X0303 4/A 2009-11-19 2009-11-20 0 0000947484 ARCH CAPITAL GROUP LTD. ACGL 0001220640 LEE KEWSONG C/O WARBURG PINCUS LLC 450 LEXINGTON AVE NEW YORK NY 10017 1 0 0 0 Common Shares, $0.01 par value per share 2009-11-19 4 J 0 3160773 D 828377 I See Footnotes (1) and (2) See Exhibit 99.1. 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. Other than 150,199 Common Shares, 12,957 of which were received by Mr. Lee pursuant to the distribution described in footnote (3) below and 13,271 of which were granted to and are directly owned by Mr. Lee in consideration of his service as a Director of the Issuer, the Warburg Pincus Entities own 828,377 Common Shares. Mr. Lee may be deemed to have an indirect pecuniary interest (within the meaning of Rule 16a-1 under the Securities Exchange Act of 1934) in an indeterminate portion of the Common Shares owned by WP VIII Bermuda, WPIP Bermuda, WPIP Netherlands I and WPIP Bermuda Ltd. Mr. Lee disclaims beneficial ownership of all shares owned by the Warburg Pincus Entities, except to the extent of any pecuniary interest therein. On November 19, 2009, WP VIII Bermuda, WPIP Bermuda and WPIP Netherlands I distributed an aggregate of 3,400,403 Common Shares to their limited and general partners. In connection with the distribution, 239,630 Common Shares were received by WPIP Bermuda Ltd. and not further distributed. Mr. Lee received 12,957 Common Shares pursuant to the distributions. The original Form 4 incorrectly reported the number of shares beneficially owned following the reported transaction as 588,747. /s/ Scott A. Arenare, as Attorney-in-fact 2009-12-08