Marimaca Copper Announces Global Offering of C$409 Million

Treasury Offering of Approximately C$136 Million (~ A$141 Million) 
Secondary Offering of Approximately C$273 Million (~ A$283 Million)

Marimaca Copper Corp. (TSX: MARI,OTC:MARIF) (ASX: MC2) ("Marimaca" or the "Company") has announced today that it has entered into agreements with Beacon Securities Limited and BMO Capital Markets as co-lead agents and joint bookrunners (together, the "Canadian Co-Lead Agents"), co-managed with National Bank Financial Inc., along with Euroz Hartleys Limited and Canaccord Genuity (Australia) Limited as co-lead agents and joint bookrunners (together, the "Australian Co-Lead Agents" and, together with the Canadian Co-Lead Agents, the "Joint Lead Managers") on behalf of a syndicate of agents to be formed in connection with a treasury offering of common shares (the "Common Shares") and CHESS Depositary Interests of the Company ("CDIs") of up to approximately C$136 million, or A$141 million1, and a secondary offering of existing Common Shares and CDIs owned and controlled by Greenstone Resources II L.P. and Greenstone Co-Investment No. 1 (Coro) L.P. (the "Greenstone Group") and certain other shareholders (together with the Greenstone Group, the "Selling Shareholders") of up to approximately C$273 million, or A$283 million1.

The Company along with the Canadian Co-Lead Agents, will conduct, on a commercially reasonable efforts agency basis, a public offering of Common Shares (the "Canadian Offering") at a price of C$10.00 per Common Share (the "Canadian Issue Price"). The Canadian Offering includes a treasury offering of Common Shares by the Company and a secondary offering of existing Common Shares owned and controlled by the Greenstone Group. The Canadian Offering is expected to close on or about February 26, 2026 and is subject to the Company receiving all necessary regulatory approvals, including approval of the Toronto Stock Exchange (the "TSX").

Concurrently with the Canadian Offering, the Company, along with the Joint Lead Managers, will complete a brokered placement of CDIs at a price of A$10.35 per CDI (the "Australian Offering", and together with the Canadian Offering, the "Global Offering"). The Australian Offering includes a treasury offering of CDIs by the Company and a secondary offering of existing CDIs owned and controlled by certain Selling Shareholders. The Australian Offering is expected to close on or about February 26, 2026. The CDIs will be issued pursuant to the ASX Listing Rule 7.1 waiver granted to Marimaca. The treasury offering of CDIs by the Company under the Australian Offering is subject to approval by the TSX.

The net proceeds from the treasury offering of Common Shares and CDIs will be used to advance the Marimaca Project, including funding the pre-construction decision engineering workstreams and early site works, to conduct a drilling campaign at Pampa Medina and for working capital and general corporate purposes. The net proceeds of the secondary offering will be payable to the Selling Shareholders. The Company will not receive any proceeds from the secondary offering.

As part of the Global Offering, the Selling Shareholders have agreed, subject to certain limited exceptions, not to sell any Common Shares or CDIs for a 90 day period.

The Canadian Offering will be made by way of a prospectus supplement (the "Prospectus Supplement") to the Company's short form base shelf prospectus dated January 9, 2026 (the "Shelf Prospectus") to purchasers in all of the provinces and territories of Canada (other than Québec and Nunavut) and may be offered in the United States to "qualified institutional buyers" under the United States Securities Act of 1933 ("QIBs"), as amended (the "U.S. Securities Act") and in those jurisdictions outside Canada and the United States pursuant to exemptions from prospectus and registration requirements.

The CDIs will be offered in Australia to professional investors or sophisticated investors who are also "wholesale clients" (within the meaning of sections 708(11), 708(10), 708(8) and 761G of the Corporations Act respectively); in the United States to QIBs and Eligible US Fund Managers; and outside Australia and the United States to certain institutional, sophisticated or professional investors in Bermuda, Brazil, Cayman Islands, European Union (excluding Austria), Hong Kong, New Zealand, Malaysia, Norway, Singapore, South Africa, Switzerland, Israel, United Arab Emirates (excluding financial centres), and United Kingdom.

The securities under the Canadian Offering and the Australian Offering have not been, and will not be, registered under the U.S. Securities Act or the securities laws of any state of the United States and may not be offered, sold or delivered, directly or indirectly, in the United States (as such term is defined in Regulation S under the U.S. Securities Act), except pursuant to an exemption from the registration requirements of the U.S. Securities Act and applicable state securities laws. This news release does not constitute an offer to sell or solicitation of an offer to buy any of these securities in the United States or in any jurisdiction in which such offer, solicitation or sale is not permitted.

