LEGISLATION GOVERNING MINING CONCESSIONS Mexico's Mining Code The basic mining laws of Mexico are contained in Article 27 of the Federal Constitution. Paragraph 4 of Article 27, as amended by decree of June 6, 1960, reads: The direct dominion of all of the natural resources...; of all minerals and substances that occur in veins, horizontal veins, masses or deposits, constitute deposits whose nature is different from the components of the land,... the deposits of precious stones, of rock salt and the salt mines formed di-rectly from marine waters; the products derived from the decomposition of rocks, when their exploitation requires subterranean work; the minerals or organic deposits susceptible of being used as fertilizers; the solid fuel minerals; petroleum and all the solid, liquid or gaseous hydrogen carbides; and the space situated above the national territory, in the extension and terms set by International Law belong to the Nation. The mining law of Mexico is technically known as the "Reglamentary Law of Consti-tutional Article 27 in the Matter of the Exploitation and Use of Mineral Resources." The law is dated February 5, 1961; it was published in the official Federal Register and became effective April 20, 1961. Following the Porfirio Diaz Revolution of 1910 and ensuing periods of armed struggle and economic chaos, additional mining properties were acquired by U.S., British, and French companies. These companies, under amendments to the old mining laws, were permitted to acquire concessions over large mineralized areas, many of which control-led the most valuable known mining districts in all of Mexico. Shortly after World War II, Mexico set out to gradually industrialize its economy so as to decrease the country's dependence on agriculture. This decision ran counter to the interests of some of the large foreign-owned mining companies (like Asarco and Penoles) that held major concessions, because they foresaw the gradual encroachment of govern-ment into the management of their affairs. Efforts on the part of the Mexican govern-ment to substitute Mexican technical management for foreign management proved un-successful. The conflict of interest between the mining industry and government reached a climax in the late 1950s and resulted in the current mining laws, which were promulgated in 1961 and provide for a minimum of 51 percent Mexican ownership. Essentially, these laws constitute a compromise between nationalization and an accomodation that permits 17