SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

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

                                 SCHEDULE 13G/A

             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
           TO RULES 13d-1(b), (c) AND (d) AND AMENDMENTS THERETO FILED
                            PURSUANT TO RULE 13d-2(b)

                                 Amendment No. 3


                                   MADECO S.A.
                                (Name of Issuer)


                                  Common Shares
                         (Title of Class of Securities)


                                    556304103
                                 (CUSIP Number)

                                   August 2005
             (Date of Event Which Requires Filing of this Statement)

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

      |_|   Rule 13d-1(b)
      |_|   Rule 13d-1(c)
      |X|   Rule 13d-1(d)




-------------------                                           ------------------
CUSIP No. 556304103                                           Page 2 of 15 Pages
-------------------                                           ------------------

--------------------------------------------------------------------------------
1.   NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Luksburg Foundation
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                         (a) |X|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY


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

     Liechtenstein
--------------------------------------------------------------------------------
               5.   SOLE VOTING POWER

                    3,010
               -----------------------------------------------------------------
 NUMBER OF     6.   SHARED VOTING POWER
   SHARES
BENEFICIALLY        2,557,163,035
  OWNED BY     -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER
 REPORTING
   PERSON           3,010
    WITH       -----------------------------------------------------------------
               8.   SHARED DISPOSITIVE POWER

                    2,557,163,035
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     2,557,144,639 (individually)
     2,557,163,035 (total group shares)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                             |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     47.8% (individually)
     47.8% (total group shares)
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON

     (HC)
--------------------------------------------------------------------------------


                                        2


-------------------                                           ------------------
CUSIP No. 556304103                                           Page 3 of 15 Pages
-------------------                                           ------------------

--------------------------------------------------------------------------------
1.   NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Guillermo Luksic Craig
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                         (a) |X|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY


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

     Chile
--------------------------------------------------------------------------------
               5.   SOLE VOTING POWER

               -----------------------------------------------------------------
 NUMBER OF     6.   SHARED VOTING POWER
   SHARES
BENEFICIALLY        2,557,163,035
  OWNED BY     -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER
  REPORTING
   PERSON
    WITH       -----------------------------------------------------------------
               8.   SHARED DISPOSITIVE POWER

                    2,557,163,035
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     2,557,141,629(individually)
     2,557,163,035(total group shares)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                             |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     47.8% (individually)
     47.8% (total group shares)
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON

     (IN)
--------------------------------------------------------------------------------


                                        3


-------------------                                           ------------------
CUSIP No. 556304103                                           Page 4 of 15 Pages
-------------------                                           ------------------

--------------------------------------------------------------------------------
1.   NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Nicolas Luksic Puga
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                         (a) |X|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY


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

     Chile
--------------------------------------------------------------------------------
               5.   SOLE VOTING POWER

                    110
               -----------------------------------------------------------------
 NUMBER OF     6.   SHARED VOTING POWER
   SHARES
BENEFICIALLY        2,557,163,035
  OWNED BY     -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER
  REPORTING
   PERSON           110
    WITH       -----------------------------------------------------------------
               8.   SHARED DISPOSITIVE POWER

                    2,557,163,035
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     2,557,141,739 (individually)
     2,557,163,035 (total group shares)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                             |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     47.8% (individually)
     47.8% (total group shares)
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON

     (IN)
--------------------------------------------------------------------------------


                                        4


-------------------                                           ------------------
CUSIP No. 556304103                                           Page 5 of 15 Pages
-------------------                                           ------------------

--------------------------------------------------------------------------------
1.   NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Inmobiliaria e Inversiones Rio Claro S.A.
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                         (a) |X|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY


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

     Chile
--------------------------------------------------------------------------------
               5.   SOLE VOTING POWER

               -----------------------------------------------------------------
 NUMBER OF     6.   SHARED VOTING POWER
   SHARES
BENEFICIALLY        2,557,163,035
  OWNED BY     -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER
 REPORTING
   PERSON
    WITH       -----------------------------------------------------------------
               8.   SHARED DISPOSITIVE POWER

                    2,557,163,035
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     2,557,141,629 (individually)
     2,557,163,035 (total group shares)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                             |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     47.8% (individually)
     47.8% (total group shares)
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON

     (HC)
--------------------------------------------------------------------------------


                                        5


-------------------                                           ------------------
CUSIP No. 556304103                                           Page 6 of 15 Pages
-------------------                                           ------------------

