CONFORMED COPY


                       SECURITIES AND EXCHANGE COMMISSION
                              Washington D.C. 20549


                                    FORM 6-K

                        REPORT OF FOREIGN PRIVATE ISSUER
                      Pursuant to Rule 13a-16 or 15d-16 of
                       the Securities Exchange Act of 1933



                          For the month of August 2005




                                BANCOLOMBIA S.A.
                                ----------------
                 (Translation of Registrant's name into English)


                               Calle 50 No. 51-66
                               Medellin, Colombia
                               ------------------
                    (Address of principal executive offices)




(Indicate by check mark whether the registrant files or will file annual reports
under cover of Form 20-F or Form 40-F.)

         Form 20-F      X                   Form 40-F            
                   -----------                        -----------

(Indicate by check mark whether the  registrant  by furnishing  the  information
contained  in this  form is  also  thereby  furnishing  the  information  to the
Commission  pursuant to Rule  12g3-2(b)  under the  Securities  Exchange  Act of
1934.)


         Yes                                No             X     
                   -----------                        ------------

(If "Yes" is marked,  indicate below the file number  assigned to the registrant
in connection with Rule 12g3-2(b): 82-______________.)

     This  Report  on Form  6-K  shall be  incorporated  by  reference  into the
     registrant's registration statement on Form F-3 (File No. 001-32535).

                                    SIGNATURE

     Pursuant to the  requirements  of the Securities  Exchange Act of 1934, the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned, thereunto duly authorized.

                                               BANCOLOMBIA S.A.
                                                 (Registrant)


Date: August 4, 2005                By  /s/  JAIME ALBERTO VELASQUEZ B.  
                                       ----------------------------------
                                       Name:  Jaime Alberto Velasquez B.
                                       Title:    Vice President of Finance

                            [BANCOLOMBIA LETTERHEAD]


             PRINCIPAL SHAREHOLDERS OF BANCOLOMBIA AFTER THE MERGER


In accordance with request 20058-78 issued by the  Superintendency of Securities
of Colombia, we hereby disclose the 20 largest shareholders of Bancolombia after
the merger,  indicating  the number of common and  preferred  shares of the bank
each of them  currently  holds and showing the  approximate  number of shares of
Bancolombia  they have the right to receive in exchange for the shares they held
in Conavi Banco Comercial y de Ahorros S.A. and Corporacion  Financiera Nacional
Y Suramericana S.A. Corfinsura (post spin-off), as a result of the merger.



                                                                                   APPROXIMATE
                                                                                    NUMBER OF                     
                                                                                  SHARES OF BC                    APPROXIMATE
                                                                                 TO BE RECEIVED     APPROXIMATE    PERCENTAGE
                                       ID           COMMON          PREFERRED        IN THE        TOTAL SHARES   OWNERSHIP OF
               NAME                  NUMBER      SHARES OF BC      SHARES OF BC     EXCHANGE            BC             BC
                                                                                                     
BIC ADR PROGRAM FIDUBIC             811001966                      106,162,095                     106.162.095       14,59%
PORTAFOLIO DE INVERSIONES
SURAMERICANA S.A                    811011258      50.846.918              --      25.289.748       76.136.666       10,46%
SURAMERICANA DE INVERSIONES S.A
SURAMERICANA                        811012271      33.890.197              --      26.848.528       60.738.725        8,35%
FIDEICOMISO CITITRUST-                                         
SURAMERICANA-IFC                    830054054      39.341.408                                       39.341.408        5,41%
CIA. DE CEMENTO ARGOS S.A           890900266      22.713.097       3,386,177       8.734.574       34.833.848        4,79%
CEMENTOS DEL VALLE S.A              890300437      29.658.125       4,120,038         951.126       34.729.289        4,77%
FONDO DE PENSIONES
OBLIGATORIAS PROTECCION             800229739       5.554.187      22,856,020         243.210       28.653.417        3,94%
INVERSIONES SPC S.A                 811033992      26.626.931                                       26.626.931        3,66%
EMMERY EQUITY CORPORATION           830064913      24,387,619                                       24,387,619        3.35%
HOLDING MERCANTIL
COLOMBIANA C.A                      830018206      22,386,979                                       22,386,979        3.08%
LORANGE INDUSTRIAL
CORPORATION                         830064912      20,612,331                                       20,612,331        2.83%
IN VALKIRIA Y CIA S EN C            811046705       7,434,799              --       8,069,420       15,504,219        2.13%
CIA. SURAMERICANA DE
CONSTRUCCIONES S.A                  890903406       7,864,587              --       3,860,233       11,724,820        1.61%
CIA. SURAMERICANA
DE SEGUROS S.A                      890903407       2,987,671              --       6,658,481        9,646,152        1.33%
INTERNATIONAL FINANCE
CORPORATION-IFC                     830053770                                       9,358,802        9,358,802        1.29%
FONDO DE PENSIONES
OBLIGATORIAS HORIZONTE              800231967       4,342,711       2,771,775       2,038,095        9,152,581        1.26%
CONSTRUCCIONES E
INVERSIONES LA PAULITA SA           811031355                                       9,012,780        9,012,780        1.24%
INVERSIONES ALASKA S.A              830505757                                       9,012,780        9,012,780        1.24%
MERCANTIL INVERSIONES Y
VALORES                             830131174       8,629,735                                        8,629,735        1.19%
FONDO DE PENSIONES
OBLIGATORIAS COLFONDOS              800227940       2,756,816       3,961,738         978,910        7,697,464        1.06%

Approximate total number of shares of BANCOLOMBIA
(Not accounting for cash payments for fractional shares)                                                        727,829,109
 

* In accordance with the Meger Agreement  approved by the General  Shareholders'
Meetings of the merged entities,  shareholders of Conavi and Corfinsura are able
to choose the class of shares of  Bancolombia  (common  or non voting  preferred
shares) to be received in the  exchange for their  Conavi or  Corfinsura  shares
within the three months following the completion of the merger.

The three-month  term  established  for the share exchange  started on August 1,
2005 and ends on October 31, 2005.  Once this term has expired,  shareholders of
Conavi and  Corfinsura  who did not exercise  their right to choose the class or
shares of Bancolombia to be received in the exchange will receive common shares.

Additionally,  the  number  of  shares  of  Bancolombia  used as a base  for the
preparation of this information does not take into account cash payments for the
fractional shares of Bancolombia that result from the exchange.

For the  foregoing  reasons,  the  information  hereby  disclosed  represents an
estimate.  The  capital  structure  of  BANCOLOMBIA  post-merger,  the number of
outstanding  shares and the total  number of ordinary and  preferred  shares can
only be known once the share exchange term has expired.

** This information is based on Bancolombia's capital structure at July 11, 2005
and Conavi's and Corfinsura's capital structure at July 29, 2005.

*** In accordance  with the  requirement of the  Superintendency  of Securities,
this  information  corresponds to the 20 largest  shareholders  of  Bancolombia,
considered individually, and does not take into account the beneficial owners of
these shares.