UBS AG — Capital/Financing Update 2012

Feb 28, 2012

Filed Pursuant to Rule 424(b)(2) Registration Statement No. 333-178960

CALCULATION OF REGISTRATION FEE

●	●	●
Title of Each Class of Securities Offered	Maximum Aggregate Offering Price	Amount of Registration Fee (1)
Return Optimization Securities linked to the S&P 500 ® Index due March 28, 2013	$4,021,840.00	$460.90

(1) Calculated in accordance with Rule 457(r) of the Securities Act of 1933.

(1) The index return excludes any cash dividend payments.

PRICING SUPPLEMENT (To Prospectus dated January 11, 2012 and Product Supplement dated January 30, 2012

UBS AG $4,021,840 Return Optimization Securities

Linked to the S&P 500 ® Index due March 28, 2013

Investment Description

UBS AG Return Optimization Securities (the “Securities”) are unsubordinated, unsecured debt securities issued by UBS AG (“UBS”) linked to the performance of the S&P 500 ® Index (the “underlying index”). If the index return is positive, UBS will repay your principal amount at maturity plus pay a return equal to 3.0 times the index return, up to the maximum gain of 15.15%. If the index return is zero, UBS will repay the full principal amount at maturity. However, if the index return is negative, UBS will repay less than the full principal amount at maturity, if anything, resulting in a loss on your investment that is proportionate to the negative index return. Investing in the Securities involves significant risks. The Securities do not pay interest. You may lose some or all of your principal amount. Any payment on the Securities, including any repayment of principal, is subject to the creditworthiness of the Issuer. If the Issuer were to default on its payment obligations you may not receive any amounts owed to you under the Securities and you could lose your entire investment.

Features

o Enhanced Growth Potential: At maturity, the Securities enhance any positive index return up to the maximum gain. If the index return is negative, investors will be exposed to the negative index return at maturity.

o Full Downside Market Exposure: If the index return is negative, investors will be exposed to the negative index return at maturity resulting in a loss of principal that is proportionate to the underlying index’s decline from the trade date to the final valuation date. Investors could lose some or all of their initial investment. Any payment on the Securities, including any repayment of principal, is subject to the creditworthiness of UBS.

Key Dates

●	●
Trade Date	February 24, 2012
Settlement Date	February 29, 2012
Final Valuation Date*	March 22, 2013
Maturity Date*	March 28, 2013

• Subject to postponement in the event of a market disruption event. See “Maturity Date” and “Final Valuation Date” under “General Terms of the Securities” in the Return Optimization Securities product supplement.

NOTICE TO INVESTORS: THE SECURITIES ARE SIGNIFICANTLY RISKIER THAN CONVENTIONAL DEBT INSTRUMENTS. THE ISSUER IS NOT NECESSARILY OBLIGATED TO REPAY THE FULL PRINCIPAL AMOUNT OF THE SECURITIES AT MATURITY, AND THE SECURITIES HAVE DOWNSIDE MARKET RISK SIMILAR TO THE UNDERLYING INDEX. THIS MARKET RISK IS IN ADDITION TO THE CREDIT RISK INHERENT IN PURCHASING A DEBT OBLIGATION OF UBS. YOU SHOULD NOT PURCHASE THE SECURITIES IF YOU DO NOT UNDERSTAND OR ARE NOT COMFORTABLE WITH THE SIGNIFICANT RISKS INVOLVED IN INVESTING IN THE SECURITIES.

YOU SHOULD CAREFULLY CONSIDER THE RISKS DESCRIBED UNDER “KEY RISKS” BEGINNING ON PAGE 5 AND UNDER “RISK FACTORS” BEGINNING ON PAGE PS-13 OF THE RETURN OPTIMIZATION SECURITIES PRODUCT SUPPLEMENT BEFORE PURCHASING ANY SECURITIES. EVENTS RELATING TO ANY OF THOSE RISKS, OR OTHER RISKS AND UNCERTAINTIES, COULD ADVERSELY EFFECT THE MARKET VALUE OF, AND THE RETURN ON, YOUR SECURITIES. YOU MAY LOSE SOME OR ALL OF YOUR INITIAL INVESTMENT IN THE SECURITIES.

