Independent Proxy Advisory Firms Recommend Alta Copper Shareholders Vote "For" Proposed Plan of Arrangement with Fortescue Ltd; Alta Copper Reminds Shareholders to Vote

• Your vote is important. Vote well in advance of the proxy voting deadline on Thursday, January 22, 2026 at 10:00 a.m. (Vancouver time)

• Shareholder questions or need voting assistance? Please contact Laurel Hill Advisory Group by email at assistance@laurelhill.com, or by texting "INFO" to, or calling, 1-877-452-7184 (North American toll-free) or 1-416-304-0211 (outside North America).

VANCOUVER, BC / ACCESS Newswire / January 19, 2026 / Alta Copper Corp. (TSX:ATCU,OTC:ATCUF)(BVL:ATCU)(OTCQX:ATCUF) ("Alta Copper" or the "Company") is pleased to announce that independent proxy advisory firms, including Institutional Shareholder Services ("ISS"), have recommended that shareholders vote "FOR" the special resolution approving the Company's plan of arrangement (the "Arrangement") with Fortescue Ltd ("Fortescue") and its wholly owned subsidiary, Nascent Exploration Pty Ltd (the "Purchaser").

The special meeting of shareholders and optionholders of Alta Copper to consider and vote on the Arrangement is scheduled for Monday, January 26, 2026 at 10:00 a.m. (Vancouver time) at Gowling WLG (Canada) LLP, Suite 2300-550 Burrard Street, Vancouver, British Columbia, Canada. Under the Arrangement, shareholders will receive C$1.40 in cash for each Alta Copper common share held.

Independent Third-Party Proxy Advisory Recommendations

ISS stated:

"The cash consideration offers a fair premium over the unaffected market price, delivering immediate value and certainty to shareholders; [...] shareholders can reasonably be assured that the consideration is competitive, with no indication of alternative offers likely to emerge. This is further supported by the positive market reaction and credibility of the valuation."

Giulio T. Bonifacio, President and Chief Executive Officer of Alta Copper, commented:

"ISS' and other proxy advisory firms' recommendations reinforce the Board's unanimous recommendation that shareholders vote FOR the Arrangement. The Arrangement provides Alta Copper shareholders with all-cash consideration of C$1.40 per share, delivering immediate value and certainty. We encourage all shareholders to vote as soon as possible and well in advance of the proxy deadline."

Benefits of the Arrangement

• All-cash consideration of C$1.40 per share, providing immediate liquidity and certainty of value

• Supported by independent fairness opinions and a formal valuation

• Negotiated and evaluated by an independent special committee of the Board

Shareholders Encouraged to Vote Ahead of the Proxy Deadline

The Board of Directors of Alta Copper recommends that shareholders vote FOR the Arrangement.

The proxy voting deadline is 10:00 a.m. (Vancouver time) on Thursday, January 22, 2026. Shareholders are encouraged to vote well in advance of the proxy voting deadline to ensure their vote is submitted in a timely manner. Due to the essence of time, shareholders may vote online or by telephone to ensure their votes are received in a timely manner. Alta Copper is using Broadridge's QuickVote^™ service to solicit votes over the telephone from eligible beneficial shareholders.

Required Vote Approval

To become effective, the Arrangement must be approved by: (i) at least 66 2/3% of the votes cast by shareholders; (ii) at least 66 2/3% of the votes cast by shareholders and optionholders, voting as a single class; and (iii) a simple majority of the votes cast by shareholders, excluding votes cast by the Purchaser and its affiliates, and other persons required to be excluded under Multilateral Instrument 61-101 - Protection of Minority Security Holders in Special Transactions of the Canadian Securities Administrators.

Shareholder Questions & Voting Assistance

Alta Copper has retained Laurel Hill Advisory Group ("Laurel Hill") to assist the Company in connection with its communication with shareholders.

Shareholders who have questions or require voting assistance may contact Laurel Hill at:

Laurel Hill Advisory Group

Call or Text Toll-Free (North America): 1-877-452-7184

Call or Text Outside North America: +1-416-304-0211

Email: assistance@laurelhill.com

Cautionary Note Regarding Forward Looking Statements

This press release may contain forward-looking information within the meaning of Canadian securities laws ("forward-looking statements"). Forward-looking statements are typically identified by words such as "believe," "expect," "anticipate," "intend," "estimate," "plans," "postulate," and similar expressions, or are those which, by their nature, refer to future events. All statements that are not statements of historical fact are forward-looking statements, including, but not limited to, statements regarding management's beliefs, plans, estimates, and intentions; the Arrangement and the ability to complete it and other transactions contemplated by the arrangement agreement; the timing and satisfaction of conditions to consummation of the Arrangement; the receipt of required securityholder, regulatory, and court approvals; the possibility of termination of the arrangement agreement; and the expected benefits to Alta Copper and its securityholders. Any forward-looking statements are made as of the date of this press release and, although Alta Copper believes such statements are reasonable, there can be no assurance that expectations and assumptions will prove to be correct. Forward-looking statements are not guarantees of future results or performance and are subject to risks, uncertainties, assumptions, and other factors that could cause actual results or outcomes to differ materially from those expressed or implied, including, but not limited to: the possibility that the Arrangement will not be completed on the terms or timing currently contemplated, or at all; failure to obtain or satisfy required regulatory (including matters in relation to the Investment Canada Act), securityholder, or court approvals and other closing conditions; the negative impact of a failed Arrangement on the price of Alta Copper Shares or the Company's business; the Purchaser's failure to pay the consideration at closing; failure to realize expected benefits of the Arrangement; restrictions imposed on Alta Copper while the Arrangement is pending; significant transaction costs or unknown liabilities; diversion of management's attention from ongoing business operations; and other risks and uncertainties affecting Alta Copper, including those relating to permitting, capital expenditures, exploration and development activity, and the future price and demand for gold, copper, and other metals. Accordingly, readers should not place undue reliance on forward-looking statements. Alta Copper disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events, or otherwise, except as required by law. The securities referred to in this press release have not been, nor will they be, registered under the United States Securities Act of 1933, as amended, and may not be offered or sold within the United States or to, or for the account or benefit of, U.S. persons absent U.S. registration or an applicable exemption from the U.S. registration requirements. Further information concerning risks, assumptions, and uncertainties associated with forward-looking statements and Alta Copper's business can be found in Alta Copper's Annual Information Form for the year ended December 31, 2024, and in subsequent filings available under the Company's profile on SEDAR+ (www.sedarplus.ca).

SOURCE: Alta Copper Corp.