SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549



                                 SCHEDULE 13G/A
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                               (AMENDMENT NO. 11)


                             ARCH CAPITAL GROUP LTD.
             ------------------------------------------------------
                                 (NAME OF ISSUER)


                     COMMON STOCK, $.01 PAR VALUE PER SHARE
             ------------------------------------------------------
                          (TITLE OF CLASS OF SECURITIES)


                                    G0450A105
             ------------------------------------------------------
                                 (CUSIP NUMBER)

     Check the appropriate box to designate the rule pursuant to which this
Schedule is filed:

[x]  Rule 13d-1(b)

[ ]  Rule 13d-1(c)

[ ]  Rule 13d-1(d)


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 the
disclosures provided in a prior cover page.

The information required in 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).





- ------------------------------------------------------------------------------
  1   NAME OF REPORTING PERSONS
      S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS

      THIRD AVENUE MANAGEMENT LLC

      (EIN 01-0690900)

- ------------------------------------------------------------------------------
- ------------------------------------------------------------------------------
  2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
       (a)  [  ]
       (b)  [  ]
- ------------------------------------------------------------------------------
- ------------------------------------------------------------------------------
  3   SEC USE ONLY

- ------------------------------------------------------------------------------
- ------------------------------------------------------------------------------
  4   CITIZENSHIP OR PLACE OF ORGANIZATION

                           DELAWARE LIMITED LIABILITY COMPANY

- ------------------------------------------------------------------------------
- ------------------------------------------------------------------------------
                   5 SOLE VOTING POWER

                           1,846,529
   NUMBER OF     ---------------------------------------------------------------
                 ---------------------------------------------------------------
     SHARES        6  SHARED VOTING POWER
  BENEFICIALLY
    OWNED BY               NONE
                 ---------------------------------------------------------------
                 ---------------------------------------------------------------
      EACH         7  SOLE DISPOSITIVE POWER
   REPORTING
     PERSON                1,918,979

                 ---------------------------------------------------------------
                 ---------------------------------------------------------------
      WITH        8   SHARED DISPOSITIVE POWER

                           NONE
- ------------------------------------------------------------------------------
- ------------------------------------------------------------------------------
 9    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
      PERSON

           1,918,979
- ------------------------------------------------------------------------------
- ------------------------------------------------------------------------------
 10   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES
      CERTAIN SHARES*
             [    ]

- ------------------------------------------------------------------------------
- ------------------------------------------------------------------------------
 11   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

           6.8%
- ------------------------------------------------------------------------------
- ------------------------------------------------------------------------------
 12   TYPE OF REPORTING PERSON*

           IA
- ------------------------------------------------------------------------------

ITEM 1.

     (A) NAME OF ISSUER:

         Arch Capital Ltd. (the "Issuer").

     (B) ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES OR,IF NONE, RESIDENCE:

         20 Horseneck Lane, Greenwich, CT 06830

ITEM 2.

     (A) NAME OF PERSON FILING:

     This schedule is being filed by Third Avenue Management LLC ("TAM").
(TAM is sometimes referred to hereinafter as "Filer").

     (B) ADDRESS OF PRINCIPAL BUSINESS OFFICE:

     The address of the principal executive office of TAM is:
     622 Third Avenue, 32 Floor, New York, New York 10017-2023.

     (C) CITIZENSHIP:

     The citizenship or place of organization of the reporting person is as
follows:

         Delaware Limited Liability Company.

     (D) TITLE OF CLASS OF SECURITIES:

         Common Stock, $.01 par value per share.

     (E) CUSIP NUMBER:

         G0450A105

ITEM 3. IF THIS STATEMENT IS BEING FILED PURSUANT TO RULES 13D-1(B), OR
13D-2(B), CHECK WHETHER THE PERSON FILING IS A:

         (E) Investment Adviser. TAM is registered under Section 203 of the
Investment Advisers Act of 1940.

ITEM 4.  OWNERSHIP.

     (a) & (b) TAM beneficially owns 1,918,979 shares, or 6.8% of the class of
securities of the issuer.

           (c)    (i) 1,846,529

                 (ii) Not applicable.

                (iii) 1,918,979

                 (iv) Not applicable.

ITEM 5.  OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS.

     If this statement is being filed to report the fact that as of the date
hereof the reporting person has ceased to be the beneficial owner of more than
five percent of the class of securities, check the following [ ].

ITEM 6.  OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON.

     Third Avenue Value Fund, an investment company registered under the
Investment Company Act of 1940, has the right to receive dividends from, and
the proceeds from the sale of, 432,300 of the shares reported by TAM, Third
Avenue Small-Cap Value Fund, an investment company registered under the
Investment Company Act of 1940, has the right to receive dividends from, and
the proceeds from the sale of, 280,000 of the shares reported by TAM, Third
Avenue Value Portfolio of the Aegon/Transamerica Series Fund, an investment
company registered under the Investment Company Act of 1940, has the right to
receive dividends from, and the proceeds from the sale of, 285,900 of the
shares reported by TAM, Third Avenue Value Portfolio of the Third Avenue
Variable Series Trust, an investment company registered under the Investment
Company Act of 1940, has the right to receive dividends from, and the proceeds
from the sale of, 113,100 of the shares reported by TAM, AXP Partners Small
Cap Value Fund, an investment company registered under the Investment Company
Act of 1940, has the right to receive dividends from, and the proceeds from the
sale of, 17,600 of the shares reported by TAM, AXP Variable Portfolio Partners
Small Cap Value Fund, an investment company registered under the Investment
Company Act of 1940, has the right to receive dividends from, and the proceeds
from the sale of, 8,000 shares reported by TAM, and Touchstone Varialbe Series
Trust of the Touchstone Third Avenue Value Fund, an investment company
registered under the Investment Company Act of 1940, has the right to receive
dividends from, and the proceeds from the sale of, 50,000 of the shares
reported by TAM. Various separately managed accounts for whom TAM acts as
investment advisor have the right to receive dividends from, and the proceeds
of the sale of, 732,079 of the shares reported by TAM.

ITEM 7. IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE
        SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY.

         Not Applicable.

ITEM 8.  IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP.

         Not applicable.

ITEM 9.  NOTICE OF DISSOLUTION OF GROUP.

         Not applicable.

ITEM 10. CERTIFICATION.

         By signing below I certify that, to the best of my knowledge and
belief, the securities referred to above were acquired in the ordinary course
of business and were not acquired for the purpose of and do not have the effect
of changing or influencing the control of the issuer of such securities and were
not acquired in connection with or as a participant in any transaction having
such purposes or effect.


                                    SIGNATURE

         After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

                            January 9, 2004
                         ---------------------------
                            (Date)




                         THIRD AVENUE MANAGEMENT LLC

                         BY:/S/ MARTIN J. WHITMAN
                            ------------------------
                            Martin J. Whitman
                            Chairman and Co-Chief Investment Officer