Security Offering

These terms relate to Return Optimization Securities linked to the S&P 500 ® Index. The return on the Securities is subject to, and will not exceed, the “maximum gain” or the corresponding “maximum payment at maturity per Security”. The Securities are offered at a minimum investment of $1,000, or 100 Securities at $10.00 per Security, and integral multiples of $10.00 in excess thereof.

●	●	●	●	●	●	●	●
Underlying Index	Index Bloomberg Symbol	Multiplier	Maximum Gain	Maximum Payment at Maturity per Security	Initial Index Level	CUSIP	ISIN
S&P 500 ® Index	SPX	3.0	15.15 %	$11.5150	1365.74	90267Y443	90267Y4439

See “Additional Information about UBS and the Securities” on page 2. The Securities will have the terms specified in the Return Optimization Securities (“ROS”) product supplement relating to the Securities, dated January 30, 2012, the accompanying prospectus and this pricing supplement.

Neither the Securities and Exchange Commission nor any other regulatory body has approved or disapproved of these securities or passed upon the adequacy or accuracy of this pricing supplement, the ROS product supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense. The Securities are not deposit liabilities of UBS AG and are not FDIC insured.

● — Issue Price to Public	Underwriting Discount	Proceeds to UBS AG
Per Security	$10.00	$0.20	$9.80
Total	$4,021,840.00	$80,436.80	$3,941,403.20

UBS Financial Services Inc. UBS Investment Bank

Pricing Supplement dated February 24, 2012

Additional Information about UBS and the Securities

UBS has filed a registration statement (including a prospectus, as supplemented by a product supplement for the Securities and an index supplement for various securities we may offer, including the Securities), with the Securities and Exchange Commission, or SEC, for the offering to which this pricing supplement relates. Before you invest, you should read these documents and any other documents relating to this offering that UBS has filed with the SEC for more complete information about UBS and this offering. You may obtain these documents without cost by visiting EDGAR on the SEC website at www.sec.gov. Our Central Index Key, or CIK, on the SEC website is 0001114446. Alternatively, UBS will arrange to send you the prospectus and the ROS product supplement and the index supplement if you so request by calling toll-free 800-722-7370.

You may access these documents on the SEC website at www.sec.gov as follows:

Ø Product supplement for Return Optimization Securities dated January 30, 2012:

http://www.sec.gov/Archives/edgar/data/1114446/000139340112000006/c300686_690694-424b2.htm

Ø Index supplement dated January 24, 2012:

http://www.sec.gov/Archives/edgar/data/1114446/000119312512021889/d287369d424b2.htm

Ø Prospectus dated January 11, 2012:

http://www.sec.gov/Archives/edgar/data/1114446/000119312512008669/d279364d424b3.htm

References to “UBS,” “we,” “our” and “us” refer only to UBS AG and not to its consolidated subsidiaries. In this pricing supplement, “Securities” refer to the Return Optimization Securities that are offered hereby, unless the context otherwise requires. Also, references to the “ROS product supplement” mean the UBS product supplement, dated January 30, 2012, references to the “index supplement” mean the UBS index supplement, dated January 24, 2012, and references to “accompanying prospectus” mean the UBS prospectus titled “Debt Securities and Warrants,” dated January 11, 2012.

2

Investor Suitability

The Securities may be suitable for you if:

Ø You fully understand the risks inherent in an investment in the Securities, including the risk of loss of your entire initial investment.

Ø You can tolerate a loss of all or a substantial portion of your investment and are willing to make an investment that has the same downside market risk as an investment in the underlying index or its constituents.

Ø You believe the underlying index will appreciate over the term of the Securities and that the appreciation is unlikely to exceed an amount equal to the maximum gain of 15.15%.

Ø You understand and accept that your potential return is limited to the maximum gain of 15.15% and you are willing to invest in the Securities based on this maximum gain.

Ø You can tolerate fluctuations in the price of the Securities prior to maturity that may be similar to or exceed the downside fluctuations in the level of the underlying index.

Ø You do not seek current income from your investment.

Ø You are willing to hold the Securities to maturity, a term of approximately 13 months, and accept that there may be little or no secondary market for the Securities.

Ø You are willing to assume the credit risk of UBS for all payments under the Securities, and understand that if UBS defaults on its obligations you may not receive any amounts due to you including any repayment of principal.

