1. Summary of significant accounting policies

a) Basis of presentation

ACE Limited is a holding company incorporated in Zurich, Switzerland. ACE Limited, through its various subsidiaries, provides a broad range of insurance and reinsurance products to insureds worldwide. ACE operates through the following business segments: Insurance – North American, Insurance – Overseas General, Global Reinsurance, and Life. Refer to Note 9 for additional information.

The interim unaudited consolidated financial statements, which include the accounts of ACE and its subsidiaries (collectively, ACE, we, us, or our), have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) and, in the opinion of management, reflect all adjustments (consisting of normally recurring accruals) necessary for a fair statement of the results and financial position for such periods. All significant intercompany accounts and transactions have been eliminated.

The results of operations and cash flows for any interim period are not necessarily indicative of the results for the full year. These consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in our 2011 Form 10-K.

Effective January 1, 2012, we retrospectively adopted new accounting guidance for costs associated with acquiring or renewing insurance contracts. Under the new guidance, the definition of acquisition costs was modified to specify that a cost must be directly related to the successful acquisition of a new or renewal insurance contract in order to be deferred. Prior year amounts contained in these consolidated financial statements have been adjusted to reflect the impact of retrospective adjustments as a result of applying this new accounting guidance.

b) Deferred policy acquisition costs and value of business acquired (VOBA)

Policy acquisition costs consist of commissions, premium taxes, and certain underwriting costs related directly to the successful acquisition of a new or renewal insurance contract. A VOBA intangible asset is established upon the acquisition of blocks of long duration contracts and represents the present value of estimated net cash flows for the contracts in force at the time of the acquisition. Acquisition costs and VOBA, collectively policy acquisition costs, are deferred and amortized. Policy acquisition costs on property and casualty (P&C) contracts are generally amortized ratably over the period in which premiums are earned. Policy acquisition costs on long duration contracts are amortized over the estimated life of the contracts, generally in proportion to premium revenue recognized. Policy acquisition costs are reviewed to determine if they are recoverable from future income, including investment income. Unrecoverable costs are expensed in the period identified.

Advertising costs are expensed as incurred except for direct-response campaigns that meet the criteria of the new guidance, principally related to accident and health (A&H) business produced by the Insurance – Overseas General segment, which are deferred and recognized as a component of policy acquisition costs. For individual direct-response marketing campaigns that we can demonstrate have specifically resulted in incremental sales to customers and such sales have probable future economic benefits, incremental costs directly related to the marketing campaigns are capitalized. Deferred marketing costs are reviewed regularly for recoverability from future income, including investment income, and amortized in proportion to premium revenue recognized, primarily over a ten year period.

c) Accounting guidance adopted

Accounting for costs associated with acquiring or renewing insurance contracts

In October 2010, the Financial Accounting Standards Board (FASB) issued new guidance related to the accounting for costs associated with acquiring or renewing insurance contracts. Under the new guidance, the definition of acquisition costs was modified to specify that a cost must be directly related to the successful acquisition of a new or renewal insurance contract in order to be deferred. We adopted this guidance retrospectively effective January 1, 2012 and reduced Retained earnings as of January 1, 2011 by $139 million which represents the cumulative effect of adjustment resulting from adoption of new accounting guidance. We adjusted prior year amounts contained in these consolidated financial statements to reflect the effect of adjustment from adoption of new accounting guidance including reducing Deferred policy acquisition costs and Retained earnings by $213 million and $181 million, respectively, as of December 31, 2011. The reduction to Deferred policy acquisition costs is primarily due to lower deferrals associated with unsuccessful efforts. We also reduced Net income by $12 million, or $0.03 per share, and $22 million, or $0.06 per share, for the three and six months ended June 30, 2011, respectively.

Fair value measurements

In May 2011, the FASB issued new guidance on fair value measurements to revise the wording used to describe the requirements for measuring fair value and for disclosing information about fair value measurements. The guidance is not necessarily intended to result in a significant change in the application of the current requirements. Instead, it is intended to clarify the intended application of existing fair value measurement requirements. It also changes certain principles or requirements for measuring fair value and disclosing information about fair value measurements. We adopted this guidance prospectively effective January 1, 2012. The application of this guidance resulted in additional fair value measurements disclosures only and did not impact our financial condition or results of operations.

