ARCH CAPITAL GROUP LTD. — Director's Dealing 2010

Mar 3, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: ARCH CAPITAL GROUP LTD. (ACGL)
CIK: 0000947484
Period of Report: 2010-03-02

Reporting Person: LEE KEWSONG (Director)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-03-02	Common Shares, $0.01 par value per share	S	588747	$74.15	Disposed	0	Indirect

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Shares, $0.01 par value per share	150199	Direct

Footnotes

F1: See Exhibit 99.1.

F2: Kewsong Lee, a Director of the Issuer, is a General Partner of WP, a Managing Director and Member of WP LLC and a beneficial owner of certain shares of capital stock of WP VIII Bermuda Ltd. and WPIP Bermuda Ltd. Mr. Lee owns 150,199 Common Shares, 13,271 of which were granted to Mr. Lee in consideration of his service as a Director of the Issuer. Mr. Lee may be deemed to have had an indirect pecuniary interest (within the meaning of Rule 16a-1 under the Securities Exchange Act of 1934) in an indeterminate portion of the shares that were owned by WP VIII Bermuda, WPIP Bermuda and WPIP Netherlands I. Mr. Lee disclaims beneficial ownership of all shares owned by the Warburg Pincus Entities, except to the extent of any pecuniary interest therein.

F3: On March 2, 2010, WPIP Bermuda sold 263,052 Common Shares, WPIP Netherlands I sold 10,958 Common Shares, and WP VIII Bermuda sold 314,737 Common Shares in a private transaction.