The Securities may not be suitable for you if:

Ø You do not fully understand the risks inherent in an investment in the Securities, including the risk of loss of your entire initial investment.

Ø You require an investment designed to provide a full return of principal at maturity.

Ø You cannot tolerate a loss of all or a substantial portion of your investment and are unwilling to make an investment that has the same downside market risk as an investment in the underlying index or its constituents.

Ø You believe that the level of the underlying index will decline during the term of the Securities and is likely to close below the initial index level on the final valuation date, or you believe the underlying index will appreciate over the term of the Securities by more than the maximum gain of 15.15%.

Ø You seek an investment that has unlimited return potential without a cap on appreciation and you are unwilling to invest in the Securities based on the maximum gain of 15.15%.

Ø You cannot tolerate fluctuations in the price of the Securities prior to maturity that may be similar to or exceed the downside fluctuations in the level of the underlying index.

Ø You seek current income from this investment.

Ø You are unable or unwilling to hold the Securities to maturity, a term of approximately 13 months, or you seek an investment for which there will be an active secondary market.

Ø You are not willing to assume the credit risk of UBS for all payments under the Securities.

The investor suitability considerations identified above are not exhaustive. Whether or not the Securities are a suitable investment for you will depend on your individual circumstances and you should reach an investment decision only after you and your investment, legal, tax, accounting and other advisors have carefully considered the suitability of an investment in the Securities in light of your particular circumstances. You should also review “Key Risks” beginning on page 5 of this pricing supplement and the more detailed “Risk Factors” beginning on page PS-13 of the ROS product supplement for risks related to an investment in the Securities.

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Final Terms

●	●
Issuer	UBS AG, Jersey Branch
Principal Amount	$10.00 per Security (subject to a minimum investment of 100 Securities)
Term	Approximately 13 months.
Maximum Gain	15.15%
Multiplier	3.0
Payment at Maturity (per Security)	If the index return is positive, UBS will pay you an amount in cash equal to:
	$10.00 + ($10.00 × the lesser of (3.0 x Index Return) and (Maximum Gain))
	If the index return is zero, UBS will pay you an amount in cash equal to your principal amount:
	$10.00
	If the index return is negative, UBS will pay you an amount that is less than your principal amount, if anything, resulting in a loss on your investment that is proportionate to the negative index return:
	$10.00 + ($10.00 x Index Return)
Index Return	Final Index Level – Initial Index Level Initial Index Level
Initial Index Level	1365.74, which is the closing level of the underlying index on the trade date.
Final Index Level	The closing level of the underlying index on the final valuation date.

Investment Timeline

INVESTING IN THE SECURITIES INVOLVES SIGNIFICANT RISKS. YOU MAY LOSE SOME OR ALL OF YOUR PRINCIPAL AMOUNT. ANY PAYMENT ON THE SECURITIES, INCLUDING ANY REPAYMENT OF PRINCIPAL, IS SUBJECT TO THE CREDITWORTHINESS OF UBS. IF UBS WERE TO DEFAULT ON ITS PAYMENT OBLIGATIONS, YOU MAY NOT RECEIVE ANY AMOUNTS OWED TO YOU UNDER THE SECURITIES AND YOU COULD LOSE YOUR ENTIRE INVESTMENT.

4

Key Risks

An investment in the Securities involves significant risks. Some of the risks that apply to the Securities are summarized here, but we urge you to read the more detailed explanation of risks relating to the Securities generally in the “Risk Factors” section of the ROS product supplement. We also urge you to consult your investment, legal, tax, accounting and other advisers before you invest in the Securities.

Ø Risk of loss — The Securities differ from ordinary debt securities in that the issuer will not necessarily repay the full principal amount of the Securities. If the index return is negative, you will lose some or all of your initial investment in an amount proportionate to the decline in the level of the underlying index from the trade date to the final valuation date.

Ø The multiplier applies only at maturity — You should be willing to hold your Securities to maturity. If you are able to sell your Securities prior to maturity in the secondary market, the price you receive will likely not reflect the full economic value of the multiplier or the Securities and the return you realize may be less than 3.0 times the index return even if such return is positive and does not exceed the maximum gain. You can receive the full benefit of the multiplier and earn the potential maximum return from UBS only if you hold your Securities to maturity.

