================================================================================
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                  SCHEDULE 13D
                                 (Rule 13d-101)

                                (Amendment No. 6)
                                 OPTIBASE, LTD.
                                (Name of Issuer)

           ORDINARY SHARES                              M7524R108
  NOMINAL VALUE NIS 0.13 PER SHARE
   (Title of class of securities)                     (CUSIP number)

                              DAVID P. STONE, ESQ.
                           WEIL, GOTSHAL & MANGES LLP
                                767 FIFTH AVENUE
                               NEW YORK, NY 10153

                  (Name, address and telephone number of person
               authorized to receive notices and communications)


                                OCTOBER 13, 2003
             (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 Rule 13d-1(e), 13d-1(f) or 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 Rule 13d-7 for other parties
to whom copies are to be sent.

                         (Continued on following pages)
                               (Page 1 of 7 Pages)

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----------------------------------- ---------------------------------------------- -------------- ----------------------------------
CUSIP No.                           M7524R108                                           13D                           Page 2 of 7
----------------------------------- ---------------------------------------------- -------------- ----------------------------------
                                                                                                    
------------------------------------------------------------------------------------------------------------------------------------
          1            NAME OF REPORTING PERSON:                                   MOSHE NAMDAR
                       I.R.S. IDENTIFICATION NO.                                                  N/A
                       OF ABOVE PERSON (ENTITIES ONLY):
---------------------- -------------------------------------------------------------------------------------------------------------
          2            CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:                                           (A) [X]
                                                                                                                   (B) [_]
---------------------- -------------------------------------------------------------------------------------------------------------
          3            SEC USE ONLY

---------------------- ------------------------------------- -----------------------------------------------------------------------
          4            SOURCE OF FUNDS:                        PF

---------------------- ------------------------------------------------------------------------------------------------------------
          5            CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
                       TO ITEM 2(d) OR 2(e):                                                                           [_]
---------------------- -------------------------------------------------------------------------- ----------------------------------
          6            CITIZENSHIP OR PLACE OF ORGANIZATION:                                      ISRAELI

----------------------------------- -------- ---------------------------------------------------- ----------------------------------
            NUMBER OF                  7     SOLE VOTING POWER:                                   1,156,274
              SHARES
                                    -------- ---------------------------------------------------- ----------------------------------
           BENEFICIALLY                8     SHARED VOTING POWER:
             OWNED BY
                                    -------- ---------------------------------------------------- ----------------------------------
               EACH                    9     SOLE DISPOSITIVE POWER:                              1,156,274
            REPORTING
                                    -------- ---------------------------------------------------- ----------------------------------
           PERSON WITH                10     SHARED DISPOSITIVE POWER:

---------------------- -------------------------------------------------------------------------- ----------------------------------
         11            AGGREGATE AMOUNT BENEFICIALLY OWNED BY REPORTING PERSON:                   1,668,436 (1)

---------------------- ------------------------------------------------------------------------------------------------------------
         12            CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES:                          [ ]
---------------------- ------------------------------------------------------------------------------------------------------------
         13            PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11):                                    13.48%

---------------------- -------------------------------------------------------------------------- ----------------------------------
         14            TYPE OF REPORTING PERSON:                                                  IN

---------------------- -------------------------------------------------------------------------- ----------------------------------

-----------------------
(1) Mr. Moshe Namdar disclaims beneficial ownership of all ordinary shares that
are owned, may be owned or deemed owned by Mr. Avraham Namdar.


----------------------------------- ---------------------------------------------- -------------- ----------------------------------
CUSIP No.                           M7524R108                                           13D                        Page 3 of 7
----------------------------------- ---------------------------------------------- -------------- ----------------------------------



------------------------------------------------------------------------------------------------------------------------------------
          1            NAME OF REPORTING PERSON:                                   AVRAHAM NAMDAR
                       I.R.S. IDENTIFICATION NO.                                                  N/A
                       OF ABOVE PERSON (ENTITY ONLY):
---------------------- -------------------------------------------------------------------------------------------------------------
          2            CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP:                                           (A) [X]
                                                                                                                   (B) [_]
---------------------- -------------------------------------------------------------------------------------------------------------
          3            SEC USE ONLY

---------------------- ------------------------------------- -----------------------------------------------------------------------
          4            SOURCE OF FUNDS:                      PF

---------------------- -------------------------------------------------------------------------------------------------------------
          5            CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
                       TO ITEM 2(d) OR 2(e):                                                                           [_]
---------------------- ----------------------------------------------------------- -------------------------------------------------
          6            CITIZENSHIP OR PLACE OF ORGANIZATION:                       ISRAELI

----------------------------------- -------- ---------------------------------------------------- ----------------------------------
            NUMBER OF                  7     SOLE VOTING POWER:                                   512,162
              SHARES
                                    -------- ---------------------------------------------------- ----------------------------------
           BENEFICIALLY                8     SHARED VOTING POWER:
             OWNED BY
                                    -------- ---------------------------------------------------- ----------------------------------
               EACH                    9     SOLE DISPOSITIVE POWER:                              512,162
            REPORTING
                                    -------- ---------------------------------------------------- ----------------------------------
           PERSON WITH                10     SHARED DISPOSITIVE POWER:

