-------------------------- OMB APPROVAL -------------------------- OMB Number: 3235-0145 Expires: December 31, 2005 Estimated average burden hours per response......11 -------------------------- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 13D Under the Securities Exchange Act of 1934 (Amendment No. 5 )* Arch Capital Group, Ltd. -------------------------------------------------------------------------------- (Name of Issuer) Common Shares, par value $0.01 per share -------------------------------------------------------------------------------- (Title of Class of Securities) G0450A105 -------------------------------------------------------------------------------- (CUSIP Number) Mark C. Wehrly Farallon Capital Management, L.L.C. One Maritime Plaza, Suite 1325 San Francisco, California 94111 (415) 421-2132 -------------------------------------------------------------------------------- (Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications) February 14, 2006 -------------------------------------------------------------------------------- (Date of Event which Requires Filing of this Statement) If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of Sections 240.13d-1(e), 13d-1(f) or 240.13d-1(g), check the following box [ ]. Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Section 240.13d-7 for other parties to whom copies are to be sent. * The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page. The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes). (Continued on following pages) Page 1 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Farallon Capital Partners, L.P. ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 California ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 1,235,551 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 1,235,551 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 1,235,551 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 1.7% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 PN ------------==================================================================== Page 2 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Farallon Capital Institutional Partners II, L.P. ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 California ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 312,036 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 312,036 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 312,036 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 0.4% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 PN ------------==================================================================== Page 3 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Farallon Capital Institutional Partners III, L.P. ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 Delaware ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 264,048 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 264,048 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 264,048 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 0.4% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 PN ------------==================================================================== Page 4 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Tinicum Partners, L.P. ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 New York ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 50,500 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 50,500 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 50,500 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 0.1% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 PN ------------==================================================================== Page 5 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) RR Capital Partners, L.P. ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 Delaware ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 28,790 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 28,790 [See Prelim ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 28,790 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 0.0% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 PN ------------==================================================================== Page 6 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Farallon Capital Management, L.L.C. ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 Delaware ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 640,964 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 640,964 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 640,964 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 0.9% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 IA, OO ------------==================================================================== Page 7 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Farallon Partners, L.L.C. ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 Delaware ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 1,890,925 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 1,890,925 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 1,890,925 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 2.6% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 OO ------------==================================================================== Page 8 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Chun R. Ding ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 United States ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 2,531,889 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 2,531,889 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 2,531,889 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 3.5% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 IN ------------==================================================================== Page 9 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) William F. Duhamel ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 United States ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 2,531,889 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 2,531,889 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 2,531,889 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 3.5% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 IN ------------==================================================================== Page 10 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Charles E. Ellwein ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 United States ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 2,531,889 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 2,531,889 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 2,531,889 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 3.5% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 IN ------------==================================================================== Page 11 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Richard B. Fried ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 United States ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 2,531,889 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 2,531,889 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 2,531,889 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 3.5% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 IN ------------==================================================================== Page 12 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Monica R. Landry ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 United States ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 2,531,889 