Ø Your potential return on the Securities is limited to the maximum gain — The return potential of the Securities is limited to the maximum gain of 15.15%. Therefore, you will not benefit from any positive index return in excess of an amount that, when multiplied by the multiplier, exceeds the maximum gain and your return on the Securities may be less than it would be in a hypothetical direct investment in the underlying index or the index constituent stocks.

Ø No interest payments — UBS will not pay any interest with respect to the Securities.

Ø Credit risk of UBS — The Securities are unsubordinated, unsecured debt obligations of the issuer, UBS, and are not, either directly or indirectly, an obligation of any third party. Any payment to be made on the Securities, including any repayment of principal, depends on the ability of UBS to satisfy its obligations as they come due. As a result, the actual and perceived creditworthiness of UBS may affect the market value of the Securities and, in the event UBS were to default on its obligations, you may not receive any amounts owed to you under the terms of the Securities and you could lose your entire initial investment.

Ø Market risk — The return on the Securities is directly linked to the performance of the underlying index and indirectly linked to the value of the stocks comprising the underlying index (“index constituent stocks”), and will depend on whether, and the extent to which, the index return is positive or negative. The levels of the underlying index can rise or fall sharply due to factors specific to the index constituent stocks, as well as general market factors, such as general market volatility and levels, interest rates and economic and political conditions. You may lose some or all of your principal amount if the index return is negative.

Ø Owning the Securities is not the same as owning the index constituent stocks — Owning the Securities is not the same as owning the index constituent stocks. As a holder of the Securities, you will not have voting rights or rights to receive dividends or other distributions or other rights that holders of the index constituent stocks would have.

Ø No assurance that the investment view implicit in the Securities will be successful — It is impossible to predict whether and the extent to which the level of the underlying index will rise or fall. There can be no assurance that the level of the underlying index will rise above the initial index level. The final index level of the underlying index will be influenced by complex and interrelated political, economic, financial and other factors that affect the index constituent stocks. You should be willing to accept the risks of owning equities in general and the index constituent stocks in particular, and the risk of losing some or all of your initial investment.

Ø The underlying index reflects excess return, not total return — The return on your Securities is based on the performance of the underlying index, which reflects the changes in the market prices of the index constituent stocks. It is not, however, linked to a “total return” index or strategy, which, in addition to reflecting those price returns, would also reflect dividends paid on the index constituent stocks. The return on your Securities will not include such a total return feature or dividend component.

Ø Changes affecting the underlying index could have an adverse effect on the value of the Securities. — The policies of Standard & Poor’s Financial Services LLC, a subsidiary of The McGraw-Hill Companies, the sponsor of the underlying index (the “index sponsor”), concerning additions, deletions and substitutions of the index constituent stocks and the manner in which the index sponsor takes account of certain changes affecting those index constituent stocks may adversely affect the level of the underlying index. The policies of the index sponsor with respect to the calculation of the underlying index could also adversely affect the level of the underlying index. The index sponsor may discontinue or suspend calculation or dissemination of the underlying index. Any such actions could have an adverse effect on the value of the Securities.

Ø UBS cannot control actions by the index sponsor and the index sponsor has no obligation to consider your interests — UBS and its affiliates are not affiliated with the index sponsor and have no ability to control or predict its actions, including any errors in or discontinuation of public disclosure regarding methods or policies relating to the calculation of the underlying index. The index sponsor is not involved in the Securities offering in any way and has no obligation to consider your interest as an owner of the Securities in taking any actions that might affect the market value of your Securities.

5

Ø There may be little or no secondary market for the Securities — The Securities will not be listed or displayed on any securities exchange or any electronic communications network. There can be no assurance that a secondary market for the Securities will develop. UBS Securities LLC and other affiliates of UBS may make a market in the Securities, although they are not required to do so and may stop making a market at any time. The price, if any, at which you may be able to sell your Securities prior to maturity could be at a substantial discount from the issue price and to the intrinsic value of the product; and as a result, you may suffer substantial losses.

Ø Price of Securities prior to maturity — The market price of the Securities will be influenced by many unpredictable and interrelated factors, including the level of the underlying index; the volatility of the underlying index; the dividends paid on the index constituent stocks; the time remaining to the maturity of the Securities; interest rates in the markets in general; geopolitical conditions and economic, financial, political and regulatory, judicial or other events; and the creditworthiness of UBS. You must hold the Securities to maturity to receive the stated payout from UBS.

