Arch Capital Group Ltd. Reports 2008 First Quarter Results.

HAMILTON, Bermuda -- Arch Capital Group Ltd. (NASDAQ: ACGL) reports that net income available to common shareholders for the 2008 first quarter was $189.4 million, or $2.78 per share, compared to $198.6 million, or $2.59 per share, for the 2007 first quarter. The Company also reported after-tax operating income available to common shareholders of $202.0 million, or $2.97 per share, for the 2008 first quarter, compared to $204.7 million, or $2.67 per share, for the 2007 first quarter. All earnings per share amounts discussed in this release are on a diluted basis.

The Company's book value per common share, including the net effect of share repurchases, increased to $56.92 at March 31, 2008 from $55.12 per share at December 31, 2007. The Company's after-tax operating income available to common shareholders represented a 21.9% annualized return on average common equity for the 2008 first quarter, compared to 24.4% for the 2007 first quarter. After-tax operating income available to common shareholders, a non-GAAP measure, is defined as net income available to common shareholders, excluding net realized gains or losses, equity in net income or loss of investment funds accounted for using the equity method and net foreign exchange gains or losses, net of income taxes. See page 7 for a further discussion of after-tax operating income available to common shareholders and Regulation G.

The following table summarizes the Company's underwriting results:

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The following table summarizes, on an after-tax basis, the Company's consolidated financial data, including a reconciliation of after-tax operating income available to common shareholders to net income available to common shareholders and related diluted per share results:

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The combined ratio represents a measure of underwriting profitability, excluding investment income, and is the sum of the loss ratio and expense ratio. A combined ratio under 100% represents an underwriting profit and a combined ratio over 100% represents an underwriting loss. The combined ratio of the Company's insurance and reinsurance subsidiaries consisted of a loss ratio of 57.1% and an underwriting expense ratio of 29.1% for the 2008 first quarter, compared to a loss ratio of 56.3% and an underwriting expense ratio of 27.1% for the 2007 first quarter. The loss ratio of 57.1% for the 2008 first quarter was comprised of 35.2 points of paid losses, 10.8 points related to reserves for reported losses and 11.1 points related to incurred but not reported reserves.

In establishing the reserves for losses and loss adjustment expenses, the Company has made various assumptions relating to the pricing of its reinsurance contracts and insurance policies and also has considered available historical industry experience and current industry conditions. The Company's reserving method to date has been, to a large extent, the expected loss method, which is commonly applied when limited loss experience exists. Any estimates and assumptions made as part of the reserving process could prove to be inaccurate due to several factors, including the fact that relatively limited historical information has been reported to the Company through March 31, 2008. For a discussion of underwriting activities and a review of the Company's results by operating segment, see "Segment Information" in the Supplemental Financial Information section of this release.

Net investment income for the 2008 first quarter was $122.2 million, compared to $110.0 million for the 2007 first quarter. The increase in net investment income in the 2008 first quarter primarily resulted from a higher level of average invested assets in the 2008 first quarter and also included $3.4 million of interest income resulting from a favorable arbitration decision. The pre-tax investment income yield increased to 4.88% (excluding the arbitration interest) for the 2008 first quarter, compared to 4.84% for the 2007 first quarter. The Company's investment portfolio, which mainly consists of high quality fixed income securities, had an average Standard & Poor's quality rating of "AA+" at March 31, 2008 and December 31, 2007. The average effective duration of the Company's investment portfolio was 3.50 years at March 31, 2008, compared to 3.29 years at December 31, 2007. The increase in the effective duration of the Company's investment portfolio in the 2008 first quarter was primarily attributable to an increase in the duration of the Company's municipal bond holdings due to the method of calculating duration on such securities, which relies on the yield relationship of municipal bonds to U.S. Treasuries.

