SEC FORM 3/A

SEC Form 3

FORM 3

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

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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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1. Name and Address of Reporting Person^*

GRANDISSON MARC

(Last)

(First)

(Middle)

WESSEX HOUSE, 45 REID STREET

(Street)

HAMILTON

HM 12

(City)

(State)

(Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
04/05/2004

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

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

	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	Reinsur. Group Chairman & CEO

5. If Amendment, Date of Original Filed (Month/Day/Year)
04/05/2005

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 Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Shares, $.01 par value per share	22,453⁽¹⁾	D
Common Shares, $.01 par value per share	220	I	By spouse

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
Stock Option (right to buy)	⁽²⁾	10/23/2011	Common Shares, $.01 par value per share	37,500	$20	D
Series A Convertible Preference Shares⁽³⁾	⁽³⁾	⁽³⁾	Common Shares, $.01 par value per share	12,905	⁽³⁾	D

Explanation of Responses:

1. 12,500 of such shares are restricted and subject to vesting on October 23, 2006; 1,926 of such shares are restricted and subject to vesting in two equal annual installments on February 20, 2005 and 2006; 2148 of such shares are restricted and subject to vesting in three equal annual installments on February 26, 2005, 2006 and 2007.

2. The stock option became exercisable in three equal annual installments commencing on October 23, 2001.

3. Subject to certain restrictions on conversion, the Series A Convertible Preference Shares are convertible on a one-for-one basis into Common Shares at the option of the holder and are manditorily convertible into Common Shares upon the occurrence of certain events. The conversion ratio is subject to antidilution and other adjustments.

	/s/ Marc Grandisson	02/27/2006
	** 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 5 (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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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