Ø Impact of fees on the secondary market price of the Securities — Generally, the price of the Securities in the secondary market is likely to be lower than the issue price to public since the issue price to public included, and the secondary market prices are likely to exclude, commissions, hedging costs or other compensation paid with respect to the Securities.

Ø Potential UBS impact on price — Trading or transactions by UBS or its affiliates in the index constituent stocks and/or over-the-counter options, futures or other instruments with returns linked to the performance of the underlying index may adversely affect the performance and, therefore, the market value of the Securities.

Ø Potential conflict of interest — UBS and its affiliates may engage in business related to the underlying index or index constituent stocks, which may present a conflict between the obligations of UBS and you, as a holder of the Securities. The calculation agent, an affiliate of the issuer, will determine the index return and the payment at maturity based on the closing level of the underlying index on the final valuation date. The calculation agent can postpone the determination of the underlying return or the maturity date if a market disruption event occurs and is continuing on the final valuation date.

Ø Potentially inconsistent research, opinions or recommendations by UBS — UBS and its affiliates publish research from time to time on financial markets and other matters that may influence the value of the Securities, or express opinions or provide recommendations that are inconsistent with purchasing or holding the Securities. Any research, opinions or recommendations expressed by UBS or its affiliates may not be consistent with each other and may be modified from time to time without notice. Investors should make their own independent investigation of the merits of investing in the Securities and the underlying index to which the Securities are linked.

Ø Dealer incentives — UBS and its affiliates act in various capacities with respect to the Securities. We and our affiliates may act as a principal, agent or dealer in connection with the sale of the Securities. Such affiliates, including the sales representatives, will derive compensation from the distribution of the Securities and such compensation may serve as an incentive to sell these Securities instead of other investments. We will pay total underwriting compensation of $0.20 per Security to any of our affiliates acting as agents or dealers in connection with the distribution of the Securities.

Ø Uncertain tax treatment — Significant aspects of the tax treatment of the Securities are uncertain. You should consult your tax advisor about your own tax situation. See ``What Are the Tax Consequences of the Securities” beginning on page 8 .

6

Hypothetical Examples and Return Table of the Securities at Maturity

The examples and table below illustrate the Payment at Maturity for a $10.00 Security on a hypothetical offering of the Securities, with the following assumptions (amounts may have been rounded for ease of analysis):

●	●
Investment Term:	13 months
Initial Index Level:	1365.74
Multiplier:	3.00
Maximum Gain:	15.15%
Range of Index Performance:*	75% to -75%

• The index performance range is provided for illustrative purposes only. The actual index return may be below -75% and you therefore may lose up to 100% of your investment in the Securities

●	●	●	●
Final Index Level	Index Return	Payment at Maturity	Security Total Return at Maturity
2390.05	75.00 %	$ 11.52	15.15 %
2253.47	65.00 %	$ 11.52	15.15 %
2116.90	55.00 %	$ 11.52	15.15 %
2048.61	50.00 %	$ 11.52	15.15 %
1980.32	45.00 %	$ 11.52	15.15 %
1912.04	40.00 %	$ 11.52	15.15 %
1843.75	35.00 %	$ 11.52	15.15 %
1775.46	30.00 %	$ 11.52	15.15 %
1707.18	25.00 %	$ 11.52	15.15 %
1638.89	20.00 %	$ 11.52	15.15 %
1502.31	10.00 %	$ 11.52	15.15 %
1434.71	5.05 %	$ 11.52	15.15 %
1399.88	2.50 %	$ 10.75	7.50 %
1365.74	0.00 %	$ 10.00	0.00 %
1297.45	-5.00 %	$ 9.50	-5.00 %
1229.17	-10.00 %	$ 9.00	-10.00 %
1160.88	-15.00 %	$ 8.50	-15.00 %
1092.59	-20.00 %	$ 8.00	-20.00 %
1024.31	-25.00 %	$ 7.50	-25.00 %
956.02	-30.00 %	$ 7.00	-30.00 %
887.73	-35.00 %	$ 6.50	-35.00 %
819.44	-40.00 %	$ 6.00	-40.00 %
751.16	-45.00 %	$ 5.50	-45.00 %
682.87	-50.00 %	$ 5.00	-50.00 %
614.58	-55.00 %	$ 4.50	-55.00 %
478.01	-65.00 %	$ 3.50	-65.00 %
341.44	-75.00 %	$ 2.50	-75.00 %

