The table below shows our gross premiums written for each line of business for each of the three months ended March 31, 2006 and 2005, and the percentage increase/decrease in gross premiums written for each such line:
As of March 31, 2006, the Company had accrued losses and loss adjustment expense reserves of $3,045.5 million. This amount represented the Company's best estimate of the ultimate liability for payment of losses and loss adjustment expenses. Of the total gross reserves for unpaid losses, $1,424.9 million, or 46.8%, represented IBNR claims. The IBNR portion of our reserves decreased by five percentage points as at December 31, 2005, as a result of a larger portion of the 2005 hurricane losses being notified. During the three months ended March 31, 2006 the Company paid losses and loss adjustment expenses of $222.5 million.
For the three months ended March 31, 2006, there was a reduction of our estimate of the ultimate claims to be paid in respect of 2005 and prior accident years. An analysis of this reduction by segment is as follows:
Table of ContentsThe key elements which gave rise to the adverse and favorable development during the three months ended March 31, 2006 were as follows:
Property Reinsurance: The $8.5 million reserve strengthening in this segment was due to the overall deterioration in estimated losses from the 2005 hurricanes.
Casualty Reinsurance: The $7.6 million reduction in the net reserves in our casualty reinsurance segment was due to better than expected claims development and the effect of commutations on 2003 and 2004 policies.
Specialty Insurance and Reinsurance: The $8.7 million reduction in the net reserves in our specialty insurance and reinsurance segment was due to favorable development on the Syndicate 2020/3030 quota shares in 2002 and 2003 and better than expected claims development on our specialty reinsurance.
Property and Casualty Insurance: Of the total release, $8.2 million was from the U.K. liability class due to much better than expected experience on 2004 accident year policies and $1.5 million was from the worldwide property account following a reduction in prior period premium estimates and their impact on ultimate claims.
For a more detailed description see ‘‘Management's Discussion and Analysis Critical Accounting Policies — Reserves for Losses and Loss Expenses,’’ included in our 2005 Annual Report on Form 10-K filed with the Securities and Exchange Commission.
Liquidity and Capital Resources
Aspen is a holding company that does not have any significant operations or assets other than its ownership of the shares of its direct and indirect subsidiaries, including Aspen Re, Aspen Bermuda and Aspen Specialty. Aspen relies primarily on dividends and other permitted distributions from these insurance subsidiaries to pay its operating expenses, interest on debt finance and dividends, if any, on its ordinary shares and preference shares. There are restrictions on the payment of dividends by Aspen Re, Aspen Bermuda and Aspen Specialty to Aspen, which are described in more detail in the ‘‘Business — Regulatory Matters’’ section of the 2005 Annual Report on Form 10-K filed with the Securities and Exchange Commission.
Our aggregate invested assets as of March 31, 2006 were $4.5 billion, compared to aggregate invested assets of $4.4 billion as of December 31, 2005. The increase in invested assets since December 31, 2005 resulted from collections of premiums on insurance policies and reinsurance contracts and investment income, offset by claims, policy acquisition expenses, reinsurance premiums and operating and administrative expenses paid.
Total net cash flow from operations from December 31, 2005 through March 31, 2006 was $64.4 million, a reduction from $210.6 million in the prior year period. The reduction was a result of significant claims having been paid in the period. For the three months ended March 31, 2006, our cash flow from operations provided us with sufficient liquidity to meet our operating requirements. On March 25, 2006, we paid a dividend of $0.15 per ordinary share to shareholders of record on March 15, 2006. On March 31, 2006, dividends totaling $3.9 million on our Perpetual Preferred Income Equity Replacement Securities (‘‘Perpetual PIERS’’) were paid to our dividend disbursing agent, for payment to our Perpetual PIERS holders on April 1, 2006.
On January 10, 2006, the over-allotment option on our Perpetual PIERS was exercised, pursuant to which we issued an additional 600,000 Perpetual PIERS and generated approximately $29 million in net proceeds. The proceeds from this offering were used for general corporate purposes, to support the operations of our insurance subsidiaries and to strengthen our balance sheet capital position.
Our contractual obligations other than our obligations to employees consist mainly of amounts outstanding under our senior notes, reserves relating to our insurance and reinsurance contracts and operating leases. Note 6 to the unaudited condensed consolidated financial statements summarizes amounts outstanding under our contractual obligations as of March 31, 2006.
For a more detailed description of our liquidity and capital resources, refer to our Annual Report on Form 10-K for the year ended December 31, 2005.
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Table of ContentsEffects of Inflation
The effects of inflation could cause the severity of claims from catastrophes or other events to rise in the future. Our calculation of reserves for losses and loss adjustment expenses includes assumptions about future payments for settlement of claims and claims-handling expenses, such as medical treatments and litigation costs. We write casualty/liability business in the United States, the United Kingdom and Australia, where claims inflation has grown particularly strong in recent years. To the extent inflation causes these costs to increase above reserves established for these claims, we will be required to increase our loss reserves with a corresponding reduction in current period earnings.