--------------------------------------------------------------------------------
1.   NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Andronico Luksic Craig
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                         (a) |X|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY


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

     Chile
--------------------------------------------------------------------------------
               5.   SOLE VOTING POWER

               -----------------------------------------------------------------
 NUMBER OF     6.   SHARED VOTING POWER
   SHARES
BENEFICIALLY        2,557,163,035
  OWNED BY     -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER
 REPORTING
   PERSON
    WITH       -----------------------------------------------------------------
               8.   SHARED DISPOSITIVE POWER

                    2,557,163,035
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     2,557,141,629 (individually)
     2,557,163,035 (total group shares)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                             |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     47.8% (individually)
     47.8% (total group shares)
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON

     (IN)
--------------------------------------------------------------------------------


                                        6


-------------------                                           ------------------
CUSIP No. 556304103                                           Page 7 of 15 Pages
-------------------                                           ------------------

--------------------------------------------------------------------------------
1.   NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Patricia Lederer Tcherniak
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                         (a) |X|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY


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

     Chile
--------------------------------------------------------------------------------
               5.   SOLE VOTING POWER

               -----------------------------------------------------------------
 NUMBER OF     6.   SHARED VOTING POWER
   SHARES
BENEFICIALLY        2,557,163,035
  OWNED BY     -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER
  REPORTING
   PERSON
    WITH       -----------------------------------------------------------------
               8.   SHARED DISPOSITIVE POWER

                    2,557,163,035
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     2,557,141,629 (individually)
     2,557,163,035 (total group shares)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                             |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     47.8% (individually)
     47.8% (total group shares)
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON

     (IN)
--------------------------------------------------------------------------------


                                        7


-------------------                                           ------------------
CUSIP No. 556304103                                           Page 8 of 15 Pages
-------------------                                           ------------------

--------------------------------------------------------------------------------
1.   NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Inversiones Consolidadas S.A.
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                         (a) |X|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY


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

     Chile
--------------------------------------------------------------------------------
               5.   SOLE VOTING POWER

                    18,286
               -----------------------------------------------------------------
 NUMBER OF     6.   SHARED VOTING POWER
   SHARES
BENEFICIALLY        2,557,163,035
  OWNED BY     -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER
  REPORTING
   PERSON           18,286
    WITH       -----------------------------------------------------------------
               8.   SHARED DISPOSITIVE POWER

                    2,557,163,035
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     2,557,159,915 (individually)
     2,557,163,035 (total group shares)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                             |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     47.8% (individually)
     47.8% (total group shares)
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON

     (HC)
--------------------------------------------------------------------------------


                                        8


-------------------                                           ------------------
CUSIP No. 556304103                                           Page 9 of 15 Pages
-------------------                                           ------------------

--------------------------------------------------------------------------------
1.   NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Andronico Luksic Lederer
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                         (a) |X|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY


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

     Chile
--------------------------------------------------------------------------------
               5.   SOLE VOTING POWER

               -----------------------------------------------------------------
 NUMBER OF     6.   SHARED VOTING POWER
   SHARES
BENEFICIALLY        2,557,163,035
  OWNED BY     -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER
  REPORTING
   PERSON
    WITH       -----------------------------------------------------------------
               8.   SHARED DISPOSITIVE POWER

                    2,557,163,035
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     2,557,141,629 (individually)
     2,557,163,035 (total group shares)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                             |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     47.8% (individually)
     47.8% (total group shares)
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON

     (IN)
--------------------------------------------------------------------------------


                                        9


-------------------                                          -------------------
CUSIP No. 556304103                                          Page 10 of 15 Pages
-------------------                                          -------------------

--------------------------------------------------------------------------------
1.   NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Davor Luksic Lederer
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                         (a) |X|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY


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

     Chile
--------------------------------------------------------------------------------
               5.   SOLE VOTING POWER

               -----------------------------------------------------------------
 NUMBER OF     6.   SHARED VOTING POWER
   SHARES
BENEFICIALLY        2,557,163,035
  OWNED BY     -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER
  REPORTING
   PERSON
    WITH       -----------------------------------------------------------------
               8.   SHARED DISPOSITIVE POWER

                    2,557,163,035
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     2,557,141,629 (individually)
     2,557,163,035 (total group shares)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                             |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     47.8% (individually)
     47.8% (total group shares)
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON

