SUBSIDIARIES & JOINT VENTURES

BIOSIGMA S.A.
December 31st, 2006

Legal status
Company name: BIOSIGMA SA
RUT: 96.991.180-9
Legal status: Private limited company

Capital subscribed and paid in
As of 31 December 2006, capital subscribed and paid in by Codelco: US$11,558,000.

Purpose
BIOSIGMA SA was established by Codelco in association with the Nippon Mining and Metals Co., Ltd., of Japan, 31 May 2002. The purpose of the company is to develop processes and technologies in the fields of genomics, proteomics and bioinformatics for mining and in general the application of micro organism-based systems, and other activities and business related to these areas. The activities it currently carries out involve research and development in the fields of genomics, proteomics and bioinformatics for
mining.

Board of Directors
Juan Enrique Morales Jaramillo, Director (*)
Pedro Antonio Morales Cerda, Director (*)
Mario Espinoza Durán, Director (*)
Masashi Kikuchi, Director
Keiichi Goto, Director
Luis Castelli Sandoval, Director Alternate (*)
Gloria Parada Zamorano, Alternate (*)
Juan González González, Alternate (*)
Takashi Suzuki, Alternate
Norio Sushima, Alternate

General Manager
Ricardo Badilla Ohlbaum

Codelco's share of capital and changes during the fiscal year
Codelco's holdings account for 66.67% of subscribed and paid in shares.

Contracts with Codelco
During the 2006 fiscal year, Codelco had the following contracts in effect with BIOSIGMA S.A.:
• Agreement for subscribing and paying shares, 28 February 2006.
Protocol of collaboration for the application of the technological agreement celebrated between Codelco and BioSigma S.A. at Codelco's Andina Division June 15th 2006.
• Agreement for subscribing and paying shares, 24 August 2006. Free loan contract for the installation of a biomass pilot production plant at the Codelco Norte Division,November 14th 2006.
• Agreement for subscribing and paying shares, November 28th 2006.

Investment as a percentage of total head office
Investment as a percentage of total head office
2006 Investment in jointly held firm US$3,192,000.
2005 Investment in subsidiary US$3,028,000.
Total investment as a percentage of head office assets 0.02%, 2006.