Corporate update, Exercise of options and warrants

London, September 25, 2025. Orosur Mining Inc. ("Orosur" or the "Company") (TSX/AIM:OMI) announces the following:

Corporate update: the Company's upsized brokered private placement to raise up to C$20 million, (the "Offering"), which was announced on September 18, 2025 is now scheduled to close on October 2, 2025. The Offering comprises the issue of up to 58,823,530 new common shares of the Company ("Common Shares").

Application has been made for up to 58,823,530 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 8:00am UK time on or around October 3, 2025.

Exercise of options and warrants: the Company has issued 260,000 Common Shares representing 0.08% of the Company's current issued share capital, following the exercise of options by two consultants of the Company at an exercise price of C$0.22 and C$0.325 for 140,000 and 120,000 Common Shares respectively. No members of the board, or Company executives have exercised any options.

Additionally, 8,675,418 Common Shares were issued for a total consideration of US$701,894 following an exercise of 8,675,418 warrants during September from the Company's block listing, announced on January 8, 2025.

Following Admission of these 260,000 Common Shares relating to the options, and also the 8,675,418 warrants exercised in September, for the purposes of the Disclosure Guidance and Transparency Rules, the Company will have 325,758,894 Common Shares in issue. 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 to their interest in, the issued share capital of the Company.

Following Admission, the Company will have 4,701,668 options outstanding and 22,834,404 warrants outstanding.