     (IN)
--------------------------------------------------------------------------------


                                       10


-------------------                                          -------------------
CUSIP No. 556304103                                          Page 11 of 15 Pages
-------------------                                          -------------------

--------------------------------------------------------------------------------
1.   NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Max Luksic Lederer
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                         (a) |X|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY


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

     Chile
--------------------------------------------------------------------------------
               5.   SOLE VOTING POWER

               -----------------------------------------------------------------
 NUMBER OF     6.   SHARED VOTING POWER
   SHARES
BENEFICIALLY        2,557,163,035
  OWNED BY     -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER
  REPORTING
   PERSON
    WITH       -----------------------------------------------------------------
               8.   SHARED DISPOSITIVE POWER

                    2,557,163,035
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     2,557,141,629 (individually)
     2,557,163,035 (total group shares)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                             |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     47.8% (individually)
     47.8% (total group shares)
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON

     (IN)
--------------------------------------------------------------------------------


                                       11


-------------------                                          -------------------
CUSIP No. 556304103                                          Page 12 of 15 Pages
-------------------                                          -------------------

--------------------------------------------------------------------------------
1.   NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Dax Luksic Lederer
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                         (a) |X|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY


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

     Chile
--------------------------------------------------------------------------------
               5.   SOLE VOTING POWER

               -----------------------------------------------------------------
 NUMBER OF     6.   SHARED VOTING POWER
   SHARES
BENEFICIALLY        2,557,163,035
  OWNED BY     -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER
  REPORTING
   PERSON
    WITH       -----------------------------------------------------------------
               8.   SHARED DISPOSITIVE POWER

                    2,557,163,035
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     2,557,141,629 (individually)
     2,557,163,035 (total group shares)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                             |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     47.8% (individually)
     47.8% (total group shares)
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON

     (IN)
--------------------------------------------------------------------------------


                                       12


-------------------                                          -------------------
CUSIP No. 556304103                                          Page 13 of 15 Pages
-------------------                                          -------------------

--------------------------------------------------------------------------------
1.   NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Inversiones Salta S.A.
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                         (a) |X|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY


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

     Chile
--------------------------------------------------------------------------------
               5.   SOLE VOTING POWER

               -----------------------------------------------------------------
 NUMBER OF     6.   SHARED VOTING POWER
   SHARES
BENEFICIALLY        2,557,163,035
  OWNED BY     -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER
  REPORTING
   PERSON
    WITH       -----------------------------------------------------------------
               8.   SHARED DISPOSITIVE POWER

                    2,557,163,035
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     2,557,141,629 (individually)
     2,557,163,035 (total group shares)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                             |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     47.8% (individually)
     47.8% (total group shares)
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON

     (HC)
--------------------------------------------------------------------------------


                                       13


-------------------                                          -------------------
CUSIP No. 556304103                                          Page 14 of 15 Pages
-------------------                                          -------------------

--------------------------------------------------------------------------------
1.   NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Quinenco S.A.
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                         (a) |X|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY


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

     Chile
--------------------------------------------------------------------------------
               5.   SOLE VOTING POWER

               -----------------------------------------------------------------
 NUMBER OF     6.   SHARED VOTING POWER
   SHARES
BENEFICIALLY        2,557,141,629
  OWNED BY     -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER
  REPORTING
   PERSON
    WITH       -----------------------------------------------------------------
               8.   SHARED DISPOSITIVE POWER

                    2,557,141,629
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     2,557,141,629 (individually)
     2,557,163,035 (total group shares)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                             |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     47.8% (individually)
     47.8% (total group shares)
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON

     (CO)
--------------------------------------------------------------------------------


                                       14


-------------------                                          -------------------
CUSIP No. 556304103                                          Page 15 of 15 Pages
-------------------                                          -------------------

--------------------------------------------------------------------------------
1.   NAMES OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)

     Inversiones Rio Grande S.A.
--------------------------------------------------------------------------------
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                                         (a) |X|
                                                                         (b) |_|
--------------------------------------------------------------------------------
3.   SEC USE ONLY


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

     Chile
--------------------------------------------------------------------------------
               5.   SOLE VOTING POWER

