VANCOUVER, BC — February 27, 2026 — Leads & Copy — Marimaca Copper Corp. (TSX:MARI)(ASX:MC2) has announced the closing of its Australian secondary offering, involving 15,200,913 existing CHESS Depositary Interests (CDIs) at A$10.35 per CDI. The CDIs were owned and controlled by Greenstone Resources II L.P. and other shareholders, resulting in aggregate gross proceeds of A$157 million.
The Australian secondary offering completes the previously announced global treasury and secondary offering, bringing the total gross proceeds to C$409 million, or A$423 million. The Canadian offering, detailed in a prior press release dated February 26, 2026, generated C$257 million, including a treasury offering of C$136.5 million and a secondary offering of C$120.5 million.
Euroz Hartleys Limited, Canaccord Genuity (Australia) Limited, Beacon Securities Limited and BMO Capital Markets acted as joint lead managers and co-lead agents and joint bookrunners for the global offering, facilitating the Australian secondary offering as a brokered placement of CDIs.
The net proceeds from the Australian secondary offering were distributed to the selling shareholders, with Marimaca Copper Corp. not receiving any of the proceeds.
Following the completion of the global offering, the Greenstone Group, comprising Greenstone Resources II L.P. and Greenstone Co-Investment No. 1 (Coro) L.P., now collectively owns and controls 2,255,198 common shares and 6,351,806 CDIs of Marimaca. This represents 6.44% of the outstanding common shares and CDIs in aggregate, which factors in the completion of the Canadian treasury offering.
Before the global offering, the Greenstone Group held 22,304,285 common shares, including 8,000,000 CDIs, accounting for 18.58% of the outstanding common shares and CDIs. Through the secondary offering, the Greenstone Group disposed of 13,697,281 common shares, including 1,648,194 CDIs, reducing their stake by 11.41% before accounting for the Canadian treasury offering, or by 12.14% after the offering.
The Greenstone Group received C$10.00 per share sold in the Canadian secondary offering and A$10.35 per CDI in the Australian secondary offering. This resulted in total proceeds of C$136,972,810 for the Greenstone Group, using an exchange rate of C$1.00 = A$0.9961, excluding commissions and expenses paid to the joint lead managers.
As part of the global offering, the selling shareholders have agreed not to sell any common shares or CDIs for 90 days, with limited exceptions. The Greenstone Group retains the option to acquire or dispose of Marimaca securities or maintain its current position, subject to market conditions and other factors.
An early warning report regarding the secondary offering will be available on SEDAR+ under Marimaca’s profile at www.sedarplus.ca. A copy of the report can be requested from Gary Mauger at greenstoneGSY@aztecgroup.co.uk or +44 1481 749 700. Greenstone Resources II L.P. is based at PO Box 656, East Wing, Trafalgar Court, Les Banques, St Peter Port, Guernsey, GY1 3PP.
Marimaca is a copper exploration and development company focusing on its flagship Marimaca Copper Project and surrounding exploration properties in the Antofagasta Region, Chile. The company’s head office is located at 5300-66 Wellington Street West, Toronto, Ontario.
The Marimaca Copper Project features the Marimaca Oxide Deposit (MOD), an IOCG-type copper deposit. Marimaca is advancing the project through detailed engineering and permit submissions, following the 2025 MOD DFS and receipt of the RCA. Concurrently, the company is exploring its extensive land package, including the Sierra de Medina property, located 25km from the MOD, and is currently completing a Phase II drilling program at Pampa Medina.
This news release was authorized by the Board of Directors of Marimaca.
Source: Marimaca Copper Corp.
