The nationalization of the Chilean copper industry, commonly described as the Chileanization of copper (Spanish: Chilenización del cobre)^[1] was the process by which the Chilean government acquired control of the major foreign-owned section of the Chilean copper mining industry. It involved the three huge mines known as 'La Gran Mineria' and three smaller operations. The Chilean-owned smaller copper mines were not affected. The process started under the government of President Carlos Ibáñez del Campo, and culminated during the government of President Salvador Allende, who completed the nationalization. This "act of sovereignty" was the espoused basis for a later international economic boycott, which further isolated Chile from the world economy, worsening the state of political polarization that led to the 1973 Chilean coup d'état.

This article needs additional citations for verification. (May 2020)

By the late 1950s, the three principal copper mines in Chile were Chuquicamata, El Salvador, and El Teniente. Chuquicamata and El Salvador were owned by the Anaconda Copper Company and El Teniente was owned by the Kennecott Copper Corporation. The La Exotica mine, an adjunct of Chuquicamata, was added to these big mines in 1966.These large mines were mainly self-contained and self-sustaining settlements with their own cities to house their workers, their own water and electrical plants, their own schools, stores, railways, and even in certain cases their own police forces.

Three other mines were eventually nationalized, Cerro de Pasco's Andina operation, which went to Codelco, and the two mines, Los Bronces and El Soldado, owned by Peñarroya's Disputada de las Condes, which were bought by ENAMI. Evidently these mines did not fit in with ENAMI's plans and Disputada de las Condes was subsequently sold (at a substantial profit) to Exxon Minerals.

On June 26, 1969, President Eduardo Frei Montalva signed an agreement with the Anaconda Copper Company, the Kennecott Utah Copper company, and the Cerro company (which was afterwards ratified by Congress). In this agreement, the government acquired the 51% of the Kennecott’s shares and 25% of the shares in both Anaconda and Cerro, allowing the U.S. to maintain some level of control in this economic sector.^[2]

This process was known as "negotiated nationalization", and was designed to avoid a conflict with international investors (and ultimately with the United States) and to allow for the acquisition of the technical, financial and marketing knowledge of the multinationals. A similar process was used to acquire a dominant ownership over the rest of the copper industry.

In the agreement, it was established that the Chilean government could buy within the next 13 years (counting from 1970) the remaining 49% of the foreign ownership from the multinational corporations, but only after having paid at least 60% of the current debt due from the purchase of the original 51%. It also fixed a clear formula for the valuation of the assets to be bought, for the liquidation of profits, for the increase of direct investment in new works, and related issues.

The process of "negotiated nationalization" met with vociferous criticism from the leftist political parties, and from a section of the President's own Christian Democratic Party. The idea was accused of bowing to American imperialism, being too slow and too expensive.

In the 1970 presidential election, the outright nationalization without compensation (known as the Chileanization of copper) became one of the main campaign issues. Two out of the three presidential candidates incorporated the idea into their political platforms, while the third opted for a faster version of the "negotiated nationalization".

After socialist candidate Salvador Allende won the election, he promised to deal with the issue head-on. In fact, at the beginning of 1971, he sent Congress a bill for a constitutional amendment that would allow him to nationalize outright all mines, and to transfer all present and future copper fields to the state. Congress passed this amendment on July 11, 1971, by a unanimous vote,^[3] and based on it, on July 16, 1971 law 17.450 was promulgated, and became effective immediately. The event was celebrated as the Day of National Dignity (Spanish: Día de la Dignidad Nacional).^[4]

In principle, there was complete agreement about the process of nationalization of the mines among all political parties represented in the Chilean Congress, as indicated by the unanimous vote that approved law 17.450. When it came down to the particulars, however, there was much concern about the political use that the Allende administration would make of it. Even so, the bigger concern was for the expected reaction of the U.S. government.

• Nationalization
• Economic history of Chile
• Chile under Allende
• Chile under Pinochet
• Miracle of Chile
• Codelco