Cautionary Statement Regarding Forward-Looking Statements
This Form 10-Q contains, and the Company may from time to time make other verbal or written, forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the ‘‘Securities Act’’), and Section 21E of the Securities Exchange Act of 1934, as amended, that involve risks and uncertainties, including statements regarding our capital needs, business strategy, expectations and intentions. Statements that use the terms ‘‘believe’’, ‘‘do not believe’’, ‘‘anticipate’’, ‘‘expect’’, ‘‘plan’’, ‘‘estimate’’, ‘‘intend’’ and similar expressions are intended to identify forward-looking statements. These statements reflect our current views with respect to future events and because our business is subject to numerous risks, uncertainties and other factors, our actual results could differ materially from those anticipated in the forward-looking statements. The risks, uncertainties and other factors set forth in the Company's 2005 Annual Report on Form 10-K filed with the Securities and Exchange Commission and other cautionary statements made in this report, as well as the following factors, should be read and understood as being applicable to all related forward-looking statements wherever they appear in this report.
All forward-looking statements address matters that involve risks and uncertainties. Accordingly, there are or will be important factors that could cause actual results to differ materially from those indicated in these statements. We believe that these factors include, but are not limited to, the following:
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| • | the impact of acts of terrorism and related legislation and acts of war; |
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| • | the possibility of greater frequency or severity of claims and loss activity, including as a result of natural or man-made catastrophic events such as Hurricanes Katrina, Rita and Wilma, than our underwriting, reserving, reinsurance purchasing or investment practices have anticipated; |
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| • | evolving interpretive issues with respect to coverage as a result of Hurricanes Katrina, Rita and Wilma; |
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| • | the level of inflation in repair costs due to limited availability of labor and materials after catastrophes; |
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| • | the effectiveness of our loss limitation methods; |
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| • | changes in the availability, cost or quality of reinsurance or retrocessional coverage; |
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| • | the reliability of, and changes in assumptions to, catastrophe pricing, accumulation and estimated loss models; |
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| • | a decline in our operating subsidiaries’ ratings with Standard & Poor's, A.M. Best Company (‘‘A.M. Best’’) or Moody's Investors Service; |
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| • | changes in general economic conditions, including inflation, foreign currency exchange rates, interest rates and other factors that could affect our investment portfolio; |
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| • | increased competition on the basis of pricing, capacity, coverage terms or other factors; |
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| • | decreased demand for our insurance or reinsurance products and cyclical downturn of the industry; |
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Table of Contents |  |  |
| • | changes in governmental regulations or tax laws in jurisdictions where we conduct business; |
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| • | Aspen Holdings or Aspen Bermuda becoming subject to income taxes in the United States or the United Kingdom; |
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| • | the effect on insurance markets, business practices and relationships of ongoing litigation, investigations and regulatory activity by the New York State Attorney General's office and other authorities concerning contingent commission arrangements with brokers and bid solicitation activities; |
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| • | the total industry losses resulting from Hurricanes Katrina, Rita and Wilma, and the actual number of our insureds incurring losses from these storms; and |
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| • | with respect to Hurricanes Katrina, Rita and Wilma, the limited actual loss reports received from our insureds to date, the preliminary nature of possible loss information received by brokers to date on behalf of cedants, our reliance on industry loss estimates and those generated by modeling techniques, the impact of these storms on our reinsurers, any changes in our reinsurers' credit quality, the amount and timing of reinsurance recoverables and reimbursements actually received by us from our reinsurers and the overall level of competition, and the related demand and supply dynamics as contracts come up for renewal. |
The foregoing review of important factors should not be construed as exhaustive and should be read in conjunction with the other cautionary statements that are included in this report. We undertake no obligation to publicly update or review any forward-looking statement, whether as a result of new information, future developments or otherwise or disclose any difference between our actual results and those reflected in such statements.
If one or more of these or other risks or uncertainties materialize, or if our underlying assumptions prove to be incorrect, actual results may vary materially from what we projected. Any forward-looking statements you read in this report reflect our current views with respect to future events and are subject to these and other risks, uncertainties and assumptions relating to our operations, results of operations, growth strategy and liquidity. All subsequent written and oral forward-looking statements attributable to us or individuals acting on our behalf are expressly qualified in their entirety by the points made above. You should specifically consider the factors identified in this report which could cause actual results to differ before making an investment decision.