---------------------- -------------------------------------------------------------------------- ----------------------------------
         11            AGGREGATE AMOUNT BENEFICIALLY OWNED BY REPORTING PERSON:                   1,668,436 (1)

---------------------- -------------------------------------------------------------------------------------------------------------
         12            CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES:                          [ ]

---------------------- -------------------------------------------------------------------------------------------------------------
         13            PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11):                                       13.48%

---------------------- ----------------------------------------------------------- -------------------------------------------------
         14            TYPE OF REPORTING PERSON:                                   IN

---------------------- ----------------------------------------------------------- -------------------------------------------------



----------------------
(1) Mr. Avraham Namdar disclaims beneficial ownership of all ordinary shares
that are owned, may be owned or deemed owned by Mr. Moshe Namdar


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CUSIP No.          M7524R108             13D                       Page 4 of 7
-------------------------------------------------------------------------------

ITEM 1.    SECURITY AND ISSUER

           This Amendment No. 6 ("Amendment No. 6") amends and supplements the
statement on Schedule 13D filed on July 24, 2002 (the "Statement"), as amended
and supplemented by Amendment No. 1, filed on August 1, 2002, Amendment No. 2,
filed on October 3, 2002, Amendment No. 3, filed on November 25, 2002, Amendment
No. 4, filed on December 30, 2002 and Amendment No. 5, filed on February 25,
2003, relating to Ordinary Shares, par value NIS 0.13 per share (the "Ordinary
Shares"), of Optibase Ltd., a corporation organized under the laws of Israel
(the "Issuer") filed on behalf of Messrs. Moshe and Avraham Mandar
(collectively, the "Reporting Persons").

ITEM 5.   INTEREST IN SECURITIES OF THE ISSUER

(a) Mr. Moshe Namdar and Mr. Avraham Namdar are brothers. As a result, each of
the Reporting Persons may be deemed to beneficially own 1,668,436 Ordinary
Shares, or approximately 13.48% of the total outstanding Ordinary Shares (based
on the number of the Issuer's Ordinary Shares outstanding as of June 15, 2003,
of 12,371,206, as stated in the Issuer's report on form 6-K, filed with the
Securities and Exchange Commission on August 15, 2003).

(b) Mr. Moshe Namdar has the power to vote or direct the vote and dispose or
direct the disposition of 1,156,274 Ordinary Shares covered by this Schedule
13D.

           Mr. Avraham Namdar has the power to vote or direct the vote and
dispose or direct the disposition of 512,162 Ordinary Shares covered by this
Schedule 13D.

(c) Transactions in the Ordinary Shares effected by the Reporting Persons since
February 26, 2003 are described in Schedule A attached hereto and incorporated
herein by reference. All such transactions were effected in the open market on
the Nasdaq National Market.

(d), (e)   Not applicable.


ITEM 7.  MATERIAL TO BE FILED AS EXHIBITS

Exhibit No.                     Description
-----------                     -----------

Schedule A          Information concerning transactions in the Ordinary Shares
                    effected by the Reporting Persons






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CUSIP No.         M7524R108               13D                       Page 5 of 7
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                                   SIGNATURE

           After reasonable inquiry and to the best of my knowledge and belief,
I certify that the information set forth in this Amendment No. 6 is true,
complete and correct.

October 23, 2003

                                          Moshe Namdar

                                           /s/ Moshe Namdar
                                          --------------------------------------



                                          Avraham Namdar

                                           /s/ Avraham Namdar
                                          --------------------------------------


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CUSIP No.        M7524R108                13D                      Page 6 of 7
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                                   SCHEDULE A

                 Schedule of Transactions in the Ordinary Shares

1. Sales of Ordinary Shares by Mr. Moshe Namdar:




              DATE OF TRANSACTION                  NUMBER OF SHARES                  PRICE PER SHARE
              -------------------                  ----------------                  ---------------
                                                                     
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                                9,233                          7.5000
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                                8,650                          7.5051
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                                8,100                          7.5100
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                                5,600                          7.5300
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                                6,300                          7.5400
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                                5,000                          7.5460
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                                1,300                          7.5500
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                                  800                          7.5600
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                                7,600                          7.5700
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                                7,889                          7.5800
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                               26,303                          7.5900
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                                4,048                          7.5935
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                                  100                          7.6000
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                                4,300                          7.6100
---------------------------------------- --------------------------------- --------------------------------------
                  10/14/2003                                  500                          7.6300
---------------------------------------- --------------------------------- --------------------------------------
                  10/21/2003                                3,103                          7.3160
---------------------------------------- --------------------------------- --------------------------------------
                  10/21/2003                                6,000                          7.3100
---------------------------------------- --------------------------------- --------------------------------------
                  10/21/2003                                3,900                          7.3900
---------------------------------------- --------------------------------- --------------------------------------

