Peru’s Buenaventura and US-based Newmont have approved construction of the Minas Conga copper-gold project, with an investment worth up to US$4.8 billion, in the first major mine investment to be approved since the election of Ollanta Humala as president.

The approval of Minas Conga – the largest mine investment in Peruvian history – came just hours after the nationalist Humala was sworn in as president in a signal that is beginning to calm the fears about the retired soldier’s economic policy.

“This is a very important decision in Buenaventura’s history, showing the company’s commitment to continue investing in Peru,” said Buenaventura’s CEO Roque Benavides in a statement.

Minas Conga, located in the northern region of Cajamarca, will produce 580,000-680,000 ounces of gold in its first five years, the companies said in separate statements.

The deposit will also produce 155-235 million pounds of copper in this period, they added.

Minas Conga, where Buenaventura and Newmont will invest $4-4.8 billion, will have a useful life of around 19 years.

This investment widely exceeds the companies’ previous estimate of US$3 billion.

The mine will begin to produce at the end of 2014 or early 2015, said Buenaventura, Peru’s largest producer of precious metals.