Closing of Private Placement for C$16 Million

London, October 6, 2026. Orosur Mining Inc. (“Orosur” or the “Company”) (TSX-V/AIM:OMI) is pleased to announce the closing of its previously announced “best efforts” private placement (the “Offering”) for aggregate gross proceeds of C$16,000,000, which includes gross proceeds of C$2,000,000 through the full exercise of the agent’s option. Pursuant to the Offering, the Company sold 50,000,000 units of the Company (the “Units”) at a price of C$0.32 per Unit (being approximately GBP £0.17 at an exchange rate of £0.53:C$1.00).

Each Unit consists of one common share of the Company (each, a "Common Share") and one-half of one common share purchase warrant (each whole warrant, a "Warrant"). Each whole Warrant entitles the holder to purchase one Common Share (each, a "Warrant Share", and the Warrant Shares underlying the Warrants together with the Common Shares to be referred to as the “Underlying Securities”) at a price of US$0.32 (being approximately C$0.46 and approximately GBP £0.24) for a period of 24 months following closing of the Offering.

The Company intends to use the net proceeds of the Offering, which should fund the Company into late 2027, principally to advance the Company's Anzá exploration project in Colombia as well as for general working capital and corporate purposes.

Red Cloud Securities Inc. ("Red Cloud") acted as sole agent and bookrunner in connection with the Offering. In consideration for its services, Red Cloud received a cash commission of C$520,000. Turner Pope Investments (TPI) Ltd and Greenwood Capital Partners Limited (collectively, the "U.K. Brokers") acted as brokers in connection with a portion of the Offering in the United Kingdom. In consideration of their services, the U.K. Brokers received aggregate cash commissions and fees of £239,760 (equivalent to approximately C$451,600).

26,562,500 Units (the “Exempt Units”) were issued in accordance with Part 5A.2 of National Instrument 45-106 – Prospectus Exemptions, as amended by Coordinated Blanket Order 45-935 – Exemptions from Certain Conditions of the Listed Issuer Financing Exemption, or pursuant to OSC Rule 72-503 – Distributions Outside of Canada. The Underlying Securities from the sale of the Exempt Units are not subject to a hold period under Canadian securities legislation.

There is an offering document dated September 22, 2026 (the “Offering Document”) related to the Offering in Canada that can be accessed under the Company’s profile at www.sedarplus.ca and on the Company’s website at www.orosur.ca.

Admission and Total Voting Rights

Application has been made for the 50,000,000 Common Shares, which rank pari passu with the existing common shares in issue, to be admitted to trading on AIM ("Admission"). It is expected that Admission will become effective and dealings will occur at 8:00 a.m. (UK time) on or around October 7, 2026. Application has also been made for the 25,000,000 Common Shares, which will satisfy the future exercise of Warrants, to be admitted to the Company’s block listing facility on or around October 7, 2026. The Warrants will not be admitted to trading and are not being exercised at this time.

Following the issue of 50,000,000 Common Shares, which, on Admission will rank pari passu with the existing Common Shares, the total number of Common Shares in issue with voting rights in the Company will be 452,196,324. Shareholders may use this figure as the denominator for the calculations by which they will determine if they are required to notify their interest in, or a change in their interest in, the share capital of the Company under the FCA’s Disclosure and Transparency Rules. There are no shares held in treasury.

The closing of the Offering remains subject to the final approval of the TSX Venture Exchange (the “TSX-V”).