Arnaldo León y Asociados S. A.
Consulting and the Promotion of Mining Investments

Los Caobos 180, La Molina Vieja, Lima 12, Perú
Telephones (511) 855 9339; 495 1035; Fax 365 5365

Compañía Minera Colquirrumi S. A.
Hualgayoc, Cajamarca, Perú

The partners of Compañía Minera Colquirrumi S.A. (Colquirrumi) are interested in selling 100% of their stake in the company, or entering into an option agreement for exploration, or establishing a joint venture with all the mining concessions (13,318 ha) that Colquirrumi owns in Hualgayoc, Cajamarca on the northern Sierra of Peru.

The aim is to attract the interest of top-level mining companies with the purpose of developing the potential of the Hualgayoc mining district. Compañía de Minas Buenaventura S.A.A. owns 73.63% of the stock in Colquirrumi.

Should your company be interested in this operation, we would appreciate your forwarding us a letter by mail, e-mail or fax stating so. A duly signed copy of the enclosed Confidentiality Agreement should accompany your letter. Upon receipt of your letter we will mail to you a copy of the Information Memorandum.

Arnaldo León y Asociados S. A. is a local consulting firm engaged in mining investment promotion in Peru. In the present operation we are acting as Colquirrumi's advisors.

Lima, February 2002

Compañía Minera Colquirrumi S. A.,
Hualgayoc, Cajamarca, Perú
February 2002


    The Hualgayoc district is made up of folded sedimentary rocks of the Cretaceous Period intruded by stocks, dikes and sills of diorite to granodiorite composition of the Middle-Late Miocene (14.5-72-thousand years). All of these bodies are emplaced within a regional lineament, strike NW-SE, which comprises the following known ore deposits: Tantahuatay, Shinchao, Cerro Jesús, Cerro San José, Cerro Corona, Minas Congas, El Galeno and Michiquillay.

    Deposits worked in the Hualgayoc mining district are of different types: veins, mantles, bodies and porphyries with disseminated mineralization and in stockworks. They contain complex Ag-Zn-Pb-Cu-Au-Mo-As-Sb ore of the Mesothermal to Epithermal type. Due to their characteristics, these mineralizations are quite similar to those of other classic districts such as Cerro de Pasco, San Cristobal, Atacocha and Colquijirca in Peru, as well as Leadville, Tintic and Park City in the USA.

    Cia. Minera Colquirrumi’s mining property encompasses a large portion of the best mineralized sectors of the Hualgayoc mining district such as: Pozos Ricos-Lambayeque, Mansita, San Agustín, Titan, La Delia, Tres Cruces and Firenze. Limited deep-exploration works carried out in this district represent an excellent potential for the discovery of new Ag-Zn-Pb-Cu-Au resources in mantles and veins and also Au-Cu-(Mo) porphyry systems similar to Cerro Corona.


    Mining activity in Hualgayoc dates back to its discovery by a Spanish citizen, Rodríguez de Ocaña, in 1771. It is worth noting that at that time traces of old mining works from the Inca Epoch were present in this area. The economic significance of these deposits was originally highlighted by scientists such as Alexander Von Humboldt, who referred to Cerro Hualgayoc as a Second Potosi and Antonio Raimondi, who also described the important mineral endowment of this district in his Notes on the Hualgayoc Ore.


    1. A listing of the properties, a description of the abundant geologic data available, a set of plans and details regarding the process for selecting the interested companies are included in an Information Memorandum. Copies of geologic reports and other documents are available in our Data Room.


    In order to receive a copy of the Information Memorandum interested parties must previously sign the enclosed Confidentiality Agreement. If necessary, we welcome any comments deemed convenient regarding the aforementioned Agreement.


    Attached to the Confidentiality Agreement you will find the List of Properties, with a total of 13,318 hectares. The list and properties may suffer minor changes during the implementation of the operation.


    A two-stage process will be carried out to select a company or an association of companies. The first stage will be the period required to visit the Data Room, make field trips and carry out due diligence activities. Upon completion of this period, we expect that interested parties submit an Indicative Proposal. Those companies that submit proposals of interest to Colquirrumi will be invited to discuss certain details and clarifications, to receive further information if required, and to submit their Final Proposal. Colquirrumi intends to close negotiations by the end of June 2002.