Item 3. Quantitative and Qualitative Disclosures about Market Risk
Interest rate risk. Our investment portfolio consists primarily of fixed income securities. Accordingly, our primary market risk exposure is to changes in interest rates. Fluctuations in interest rates have a direct impact on the market valuation of these securities. As interest rates rise, the market value of our fixed-income portfolio falls, and the converse is also true. We expect to manage interest rate risk by selecting investments with characteristics such as duration, yield, currency and liquidity, taking into account the anticipated cash outflow characteristics of Aspen Re's, Aspen Bermuda's and Aspen Specialty's insurance and reinsurance liabilities.
Our strategy for managing interest rate risk also includes maintaining a high quality portfolio with a relatively short duration to reduce the effect of interest rate changes on book value. The portfolio is actively managed and trades are made to balance our exposure to interest rates.
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Table of ContentsAs at March 31, 2006, our fixed income portfolio had an approximate duration of 2.91 years. The table below depicts interest rate change scenarios and the effect on our interest-rate sensitive invested assets:

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Effect of changes in interest rates on portfolio given a parallel shift in the yield curve |
Movement in rates in basis points |  | -100 |  | -50 |  | 0 |  | 50 |  | 100 |
|  | ($ in thousands, except percentages) |
Market value $ in thousands |  | $ | 4,154,817 | |  | $ | 4,100,141 | |  | $ | 4,045,900 | |  | $ | 3,992,327 | |  | $ | 3,939,609 | |
Gain/(loss) $ in thousands |  | $ | 108,917 | |  | $ | 54,241 | |  | $ | 0 | |  | $ | (53,573 | ) |  | $ | (106,291 | ) |
Percentage of portfolio |  | | 2.69 | % |  | | 1.34 | % |  | | 0.00 | % |  | | (1.32 | )% |  | | (2.63 | )% |
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Foreign currency risk. Our reporting currency is the U.S. Dollar. The functional currencies of our segments are U.S. Dollars and British Pounds. As of March 31, 2006, approximately 78% of our cash and investments are held in U.S. Dollars, approximately 15% are in British Pounds and approximately 7% are in currencies other than the U.S. Dollar and the British Pound. For the three months ended March 31, 2006, 15% of our gross premiums were written in currencies other than the U.S. Dollar and the British Pound and we expect that a similar proportion will be written in currencies other than the U.S. Dollar and the British Pound in 2006. Other foreign currency amounts are remeasured to the appropriate functional currency and the resulting foreign exchange gains or losses are reflected in the statement of operations. Functional currency amounts of assets and liabilities are then translated into U.S. Dollars. The unrealized gain or loss from this translation, net of tax, is recorded as part of shareholders' equity. The change in unrealized foreign currency translation gain or loss during the year, net of tax, is a component of comprehensive income. Both the remeasurement and translation are calculated using current exchange rates for the balance sheets and average exchange rates for the statement of operations. We may experience exchange losses to the extent our foreign currency exposure is not properly managed or otherwise hedged, which in turn would adversely affect our results of operations and financial condition. Management estimates that a 10% change in the exchange rate between British Pounds and U.S. Dollars as at March 31, 2006, would have impacted reported net comprehensive income by approximately $13.0 million for the three months ended March 31, 2006.
We attempt to manage our foreign currency risk by seeking to match our liabilities under insurance and reinsurance policies that are payable in foreign currencies with investments that are denominated in these currencies. Although in the past we have entered into forward foreign currency exchange contracts, we had no outstanding forward contracts as at March 31, 2006.
Credit risk. We have exposure to credit risk primarily as a holder of fixed income securities. Our risk management strategy and investment policy is to invest in debt instruments of high credit quality issuers and to limit the amount of credit exposure with respect to particular ratings categories and any one issuer. Under our policy, no more than 5% of the fixed-income securities in our investment portfolio may be rated below ‘‘A−’’. As at March 31, 2006, the average rate of fixed income securities in our investment portfolio was ‘‘AAA’’. In addition, we are exposed to the credit risk of our insurance and reinsurance brokers to whom we make claims payments for insureds and our reinsureds, as well as to the credit risk of our reinsurers and retrocessionaires who assume business from us. Other than fully collateralized reinsurance, the substantial majority of our reinsurers have a rating of ‘‘A’’ (Excellent), the third highest of fifteen rating levels, or better by A.M. Best and the minimum rating of any of our material reinsurers is ‘‘A−’’ (Excellent), the fourth highest of fifteen rating levels, by A.M. Best.
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Table of ContentsItem 4. Controls and Procedures
Evaluation of Disclosure Controls and Procedures
During the fourth quarter of 2005, we successfully transitioned to a new financial reporting ledger system. We are in the process of finalizing the implementation of a new underwriting system that is expected to be complete during 2006. Later in 2006, the new underwriting system will automatically interface with the new financial reporting ledger. The introduction of the new systems is the final stage of the process to improve functionality and transition away for the IT facilities and services previously provided by Wellington.