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 2,531,889 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 2,531,889 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 3.5% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 IN ------------==================================================================== Page 13 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) William F. Mellin ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 United States ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 2,531,889 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 2,531,889 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 2,531,889 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 3.5% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 IN ------------==================================================================== Page 14 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Stephen L. Millham ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 United States [See Preliminary Note] ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 2,531,889 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 2,531,889 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 2,531,889 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 3.5% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 IN ------------==================================================================== Page 15 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Rajiv A. Patel ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 United States ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 2,531,889 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 2,531,889 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 2,531,889 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 3.5% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 IN ------------==================================================================== Page 16 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Derek C. Schrier ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 United States ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 2,531,889 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 2,531,889 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 2,531,889 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 3.5% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 IN ------------==================================================================== Page 17 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Thomas F. Steyer ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 United States ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 2,531,889 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 2,531,889 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 2,531,889 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 3.5% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 IN ------------==================================================================== Page 18 of 25 Pages 13D =================== CUSIP No. G0450A105 =================== ------------==================================================================== NAMES OF REPORTING PERSONS 1 I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Mark C. Wehrly ------------==================================================================== CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (See Instructions) (a) [ ] (b) [ X ]** 2 ** The reporting persons making this filing hold an aggregate of 2,531,889 Common Shares, which is 3.5% of the class of securities. The reporting person on this cover page, however, is a beneficial owner only of the securities reported by it on this cover page. [See Preliminary Note] ------------==================================================================== 3 SEC USE ONLY ------------==================================================================== SOURCE OF FUNDS (See Instructions) 4 N/A ------------==================================================================== CHECK IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT 5 TO ITEMS 2(d) OR 2(e) [ ] ------------==================================================================== CITIZENSHIP OR PLACE OF ORGANIZATION 6 United States ------------==================================================================== SOLE VOTING POWER 7 NUMBER OF -0- ------------=========================================== SHARES SHARED VOTING POWER BENEFICIALLY 8 OWNED BY 2,531,889 [See Preliminary Note] ------------=========================================== EACH SOLE DISPOSITIVE POWER 9 REPORTING -0- PERSON WITH ------------=========================================== SHARED DISPOSITIVE POWER 10 2,531,889 [See Preliminary Note] ------------==================================================================== AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11 2,531,889 [See Preliminary Note] ------------==================================================================== CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES 12 CERTAIN SHARES (See Instructions) [ ] ------------==================================================================== PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 13 3.5% [See Preliminary Note] ------------==================================================================== TYPE OF REPORTING PERSON (See Instructions) 14 IN ------------==================================================================== Page 19 of 25 Pages This Amendment No. 5 to Schedule 13D amends the Schedule 13D initially filed on April 12, 2002 (collectively, with all amendments thereto, the "Schedule 13D"). Preliminary Note: The Reporting Persons are filing this Schedule 13D with respect to the Common Shares, par value $0.01 per share (the "Common Shares"), of Arch Capital Group Ltd. (the "Company"). As reported in the last Schedule 13D, certain of the Reporting Persons had owned, in aggregate, (i) 1,115,688 Common Shares and (ii) 1,416,201 Series A Convertible Preference Shares (the "Preference A Shares") issued by the Company, each Preference A Share immediately convertible into one Common Share. On December 30, 2005, the Reporting Persons converted all of their Preference A Shares into Common Shares. As of February 16, 2006, the Reporting Persons have not disposed of any of the Common Shares (including Common Shares beneficially owned through ownership of Preference A Shares) reported in the prior Schedule 13D. Due to the additional Common Shares issued by the Company in conjunction with the conversion of Preference A Shares by the Reporting Persons and by other holders of Preference A Shares, the Reporting Persons are now the beneficial holders, in aggregate, of less than 5% of the Common Shares outstanding. Item 3. Source And Amount Of Funds And Other Consideration ------ -------------------------------------------------- Item 3 of the Schedule 13D is amended and supplemented by the following: No consideration was paid by the Reporting Persons with respect to the conversion of their Preference A Shares. Item 5. Interest In Securities Of The Issuer ------ ------------------------------------ Item 5 of the Schedule 13D is amended and restated in its entirety as follows: (a) The Farallon Funds ------------------ (a),(b) The information set forth in Rows 7 through 13 of the cover page hereto for each Farallon Fund is incorporated herein by reference for each such Farallon Fund. The percentage amount set forth in Row 13 for all cover pages filed herewith is calculated based upon the 73,334,870 Common Shares outstanding as of December 31, 2005 as reported by the Company in its Current Report on Form 8-K filed with the Securities and Exchange