The Company's investment portfolio includes certain funds that invest in fixed maturity securities which, due to the ownership structure of the funds, are accounted for by the Company using the equity method. In applying the equity method, these investments are initially recorded at cost and are subsequently adjusted based on the Company's proportionate share of the net income or loss of the funds (which include changes in the market value of the underlying securities in the funds). This method of accounting is different from the way the Company accounts for its other fixed maturity securities. Investment funds accounted for using the equity method totaled $294.4 million at March 31, 2008, compared to $236.0 million at December 31, 2007 and $153.6 million at March 31, 2007.

For the 2008 and 2007 first quarters, the effective tax rates on income before income taxes were 3.9% and 4.0%, respectively, and the effective tax rates on pre-tax operating income available to common shareholders were 2.5% and 4.7%, respectively. The Company's effective tax rates may fluctuate from period to period based on the relative mix of income reported by jurisdiction primarily due to the varying tax rates in each jurisdiction. The Company's quarterly tax provision is adjusted to reflect changes in its expected annual effective tax rates, if any.

A significant portion of the Company's catastrophe-exposed property business is written by a Bermuda-based subsidiary. As a result, on a relative basis, the Company's effective tax rate is likely to be favorably affected in periods that have a low level of catastrophic losses incurred and adversely impacted in periods with significant catastrophic claims activity. The Company currently expects that its annual effective tax rate on pre-tax operating income available to common shareholders for the year ended December 31, 2008 will be in the range of 2.0% to 4.0%. In addition, the Company's Bermuda-based reinsurer incurs federal excise taxes for premiums assumed on U.S. risks. Such expenses are included in the Company's acquisition expenses.

Net foreign exchange losses for the 2008 first quarter of $23.6 million consisted of net unrealized losses of $22.3 million and net realized losses of $1.3 million, compared to net foreign exchange losses for the 2007 first quarter of $9.7 million which consisted of net unrealized losses of $17.2 million and net realized gains of $7.5 million. Net unrealized foreign exchange gains or losses result from the effects of revaluing the Company's net insurance liabilities required to be settled in foreign currencies at each balance sheet date. The Company holds investments in foreign currencies which are intended to mitigate its exposure to foreign currency fluctuations in its net insurance liabilities. However, changes in the value of such investments due to foreign currency rate movements are reflected as a direct increase or decrease to shareholders' equity and are not included in the statement of income.

Diluted weighted average common shares and common share equivalents outstanding, used in the calculation of after-tax operating income and net income per common share, were 68.0 million in the 2008 first quarter, compared to 76.6 million in the 2007 first quarter. The lower level of weighted average shares outstanding in the 2008 first quarter was primarily due to the impact of share repurchases as discussed below. Share repurchases during the 2007 first quarter had a minimal impact on the weighted average shares outstanding in the period due to the timing of such transactions.

In February 2007, ACGL's Board of Directors authorized the investment of up to $1 billion in ACGL's common shares through a share repurchase program. Repurchases under the program may be effected from time to time in open market or privately negotiated transactions through February 2009. During the 2008 first quarter, ACGL repurchased approximately 2.7 million common shares under the share repurchase program for an aggregate purchase price of $189.8 million. Since the inception of the share repurchase program, ACGL has repurchased approximately 10.5 million common shares for an aggregate purchase price of $726.9 million. As a result of the share repurchase transactions to date, book value per common share was reduced by $1.70 per share at March 31, 2008, compared to $1.45 at December 31, 2007, and weighted average shares outstanding for the 2008 first quarter were reduced by 9.4 million shares. The timing and amount of the repurchase transactions under this program will depend on a variety of factors, including market conditions and corporate and regulatory considerations. For additional information on the Company's share repurchase program, refer to the supplemental financial information portion of this release.

At March 31, 2008, the Company's capital of $4.3 billion consisted of $300.0 million of senior notes, representing 7.0% of the total, $325.0 million of preferred shares, representing 7.6% of the total, and common shareholders' equity of $3.68 billion, representing the balance.