2. Acquisitions

On June 13, 2012, we announced that we and our local partner had signed a definitive agreement to acquire PT Asuransi Jaya Proteksi (JaPro), one of Indonesia’s leading general insurers. This transaction, which is subject to regulatory approvals and other closing conditions, is expected to be completed by the end of 2012.

We acquired New York Life’s Korea operations on February 1, 2011 and New York Life’s Hong Kong operations on April 1, 2011 for approximately $450 million in cash. These acquired businesses operate under our Life segment, expand our presence in the North Asia market and complement our life insurance business established in that region. In 2012, we finalized purchase price allocations resulting in $91 million of goodwill, none of which is expected to be deductible for income tax purposes, and $163 million of intangible assets. The most significant intangible asset is VOBA.

We acquired Penn Millers Holding Corporation (PMHC) on November 30, 2011 for approximately $107 million in cash. PMHC’s primary insurance subsidiary, Penn Millers Insurance Company, is a well-established underwriter in the agribusiness market since 1887. PMHC operates under our Insurance – North American segment.

We acquired Rio Guayas Compania de Seguros y Reaseguros (Rio Guayas), a general insurance company in Ecuador on December 28, 2011. Rio Guayas sells a range of insurance products, including auto, life, property, and A&H. The acquisition of Rio Guayas expands our capabilities in terms of geography, products, and distribution. Rio Guayas operates under our Insurance – Overseas General segment.

3. Investments

a) Fixed maturities

The following tables present the amortized cost and fair value of fixed maturities and related OTTI recognized in AOCI:

As discussed in Note 3 c), if a credit loss is indicated on an impaired fixed maturity, an OTTI is considered to have occurred and the portion of the impairment not related to credit losses (non-credit OTTI) is recognized in OCI. Included in the “OTTI Recognized in AOCI” columns above are the cumulative amounts of non-credit OTTI recognized in OCI adjusted for subsequent sales, maturities, and redemptions. OTTI recognized in AOCI does not include the impact of subsequent changes in fair value of the related securities. In periods subsequent to a recognition of OTTI in OCI, changes in the fair value of the related fixed maturities are reflected in Unrealized appreciation (depreciation) in the consolidated statement of shareholders’ equity. For the three and six months ended June 30, 2012, $16 million and $84 million, respectively, of net unrealized appreciation related to such securities is included in OCI. For the three and six months ended June 30, 2011, $25 million and $8 million, respectively, of net unrealized depreciation related to such securities is included in OCI. At June 30, 2012 and December 31, 2011, AOCI includes net unrealized depreciation of $74 million and $155 million, respectively, related to securities remaining in the investment portfolio at those dates for which ACE has recognized a non-credit OTTI.

Mortgage-backed securities (MBS) issued by U.S. government agencies are combined with all other to be announced mortgage derivatives held (refer to Note 6 a) (iv)) and are included in the category, “Mortgage-backed securities”. Approximately 86 percent and 84 percent of the total mortgage-backed securities at June 30, 2012 and December 31, 2011, respectively, are represented by investments in U.S. government agency bonds. The remainder of the mortgage exposure consists of collateralized mortgage obligations and non-government mortgage-backed securities, the majority of which provide a planned structure for principal and interest payments and carry a rating of AAA by the major credit rating agencies.

The following table presents fixed maturities by contractual maturity:

Expected maturities could differ from contractual maturities because borrowers may have the right to call or prepay obligations, with or without call or prepayment penalties.

b) Equity securities

The following table presents the cost and fair value of equity securities:

c) Net realized gains (losses)

In accordance with guidance related to the recognition and presentation of OTTI, when an impairment related to a fixed maturity has occurred, OTTI is required to be recorded in net income if management has the intent to sell the security or it is more likely than not that we will be required to sell the security before the recovery of its amortized cost. Further, in cases where we do not intend to sell the security and it is more likely than not that we will not be required to sell the security, ACE must evaluate the security to determine the portion of the impairment, if any, related to credit losses. If a credit loss is indicated, an OTTI is considered to have occurred and any portion of the OTTI related to credit losses must be reflected in net income while the portion of OTTI related to all other factors is recognized in OCI. For fixed maturities held to maturity, OTTI recognized in OCI is accreted from AOCI to the amortized cost of the fixed maturity prospectively over the remaining term of the securities.