Example 1 — On the final valuation date, the underlying index closes 2.50% above the initial index level. Since the index return is 2.50%, UBS will pay you 3.0 × the index return, or a 7.50% total return, and the payment at maturity per $10.00 principal amount of the Securities will be calculated as follows:

$10.00 + ($10.00 × 3.0 × 2.50%) = $10.00 + $0.75 = $10.75

Example 2 — On the final valuation date, the underlying index closes 35% above the initial index level. Since 3.0 × the index return of 35% is more than the maximum gain of 15.15%, UBS will pay you the maximum gain of 15.15%, and the payment at maturity is equal to $11.52 per Security.

Example 3 — On the final valuation date, the closing level of the underlying index is equal to the initial index level. Since the index return is 0%, UBS will repay the full principal amount and the payment at maturity is equal to $10.00 per Security.

Example 4 — On the final valuation date, the underlying index closes 35% below the initial index level. Since the index return is -35%, UBS will pay you less than the full principal amount and the payment at maturity per Security is as follows:

$10.00 + ($10.00 × -35%) = $6.50

Accordingly, if the final index level is below the initial index level, UBS will pay you less than the full principal amount, if anything, resulting in a loss on your investment that is proportionate to the negative index return. You may lose up to 100% of your principal.

7

What Are the Tax Consequences of the Securities?

The United States federal income tax consequences of your investment in the Securities are uncertain. Some of these tax consequences are summarized below, but we urge you to read the more detailed discussion in |mJ|mJSupplemental U.S. Tax Considerations” beginning on page PS-32 of the ROS product supplement and discuss the tax consequences of your particular situation with your tax advisor.

There are no statutory provisions, regulations, published rulings or judicial decisions addressing the characterization for U.S. federal income tax purposes of securities with terms that are substantially the same as the Securities. Pursuant to the terms of the Securities, UBS and you agree, in the absence of a statutory, regulatory, administrative or judicial ruling to the contrary, to characterize your Securities as a pre-paid derivative contract with respect to the underlying index. If your Securities are so treated, you should generally not accrue any income with respect to your Securities prior to their maturity, sale or exchange and you should generally recognize capital gain or loss upon the sale or maturity of your Securities in an amount equal to the difference between the amount you receive at such time and the amount you paid for your Securities. Such again or loss should be long-term if you have held your Securities for more than one year.

In the opinion of our counsel, Cadwalader, Wickersham & Taft LLP, it would be reasonable to treat your Securities in the manner described above. However, because there is no authority that specifically addresses the tax treatment of the Securities, it is possible that your Securities could alternatively be treated for tax purposes in the manner described under “Supplemental U.S. Tax Considerations — Alternative Treatments” on page PS-33 of the product supplement.

In 2007, the Internal Revenue Service released a notice that may affect the taxation of holders of the Securities. According to the notice, the Internal Revenue Service and the Treasury Department are actively considering whether the holder of an instrument similar to the Securities should be required to accrue ordinary income on a current basis, and they are seeking taxpayer comments on the subject. It is not possible to determine what guidance they will ultimately issue, if any. It is possible, however, that under such guidance, holders of the Securities will ultimately be required to accrue income currently and this could be applied on a retroactive basis. The Internal Revenue Service and the Treasury Department are also considering other relevant issues, including whether additional gain or loss from such instruments should be treated as ordinary or capital, whether foreign holders of such instruments should be subject to withholding tax on any deemed income accruals, and whether the special |mJ|mJconstructive ownership rules” of Section 1260 of the Internal Revenue Code of 1986, as amended (the “Code”) above should be applied to such instruments. Holders are urged to consult their tax advisors concerning the significance, and the potential impact, of the above considerations. Except to the extent otherwise required by law, UBS intends to treat your Securities for United States federal income tax purposes in accordance with the treatment described above and under |mJ|mJSupplemental U.S. Tax Considerations” beginning on page PS-32 of the ROS product supplement, unless and until such time as the Treasury Department and Internal Revenue Service determine that some other treatment is more appropriate.