The Company will hold a conference call for investors and analysts at 11:00 a.m. Eastern Time on Friday, April 25, 2008. A live webcast of this call will be available via the Media-Earnings Webcasts section of the Company's website at http://www.archcapgroup.bm and will be archived on the website from 1:00 p.m. Eastern Time on April 25 through midnight Eastern Time on May 25, 2008. A telephone replay of the conference call also will be available beginning on April 25 at 1:00 p.m. Eastern Time until May 2 at midnight Eastern Time. To access the replay, domestic callers should dial 888-286-8010 (passcode 76628884), and international callers should dial 617-801-6888 (passcode 76628884).

Arch Capital Group Ltd., a Bermuda-based company with over $4.3 billion in capital at March 31, 2008, provides insurance and reinsurance on a worldwide basis through its wholly owned subsidiaries.

Cautionary Note Regarding Forward-Looking Statements

The Private Securities Litigation Reform Act of 1995 ("PLSRA") provides a "safe harbor" for forward-looking statements. This release or any other written or oral statements made by or on behalf of the Company may include forward-looking statements, which reflect the Company's current views with respect to future events and financial performance. All statements other than statements of historical fact included in or incorporated by reference in this release are forward-looking statements. Forward-looking statements, for purposes of the PLSRA or otherwise, can generally be identified by the use of forward-looking terminology such as "may," "will," "expect," "intend," "estimate," "anticipate," "believe" or "continue" and similar statements of a forward-looking nature or their negative or variations or similar terminology.

Forward-looking statements involve the Company's current assessment of risks and uncertainties. Actual events and results may differ materially from those expressed or implied in these statements. Important factors that could cause actual events or results to differ materially from those indicated in such statements are discussed below and elsewhere in this release and in the Company's periodic reports filed with the Securities and Exchange Commission (the "SEC"), and include:

* the Company's ability to successfully implement its business strategy during "soft" as well as "hard" markets;

* acceptance of the Company's business strategy, security and financial condition by rating agencies and regulators, as well as by brokers and its insureds and reinsureds;

* the Company's ability to maintain or improve its ratings, which may be affected by its ability to raise additional equity or debt financings, by ratings agencies' existing or new policies and practices, as well as other factors described herein;

* general economic and market conditions (including inflation, interest rates, foreign currency exchange rates and prevailing credit terms) and conditions specific to the reinsurance and insurance markets in which the Company operates;

* competition, including increased competition, on the basis of pricing, capacity, coverage terms or other factors;

* the Company's ability to successfully integrate, establish and maintain operating procedures (including the implementation of improved computerized systems and programs to replace and support manual systems) to effectively support its underwriting initiatives and to develop accurate actuarial data;

* the loss of key personnel;

* the integration of businesses the Company has acquired or may acquire into its existing operations;

* accuracy of those estimates and judgments utilized in the preparation of the Company's financial statements, including those related to revenue recognition, insurance and other reserves, reinsurance recoverables, investment valuations, intangible assets, bad debts, income taxes, contingencies and litigation, and any determination to use the deposit method of accounting, which for a relatively new insurance and reinsurance company, like the Company, are even more difficult to make than those made in a mature company since relatively limited historical information has been reported to the Company through March 31, 2008;

* greater than expected loss ratios on business written by the Company and adverse development on claim and/or claim expense liabilities related to business written by its insurance and reinsurance subsidiaries;

* severity and/or frequency of losses;

* claims for natural or man-made catastrophic events in the Company's insurance or reinsurance business could cause large losses and substantial volatility in its results of operations;

* acts of terrorism, political unrest and other hostilities or other unforecasted and unpredictable events;

* losses relating to aviation business and business produced by a certain managing underwriting agency for which the Company may be liable to the purchaser of its prior reinsurance business or to others in connection with the May 5, 2000 asset sale described in the Company's periodic reports filed with the SEC;

* availability to the Company of reinsurance to manage its gross and net exposures and the cost of such reinsurance;

* the failure of reinsurers, managing general agents, third party administrators or others to meet their obligations to the Company;

* the timing of loss payments being faster or the receipt of reinsurance recoverables being slower than anticipated by the Company;

* the Company's investment performance;

* material differences between actual and expected assessments for guaranty funds and mandatory pooling arrangements;

* changes in accounting principles or policies or in the Company's application of such accounting principles or policies;

* changes in the political environment of certain countries in which the Company operates or underwrites business;

* statutory or regulatory developments, including as to tax policy and matters and insurance and other regulatory matters such as the adoption of proposed legislation that would affect Bermuda-headquartered companies and/or Bermuda-based insurers or reinsurers and/or changes in regulations or tax laws applicable to the Company, its subsidiaries, brokers or customers; and

* the other matters set forth under Item 1A "Risk Factors", Item 7 "Management's Discussion and Analysis of Financial Condition and Results of Operations" and other sections of the Company's Annual Report on Form 10-K, as well as the other factors set forth in the Company's other documents on file with the SEC, and management's response to any of the aforementioned factors.

In addition, other general factors could affect the Company's results, including developments in the world's financial and capital markets and its access to such markets.

All subsequent written and oral forward-looking statements attributable to the Company or persons acting on its behalf are expressly qualified in their entirety by these cautionary statements. The foregoing review of important factors should not be construed as exhaustive and should be read in conjunction with other cautionary statements that are included herein or elsewhere. The Company undertakes no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise.

Comment on Regulation G

Throughout this release, the Company presents its operations in the way it believes will be the most meaningful and useful to investors, analysts, rating agencies and others who use the Company's financial information in evaluating the performance of the Company. This presentation includes the use of after-tax operating income available to common shareholders, which is defined as net income available to common shareholders, excluding net realized gains or losses, equity in net income or loss of investment funds accounted for using the equity method and net foreign exchange gains or losses, net of income taxes. The presentation of after-tax operating income available to common shareholders is a "non-GAAP financial measure" as defined in Regulation G. The reconciliation of such measure to net income available to common shareholders (the most directly comparable GAAP financial measure) in accordance with Regulation G is included on page 2 of this release.

The Company believes that net realized gains or losses, equity in net income or loss of investment funds accounted for using the equity method and net foreign exchange gains or losses in any particular period are not indicative of the performance of, or trends in, the Company's business performance. Although net realized gains or losses, equity in net income or loss of investment funds accounted for using the equity method and net foreign exchange gains or losses are an integral part of the Company's operations, the decision to realize investment gains or losses, the recognition of equity in net income or loss of investment funds accounted for using the equity method and the recognition of foreign exchange gains or losses are independent of the insurance underwriting process and result, in large part, from general economic and financial market conditions. Furthermore, certain users of the Company's financial information believe that, for many companies, the timing of the realization of investment gains or losses is largely opportunistic, and, under applicable GAAP accounting, losses on the Company's investments can be realized as the result of other-than-temporary declines in value without actual realization. The use of the equity method on certain of the Company's investments in certain funds that invest in fixed maturity securities is driven by the ownership structure of such funds (either limited partnerships or limited liability companies). In applying the equity method, these investments are initially recorded at cost and are subsequently adjusted based on the Company's proportionate share of the net income or loss of the funds (which include changes in the market value of the underlying securities in the funds). This method of accounting is different from the way the Company accounts for its other fixed maturity securities and the timing of the recognition of equity in net income or loss of investment funds accounted for using the equity method may differ from gains or losses in the future upon sale or maturity of such investments. Due to these reasons, the Company excludes net realized gains or losses, equity in net income or loss of investment funds accounted for using the equity method and net foreign exchange gains or losses from the calculation of after-tax operating income available to common shareholders.

The Company believes that showing net income available to common shareholders exclusive of the items referred to above reflects the underlying fundamentals of the Company's business since the Company evaluates the performance of and manages its business to produce an underwriting profit. In addition to presenting net income available to common shareholders, the Company believes that this presentation enables investors and other users of the Company's financial information to analyze the Company's performance in a manner similar to how the Company's management analyzes performance. The Company also believes that this measure follows industry practice and, therefore, allows the users of the Company's financial information to compare the Company's performance with its industry peer group. The Company believes that the equity analysts and certain rating agencies which follow the Company and the insurance industry as a whole generally exclude these items from their analyses for the same reasons.