Each quarter, securities in an unrealized loss position (impaired securities), including fixed maturities, securities lending collateral, equity securities, and other investments, are reviewed to identify impaired securities to be specifically evaluated for a potential OTTI.

For all non-fixed maturities, OTTI is evaluated based on the following:

As a general rule, we also consider that equity securities in an unrealized loss position for twelve consecutive months are impaired.

We review each fixed maturity in an unrealized loss position to assess whether the security is a candidate for credit loss. Specifically, we consider credit rating, market price, and issuer-specific financial information, among other factors, to assess the likelihood of collection of all principal and interest as contractually due. Securities for which we determine that credit loss is likely are subjected to further analysis to estimate the credit loss recognized in net income, if any. In general, credit loss recognized in net income equals the difference between the security’s amortized cost and the net present value of its projected future cash flows discounted at the effective interest rate implicit in the debt security. All significant assumptions used in determining credit losses are subject to change as market conditions evolve.

Projected cash flows for corporate securities (principally senior unsecured bonds) are driven primarily by assumptions regarding probability of default and also the timing and amount of recoveries associated with defaults. We develop these estimates using information based on market observable data, issuer-specific information, and credit ratings. ACE developed its default assumption by using historical default data by Moody’s Investors Service (Moody’s) rating category to calculate a 1-in-100 year probability of default, which results in a default assumption in excess of the historical mean default rate. We believe that use of a default assumption in excess of the historical mean is reasonable in light of current market conditions.

For the three and six months ended June 30, 2012, credit losses recognized in net income for corporate securities were $1 million and $4 million, respectively. There were no credit losses recognized in net income for corporate securities in 2011.

For mortgage-backed securities, credit impairment is assessed using a cash flow model that estimates the cash flows on the underlying mortgages, using the security-specific collateral and transaction structure. The model estimates cash flows from the underlying mortgage loans and distributes those cash flows to various tranches of securities, considering the transaction structure and any subordination and credit enhancements that exist in that structure. The cash flow model incorporates actual cash flows on the mortgage-backed securities through the current period and then projects the remaining cash flows using a number of assumptions, including default rates, prepayment rates, and loss severity rates (the par value of a defaulted security that will not be recovered) on foreclosed properties.

For the three and six months ended June 30, 2012, credit losses recognized in net income for mortgage-backed securities were nil and $3 million, respectively. For the three and six months ended June 30, 2011, credit losses recognized in net income for mortgage-backed securities were $2 million and $3 million, respectively.

The following table presents the Net realized gains (losses) and the losses included in Net realized gains (losses) and OCI as a result of conditions which caused us to conclude the decline in fair value of certain investments was “other-than-temporary”:

The following table presents a roll-forward of pre-tax credit losses related to fixed maturities for which a portion of OTTI was recognized in OCI:

d) Gross unrealized loss

At June 30, 2012, there were 2,574 fixed maturities out of a total of 22,842 fixed maturities in an unrealized loss position. The largest single unrealized loss in the fixed maturities was $6 million. There were approximately 81 equity securities out of a total of 191 equity securities in an unrealized loss position. The largest single unrealized loss in the equity securities was $19 million. Fixed maturities in an unrealized loss position at June 30, 2012 comprised both investment grade and below investment grade securities for which fair value declined primarily due to widening credit spreads since the date of purchase. Equity securities in an unrealized loss position include foreign fixed income securities held in a commingled fund structure for which fair value declined primarily due to widening credit spreads since the date of purchase.

The following tables present, for all securities in an unrealized loss position (including securities on loan), the aggregate fair value and gross unrealized loss by length of time the security has continuously been in an unrealized loss position: