Comment on Regulation G

XL presents its operations in the way it believes will be most meaningful and useful to investors, analysts, rating agencies and others who use XL’s financial information in evaluating XL’s performance. This press release contains the presentation of (i) operating net income (loss) (“Operating Net Income”), which is defined as net income (loss) attributable to ordinary shareholders excluding net realized gains and losses on investments, net realized and unrealized gains and losses on credit, structured financial and investment derivatives, net of tax, for the Company and its share of these items for the Company’s insurance company affiliates for the periods presented, the gains recognized on the repurchase of the Company’s preference ordinary shares, as well as foreign exchange gains or losses, net of tax, (ii) annualized return on ordinary shareholders’ equity (“ROE”) based on operating net income (loss) (“Operating ROE”) and (iii) book value per ordinary share (ordinary shareholders’ equity divided by the number of shares outstanding at the period end date) and fully diluted book value per ordinary share (book value per share combined with the dilutive impact of potential future share issues at any period end). These items are “non-GAAP financial measures” as defined in Regulation G. The reconciliation of such measures to the most directly comparable GAAP financial measures in accordance with Regulation G is included in this press release.

Although the investment of premiums to generate income (or loss) and realized capital gains (or losses) is an integral part of XL’s operations and the Company’s insurance company operating affiliates, the determination to realize capital gains (or losses) is independent of the underwriting process. In addition, under applicable GAAP accounting requirements, losses can be created as the result of other than temporary declines in value without actual realization. In this regard, certain users of XL’s financial information, including certain rating agencies, evaluate earnings before tax and capital gains to understand the profitability of the recurring sources of income without the effects of this variable. Furthermore, these users believe that, for many companies, the timing of the realization of capital gains is largely a function of economic and interest rate conditions.

Investment derivatives include all derivatives entered into by XL other than credit derivatives. With respect to credit derivatives, because XL and its insurance company operating affiliates generally hold financial guaranty contracts written in credit default derivative form to maturity, the net effects of the changes in fair value of these credit derivatives are excluded (similar with other companies’ treatment of such contracts) as the changes in fair value each quarter are not indicative of underlying business performance.