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(1) Excludes the effects of 5,400,266 and 5,486,033 stock options and 115,053 and 116,453 restricted stock units outstanding at March 31, 2008 and December 31, 2007, respectively.

(2) As the average price per share repurchased during the periods exceeded the book value per common share at March 31, 2008 and December 31, 2007, the repurchase of shares during the periods reduced book value per common share in the periods presented.

(3) The estimated impact on diluted earnings per share was calculated comparing reported results versus (i) net income per share plus an estimate of lost net investment income on the share repurchases divided by (ii) weighted average diluted shares outstanding excluding the weighted average impact of share repurchases. The repurchase of shares was accretive to diluted earnings per share in the 2008 first quarter. The repurchase of shares during the 2007 first quarter had a minimal impact on diluted earnings per share due to the timing of such transactions.

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(1) Equals estimated losses from catastrophic events occurring in the current accident year, net of reinsurance and reinstatement premiums. Amounts shown for the insurance segment are for named catastrophic events only. Amounts shown for the reinsurance segment include (i) named events with over $5 million of losses incurred by its Bermuda operations and (ii) all catastrophe losses incurred by its U.S. operations.

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(1) In securities lending transactions, the Company receives collateral in excess of the fair value of the fixed maturities and short-term investments pledged under securities lending agreements. For purposes of this table, the Company has excluded the collateral received at March 31, 2008 and December 31, 2007 of $1.23 billion and $1.5 billion, respectively, which is reflected as "short-term investment of funds received under securities lending agreements, at fair value" and included the $1.19 billion and $1.46 billion, respectively, of "fixed maturities and short-term investments pledged under securities lending agreements, at fair value."

(2) Other investments include (i) mutual funds which invest in fixed maturity securities and international equity index funds; and (ii) privately held securities and other which include the Company's investment in Aeolus LP and other privately held securities and preferred stocks.

(3) The Company's investment portfolio includes certain funds that invest in fixed maturity securities which, due to the ownership structure of the funds, are accounted for by the Company using the equity method. In applying the equity method, these investments are initially recorded at cost and are subsequently adjusted based on the Company's proportionate share of the net income or loss of the funds (which include changes in the market value of the underlying securities in the funds). Changes in the carrying value of such investments are recorded as 'Equity in net income (loss) of investment funds accounted for using the equity method' rather than as an unrealized gain or loss component of accumulated other comprehensive income in shareholders' equity as are changes in the carrying value of the Company's other fixed income investments.

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ARCH CAPITAL GROUP LTD. AND SUBSIDIARIES

SEGMENT INFORMATION

The Company classifies its businesses into two underwriting segments - insurance and reinsurance - and a corporate and other segment (non-underwriting). The Company's insurance and reinsurance operating segments each have segment managers who are responsible for the overall profitability of their respective segments and who are directly accountable to the Company's chief operating decision makers, the President and Chief Executive Officer of ACGL and the Chief Financial Officer of ACGL. The chief operating decision makers do not assess performance, measure return on equity or make resource allocation decisions on a line of business basis. The Company determined its reportable operating segments using the management approach described in SFAS No. 131, "Disclosures About Segments of an Enterprise and Related Information."

Management measures segment performance based on underwriting income or loss. The Company does not manage its assets by segment and, accordingly, investment income is not allocated to each underwriting segment. In addition, other revenue and expense items are not evaluated by segment. The accounting policies of the segments are the same as those used for the preparation of the Company's consolidated financial statements. Inter-segment insurance business is allocated to the segment accountable for the underwriting results.

