Fortescue to Acquire Alta Copper for C$1.40 per Share

VANCOUVER, BC / ACCESS Newswire / December 14, 2025 / Alta Copper Corp. (TSX:ATCU)(OTCQX:ATCUF)(BVL:ATCU) ("Alta Copper" or the "Company") is pleased to announce that it has entered into a definitive arrangement agreement (the "Arrangement Agreement") with Fortescue Ltd ("Fortescue") and its wholly owned subsidiary, Nascent Exploration Pty Ltd ("Nascent" or the "Purchaser"), pursuant to which the Purchaser will acquire all of the issued and outstanding common shares of Alta Copper (the "Alta Copper Shares") not already held by the Purchaser (the "Transaction"). The Purchaser currently holds 33,638,304 Alta Copper Shares, representing 35.7% of the issued and outstanding Alta Copper Shares.

Under the terms of the Transaction, holders of Alta Copper Shares ("Alta Copper Shareholders") will receive C$1.40 in cash per Alta Copper Share (the "Purchase Price"), valuing the Company at approximately C$138.8 million on a fully diluted basis. The consideration will be funded from Fortescue's existing cash reserves.

The Board of Directors of Alta Copper (the "Board") and its special committee have 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 is in the best interests of Alta Copper, and the Board recommends that Alta Copper Shareholders vote FOR the Transaction. Alta Copper believes the Transaction is in the best interests of Alta Copper Shareholders for the following reasons:

• The Purchase Price represents a significant premium, including:

• 50% premium to the 30-day volume-weighted average trading price ("VWAP") of the Alta Copper Shares in Canada of C$0.94 per share for the period ended December 12, 2025, being the last trading day before the Arrangement Agreement was entered into; and

• 100% premium to the 30-day VWAP of the Alta Copper Shares in Canada of C$0.70 per share for the period ended November 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.

• 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.