               -----------------------------------------------------------------
 NUMBER OF     6.   SHARED VOTING POWER
   SHARES
BENEFICIALLY        287,359,836
  OWNED BY     -----------------------------------------------------------------
    EACH       7.   SOLE DISPOSITIVE POWER
  REPORTING
   PERSON
    WITH       -----------------------------------------------------------------
               8.   SHARED DISPOSITIVE POWER

                    287,359,836
--------------------------------------------------------------------------------
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     287,359,836 (individually)
     2,557,163,035 (total group shares)
--------------------------------------------------------------------------------
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
                                                                             |_|
--------------------------------------------------------------------------------
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

     5.4% (individually)
     47.8% (total group shares)
--------------------------------------------------------------------------------
12.  TYPE OF REPORTING PERSON

     (HC)
--------------------------------------------------------------------------------


                                       15


Item 2(a).  Name of Persons Filing:

      Item 2(a) of the Schedule 13G is hereby amended in its entirety as
follows:

      This statement is being filed by the Luksburg Foundation, Guillermo Luksic
Craig, Nicolas Luksic Puga, Inmobiliaria e Inversiones Rio Claro S.A., Andronico
Luksic Craig, Patricia Lederer Tcherniak, Inversiones Consolidadas S.A.,
Andronico Luksic Lederer, Davor Luksic Lederer, Max Luksic Lederer, Dax Luksic
Lederer, Inversiones Salta S.A., Quinenco S.A. and Inversiones Rio Grande S.A.

Item 2(b).  Address of Principal Business Office or, if None, Residence:

            Item 2(b) of the Schedule 13G is hereby amended in its entirety as
            follows:

            The address of the principal business office (or, if none, the
            residence) of each person filing this Schedule is as follows:

            The Luksburg Foundation has its principal business address at
            Heiligkreuz 6, FL-9490 Vaduz, Liechtenstein;

            Guillermo Luksic Craig resides in Chile and has his principal
            business address at Enrique Foster Sur 20, 16th Floor, Santiago,
            Chile;

            Nicolas Luksic Puga resides in Chile and has his principal business
            address at Enrique Foster Sur 20, 18th Floor, Las Condes, Santiago,
            Republic of Chile;

            Inmobiliaria e Inversiones Rio Claro S.A. is located at Enrique
            Foster Sur 20, 18th Floor, Santiago, Chile;

            Andronico Luksic Craig resides in Chile and has his principal
            business address at Enrique Foster Sur 20, 16th Floor, Santiago,
            Chile;

            Patricia Lederer Tcherniak resides in Chile and has her principal
            business address at Enrique Foster Sur 20, 18th Floor, Santiago,
            Chile;

            Inversiones Consolidadas S.A. is located at Enrique Foster Sur 20,
            18th Floor, Santiago, Chile;

            Andronico Luksic Lederer resides in Chile and has his principal
            business address at Enrique Foster Sur 20, 18th Floor, Las Condes,
            Santiago, Chile;

            Davor Luksic Lederer resides in Chile and has his principal business
            address at Enrique Foster Sur 20, 18th Floor, Las Condes, Santiago,
            Chile;


                                       16


            Max Luksic Lederer (minor), son of Andronico Luksic Craig and
            Patricia Lederer Tcherniak, resides in Chile and has his principal
            business address at Enrique Foster Sur 20, 18th Floor, Las Condes,
            Santiago, Chile;

            Dax Luksic Lederer (minor), son of Andronico Luksic Craig and
            Patricia Lederer Tcherniak, resides in Chile and has his principal
            business address at Enrique Foster Sur 20, 18th Floor, Las Condes,
            Santiago, Chile;

            Inversiones Salta S.A. is located at Enrique Foster Sur 20, 18th
            Floor, Santiago, Chile;

            Quinenco S.A. is located at Enrique Foster Sur 20, 14th Floor, Las
            Condes, Santiago, Chile; and

            Inversiones Rio Grande S.A. is located at Enrique Foster Sur 20,
            14th Floor, Las Condes, Santiago, Chile.