The insurance segment consists of the Company's insurance underwriting subsidiaries which primarily write on both an admitted and non-admitted basis. The insurance segment consists of nine specialty product lines: casualty; construction and national accounts; executive assurance; healthcare; professional liability; programs; property, marine and aviation; surety; and other (consisting of collateral protection business, excess workers' compensation and employers' liability business and travel and accident business).

The reinsurance segment consists of the Company's reinsurance underwriting subsidiaries. The reinsurance segment generally seeks to write significant lines on specialty property and casualty reinsurance treaties. Classes of business include: casualty; marine and aviation; other specialty; property catastrophe; property excluding property catastrophe (losses on a single risk, both excess of loss and pro rata); and other (consisting of non-traditional and casualty clash business).

The corporate and other segment (non-underwriting) includes net investment income, other fee income, net of related expenses, other income (loss), other expenses incurred by the Company, interest expense, net realized gains or losses, equity in net income (loss) of investment funds accounted for using the equity method, net foreign exchange gains or losses and income taxes. In addition, results for the corporate and other segment included dividends on the Company's non-cumulative preferred shares.

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(1) Certain amounts included in the gross premiums written of each segment are related to intersegment transactions and are included in the gross premiums written of each segment. Accordingly, the sum of gross premiums written for each segment does not agree to the total gross premiums written as shown in the table above due to the elimination of intersegment transactions in the total.

(2) The acquisition expense ratio is adjusted to include certain fee income.

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(1) Certain amounts included in the gross premiums written of each segment are related to intersegment transactions and are included in the gross premiums written of each segment. Accordingly, the sum of gross premiums written for each segment does not agree to the total gross premiums written as shown in the table above due to the elimination of intersegment transactions in the total.

(2) The acquisition expense ratio is adjusted to include certain fee income.

The following table sets forth the insurance segment's net premiums written and earned by major line of business, together with net premiums written by client location:

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(1) Includes excess workers' compensation and employers' liability business and travel and accident business.

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(1) Includes professional liability, executive assurance and healthcare business.

(2) Includes facultative business.

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Gross premiums written by the insurance segment in the 2008 first quarter were 5.3% lower than in the 2007 first quarter, while net premiums written were 6.0% lower as the insurance segment maintained underwriting discipline in response to the current rate environment. Net premiums earned by the insurance segment in the 2008 first quarter were 1.3% higher than in the 2007 first quarter, and reflect changes in net premiums written over the previous five quarters, including the mix and type of business written.

The loss ratio for the insurance segment was 68.6% in the 2008 first quarter, compared to 62.7% for the 2007 first quarter. The 2008 first quarter loss ratio included 4.8 points related to the Australian floods in the period and 2.8 points related to large specific risk losses in short-tail lines in the period, while the 2007 first quarter loss ratio included 1.3 points related to large specific risk losses. The 2008 first quarter loss ratio reflected a 1.4 point reduction related to estimated net favorable development in prior year loss reserves, compared to a 0.2 point reduction in prior year loss reserves in the 2007 first quarter. The estimated net favorable development in the 2008 first quarter was primarily in medium-tail and longer-tail lines, partially offset by adverse development from short-tail lines which primarily resulted from higher than expected claims development on property, marine and aviation business. The insurance segment's loss ratio in the 2008 first quarter also reflects an increase in expected loss ratios across a number of lines of business and changes in the mix of business.

The insurance segment's underwriting expense ratio was 29.8% in the 2008 first quarter, compared to 27.7% in the 2007 first quarter. The acquisition expense ratio was 12.2% for the 2008 first quarter, compared to 11.1% for the 2007 first quarter. The acquisition expense ratio is influenced by, among other things, (1) the amount of ceding commissions received from unaffiliated reinsurers, (2) the amount of business written on a surplus lines (non-admitted) basis and (3) mix of business. The acquisition expense ratio in the 2008 first quarter reflects changes in the form of reinsurance ceded and the mix of business. The insurance segment's other operating expense ratio was 17.6% for the 2008 first quarter, compared to 16.6% in the 2007 first quarter. The higher operating expense ratio in the 2008 first quarter compared to the 2007 first quarter was primarily due to growth in operating expenses without a proportionate increase in net premiums earned.

