Micro- here is the section of the Mexican mining l

Micro- here is the section of the Mexican mining law that tells about foriegn interests. As anyone can see, even those involved aren't sure what is and what isn't needed.  Everything is mentioned even the trusts! I wasn't sure if this has been posted yet or not.

3.8. Foreign ownership

As explained above, the Constitution allows Mexican and foreign individuals and Mexican companies to hold mining concessions. Foreign companies are thus unable to be concessionaires. However, all recent mining laws have also prevented foreign individuals from holding concessions, based upon the fact that the wording of Article 27 of the Constitution makes it discretionary to grant concession rights to such foreign individuals. Participation of foreigners in Mexican mining is therefore carried out through Mexican companies. In this regard, starting in 1961 foreigners were restricted to owning no more than 49% of the shares of Mexican mining companies, making Mexico quite unattractive for foreign investment. The regulations of the mining law of 1990 allowed foreigners to indirectly hold the remaining 51% of the shares through the establishment of trusts, spurring a boom in foreign exploration investment. When enacted in 1992, the Law put no restrictions other than complying with the Foreign Investment Law, which in 1993 allowed full foreign investment in mining, always through Mexican companies.
     Amendments to the Foreign Investment Law published on December 24, 1996 made it legally possible for "foreigners" to hold mining concessions (prior acceptance of the Calvo Clause, mentioned in (2) above), regardless of the provisions of the Law denying them said right.¹¹ There is disagreement, however, on whether "foreigners" means only foreign individuals, or if the term includes foreign companies. The Mexican foreign investment authorities take the position that it includes both, but a correct interpretation of Article 27 of the Constitution leads one to conclude that such position is mistaken, for reasons that go beyond the scope of this article. The discussion is somewhat academic, because the Regulations (issued, as stated above, by the President in 1999), in the exercise of the executive's constitutionally allowed discretion to grant concessions to foreigners, continue to bar all foreigners from directly obtaining mining concessions.