Item 2(c).  Citizenship:

            Item 2(c) of the Schedule 13G is hereby amended in its entirety as
            follows:

            See item 4 on Page 2
            See item 4 on Page 3
            See item 4 on Page 4
            See item 4 on Page 5
            See item 4 on Page 6
            See item 4 on Page 7
            See item 4 on Page 8
            See item 4 on Page 9
            See item 4 on Page 10
            See item 4 on Page 11
            See item 4 on Page 12
            See item 4 on Page 13
            See item 4 on Page 14
            See item 4 on Page 15

Item 4.     Ownership

            Item 4 of the Schedule 13G is hereby amended in its entirety as
            follows:

            (a)   Amount beneficially owned:

                  See item 9 on Page 2
                  See item 9 on Page 3
                  See item 9 on Page 4


                                       17


                  See item 9 on Page 5
                  See item 9 on Page 6
                  See item 9 on Page 7
                  See item 9 on Page 8
                  See item 9 on Page 9
                  See item 9 on Page 10
                  See item 9 on Page 11
                  See item 9 on Page 12
                  See item 9 on Page 13
                  See item 9 on Page 14
                  See item 9 on Page 15

            (b)   Percent of class:

                  See item 11 on Page 2
                  See item 11 on Page 3
                  See item 11 on Page 4
                  See item 11 on Page 5
                  See item 11 on Page 6
                  See item 11 on Page 7
                  See item 11 on Page 8
                  See item 11 on Page 9
                  See item 11 on Page 10
                  See item 11 on Page 11
                  See item 11 on Page 12
                  See item 11 on Page 13
                  See item 11 on Page 14
                  See item 11 on Page 15
                  See item 11 on Page 16

            (c)   Number of shares as to which such person has:

                  (i)      Sole power to vote or to direct the vote:

                           See item 5 on Page 2
                           See item 5 on Page 4
                           See item 5 on Page 8

                  (ii)     Shared power to vote or to direct the vote:

                           See item 6 on Page 2
                           See item 6 on Page 3
                           See item 6 on Page 4
                           See item 6 on Page 5
                           See item 6 on Page 6
                           See item 6 on Page 7


                                       18


                           See item 6 on Page 8
                           See item 6 on Page 9
                           See item 6 on Page 10
                           See item 6 on Page 11
                           See item 6 on Page 12
                           See item 6 on Page 13
                           See item 6 on Page 14
                           See item 6 on Page 15

                  (iii)    Sole power to dispose or to direct the disposition
                           of:

                           See item 7 on Page 2
                           See item 7 on Page 4
                           See item 7 on Page 8

                  (iv)     Shared power to dispose or to direct the disposition
                           of:

                           See item 8 on Page 2
                           See item 8 on Page 3
                           See item 8 on Page 4
                           See item 8 on Page 5
                           See item 8 on Page 6
                           See item 8 on Page 7
                           See item 8 on Page 8
                           See item 8 on Page 9
                           See item 8 on Page 10
                           See item 8 on Page 11
                           See item 8 on Page 12
                           See item 8 on Page 13
                           See item 8 on Page 14
                           See item 8 on Page 15

Item 7.     Identification and Classification of the Subsidiary Which Acquired
            the Security Being Reported on by the Parent Holding Company.

            Item 7 of the Schedule 13G is hereby amended in its entirety as
            follows:

            See Exhibit B.

Item 8.     Identification and Classification of Members of the Group.

            Item 8 of the Schedule 13G is hereby amended in its entirety as
            follows:

            See Exhibit C.


                                       19


                                    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.


Date: March 17, 2006


Luksburg Foundation


By:  /s/ Guillermo Luksic Craig
    -------------------------------------
Name: Guillermo Luksic Craig


By:  /s/ Jean-Paul Luksic Fontbona
    -------------------------------------
Name: Jean-Paul Luksic Fontbona


Quinenco S.A.
Inversiones Rio Grande S.A.


By: /s/ Luis Fernando Antunez Bories
    -------------------------------------
    Name: Luis Fernando Antunez Bories
    Title: Attorney-In-Fact


Guillermo Luksic Craig
Nicolas Luksic Puga
Immobiliaria e Inversiones Rio Claro S.A.


By:  /s/ Mario Garrido Taraba
    -------------------------------------
    Name: Mario Garrido Taraba
    Title: Attorney-In-Fact


                                       20


Andronico Luksic Craig
Patricia Lederer Tcherniak
Inversiones Consolidadas S.A.
Andronico Luksic Lederer
Davor Luksic Lederer
Max Luksic Lederer
Dax Luksic Lederer
Inversiones Salta S.A.


