Arch Insurance Establishes Two Principal Underwriting Units - Property & Casualty Group and Financial & Professional Liability Group

Arch Insurance Group, a division of Arch Capital Group Ltd. (NASDAQ: ACGL), today announced that Arch Insurance has established two principal underwriting groups in its U.S.-based operations: the Arch Property & Casualty Group and the Arch Financial & Professional Liability Group. The new groups are designed to help Arch Insurance maximize underwriting opportunities as the market transitions.

Michael Murphy, who joined the Company in 2002, has been promoted to the position of President of the Property & Casualty Group. Mr. Murphy has 20 years of specialty lines experience and served most recently as a Senior Executive Vice President of Arch Insurance Group. David McElroy, who recently joined the Company, serves as President of the Financial & Professional Liability Group. Mr. Murphy and Mr. McElroy will work closely with John Edack, Arch Insurance's Chief Regional and Marketing Officer, to maximize Arch Insurance's capabilities in the marketplace. Messrs. Murphy, McElroy and Edack report directly to Mark Lyons, Chairman and Chief Executive Officer of Arch Worldwide Insurance Group.

Arch Insurance Group also announced that John Rafferty has joined the Company as head of the Executive Assurance division of the Financial & Professional Liability Group. Mr. Rafferty is a highly regarded insurance professional with over 20 years of executive assurance experience. Mr. Rafferty most recently led Hartford's Financial Products division. At Arch, Mr. Rafferty will report directly to Mr. McElroy.

Arch Insurance Group is a division of Arch Capital Group Ltd., a Bermuda-based company that 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 provides a "safe harbor" for forwarda^'looking statements. This release or any other written or oral statements made by or on behalf of Arch Capital Group Ltd. and its subsidiaries may include forwarda^'looking statements, which reflect our 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 forwarda^'looking statements.

Forwarda^'looking statements can generally be identified by the use of forwarda^'looking terminology such as "may," "will," "expect," "intend," "estimate," "anticipate," "believe" or "continue" or their negative or variations or similar terminology. Forwarda^'looking statements involve our current assessment of risks and uncertainties. Actual events and results may differ materially from those expressed or implied in these statements. A non-exclusive list of the important factors that could cause actual results to differ materially from those in such forward-looking statements includes the following: adverse general economic and market conditions; increased competition; pricing and policy term trends; fluctuations in the actions of rating agencies and our ability to maintain and improve our ratings; investment performance; the loss of key personnel; the adequacy of our loss reserves, severity and/or frequency of losses, greater than expected loss ratios and adverse development on claim and/or claim expense liabilities; greater frequency or severity of unpredictable natural and man-made catastrophic events; the impact of acts of terrorism and acts of war; changes in regulations and/or tax laws in the United States or elsewhere; our ability to successfully integrate, establish and maintain operating procedures as well as integrate the businesses we have acquired or may acquire into the existing operations; changes in accounting principles or policies; material differences between actual and expected assessments for guaranty funds and mandatory pooling arrangements; availability and cost to us of reinsurance to manage our gross and net exposures; the failure of others to meet their obligations to us; and other factors identified in our filings with the U.S. Securities and Exchange Commission.

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. All subsequent written and oral forwarda^'looking statements attributable to us or persons acting on our behalf are expressly qualified in their entirety by these cautionary statements. We undertake no obligation to publicly update or revise any forwarda^'looking statement, whether as a result of new information, future events or otherwise.

SOURCE: Arch Insurance Group

Arch Insurance Group Inc. 
Martin Nilsen, 201-743-4123