2. Sales of Ordinary Shares by Mr. Avraham Namdar:


              DATE OF TRANSACTION                    NUMBER OF SHARES                    PRICE PER SHARE
              -------------------                    ----------------                    ---------------
------------------------------------------- ------------------------------------- -------------------------------
                     9/4/2003                               25,647                             6.7925
------------------------------------------- ------------------------------------- -------------------------------
                     9/4/2003                               22,300                             6.7957
------------------------------------------- ------------------------------------- -------------------------------
                     9/7/2003                                2,800                             7.0500
------------------------------------------- ------------------------------------- -------------------------------
                    9/10/2003                                3,000                             6.5000
------------------------------------------- ------------------------------------- -------------------------------
                    9/11/2003                                  900                             6.4000
------------------------------------------- ------------------------------------- -------------------------------
                    9/11/2003                                  400                             6.5000
------------------------------------------- ------------------------------------- -------------------------------
                    9/12/2003                                  500                             6.3000
------------------------------------------- ------------------------------------- -------------------------------
                    9/12/2003                                2,400                             6.3500
------------------------------------------- ------------------------------------- -------------------------------
                    9/12/2003                                2,000                             6.4000
------------------------------------------- ------------------------------------- -------------------------------
                    9/14/2003                               19,638                             6.2002
------------------------------------------- ------------------------------------- -------------------------------
                    9/15/2003                                2,053                             6.7925
------------------------------------------- ------------------------------------- -------------------------------
                    10/13/2003                               5,000                             7.2600
------------------------------------------- ------------------------------------- -------------------------------
                    10/13/2003                               5,000                             7.3100
------------------------------------------- ------------------------------------- -------------------------------
                    10/13/2003                               9,050                             7.3400
------------------------------------------- ------------------------------------- -------------------------------
                    10/13/2003                               6,242                             7.3600
------------------------------------------- ------------------------------------- -------------------------------
                    10/13/2003                               6,450                             7.3700
------------------------------------------- ------------------------------------- -------------------------------
                    10/13/2003                              10,500                             7.3800
------------------------------------------- ------------------------------------- -------------------------------
                    10/13/2003                                 300                             7.3810
------------------------------------------- ------------------------------------- -------------------------------
                    10/13/2003                               5,800                             7.3900
------------------------------------------- ------------------------------------- -------------------------------
                    10/13/2003                              10,000                             7.4000
------------------------------------------- ------------------------------------- -------------------------------
                    10/13/2003                               3,850                             7.4100
------------------------------------------- ------------------------------------- -------------------------------


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CUSIP No.        M7524R108                13D                      Page 7 of 7
-------------------------------------------------------------------------------

              DATE OF TRANSACTION                    NUMBER OF SHARES                    PRICE PER SHARE
              -------------------                    ----------------                    ---------------
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                   2,550                             7.4200
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                   7,600                             7.4300
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                  22,128                             7.4400
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                   2,116                             7.4500
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                     500                             7.4600
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                     800                             7.4800
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                  23,600                             7.4900
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                  14,900                             7.5000
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                   3,000                             7.5100
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                     100                             7.5400
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                   5,000                             7.0262
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                   5,000                             7.1210
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                   5,000                             7.2000
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                   3,200                             7.2000
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                   1,800                             7.1200
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                  10,000                             7.2600
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                   3,900                             7.5200
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                   1,100                             7.3700
------------------------------------------- ----------------------------------------- -------------------------------
                    10/13/2003                                     500                             7.2700
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   2,000                             7.5200
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   5,000                             7.4200
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   5,000                             7.4488
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                  10,000                             7.4700
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   5,800                             7.4800
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   2,200                             7.4800
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                  10,000                             7.5100
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   4,500                             7.5014
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   4,700                             7.4113
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   9,000                             7.4400
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   3,300                             7.4402
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   3,650                             7.4800
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   1,450                             7.4845
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   1,000                             7.4860
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   2,950                             7.4897
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   9,900                             7.4900
------------------------------------------- ----------------------------------------- -------------------------------
                    10/14/2003                                   5,067                             7.5000
------------------------------------------- ----------------------------------------- -------------------------------
                    10/15/2003                                   1,800                             7.4800
------------------------------------------- ----------------------------------------- -------------------------------
                    10/15/2003                                   1,550                             7.1900
------------------------------------------- ----------------------------------------- -------------------------------
                    10/15/2003                                     500                             7.2000
------------------------------------------- ----------------------------------------- -------------------------------
                    10/15/2003                                   2,800                             7.2100
------------------------------------------- ----------------------------------------- -------------------------------
                    10/15/2003                                     100                             7.5100
------------------------------------------- ----------------------------------------- -------------------------------
                    10/15/2003                                   3,500                             7.5200
------------------------------------------- ----------------------------------------- -------------------------------
                    10/15/2003                                   2,850                             7.5300
------------------------------------------- ----------------------------------------- -------------------------------
                    10/15/2003                                   2,800                             7.5400
------------------------------------------- ----------------------------------------- -------------------------------
                    10/20/2003                                   7,800                             7.3096
------------------------------------------- ----------------------------------------- -------------------------------
                    10/21/2003                                  16,297                             7.3160
------------------------------------------- ----------------------------------------- -------------------------------