By:  /s/ Rodrigo Terre Fontbona
    -------------------------------------
    Name: Rodrigo Terre Fontbona
    Title: Attorney-In-Fact


                                       21


                                  EXHIBIT INDEX

Exhibit        Description                                                 Page
-------        -----------                                                 ----

Exhibit A      1.   Joint Filing Agreement of Luksburg Foundation
                    (together with power of attorney) ...................    23

               2.   Joint Filing Agreement of Quinenco S.A. and
                    Inversiones Rio Grande S.A. .........................    24

               3.   Joint Filing Agreement of Guillermo Luksic
                    Craig, Nicolas Luksic Puga and Inmobiliaria e
                    Inversiones Rio Claro S.A. ..........................    25

               4.   Joint Filing Agreement of Andronico Luksic
                    Craig, Patricia Lederer Tcherniak, Inversiones
                    Consolidadas S.A., Andronico Luksic Lederer,
                    Davor Luksic Lederer, Max Luksic Lederer, Dax
                    Luksic Lederer and Inversiones Salta S.A. ...........    26

Exhibit B      Entities Owned by the Luksburg Foundation ................    27

Exhibit C      Identification of Members of a Group .....................    28


                                       22


                                                   Exhibit A-1 to Schedule 13G/A

      1. The undersigned persons (the "Reporting Persons") hereby agrees that a
joint statement of this schedule 13G/A, and any amendments thereto, be filed on
his behalf by Guillermo Luksic Craig, whose address is Enrique Foster Sur 20,
16th Floor, Santiago, Chile and Jean-Paul Luksic Fontbona, whose address is
Ahumada 11, 10th Floor, Santiago, Chile.

      Each of the Reporting Persons is responsible for the completeness and
accuracy of the information concerning each of the items contained therein, but
none of the Reporting Persons is responsible for the completeness or accuracy of
the information concerning any other Reporting Person.

Date: March 17, 2006


                                       Luksburg Foundation


                                       By: /s/ Guillermo Luksic Craig
                                           --------------------------------
                                       Name: Guillermo Luksic Craig


                                       By: /s/ Jean-Paul Luksic Fontbona
                                           --------------------------------
                                       Name: Jean-Paul Luksic Fontbona


                                       23


                                                   Exhibit A-2 to Schedule 13G/A

      2. The undersigned persons (the "Reporting Persons") hereby agree that a
joint statement of this schedule 13G/A, and any amendments thereto, be filed on
their behalf by Luis Fernando Antunez Bories, whose address is Enrique Foster
Sur 20, piso 14, Las Condes, Santiago, Chile.

      Each of the Reporting Persons is responsible for the completeness and
accuracy of the information concerning each of the items contained therein, but
none of the Reporting Persons is responsible for the completeness or accuracy of
the information concerning any other Reporting Person.

Date: March 17, 2006


                                       Quinenco S.A
                                       Inversiones Rio Grande S.A.


                                       By: /s/ Luis Fernando Antunez Bories
                                           --------------------------------
                                       Name: Luis Fernando Antunez Bories
                                       Title: Attorney-in-fact


                                       24


                                                   Exhibit A-3 to Schedule 13G/A

      3. The undersigned persons (the "Reporting Persons") hereby agree that a
joint statement of this schedule 13G/A, and any amendments thereto, be filed on
their behalf by Mario Garrido Taraba, whose address is Enrique Foster Sur 20,
piso 18, Las Condes, Santiago, Chile.

      Each of the Reporting Persons is responsible for the completeness and
accuracy of the information concerning each of the items contained therein, but
none of the Reporting Persons is responsible for the completeness or accuracy of
the information concerning any other Reporting Person.

Date: March 17, 2006

                                       Guillermo Luksic Craig
                                       Nicolas Luksic Puga
                                       Inmobiliaria e Inversiones Rio Claro S.A.


                                       By: /s/ Mario Garrido Taraba
                                           --------------------------------
                                       Name: Mario Garrido Taraba
                                       Title: Attorney-in-fact


                                       25


                                                   Exhibit A-4 to Schedule 13G/A

      4. The undersigned persons (the "Reporting Persons") hereby agree that a
joint statement of this schedule 13G/A, and any amendments thereto, be filed on
their behalf by Rodrigo Terre Fontbona, whose address is Enrique Foster Sur 20,
piso 18, Las Condes, Santiago, Chile.

      Each of the Reporting Persons is responsible for the completeness and
accuracy of the information concerning each of the items contained therein, but
none of the Reporting Persons is responsible for the completeness or accuracy of
the information concerning any other Reporting Person.