Moreover, in 2007, legislation was introduced in Congress that, if it had been enacted, would have required holders of Securities purchased after the bill was enacted to accrue interest income over the term of the Securities despite the fact that there will be no interest payments over the term of the Securities. It is not possible to predict whether a similar or identical bill will be enacted in the future, or whether any such bill would affect the tax treatment of your Securities.

Beginning in 2013, U.S. holders that are individuals, estates, and certain trusts will be subject to an additional 3.8% tax on all or a portion of their “net investment income,” which may include any gain realized with respect to the Securities, to the extent of their net investment income that when added to their other modified adjusted gross income, exceeds $200,000 for an unmarried individual, $250,000 for a married taxpayer filing a joint return (or a surviving spouse), or $125,000 for a married individual filing a separate return. U.S. holders should consult their tax advisors with respect to their consequences with respect to the 3.8% Medicare tax.

Under recently enacted legislation, individuals (and to the extent provided in future regulations, entities) that own “specified foreign financial assets” in excess of an applicable threshold may be required to file information with respect to such assets with their income tax returns, especially if such assets are held outside the custody of a U.S. financial institution. You are urged to consult your tax advisor as to the application of this legislation to your ownership of the Securities.

Non-United States Holders. If you are not a United States holder, you will generally not be subject to United States withholding tax with respect to payments on your Securities and you should not be subject to generally applicable information reporting and backup withholding requirements with respect to payments on your Securities if you comply with certain certification and identification requirements as to your foreign status. Gain from the sale or exchange of a Security or settlement at maturity generally will not be subject to U.S. tax unless such gain is effectively connected with a trade or business conducted by the non-U.S. holder in the United States or unless the non-U.S. holder is a non-resident alien individual and is present in the U.S. for 183 days or more during the taxable year of such sale, exchange or settlement and certain other conditions are satisfied.

PROSPECTIVE PURCHASERS OF SECURITIES SHOULD CONSULT THEIR TAX ADVISORS AS TO THE U.S. FEDERAL, STATE, LOCAL AND OTHER TAX CONSEQUENCES TO THEM OF THE PURCHASE, OWNERSHIP AND DISPOSITION OF THE SECURITIES.

8

S&P 500 ® Index

We have derived all information contained in this pricing supplement regarding the S&P 500 ® Index, including without limitation, its make-up, method of calculation and changes in its components from publicly available information. Such information reflects the policies of, and is subject to change by Standard & Poor’s Financial Services LLC, a subsidiary of The McGraw-Hill Companies, Inc. (“S&P”). We make no representations or warranty as to the accuracy or completeness of the information derived from these public sources.

S&P has no obligation to continue to publish the S&P 500 ® Index, and may discontinue publication of the S&P 500 ® Index at any time. The S&P 500 ® Index is determined, comprised and calculated by S&P without regard to the Securities.

The S&P 500 ® Index is published by S&P. As discussed more fully in the index supplement under the heading ``Underlying Indices and Underlying Index Publishers — S&P 500 ® Index”, the S&P 500 ® Index is intended to provide an indication of the pattern of common stock price movement. The calculation of the value of the S&P 500 ® Index is based on the relative value of the aggregate market value of the common stock of 500 companies as of a particular time compared to the aggregate average market value of the common stocks of 500 similar companies during the base period of the years 1941 through 1943. Ten main groups of companies comprise the S&P 500 ® Index, with the number of companies included in each group as of February 24, 2012 indicated below: Consumer Discretionary (80); Consumer Staples (42); Energy (43); Financials (81); Health Care (52); Industrials (61); Information Technology (71); Materials (30); Telecommunications Services (7); and Utilities (33).

Information from outside sources is not incorporated by reference in, and should not be considered part of, this pricing supplement or any accompanying prospectus. We make no representation or warranty as to the accuracy or completeness of the information contained in outside sources.

Historical Information

The following table sets forth the quarterly high and low closing levels for the underlying index, based on daily closing levels, as reported by Bloomberg Professional service (“Bloomberg”), without independent verification. We make no representation or warranty as to the accuracy or completeness of the information obtained from Bloomberg. The closing level of the underlying index on February 24, 2012 was 1365.74. Past performance of the underlying index is not indicative of the future performance of the underlying Index.

