The 30-year bond has a 4.5% coupon, one of the lowest for a Mexican company in 30 years. The issue was rated at BBB+ by S&P Global Ratings and Fitch Ratings. The company's indebtedness is now $9.4 billion.

"With these resources we have sufficient for these three projects through 2022, a little for 2023 and start producing in that year," said VP finance Marlene Finny de la Torre, reported local press.

The Investment in Buenavista Zinc will be $413 million to build a concentrator at the Cananea copper complex which will produce 80,000 tonnes a year of zinc and 20,000tpy of copper from the second half of 2022.

At Pilares, $159 million will be invested so the openpit mine can produce 35,000tpy of copper in concentrate from 2021.

El Pilar will produce 35,000tpy of copper cathodes and will receive investment of $310 million to generate synergies with Buenavista del Cobre from 2023.

Grupo Mexico subsidiary Southern Copper intends to invest $8.1 billion through 2025 in various projects, including $1.4 billion at Tía María in Arequipa, Peru.

Shares in Grupo Mexico are trading at 47.22 pesos, valuing the company at 368 billion pesos (US$18.8 billion).