Date: March 17, 2006


                                       Andronico Luksic Craig
                                       Patricia Lederer Tcherniak
                                       Inversiones Consolidadas S.A.
                                       Andronico Luksic Lederer
                                       Davor Luksic Lederer
                                       Max Luksic Lederer
                                       Dax Luksic Lederer
                                       Inversiones Salta S.A.


                                       By: /s/ Rodrigo Terre Fontbona
                                           --------------------------------
                                       Name: Rodrigo Terre Fontbona
                                       Title: Attorney-in-fact


                                       26


                                                     Exhibit B to Schedule 13G/A

                    Entities Owned by the Luksburg Foundation

      The Luksburg Foundation ("Luksburg") holds its 607,566,826 common shares
of Quinenco S.A. through a series of entities that it owns or controls directly
or indirectly, including Dolberg Finance Corporation Establishment ("Dolberg"),
a Liechtenstein establishment, Ruana Copper Corporation Establishment ("Ruana"),
a Liechtenstein establishment, Lanzville Investments Establishment
("Lanzville"), a Liechtenstein establishment, and Geotech Establishment
("Geotech"), a Liechtenstein establishment. Luksburg holds 240,938,000 common
shares (22.3%) of Quinenco S.A. through Ruana (the registered holder of these
shares is Ruana Copper A.G. Agencia Chile, a Chilean agency, ("Ruana Chile")).
Ruana Chile owns directly 9.1% and indirectly through its 97.4% interest in Cia.
de Inversiones Adriatico S.A., 90.4% of Inversiones Orengo S.A. ("Orengo").
Orengo in turn owns an additional 2,465,667 shares of Quinenco S.A. The
remainder of the shares are held through Dolberg, Lanzville and Geotech, which
respectively own 50.7%, 14.1% and 29.8%, of Andsberg Ltd ("Andsberg Jersey"), a
Jersey limited liability company, which in turn owns 100% of Andsberg Inv. Ltd,
a Jersey limited liability company, which in turn owns 100% of Andsberg
Inversiones Ltda ("Andsberg Chile"), a Chilean limited liability partnership.
Andsberg Chile owns 364,163,159 common shares (33.7%) of Quinenco S.A.

      Andsberg Inv. Ltd is located at 22 Grenville Street, St. Helier, Jersey,
Channel Islands JE48PX.

      Andsberg Inversiones Ltda. is located at Ahumada 11, Oficina 206,
Santiago, Chile.

      Andsberg Ltd is located at 22 Grenville Street, St. Helier, Jersey,
Channel Islands JE48PX.

      Cia. de Inversiones Adriatico S.A. is located at Ahumada 11, Oficina 206,
Santiago, Chile.

      Dolberg Finance Corporation Establishment is located at Heiligkreuz 6,
FL-9490 Vaduz, Liechtenstein.

      Geotech is located at Heiligkreuz 6, FL-9490 Vaduz, Liechtenstein.

      Inversiones Orengo S.A. is located at Ahumada 11, Oficina 206, Santiago,
Chile.Lanzville Investments Establishment is located at Heiligkreuz 6, FL-9490
Vaduz, Liechtenstein.

      Ruana Copper A.G. Agencia Chile is located at Ahumada 11, Oficina 206,
Santiago, Chile.

      Ruana Copper Corporation Establishment is located at Heiligkreuz 6,
FL-9490 Vaduz, Liechtenstein.


                                       27


                                                     Exhibit C to Schedule 13G/A

                                Members of Group:

Luksburg Foundation                                                        (HC)
Guillermo Luksic Craig                                                     (IN)
Nicolas Luksic Puga                                                        (IN)
Inmobiliaria e Inversiones Rio Claro S.A.                                  (HC)
Andronico Luksic Craig                                                     (IN)
Patricia Lederer Tcherniak                                                 (IN)
Inversiones Consolidadas S.A.                                              (HC)
Andronico Luksic Lederer                                                   (IN)
Davor Luksic Lederer                                                       (IN)
Max Luksic Lederer                                                         (IN)
Dax Luksic Lederer                                                         (IN)
Inversiones Salta S.A.                                                     (HC)
Quinenco S.A.                                                              (CO)
Inversions Rio Grande S.A.                                                 (HC)

Aggregate amount of common shares beneficially owned by group: 2,557,163,035

Percent of class: 47.8%


                                       28