portf olio, investment
portfolio, or loan commitments outstanding;
• Creating new credit exposure fo r your own trading purposes;
• Reflecting credit exposures taken for the benefit of your clients; and
• Providing an offset to credit exposure taken for the benefit of clients.

Also, please discuss your overall strategies employed in your credit derivatives
portfolio as well as any changes in those strategies during the periods presented.

Mr. John Cryan
UBS AG September 23, 2009 Page 3

5. In addition to the above, please tell us and consider disclosing the following
information in future filings rela ted to your credit derivatives:

• Discuss any trends experienced within the portfolio both in terms of positions
held and realized gains and losses. Specifically disclose the reasons for the significant changes in the notional amounts as well as the reasons for the
changes in the fair values of the credit derivatives. Discuss any expected
changes to those trends.
• Discuss the types of counterparties (e.g. broker-dealers, other financial
institutions, non-financial institutions, and insurance and financial guaranty
firms) to your credit protection purchased. Consider quantifying the notional amount of credit derivatives by type of counterparty, separated between
whether you purchased protection from the counterparty or sold protection to
the counterparty.

6. You disclose on page 323 that you reflect  your own credit changes in valuations
for those financial liabilities at fair va lue, including derivativ e liabilities, where
your own credit risk would be considered  by market participants and excludes
fully collateralized transactions and othe r instruments for which it is established
market practice not to include an entity-s pecific adjustment for own credit.  Please
specifically tell us if you believe that your  own credit risk is c onsidered by market
participants as it relates to  the valuation of your deri vatives and tell us during
which periods you made adjustments to your derivative valuations due to your
own credit.
 Note 26 Fair value of financial instruments, page 322

7. We note your fair value disclosures in  Note 26 of your Form 20-F and your
disclosures in your Quarterly Report 2Q 09 included in your Form 6-K filed
August 4, 2009.  You discuss and/or present movements in Level 3 instruments based on three categories: trading portfo lio assets, derivative instruments, and
financial liabilities designated at fair value.  Please te ll us what consideration you
gave to further breaking these categories down into additional classes of financial
instruments.  Please provide us with your  proposed revised disclosure for future
filings, if applicable.
 8. We note your discussion on page 325 of mate rial changes in Level 3 instruments
for the year.  You state that there were transfers into Level 3, because valuation
inputs became less observable.  Please te ll us the significant sp ecific inputs that
became unobservable and consider expandi ng your disclosure to discuss the
specific inputs in future filings.

Mr. John Cryan
UBS AG September 23, 2009 Page 4   Note 29 Measurement categories of financial assets and financial liabilities, page 331

 b) Reclassification of financial assets, page 332

9. You disclose that the reclassification of th ese financial assets reflects your change
in intent and ability to hold these financia l assets for the foreseeable future rather
than for trading in the near term.  Please tell us in detail and discuss in future filings how you defined foreseeable futu re on the date of reclassification.
Additionally, please quantif y the numeric time period used for evaluating the
foreseeable future and discuss if it varied by asset type.
 Note 38 Reorganizations and disposals, page 358

 Sale of US residential mo rtgage-backed securities to BlackRock fund, page 358

 10. Please tell us how you accounted for the sale of RMBS to the RMBS
Opportunities Master Fund, LP.  Please tell us how you determined it was appropriate to derecognize the financial assets transferred, an d provide us with
any analysis you performed.  Additionally, te ll us, and disclose in future filings,
the fair value of the coll ateral securing the loan, a nd the payment terms of the
loan.  Furthermore, your disclosure on page 39 of your Form 6-K filed on August
4, 2009, indicates that the payment stream s to the SPE have slowed due to
declines in floating interest rate paym ents and increasing mortgage defaults.
Please discuss the impact that this slowi ng of payments to the SPE has had on the
payments being received on the loan from the SPE and the impact it has had on your analysis regarding the cons olidation status of the fund.
 11. You disclose that the USD 15 billion proceeds were approximately in line with
the fair value of the assets reco rded by UBS at 31 March 2008.  Please
specifically tell us how you determined the fair value of the assets transferred;
discuss how you incorporated any in surance from monolines, etc.

