Note 42 Additional Disclosures Required under US GAAP and SEC Rules

Note 42.1 Variable Interest Entities

Introduction

Since 1 January 2004, UBS has fully applied Financial Accounting Standards Board (FASB) Interpretation No. 46, Consolidation of Variable Interest Entities (revised December 2003), an interpretation of Accounting Research Bulletin No. 51 (FIN 46-R). Until 31 December 2003 the predecessor standard, FIN 46, had application to UBS only with respect to transitional disclosure requirements, and consolidation requirements for certain VIEs created after 31 January 2003.

Identification of variable interest entities (VIEs) and measurement of variable interests

Qualifying special purpose entities (QSPEs) per Statement of Financial Accounting Standards (SFAS) No. 140 Accounting for Transfers and Servicing of Financial Assets and Extinguishments of Liabilities are excluded from the scope of FIN 46-R. In most other cases, US GAAP requires that control over an entity be assessed first based on voting interests; if voting interests do not exist, or differ significantly from economic interests, the entity is considered a VIE under FIN 46-R, and control is assessed based on its variable interests. Specifically, VIEs are entities in which no equity investors exist, or the equity investors:

– do not have sufficient equity at risk for the entity to finance its activities without additional subordinated financial support from other parties; or

– do not have the characteristics of a controlling financial interest; or

– have voting rights that are not proportionate to their economic interests, and the activities of the entity involve or are conducted on behalf of investors with disproportionately small or no voting interests.

Variable interests are interests held in a VIE that change with changes in the fair value of a VIE’s net assets, exclusive of variable interests. Interests of related parties (including management, employees, affiliates and agents) are included in the evaluation as if owned directly by the enterprise.

A primary beneficiary is an enterprise which absorbs a majority of a VIE’s expected losses, expected residual returns, or both – it must consolidate the VIE and provide certain disclosures. The holder of a significant variable interest in a VIE is required to make disclosures only. UBS treats variable interests of more than 20% of a VIE’s expected losses, expected residual returns, or both, as significant.

The FASB Emerging Issues Task Force (EITF) has summarized four different general approaches to the application of FIN 46-R in EITF issue No. 04-7. In applying FIN 46-R, UBS has adopted a quantitative approach, particularly for derivatives, which is known as “View A_, and is based on variability in the fair value of the net assets in the VIE, exclusive of variable interests.

Under View A, investments or derivatives in a VIE either create (increase), or absorb (decrease) variability in the fair value of a VIE’s net assets. The VIE counterparty is a risk creator (risk maker), or risk absorber (risk taker), respectively. Only risk absorption (risk taker) positions are assessed; risk creation interests are deemed not to be variable interests.

VIEs often contain multiple risk factors, such as credit, equity, foreign currency and interest rate risks, which require quantification by variable interest holders. UBS analyzes these risks into components, identifies the parties absorbing them, and uses models to quantify and compare them. These models are based on internally approved valuation models and in some cases require the use of Monte Carlo simulation techniques.

They are applied when UBS first becomes involved with a VIE, or after a major restructuring.

Measurement of maximum exposure to loss

Maximum exposure to loss is disclosed for VIEs in which UBS has a significant variable interest.

UBS’s maximum exposure to loss is generally measured as its net investment in the VIE, plus any additional amounts it may be obligated to invest. If UBS receives credit protection from credit derivatives it is measured as any positive replacement value of the derivatives. If UBS has provided guarantees or other types of credit protection to a VIE it is measured as the notional amount of the credit protection instruments or credit derivatives. In other derivative transactions exposing UBS to potential losses, there is no theoretical limit to the maximum loss which could be incurred before considering offsetting positions or hedges entered into outside of the VIE. However, UBS’s general risk management process involves the hedging of risk exposures for VIEs, on the same basis as for non-VIE counterparties. See Note 28 for a further discussion of UBS’s risk mitigation strategies.

VIEs in which UBS is the primary beneficiary

VIEs in which UBS is the primary beneficiary require consolidation, which may increase both total assets and liabilities of the US GAAP Financial Statements, or in other cases may result in a reclassification of existing assets or liabilities.

In certain cases, an entity not consolidated under IFRS is consolidated under FIN 46-R because UBS is the primary beneficiary. Significant groups of these include CHF 0.7 billion of investment fund products, and CHF 1.1 billion of securitization VIEs, which includes some third-party VIEs mentioned below.

The other significant group of VIEs which have previously been consolidated for US GAAP but not under IFRS were employee equity compensation trusts, for which UBS is the primary beneficiary because of the variable interests of employees. For US GAAP purposes, these trusts have been consolidated since 1 January 2004. For IFRS purposes, on 1 January 2005, these trusts were retrospectively consolidated from 1 January 2003. See Note 41.1h) Equity Participation Plans for further details.

UBS has reviewed the population of potential third-party VIEs it is involved with. Those identified in which UBS is the primary beneficiary, and which are consolidated for US GAAP purposes, have combined assets of approximately CHF 3.5 billion and are included in the table below.

Many entities consolidated under US GAAP due to FIN 46-R are already consolidated under IFRS, based on the determination of exercise of control under IFRS. The total size of this population is approximately CHF 13.9 billion, mostly comprising investment funds managed by UBS, other investment fund products, employee equity compensation trusts mentioned previously, and private equity investments.

Certain VIEs in which UBS is the primary beneficiary, but for which UBS also holds a majority voting interest, are consolidated, but do not require disclosure in the table below. In most cases such VIEs, or their financial position and performance, are already consolidated under IFRS.

