Notes to the Financial Statements

UBS AG's ("UBS") consolidated financial statements (Financial Statements) are prepared in accordance with International Financial Reporting Standards (IFRS) and stated in Swiss francs (CHF). In preparing the interim Financial Statements, the same accounting principles and methods of computation are applied as in the Financial Statements on 31 December 2005 and for the year then ended except for the changes set out below. The interim Financial Statements are unaudited. In the opinion of management, all adjustments necessary for a fair presentation of the results of operations for the interim periods have been made. These interim Financial Statements should be read in conjunction with the audited Financial Statements included in the UBS Financial Report 2005. On 2 June 2006, UBS issued a restated Financial Report 2005 to present Motor-Columbus, a financial holding company with a significant interest in the Atel Group that was sold on 23 March 2006, as a discontinued operation.

UBS sponsors the formation of companies, which may or may not be directly or indirectly owned subsidiaries, for the purpose of asset securitization transactions and to accomplish certain narrow and well-defined objectives. These companies may acquire assets directly or indirectly from UBS or its affiliates. Some of these companies are bankruptcy-remote entities whose assets are not available to satisfy the claims of creditors of UBS or any of its subsidiaries. Such companies are consolidated in the Financial Statements when the relationship between UBS and the company indicates that it is controlled by UBS.

Changes in accounting policies and other adjustments

Amendment to the fair value option

In June 2005, the IASB issued amendments to IAS 39 Financial Instruments: Recognition and Measurement in relation to the fair value option ("Revised Fair Value Option"). UBS adopted the Revised Fair Value Option for financial instruments on a prospective basis on 1 January 2006. Prior to 1 January 2006, UBS classified almost all of its issued hybrid debt instruments as Financial liabilities designated at fair value through profit or loss. These liabilities are presented in a separate line on the face of the balance sheet. A small amount of financial assets were also classified as Financial assets designated at fair value through profit or loss, and they are likewise presented in a separate line. A financial instrument may only be designated at inception at fair value through profit or loss and cannot subsequently be changed. All fair value changes related to Financial assets and Financial liabilities designated at fair value through profit or loss are recognized in Net trading income. Under the revised accounting standard, UBS continues to apply the fair value option for these existing financial instruments. The conditions for such designation are still met on the basis that they are either hybrid instruments which would otherwise have to be bifurcated into debt host contracts and embedded derivatives or because they are items that are part of a portfolio which is risk managed on a fair value basis and reported to senior management as such. In second quarter 2006, UBS started applying the fair value option to certain new loans and loan commitments and extended the use of the fair value option to additional new loans and loan commitments in the second half 2006. These loans and loan commitments are substantially hedged with credit derivatives. In the ­second half 2006, UBS applied the fair value option to certain hybrid instruments resulting from structured repurchase and reverse repurchase agreements and to a hedge fund investment which is part of a portfolio managed on a fair value basis.

Staff Accounting Bulletin (SAB) 108

In response to the release of the Securities and Exchange Commission (SEC) Staff Accounting Bulletin (SAB) 108, Considering the Effects of Prior Year Misstatements when Quantifying ­Misstatements in Current Year Financial Statements, UBS elected to adopt a modified quantitative framework for ­assessing whether the financial statement effect of a misstatement is material because it renders a better evaluation of those effects. The new method, which UBS adopted in December 2006, uses a dual approach for quantifying the effect of a ­misstatement. Prior to 2006, UBS applied only one of those methods, the "roll-over" method, which focused on the ­current-year income statement impact of a misstatement. ­Under the new policy, UBS applies a dual approach that considers both the carryover and reversing effects of prior-year misstatements. As a result of the new policy, the opening balance of Accrued expenses and deferred income at 1 January 2002 was increased by CHF 247 million, Retained earnings were reduced by CHF 194 million and Deferred tax assets of CHF 53 million were recognized on the balance sheet. These adjustments relate to the ­underaccrual of unused vacation and sabbatical leave. The restatement impact of adopting this new policy is immaterial to all quarterly and annual income statements, earnings per share amounts, and balance sheets since 1 January 2002.