Sale of assets to a third-party fund contro lled by the Swiss National Bank (SNB), page
358
 12. Please tell us how you accounted for the sale  of securities and other positions to a
fund owned and controlled by the Swiss National Bank.  Please tell us how you
determined it was appropriate to derec ognize the financial assets transferred, and
provide us with any analysis you perform ed.  In particular, tell us how you
considered the guarantee made to the SNB, entitling the SNB to receive 100 million UBS ordinary shares if the SNB in curs a loss on the loan it has made to
the fund.  Please cite the specific guidance that you relied upon to determine the
appropriate accounting for this transaction.

Mr. John Cryan
UBS AG September 23, 2009 Page 5   13. You disclose on page 16 of your An nual Report 2008 that the value of the
securities as of 30 September 2008 was determined by the SNB based on a valuation conducted by third-party valuati on experts, and that you recorded a loss
equal to the difference between the valu e that you had previously assigned to
these securities and the value assigned by th e third-party experts.  Please tell us
how you considered Securities Act Rule 436 when determining whether you were required to name the experts and obtain th eir consents for inclusion in your filing
which is incorporated by reference in to several registration statements.
 Form 6-K filed August 4, 2009

14. Please tell us the extent to which your results for the six months ended June 30,
2009 were impacted by the early settlement  of derivative contracts where the
counterparty was AIG.  If your results we re impacted by such activities, please
tell us and revise your future filings to  discuss the circumstances surrounding the
settlements, quantify the no tional amount of the contract s involved, the amount of
the gain or loss upon early settlement, and identify the line item in which such amounts are presented.
 Risk Management and control, page 36

Credit risk, page 36
 15. You disclose that effective 1 Apr il 2009, you implemented a new policy for
designating a reclassified security as an  “impaired loan” and that you restated
your Investment Bank impaired lending portf olio to reflect the new policy.  Please
explain to us the reason for the new policy and how you determined that this new policy is the most appropriate.  Also te ll us what your polic y was prior to the
change related to these instruments.
 Note 9 Income Taxes, page 69

 16. You disclose that you recognized a deferred tax benefit of CHF 371 million,
which mainly relates to a release of va luation allowances against deferred tax
assets in respect of tax losses and tem porary differences, taking into account the
latest forecasts of taxable profits.  Please provide us with more detail regarding
how you determined that it was appropria te to release this portion of your
valuation allowance.  Tell us the positive criteria that you considered and tell us
any significant assumptions that you relied upon.

Mr. John Cryan
UBS AG September 23, 2009 Page 6   Note 11 Fair value of financial instruments, page 70

 17. You disclose on page 61 that you have  included the relevant fair value
requirements from IFRS 7 Amendment “Improving Disclosures about Financial Instruments” in Note 11.  In future fili ngs please also disclose the following: the
location of gains/losses in th e statement of comprehensive income or the separate
income statement, significant transfers between Level 1 and Level 2, and the amount of gains/losses attribut able to assets and liabiliti es held at the end of the
reporting period.  Please pr ovide us with your proposed revised disclosure for
future filings.

*    *    *    *

As appropriate, please respond to these co mments within 10 business days or tell
us when you will provide us with a response.  Please furnish a cover letter with your
response that keys your response to ou r comments and provides any requested
information.  Detailed cover le tters greatly facilitate our re view.  Please understand that
we may have additional comments after re viewing your responses to our comments.

 We urge all persons who are responsible  for the accuracy and adequacy of the
disclosure in the filing to be certain that the filing includes all in formation required under
the Securities Exchange Act of 1934 and th at they have provided all information
investors require for an informed invest ment decision.  Since the company and its
management are in possession of all facts re lating to a company’s disclosure, they are
responsible for the accuracy and adequacy of the disclosures they have made.
  In connection with responding to our comments, please provide, in writing, a
statement from the company acknowledging that:
• the company is responsible for the adequacy  and accuracy of the disclosure in the
filing;

• staff comments or changes to disclosure  in response to staff comments do not
foreclose the Commission from taking any action with respect to the filing; and

• the company may not assert staff comments as a defense in any proceeding initiated
by the Commission or any person under the federal securities laws of the United
States.
 In addition, please be advise d that the Division of Enfo rcement has access to all
information you provide to the staff of the Divi sion of Corporation Fi nance in our review
of your filing or in response to our comments on your filing.

Mr. John Cryan
UBS AG September 23, 2009 Page 7
If you have any questions, you may contact  Eric McPhee at (202) 551-3693 or me
at (202) 551-3782.

Sincerely,    Jessica Barberich
Assistant Chief Accountant