Access to the Prospectus Supplement, the Shelf Prospectus and any amendment to such documents is provided in accordance with securities legislation relating to the procedures for providing access to a shelf prospectus supplement, a base shelf prospectus and any amendment. The Shelf Prospectus is, and the Prospectus Supplement will be (within two business days from the date hereof), accessible on SEDAR+ at www.sedarplus.ca. An electronic or paper copy of the Prospectus Supplement, Shelf Prospectus, and any amendment to such documents may be obtained, without charge, from Beacon Securities Limited at syndication@beaconsecurities.ca, BMO Capital Markets at Brampton Distribution Centre C/O The Data Group of Companies, 9195 Torbram Road, Brampton, Ontario, L6S 6H2 by telephone at 905-791-3151 Ext 4312 or by email at torbramwarehouse@datagroup.ca., by providing the contact with an email address or address, as applicable.

About Marimaca

Marimaca is a copper exploration and development company focused on its 100%-owned flagship Marimaca Copper Project and surrounding exploration properties located in Antofagasta Region, Chile.

The Marimaca Copper Project hosts the Marimaca Oxide Deposit (the "MOD"), an IOCG-type copper deposit. The Company is currently progressing the Marimaca Copper Project through detailed engineering and submission for sectorial permits following the release of the 2025 MOD DFS and receipt of the RCA. In parallel, the Company is exploring its extensive land package in the Antofagasta region, including the >15,000ha wholly-owned Sierra de Medina property block, located 25km from the MOD. The Company is currently completing a Phase II drilling program (30,000m) at Pampa Medina, located in the Sierra de Medina property, after a successful discovery drilling program in 2025 identified a high-grade sedimentary horizon at depth.

This news release is authorized for release by the Board of Directors of Marimaca.

Forward-Looking Statements

This news release includes certain "forward-looking statements" under applicable Canadian securities legislation, including statements related to the anticipated participation in and size of the Canadian Offering or Australian Offering, anticipated timing and closing date of the Canadian Offering or Australian Offering, advisory fees payable, the use of proceeds and receipt of regulatory approvals and other approvals, including approval of the TSX. There can be no assurance that such statements will prove to be accurate and actual results and future events could differ materially from those anticipated in such statements. Forward-looking statements reflect the beliefs, opinions and projections on the date the statements are made and are based upon a number of assumptions and estimates that, while considered reasonable by Marimaca, are inherently subject to significant business, economic, competitive, political and social uncertainties and contingencies. Many factors, both known and unknown, could cause actual results, performance or achievements to be materially different from the results, performance or achievements that are or may be expressed or implied by such forward-looking statements and the parties have made assumptions and estimates based on or related to many of these factors. Such factors include, without limitation: risks related to the receipt of required regulatory approvals, including timing of approval by the TSX, risks related to share price, market conditions, market demand and success of the bookbuild, the inherent risks involved in the mining, exploration and development of mineral properties, the uncertainties involved in interpreting drilling results and other geological data, fluctuating metal prices, the possibility of project delays or cost overruns or unanticipated excessive operating costs and expenses, uncertainties related to the necessity of financing, uncertainties relating to regulatory procedure and timing for permitting reviews, the availability of and costs of financing needed in the future. The intended use of the proceeds of the Global Offering by the Company might change if the board of directors of the Company determines that it would be in the best interests of the Company and amounts actually allocated and spent will depend on a number of factors, including the Company's ability to execute on its business plan. Many of these risks and uncertainties and additional risk factors generally applicable to the Company are described in the Company's annual information form of the Company dated March 27, 2025 and other filings made by the Company with the Canadian securities regulatory authorities (which may be viewed at www.sedarplus.ca). Accordingly, readers should not place undue reliance on forward-looking statements. The Company undertakes no obligation to update publicly or otherwise revise any forward-looking statements contained herein, whether as a result of new information or future events or otherwise, except as may be required by law.

None of the TSX, ASX or the Canadian Investment Regulatory Organization accepts responsibility for the adequacy or accuracy of this release.

¹ Based on an AUD.CAD exchange rate of 0.9661.

Not for release to United States news wire services or for dissemination in the United States

To view the source version of this press release, please visit https://www.newsfilecorp.com/release/284242