Brokered LIFE Private Placement is Oversubscribed

Orosur Announces that its Brokered LIFE Private Placement is Oversubscribed and Fully Allocated

London, September 25th, 2026. Orosur Mining Inc. (“Orosur” or the “Company”) (TSX-V/AIM:OMI) is pleased to announce that, further to its news release dated September 22, 2026, the Company’s previously announced “best efforts” private placement (the “Base Offering”) is oversubscribed and fully allocated. Pursuant to the Base Offering, the Company intends to raise gross proceeds of up to C$14,000,000 through the sale of up to 43,750,000 units of the Company (the “Units”) at a price of C$0.32 (being approximately GBP £0.17) per Unit (the “Offering Price”). Red Cloud Securities Inc. (the “Agent”) is acting as sole agent and bookrunner, together with U.K. corporate brokers Turner Pope Investments (TPI) Ltd. and Greenwood Capital Partners Limited, in connection with the Offering (as herein defined).

Orosur Executive Chairman Louis Castro commented:

“We are delighted at the take up of the Offering and the oversubscription in difficult market conditions. We appreciate the support of existing and new investors. The proceeds will be spent almost exclusively on drilling at the Company’s Anza project in Colombia, including at our most recent target at El Cedro. The funds will allow us to start to show the true potential of the project”

Each Unit will consist 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 shall entitle the holder to purchase one common share of the Company (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$0.45 and approximately GBP £0.24) at any time during the period beginning on the date that is 61 days following the Closing Date (as herein defined) and ending on the date which is 24 months following the Closing Date.

The Company has also granted the Agent the option, exercisable in full or in part, up to 48 hours prior to the Closing Date, to sell up to an additional 6,250,000 Units at the Offering Price for up to an additional C$2,000,000 in gross proceeds (the "Agent’s Option", and together with the Base Offering, the “Offering”).

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

Subject to compliance with applicable regulatory requirements and in accordance with National Instrument 45-106 – Prospectus Exemptions (“NI 45-106”), up to 43,125,000 Units (the “LIFE Units”) may be offered and sold in Canada to purchasers resident in the provinces of Alberta, British Columbia, Manitoba, Ontario, and Saskatchewan pursuant to the listed issuer financing exemption under Part 5A of NI 45-106, as amended by Coordinated Blanket Order 45-935 – Exemptions from Certain Conditions of the Listed Issuer Financing Exemption (the “Listed Issuer Financing Exemption”). The Underlying Securities from the sale of the LIFE Units will not be subject to a hold period under Canadian securities legislation. All Units not sold to Canadian purchasers pursuant to the Listed Issuer Financing Exemption (the “Non-LIFE Units”) will be offered by way of the “accredited investor” and “minimum amount investment” exemptions under NI 45-106 in the Canadian Selling Jurisdictions. The Underlying Securities issuable from the sale of Non-LIFE Units will be subject to a hold period in Canada under Canadian securities legislation. The Units may also be offered for sale to purchasers outside of Canada, including but not limited to purchasers resident in the United States, pursuant to an available exemption from the registration requirements of the United States Securities Act of 1933, as amended (the “U.S. Securities Act”) and similar exemptions under applicable securities laws of any state of the United States (as such term is defined in Rule 902(l) of Regulation S under the U.S. Securities Act).

The Offering is scheduled to close on or around October 6, 2026 (the “Closing Date”), or such other date as the Company and the Agent may agree and is subject to certain conditions including, but not limited to, receipt of all necessary approvals including the approval of the TSX Venture Exchange and admission of the Common Shares to the AIM Market of London Stock Exchange plc.

There is an offering document (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. Prospective investors in Canada should read the Offering Document before making an investment decision.

The securities offered have not been, nor will they be, registered under the U.S. Securities Act, or any state securities laws, and may not be offered, sold or delivered, directly or indirectly, within the United States or to, or for the account or benefit of, U.S. persons (as such terms are defined in Regulation S under the U.S. Securities Act), absent registration or an exemption from such registration requirements. This news release does not constitute an offer to sell or the solicitation of an offer to buy nor shall there be any sale of securities in any state in the United States in which such offer, solicitation or sale would be unlawful.

For further information, visit www.orosur.ca, follow on X @orosurm or please contact:

Orosur Mining Inc

Louis Castro, Chairman,

Brad George, CEO

[email protected]

Tel: +1 (778) 373-0100

SP Angel Corporate Finance LLP – Nomad & Joint Broker

Jen Clarke / Caroline Rowe / Devik Mehta

Tel: +44 (0) 20 3470 0470

Turner Pope Investments (TPI) Ltd – Joint Broker

Andy Thacker/Guy McDougall
Tel: +44 (0)20 3657 0050

Flagstaff Communications and Investor Communications

Tim Thompson
Alison Allfrey
Fergus Mellon

[email protected]

Tel: +44 (0)207 129 1474

The information contained within this announcement is deemed by the Company to constitute inside information as stipulated under the Market Abuse Regulations (EU) No. 596/2014 ('MAR') which has been incorporated into UK law by the European Union (Withdrawal) Act 2018. Upon the publication of this announcement via Regulatory Information Service ('RIS'), this inside information is now considered to be in the public domain.

Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.