"The issue price and size of the offering will be determined by considering investment intentions expressed by institutional investors during the book-building process," Aura said, adding its shares would continue to trade on the TSX.
It plans to use the proceeds to fund operating assets, for exploration and development and to reinforce its capital structure.
Aura has the San Andres gold mine in Honduras which resumed operations in February, the Ernesto/Pau-a-Pique gold mine in Brazil and the Aranzazu copper-gold-silver mine in Mexico, which began commercial production at the end of 2018.
It also announced last month it had entered an agreement to purchase the Gold Road mine in Arizona from Para Resources (TSXV: PBR) for $1, along with assuming liabilities of about $35 million.
Aura also has gold projects in Brazil and Colombia.
The ramp-up at Aranzazu and San Andres, plus higher gold prices, saw Aura's net revenues increase to almost US$70 million in the third and fourth quarters of 2019.
The company produced 114,307 ounces of gold and about 33 million pounds of copper for the year.
"After three years of critical transformation supported by a high-performance team, Aura is now showing its true potential," CEO Rodrigo Barbosa said last month.
Its shares have more than tripled in value in the past month.
Having spent much of 2019 around the C$20 mark, they shot up as high as $91.81 last week.
Aura closed up 1.25% yesterday to $81, to capitalise it about $353 million (US$264 million).