SolGold again postponed the pre-feasibility study of the Cascabel copper project.

Shares of Ecuador-focused SolGold fell in London and Toronto on Tuesday after SolGold announced its decision to delay the release of (PFS), a pre-feasibility study for its flagship Cascabel copper and gold project in Ecuador.

The mining company said the delay would allow it to identify assumptions that affect the study, such as whether it should include upside options.

It will also settle Darryl Cuzzubbo, the incoming chief executive, SolGold points out.

The company said it would provide an update on when PFS is expected to be completed at its annual general meeting on December 15.

It also said it signed an agreement with the Ecuadorian government last week to invest a total of $430 million in Cascabel exploration over the 10-year period from 2013 to 2023.

Ingo Hofmaier, acting chief financial officer of SolGold, said Tuesday that the agreement provides more protection for the company's shareholders' investment in Ecuador.

BHP Billiton, the world's largest mining company, owns 13.5 per cent of the company, and the prospect of an acquisition could increase once SolGold's long-delayed pre-feasibility study is completed, experts say.

The sixth largest copper mine

Ecuador's Ministry of Energy said in 2019 that it "could become the largest underground silver mine, the third largest gold mine and the sixth largest copper mine in the world".

Alpala is the largest deposit discovered so far under the Cascabel concession, measuring and showing a resource of 2.7 billion tons and a copper equivalent of 0.53 per cent (0.37 per cent of copper, 0.25g of gold per ton, 1.08ppm of silver) of 9.9 million tons of copper, 2170 ounces of gold and 9220 ounces of silver.

Once completed, Cascabel expects to produce an average of 150000 tons of copper, 245000 ounces of gold and 913000 ounces of silver concentrate per year over its 55-year mine life.

In the first 25 years of mining, average annual production is expected to be 207000 tons of copper, 438000 ounces of gold and 1.4 million ounces of silver.

BHP has reportedly been pushing for re-election of the entire board of SolGold at its annual general meeting scheduled for December.

Chairman Liam Tvig recently proposed that in order to maintain the stability of the company, only three of the directors and the company's new chief executive who did not participate in the re-election last year will vote at the general meeting of shareholders.

Ecuador has been a destination for mining investment in the past two years, but opposition to the exploitation of the country's resources could hamper the government's plans to attract $3.7 billion in mining investment by next year.

Last year, Ecuador's mining industry generated $810 million in exports, $430 million in taxes and $374 million in foreign direct investment.