The Company, under the supervision and with the participation of the Company's management, including the Company's Chief Executive Officer and Chief Financial Officer, has evaluated the design and operation of the Company's disclosure controls and procedures as of the end of the period of this report. Our management does not expect that our disclosure controls or our internal controls will prevent all errors and all fraud. A control system, no matter how well conceived and operated, can provide only reasonable, not absolute, assurance that the objectives of the control system are met. Further, the design of a control system must reflect the fact that there are resource constraints, and the benefits of controls must be considered relative to their costs. As a result of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that all control issues and instances of fraud, if any, within the Company have been detected. These inherent limitations include the realities that judgments in decision-making can be faulty, and that breakdowns can occur because of simple error or mistake. Additionally, controls can be circumvented by the individual acts of some persons or by collusion of two or more people. The design of any system of controls also is based in part upon certain assumptions about the likelihood of future events, and there can be no assurance that any design will succeed in achieving its stated goals under all potential future conditions; over time, controls may become inadequate because of changes in conditions, or the degree of compliance with the policies or procedures may deteriorate. As a result of the inherent limitations in a cost-effective control system, misstatement due to error or fraud may occur and not be detected. Accordingly, our disclosure controls and procedures are designed to provide reasonable, not absolute, assurance that the disclosure controls and procedures are met. Based on the evaluation of the disclosure controls and procedures, the Chief Executive Officer and Chief Financial Officer have concluded that the Company's disclosure controls and procedures were effective in ensuring that information required to be disclosed by the Company in this report is recorded, processed, summarized and reported in a timely fashion.
Changes in internal control over financial reporting
The Company's management has performed an evaluation, with the participation of the Company's Chief Executive Officer and the Company's Chief Financial Officer, of changes in the Company's internal control over financial reporting that occurred during the quarter ended March 31, 2006. Based upon that evaluation, the Company's management is not aware of any change in its internal control over financial reporting that occurred during quarter ended March 31, 2006 that has materially affected, or is reasonably likely to materially affect, the Company's internal control over financial reporting.
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Table of ContentsPART II
OTHER INFORMATION
Item 1. Legal Proceedings
Similar to the rest of the insurance and reinsurance industry, we are subject to litigation and arbitration in the ordinary course of business. We are not currently involved in any material pending litigation or arbitration proceedings.
Item 1A. Risk Factors
There have been no significant changes in the Company’s risk factors as discussed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2005.
Item 2. Unregistered Sales of Equity Securities and Use of Proceeds
In connection with the options held by the Names’ Trustee as described further in Note 4 to our financial statements, the Names’ Trustee may exercise the options on a monthly basis. The options were exercised on both a cash and cashless basis at the exercise price as described in Note 4 to our financial statements. As a result, we issued the following unregistered shares to the Names’ Trustee and its beneficiaries as described below.

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Date Issued |  | Number of Shares Issued |
January 17, 2006 |  | | 993 | |
February 15, 2006 |  | | 537 | |
March 15, 2006 |  | | 312 | |
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None of the transactions involved any underwriters, underwriting discounts or commissions, or any public offering and we believe that each transaction, if deemed to be a sale of a security, was exempt from the registration requirements of the Securities Act by virtue of Section 4(2) thereof or Regulation S for offerings of securities outside the United States. Such securities were restricted as to transfers and appropriate legends were affixed to the share certificates and instruments in such transactions.
Item 3. Defaults Upon Senior Securities
None.
Item 4. Submission of Matters to a Vote of Security Holders
No matters were submitted to a vote of the Company's shareholders during the first quarter of 2006.
Item 5. Other Information
None.
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Table of ContentsItem 6. Exhibits
The following sets forth those exhibits filed pursuant to Item 601 of Regulation S-K:

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Exhibit Number |  | Description |
31.1 |  | Officer Certification of Christopher O'Kane, Chief Executive Officer of Aspen Insurance Holdings Limited, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002, filed with this report. |
31.2 |  | Officer Certification of Julian Cusack, Chief Financial Officer of Aspen Insurance Holdings Limited, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002, filed with this report. |
32.1 |  | Officer Certification of Christopher O'Kane, Chief Executive Officer of Aspen Insurance Holdings Limited, and Julian Cusack, Chief Financial Officer of Aspen Insurance Holdings Limited, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, submitted with this report. |
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Table of ContentsSIGNATURES
Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

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|  | |  | ASPEN INSURANCE HOLDINGS LIMITED (Registrant) |
Date: May 9, 2006 |  | By: |  | /s/ Christopher O’Kane |
|  | |  | Christopher O’Kane Chief Executive Officer |
Date: May 9, 2006 |  | By: |  | /s/ Julian Cusack |
|  | |  | Julian Cusack Chief Financial Officer |
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31