The creditors or beneficial interest holders of VIEs in which UBS is the primary beneficiary do not have any recourse to the general credit of UBS.

Third-party VIEs not otherwise classified

FIN 46-R requires UBS to consider all VIEs for consolidation, including VIEs which UBS has not created, but in which it holds variable interests as a third-party counterparty, either through direct or indirect investment, or through derivative transactions.

UBS has identified that it holds variable interests in 88 third party VIEs that in some cases could result in UBS being considered the primary beneficiary, but the information necessary to make this determination, or perform the accounting required to consolidate the VIE was held by third parties, and was not available to UBS. Additional disclosures for these VIEs are provided in the table below.

Future developments

Note 42.2 Industrial Holdings’ Income Statement

In 2004, following the acquisition of an additional 20% stake in Motor-Columbus, a Swiss holding company whose most significant asset is a 59.3% interest in Atel, a Swiss-based European energy provider, UBS now holds a majority ownership interest in the company. As a result, UBS has fully consolidated Motor-Columbus in its Financial Statements since 1 July 2004. In addition, due to the adoption of IAS 27 Consolidated and Separate Financial Statements which is further described in Note 1aa), UBS retrospectively consolidated certain private equity investments to 1 January 2003. The following table provides information required by Regulation S-X for commercial and industrial companies, including a condensed income statement and certain additional balance sheet information:

Note 42.3 Indemnifications

In the normal course of business, UBS provides representations, warranties and indemnifications to counterparties in connection with numerous transactions. These provisions are generally ancillary to the business purposes of the contracts in which they are embedded. Indemnification clauses are generally standard contractual terms related to the Group’s own performance under a contract and are entered into based on an assessment that the risk of loss is remote. Indemnifications may also protect counterparties in the event that additional taxes are owed due either to a change in applicable tax laws or to adverse interpretations of tax laws. The purpose of these clauses is to ensure that the terms of a contract are met at inception.

The most significant business where UBS provides representations and warranties is asset securitizations. UBS generally represents that certain securitized assets meet specific requirements, for example documentary attributes. UBS may be required to repurchase the assets and/or indemnify the purchaser of the assets against losses due to any breaches of such representations or warranties. Generally, the maximum amount of future payments the Group would be required to make under such repurchase and/or indemnification provisions would be equal to the current amount of assets held by such securitization-related SPEs as at 31 December 2005, plus, in certain circumstances, accrued and unpaid interest on such assets and certain expenses. The potential loss due to such repurchase and/or indemnity is mitigated by the due diligence UBS performs to ensure that the assets comply with the requirements set forth in the representations and warranties. UBS receives no compensation for representations and warranties, and it is not possible to determine their fair value because they rarely, if ever, result in a payment. Historically, losses incurred on such repurchases and / or indemnifications have been insignificant. Management expects the risk of material loss to be remote. No liabilities related to such representations, warranties, and indemnifications are included in the balance sheet at 31 December 2005 and 2004.

Note 42.4 Supplemental Guarantor Information

Guarantee of PaineWebber securities

Following the acquisition of Paine Webber Group Inc., UBS AG made a full and unconditional guarantee of the senior and subordinated notes and trust preferred securities (“Debt Securities_) of PaineWebber. Prior to the acquisition, PaineWebber was an SEC Registrant. Upon the acquisition, PaineWebber was merged into UBS Americas Inc., a wholly owned subsidiary of UBS.

Under the guarantee, if UBS Americas Inc. fails to make any timely payment under the Debt Securities agreements, the holders of the Debt Securities or the Debt Securities trustee may demand payment from UBS without first proceeding against UBS Americas Inc. UBS’s obligations under the subordinated note guarantee are subordinated to the prior payment in full of the deposit liabilities of UBS and all other liabilities of UBS. At 31 December 2005, the amount of senior liabilities of UBS to which the holders of the subordinated debt securities would be subordinated is approximately CHF 1,997 billion.

The information presented in this note is prepared in accordance with IFRS and should be read in conjunction with the Consolidated Financial Statements of UBS of which this information is a part. At the bottom of each column, Net profit and Shareholders’ equity has been reconciled to US GAAP. See Note 41 for a detailed reconciliation of the IFRS Financial Statements to US GAAP for UBS on a consolidated basis.

Guarantee of other securities

In October 2000, UBS AG, acting through a wholly owned subsidiary, issued USD 1.5 billion of 8.622% UBS Trust Preferred Securities. In June 2001, UBS issued an additional USD 800 million of such securities (USD 300 million at 7.25% and USD 500 million at 7.247%). In May 2003, UBS issued USD 300 million of Floating Rate Non-Cumulative Trust Preferred Securities at 0.7% above one-month LIBOR of such securities. UBS AG has fully and unconditionally guaranteed these securities. UBS’s obligations under the trust preferred securities guarantee are subordinated to the prior payment in full of the deposit liabilities of UBS and all other liabilities of UBS. At 31 December 2005, the amount of senior liabilities of UBS to which the holders of the subordinated debt securities would be subordinated is approximately CHF 1,997 billion.

Note 42.5 Pro-Forma Effect of the Fair Value Method of Accounting on US GAAP Net Profit

The following table presents US GAAP Net profit and earnings per share for the years ended 31 December 2004 and 31 December 2003 as if UBS had applied the fair value method of accounting for its share-based compensation plans in that period. With the adoption of SFAS 123-R on 1 January 2005, UBS adopted the fair value method of accounting for its share-based compensation plans using the modified prospective method. See Note 41.1h) for details.