Mr. Giulio Bonifacio reports

ALTA COPPER ANNOUNCES FILING AND MAILING OF MEETING MATERIALS FOR THE SPECIAL MEETING OF SHAREHOLDERS AND OPTIONHOLDERS TO BE HELD ON JANUARY 26, 2026

The Supreme Court of British Columbia issued an interim order dated Dec. 19, 2025, in connection with an arrangement involving Alta Copper Corp., Fortescue Ltd. and Nascent Exploration Pty. Ltd., a wholly owned subsidiary of Fortescue (the purchaser), authorizing the calling and holding of the special meeting of the holders of common shares of the company and the holders of options to purchase Alta Copper shares, and other matters related to the conduct of the meeting.

The notice of meeting, management information circular (the "Circular") and related documents (collectively, the "meeting materials") in connection with the meeting have been filed with securities regulators. The meeting materials have also been mailed to Alta Copper shareholders and optionholders and can be accessed on the company's website at www.altacopper.com or on Alta Copper's SEDAR+ profile at www.sedarplus.ca.

Meeting details

The meeting is to be held on Monday, Jan. 26, 2026, at 10 a.m. (Vancouver time) at the offices of Gowling WLG (Canada) LLP located at suite 2300 -- 550 Burrard St., Vancouver, B.C., Canada, V6C 2B5. Only Alta Copper shareholders and optionholders of record as of the close of business on Monday, Dec. 15, 2025, the record date for the meeting, are entitled to receive notice of, attend and vote at the meeting.

At the meeting, Alta Copper shareholders and optionholders will be asked to pass, with or without variation, a special resolution approving the transaction whereby Fortescue will, among other things, indirectly through the purchaser acquire all of the issued and outstanding Alta Copper shares (other than those held by the purchaser and its affiliates) and all of the outstanding convertible securities will be exchanged for the applicable consideration and cancelled. Alta Copper shareholders will receive $1.40 for each Alta Copper share held, optionholders will receive $1.40 less the applicable exercise price, per underlying share, for the company options held and holders of deferred share units of the company (company DSUs) and restricted share units of the company (company RSUs) will receive $1.40 per underlying share, for the company DSUs and company RSUs, respectively, held.

Special committee recommendation and board approval

In connection with its review of the transaction, the board of directors of Alta Copper formed a special committee of the board (comprising the sole independent and non-interested director of the board). The special committee obtained an independent formal valuation from Fort Capital Partners as required by Multilateral Instrument 61-101. The formal valuation determined that in Fort Capital's opinion, based on and subject to certain assumptions, limitations and qualifications, the fair market value of the Alta Copper shares as at Dec. 13, 2025, was in the range of 95 cents to $1.65 per Alta Copper share. Fort Capital also delivered a fairness opinion to the special committee and to the board that, as of Dec. 13, 2025, and subject to certain assumptions, limitations and qualifications, the consideration to be received by holders of Alta Copper shares pursuant to the transaction is fair, from a financial point of view, to the Alta Copper shareholders (other than the purchaser and its affiliates).

Additionally, Haywood Securities Inc., financial adviser to the special committee, provided a fairness opinion to the special committee stating that as of Dec. 13, 2025, and subject to certain assumptions, limitations and qualifications, the consideration to be received by the Alta Copper shareholders pursuant to the transaction is fair, from a financial point of view, to the Alta Copper shareholders (other than the purchaser and its affiliates).

The board, based on its considerations, investigations and deliberations, including its review of the terms and conditions of the definitive arrangement agreement with Fortescue and the purchaser, the formal valuation and the Fort Capital fairness opinion and other relevant matters, and taking into account the best interests of the company, and after consultation with management and its legal advisers and having received and reviewed the recommendation of the special committee which took into account, among other things, the formal valuation and the fairness opinions, has (subject to two directors having a disclosable interest within the meaning of the Business Corporations Act (British Columbia) and abstaining from voting) unanimously determined that the transaction is fair, from a financial point of view, to Alta Copper shareholders other than the purchaser and its affiliates, and the transaction and the entering into of the arrangement agreement are in the best interests of Alta Copper. Accordingly, the board has unanimously approved the transaction and the entering into of the arrangement agreement and unanimously recommends that the Alta Copper shareholders and optionholders vote for the transaction.

Board members Christine Nicolau and Andrew Hamilton each abstained from voting with respect to the transaction, as they are employees of Fortescue and each therefore has a disclosable interest in the transaction.

Benefits to Alta Copper

• Significant premium. The purchase price represents a significant premium, including:
  • A 50-per-cent premium to the 30-day volume-weighted average trading price (VWAP) of the Alta Copper shares in Canada of 94 cents per share for the period ended Dec. 12, 2025, being the last trading day before the arrangement agreement was entered into;
  • A 100-per-cent premium to the 30-day VWAP of the Alta Copper shares in Canada of 70 cents per share for the period ended Nov. 7, 2025, being the last trading day before Fortescue and Alta Copper commenced exclusive negotiations.
• The purchase price also exceeds Alta Copper's 10-year-high share price, providing immediate value at a level not achieved in the public markets over the past decade.
• Immediate term liquidity. The all-cash purchase price provides immediate, full liquidity at a premium price which is an outcome that may not otherwise be achievable given Alta Copper's trading profile. Alta Copper shares have historically traded with limited liquidity, restricting Alta Copper shareholders' ability to exit their investment or realize meaningful value through market sales.
• No further dilution. Alta Copper requires financing to progress community engagement, permitting activities and technical studies for its Canariaco copper project. Advancing the project independently will require material equity financing and will result in substantial dilution for Alta Copper shareholders. The transaction allows Alta Copper shareholders to realize value without providing further capital.
• Transaction avoids risk exposure. Advancing the project independently would require Alta Copper to navigate a complex, multiyear community and regulatory approvals process in northern Peru, with no assurance of success. The transaction allows Alta Copper shareholders to avoid these material risks by transferring the development and approvals burden to Fortescue.
• Limited prospects for an alternative transaction. Fortescue currently owns 35.7 per cent of Alta Copper's outstanding shares and has informed Alta Copper that it intends to vote against any alternative proposal.
• Other factors. The special committee and the board also carefully considered the transaction with reference to current economic, industry and market trends affecting the company, additional information concerning the business, operations, interests, assets, financial condition, operating results and prospects of the company, the company's need to arrange for financing to fund future obligations, and the historical trading prices of the Alta Copper shares.

Your vote is important. The board (with two directors having disclosable interests abstaining from voting) unanimously recommends that Alta Copper shareholders and optionholders vote for the arrangement resolution. The deadline for voting Alta Copper shares and company options by proxy is 10 a.m. (Vancouver time) on Jan. 22, 2026.

About Alta Copper Corp.

Alta Copper is focused on the development of its 100-per-cent-owned Canariaco advanced-staged copper project. Canariaco comprises 91 square kilometres of highly prospective land located 102 km northeast of the city of Chiclayo, Peru, which includes the Canariaco Norte deposit, the Canariaco Sur deposit and the Quebrada Verde prospect, all within a four-kilometre northeast-southwest trend in northern Peru's prolific mining district. Canariaco is one of the largest copper deposits in the Americas not held by a major.

We seek Safe Harbor.