●	●	●	●	●
Quarter Begin	Quarter End	Quarterly High	Quarterly Low	Quarterly Close
1/2/2008	3/31/2008	1447.16	1273.37	1322.70
4/1/2008	6/30/2008	1426.63	1278.38	1280.00
7/1/2008	9/30/2008	1305.32	1106.39	1166.36
10/1/2008	12/31/2008	1161.06	752.44	903.25
1/2/2009	3/31/2009	934.70	676.53	797.87
4/1/2009	6/30/2009	946.21	811.08	919.32
7/1/2009	9/30/2009	1071.66	879.13	1057.08
10/1/2009	12/31/2009	1127.78	1025.21	1115.10
1/4/2010	3/31/2010	1174.17	1056.74	1169.43
4/1/2010	6/30/2010	1217.28	1030.71	1030.71
7/1/2010	9/30/2010	1148.67	1022.58	1141.20
10/1/2010	12/31/2010	1259.78	1137.03	1257.64
1/3/2011	3/31/2011	1343.01	1256.88	1325.83
4/1/2011	6/30/2011	1363.61	1265.42	1320.64
7/1/2011	9/30/2011	1353.22	1119.46	1131.42
10/3/2011	12/30/2011	1285.09	1099.23	1257.60
1/3/2012*	2/24/2012*	1365.74	1277.06	1365.74

• As of the date of this pricing supplement, available information for the first calendar quarter of 2012 includes data for the period from January 3, 2012 through February 24, 2012. Accordingly, the “Quarterly High,” “Quarterly Low” and “Quarterly Close” data indicated are for this shortened period only and do not reflect complete data for the first calendar quarter of 2012.

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The graph below illustrates the performance of the underlying index from January 3, 2000 through February 24, 2012, based on information from Bloomberg. Past performance of the underlying index is not indicative of the future performance of the underlying index.

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Supplemental Plan of Distribution (Conflicts of Interest)

We have agreed to sell to UBS Financial Services Inc. and certain of its affiliates, together the “Agents,” and the Agents have agreed to purchase, all of the Securities at the issue price less the underwriting discount indicated on the cover of this pricing supplement, the document filed pursuant to Rule 424(b) containing the final pricing terms of the Securities.

We or one of our affiliates may enter into swap agreements or related hedge transactions with one of our other affiliates or unaffiliated counterparties in connection with the sale of the Securities and UBS or its affiliates may earn additional income as a result of payments pursuant to the swap or related hedge transactions.

Conflicts of Interest — Each of UBS Securities LLC and UBS Financial Services Inc. is an affiliate of UBS and, as such, has a “conflict of interest” in this offering within the meaning of FINRA Rule 5121. In addition, UBS will receive the net proceeds (excluding the underwriting discount) from the initial public offering of the Securities, thus creating an additional conflict of interest within the meaning of Rule 5121. Consequently, the offering is being conducted in compliance with the provisions of Rule 5121. Neither UBS Securities LLC nor UBS Financial Services Inc. is permitted to sell Securities in this offering to an account over which it exercises discretionary authority without the prior specific written approval of the account holder.

Structured Product Categorization

To help investors identify appropriate Structured Products (“Structured Products”), UBS organizes its Structured Products into four categories: Protection Strategies, Optimization Strategies, Performance Strategies and Leverage Strategies. The Securities are classified by UBS as an Optimization Strategy for this purpose. The description below is intended to describe generally the four categories of Structured Products and the types of principal repayment features that may be offered on those products. This description should not be relied upon as a description of any particular Structured Product.

Ø Protection Strategies are structured to complement and provide the potential to outperform traditional fixed income instruments. These Structured Products are generally designed for investors with low to moderate risk tolerances.

Ø Optimization Strategies provide the opportunity to enhance market returns or yields and can be structured with full downside market exposure or with buffered or contingent downside market exposure. These structured products are generally designed for investors who can tolerate downside market risk.

Ø Performance Strategies provide efficient access to markets and can be structured with full downside market exposure or with buffered or contingent downside market exposure. These structured products are generally designed for investors who can tolerate downside market risk.

Ø Leverage Strategies provide leveraged exposure to the performance of an underlying asset. These Structured Products are generally designed for investors with high risk tolerances.

In order to benefit from any type of principal repayment feature, investors must hold the Securities to maturity.

Classification of Structured Products into categories is for informational purposes only and is not intended to guarantee particular results or performance.

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