FRONTERA AND KUPARI ANNOUNCE COMMENCEMENT OF STRATEGIC SALE PROCESS FOR THE JOINTLY OWNED PIEDRAS VERDES COPPER MINE COMPLEX IN SONORA, MEXICO

MEXICO CITY, June 23, 2026 /PRNewswire/ -- Frontera Copper Corporation, S.A.P.I. de CV and Kupari Investments Ltd. ("Kupari"), collectively the "Companies", announced today that Frontera Copper Corporation ("Frontera"), and Kupari Metals A.G., a wholly-owned subsidiary of Kupari, have commenced a strategic sale process for the Piedras Verdes mine complex. Any mention of the Piedras Verdes mine complex refers to 100% of the equity in both Frontera and Kupari Metals. The Companies have retained BMO Capital Markets as financial advisor and Blake, Cassels & Graydon LLP as legal advisor in connection with the process.

Piedras Verdes is a producing copper mine located in the stable and mining-friendly state of Sonora, Mexico, with nearby access to supportive infrastructure and a skilled workforce. As a result of copper supply shortages due to continued strong copper demand, secular electrification trends, and lengthy development processes, management believes that a sale today has the potential to generate significant proceeds, while acquirers can benefit from immediate commercial production and expansion opportunities.

BMO Capital Markets has begun speaking with a number of prospective acquirers and the Companies will be opening a data room with confidential information to potential acquirers who have entered into satisfactory confidentiality agreements.

About Frontera Copper Corporation

Frontera Copper Corporation is a copper mining company that extracts and processes sulfide and oxide ores, produces London Metals Exchange Grade "A" copper cathode, and sells primarily hypogene ore to Kupari Metals.

About Kupari Metals

Kupari Metals is a base metals tolling company that processes copper–bearing material into copper concentrates for sale. Kupari Metals processes hypogene sulfide ore from the Piedras Verdes operation.

Advisors and Counsel

The Companies have engaged BMO Capital Markets as financial advisor and Blake, Cassels & Graydon LLP as legal advisor in connection with the process.

For additional information, please contact:
BMO Capital Markets
Email: ProjectFaradaySaleProcess@bmo.com