Commission on February 14, 2006. (c) The trade dates, number of Common Shares purchased or sold and the price per Common Share (including commissions) for all purchases and sales of the Common Shares by the Farallon Funds in the past 60 days are listed below. All of such transactions represent the December 30, 2005 conversion of 100% of each of the Farallon Fund's Preference A Shares into Common Shares. Pursuant to the terms of the Preference A Shares, no consideration was paid with respect to such conversion. Page 20 of 25 Pages Farallon Fund Common Shares Acquired ------------- ---------------------- FCP 916,165 FCIP II 207,292 FCIP III 165,235 Tinicum 1,536 RR 26,272 (d) The Farallon General Partner has the power to direct the receipt of dividends relating to, or the disposition of the proceeds of the sale of, all of the Common Shares held by the Farallon Funds as reported herein. The Farallon Individual Reporting Persons are managing members of the Farallon General Partner. (e) Based on the new Common Share outstanding number reported by the Company on February 14, 2006, as of December 31, 2005, the Farallon Funds were the beneficial holders of less than 5% of the Common Shares. (b) The Management Company ---------------------- (a),(b) The information set forth in Rows 7 through 13 of the cover page hereto for the Management Company is incorporated herein by reference. (c) The trade dates, number of Common Shares purchased or sold and the price per Common Share (including commissions) for all purchases and sales of the Common Shares by the Management Company on behalf of the Managed Account in the past 60 days is listed below. Such transaction represents the conversion of 100% of the Managed Account's Preference A Shares into Common Shares on December 30, 2005. Pursuant to the terms of the Preference A Shares, no consideration was paid with respect to such conversion. Entity Common Shares Acquired ------ ---------------------- Managed 99,701 Account (d) The Management Company has the power to direct the receipt of dividends relating to, or the disposition of the proceeds of the sale of, all of the Common Shares held by the Managed Account as reported herein. The Farallon Individual Reporting Persons are managing members of the Management Company. (e) Based on the new Common Share outstanding number reported by the Company on February 14, 2006, as of December 31, 2005, the Management Company was the beneficial holder of less than 5% of the Common Shares. Page 21 of 25 Pages (c) The Farallon General Partner ---------------------------- (a),(b) The information set forth in Rows 7 through 13 of the cover page hereto for the Farallon General Partner is incorporated herein by reference. (c) None. (d) The Farallon General Partner has the power to direct the receipt of dividends relating to, or the disposition of the proceeds of the sale of, all of the Common Shares held by the Farallon Funds as reported herein. The Farallon Individual Reporting Persons are managing members of the Farallon General Partner. (e) Based on the new Common Share outstanding number reported by the Company on February 14, 2006, as of December 31, 2005, the Farallon General Partner was the beneficial holder of less than 5% of the Common Shares. (d) The Farallon Individual Reporting Persons ----------------------------------------- (a),(b) The information set forth in Rows 7 through 13 of the cover page hereto for each Farallon Individual Reporting Person is incorporated herein by reference for each such Farallon Individual Reporting Person. (c) None. (d) The Farallon General Partner has the power to direct the receipt of dividends relating to, or the disposition of the proceeds of the sale of, all of the Common Shares held by the Farallon Funds as reported herein. The Management Company has the power to direct the receipt of dividends relating to, or the disposition of the proceeds of the sale of, all the Common Shares held by the Managed Account as reported herein. The Farallon Individual Reporting Persons are managing members of both the Farallon General Partner and the Management Company. (e) Based on the new Common Share outstanding number reported by the Company on February 14, 2006, as of December 31, 2005, the Farallon Individual Reporting Persons were the beneficial holders of less than 5% of the Common Shares. The Common Shares reported hereby for the Farallon Funds are owned directly by the Farallon Funds and those reported by the Management Company on behalf of the Managed Account are owned directly by the Managed Account. The Management Company, as investment adviser to the Managed Account, may be deemed to be the beneficial owner of all such Common Shares owned by the Managed Account. The Farallon General Partner, as general partner to the Farallon Funds, Page 22 of 25 Pages may be deemed to be the beneficial owner of all such Common Shares owned by the Farallon Funds. The Farallon Individual Reporting Persons, as managing members of both the Farallon General Partner and the Management Company with the power to exercise investment discretion, may each be deemed to be the beneficial owner of all such Common Shares owned by the Farallon Funds and the Managed Account. Each of the Management Company, the Farallon General Partner and the Farallon Individual Reporting Persons hereby disclaims any beneficial ownership of any such Common Shares. Page 23 of 25 Pages SIGNATURES ---------- After reasonable inquiry and to the best of our knowledge and belief, the undersigned certify that the information set forth in this statement is true, complete and correct. Dated: February 17, 2006 /s/ Monica R. Landry ---------------------------------------- FARALLON PARTNERS, L.L.C., On its own behalf and as the General Partner of FARALLON CAPITAL PARTNERS, L.P., FARALLON CAPITAL INSTITUTIONAL PARTNERS II, L.P., FARALLON CAPITAL INSTITUTIONAL PARTNERS III, L.P., TINICUM PARTNERS, L.P. and RR CAPITAL PARTNERS, L.P. By Monica R. Landry, Managing Member /s/ Monica R. Landry ---------------------------------------- FARALLON CAPITAL MANAGEMENT, L.L.C. By Monica R. Landry, Managing Member /s/ Monica R. Landry ---------------------------------------- Monica R. Landry, individually and as attorney-in-fact for each of Chun R. Ding, William F. Duhamel, Charles E. Ellwein, Richard B. Fried, William F. Mellin, Stephen L. Millham, Rajiv A. Patel, Derek C. Schrier, Thomas F. Steyer and Mark C. Wehrly The Powers of Attorney executed by Duhamel, Fried, Mellin, Millham, Steyer and Wehrly authorizing Landry to sign and file this Schedule 13D on each person's behalf, which were filed with Amendment No. 2 to the Schedule 13D filed with the Securities and Exchange Commission on July 16, 2003, by such Reporting Persons with respect to the Common Stock of New World Restaurant Group, Inc., are hereby incorporated by reference. The Powers of Attorney executed by Ding and Schrier authorizing Landry to sign and file this Schedule 13D on each person's behalf, which were filed with Amendment No. 1 to the Schedule 13D filed with the Securities and Exchange Commission on July 2, 2003, by such Reporting Persons with respect to the Common Stock of Salix Pharmaceuticals, Ltd., are hereby incorporated by reference. The Powers of Attorney executed by Ellwein and Patel authorizing Landry to sign and file this Schedule 13D on each person's behalf, which were filed with Amendment No. 4 to the Schedule 13G filed with the Securities and Exchange Page 24 of 25 Pages Commission on January 8, 2004, by such Reporting Persons with respect to the Common Stock of Catalytica Energy Systems, Inc., are hereby incorporated by reference. Page 25 of 25 Pages