SEC FORM 4/A

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person^*

LEE KEWSONG

(Last)

(First)

(Middle)

WARBURG PINCUS LLC

466 LEXINGTON AVENUE

(Street)

NEW YORK

10017

(City)

(State)

(Zip)

2. Issuer Name and Ticker or Trading Symbol
ARCH CAPITAL GROUP LTD. [ ACGL ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director	10% Owner
	Officer (give title below)	Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
04/28/2005

4. If Amendment, Date of Original Filed (Month/Day/Year)
05/02/2005

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Shares, $.01 par value per share⁽¹⁾⁽²⁾	04/28/2005		A		999	A	⁽³⁾	6,496	D
Common Shares, $.01 par value per share⁽¹⁾⁽²⁾	04/28/2005		A		875	A	⁽⁴⁾	7,371	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

1. The security holders are Warburg Pincus (Bermuda) Private Equity VIII, L.P. ("WP VIII Bermuda"), Warburg Pincus (Bermuda) International Partners, L.P. ("WPIP Bermuda") and Warburg Pincus Netherlands International Partners I, C.V. ("WPIP Netherlands I"). Warburg Pincus (Bermuda) Private Equity Ltd. ("WP VIII Bermuda Ltd.") is the sole general Partner of WP VIII Bermuda. Warburg Pincus (Bermuda) International Ltd. ("WPIP Bermuda Ltd.") is the sole general partner of WPIP Bermuda. Warburg Pincus Partners LLC ("WP Partners LLC"), a subsidiary of Warburg Pincus & Co. ("WP") is the sole gerneral partner of WPIP Netherlands I. WP VII Bermuda, WPIP Bermuda and WPIP Netherlands I are managed by Warburg Pincus LLC ("WP LLC").

2. 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 7,371 Common Shares of the Issuer which are granted to Mr. Lee in consideration of his service as a director of the Issuer, the Warburg Pincus entities own 2,003,918 Common Shares and 20,906,560 Series A Convertible Preference Shares which are convertible into Common Shares on a 1:1 basis (subject to adjustment). 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 shares owned by WP VIII Bermuda, WPIP Bermuda and WPIP Netherlands I. Mr. Lee disclaims beneficial ownership of all shares owned by these Warburg Pincus entities.

3. Represents shares granted as part of the director-elected annual retainer for serving as a director of the Issuer.

4. Subject to the terms of the restricted share agreement, this represents restricted shares that will vest on April 27, 2006.

	/s/ Kewsong Lee	05/17/2005
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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