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Gross premiums written by the reinsurance segment in the 2008 first quarter were 22.3% lower than in the 2007 first quarter, with reductions in all treaty lines of business. The reinsurance segment's Bermuda-based reinsurer, Arch Re Bermuda, ceded certain lines of property and marine premiums written under a quota share reinsurance treaty (the "Treaty") to Flatiron Re Ltd. Under the Treaty, Flatiron Re Ltd. assumed a 45% quota share of certain lines of property and marine business underwritten by Arch Re Bermuda for the 2006 and 2007 underwriting years (the percentage ceded was increased from 45% to 70% of covered business bound from June 28, 2006 until August 15, 2006 provided such business did not incept beyond September 30, 2006). On December 31, 2007, the Treaty expired by its terms. For its January 1 renewals, Arch Re Bermuda adjusted its book of business in light of the expiration of the Treaty. In addition, other reductions in the reinsurance segment's book of business resulted from continued competition which led to non-renewals or lower shares written.

Ceded premiums written by the reinsurance segment were 5.8% of gross premiums written for the 2008 first quarter, compared to 20.6% for the 2007 first quarter. In the 2008 first quarter, Arch Re Bermuda ceded $18.4 million, or 4.2% of gross premiums written, of certain lines of property and marine premiums written under the Treaty to Flatiron Re Ltd., compared to $108.9 million, or 19.5%, in the 2007 first quarter, with the lower level due to the expiration of the Treaty. On an earned basis, Arch Re Bermuda ceded $58.9 million to Flatiron Re Ltd. in the 2008 first quarter, compared to $66.0 million in the 2007 first quarter. Commission income from the Treaty (in excess of the reimbursement of direct acquisition expenses) reduced the reinsurance segment's acquisition expense ratio by 3.3 points in the 2008 first quarter, compared to 2.8 points in the 2007 first quarter. At March 31, 2008, $104.5 million of premiums ceded to Flatiron Re Ltd. were unearned. The attendant premiums earned, losses incurred and acquisition expenses will primarily be reflected in the reinsurance segment's results during the balance of 2008.

Net premiums written by the reinsurance segment in the 2008 first quarter were 7.9% lower than in the 2007 first quarter, while net premiums earned in the 2008 first quarter were 12.8% lower than in the 2007 first quarter. The decrease in net premiums earned in the 2008 first quarter primarily resulted from changes in net premiums written over the previous five quarters, including the mix and type of business written.

The reinsurance segment's loss ratio was 40.5% in the 2008 first quarter, compared to 48.5% for the 2007 first quarter. The loss ratio for the 2008 first quarter reflected a 17.7 point reduction related to estimated net favorable development in prior year loss reserves, compared to a 14.1 point reduction in the 2007 first quarter. The estimated net favorable development in the 2008 first quarter was primarily in short-tail lines and resulted from better than anticipated loss emergence. The 2008 first quarter loss ratio also reflected approximately 2.0 points of catastrophic activity, while the 2007 first quarter loss ratio reflected approximately 4.8 points of catastrophic activity. The reinsurance segment's loss ratio in the 2008 first quarter also reflected an increase in expected loss ratios across a number of lines of business and changes in the mix of business.

The underwriting expense ratio for the reinsurance segment was 28.0% in the 2008 first quarter, compared to 26.3% in the 2007 first quarter. The acquisition expense ratio for the 2008 first quarter was 21.7%, compared to 22.1% for the 2007 first quarter. The acquisition expense ratio is influenced by, among other things, the mix and type of business written and earned and the level of ceding commission income. The reinsurance segment's other operating expense ratio was 6.3% for the 2008 first quarter, compared to 4.2% for the 2007 first quarter. The higher ratio in the 2008 first quarter primarily resulted from expenses related to the reinsurance segment's property facultative reinsurance operation, which commenced operations during the 2007 second quarter, and a lower level of net premiums earned.