Panther Metals PLC - Winston: SRK appointed

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PANTHER METALS PLC

("Panther" or the "Company")

(Incorporated in the Isle of Man with company number 009753V)

22 September 2025

Winston Tailings Project: Mineral Resource Appointment

SRK Appointed To Conduct Mineral Resource Estimate

Panther Metals Plc (LSE: PALM), the exploration company focused on mineral projects in Canada, is pleased to announce the appointment of SRK Exploration Ltd ("SRK EX") as independent consultants to conduct a Mineral Resource estimate ("MRE") for the Winston Tailings Project in Ontario, Canada.^{1, 2, 3}

The MRE will be one of a series of workstreams to quantify, evaluate and permit the contained high-grade gold (Au), gallium (Ga), silver (Ag), zinc (Zn), copper (Cu) and cobalt (Co) and other recoverable minerals located within the historic Winston Lake Mine tailings storage facility ("TSF").

The MRE is an integral part of the process to advance the Winston Tailing Project through permitting towards a cashflow proposition and will be based upon the resource drilling programme, mineralogical and metallurgical testwork and associated studies which will be conducted during Q3 and Q4 2025.

Panther is aiming for a seamless transition from MRE to Ore Reserves in as short a time as possible, and it is envisaged that successful outcomes to the tailing MRE, will in turn support the declaration of Ore Reserves following further technical studies.  The SRK EX work will also provide inputs into the Application for Recovery of Minerals Permit (the "Recovery Permit") process as announced 1 September 2025.^{3, 4}

The MRE will be reported in compliance with the standards and best practices set out by the Canadian Institute of Mining, Metallurgy and Petroleum's ("CIM") for reporting Mineral Resources, Ore Reserves, and related exploration information. This will also facilitate future NI 43-101 reporting, as required.

About SRK Exploration

SRK EX is an associate company of the international group holding company, SRK Consulting (Global) Ltd (the "SRK Group"), which constitutes one of the world's premier independent mining consultancies and which includes over 1,800 professional personnel in 43 offices in 19 countries worldwide, providing expertise in a wide range of exploration, mining and engineering disciplines. The SRK Group has a demonstrated track record in undertaking independent assessments of Mineral Resources and Ore Reserves, project evaluations and audits, competent person's reports and independent feasibility evaluations on behalf of exploration and mining companies and financial institutions world-wide.

SRK EX will work in conjunction with resource, tailings and mineral processing specialists based in SRK Group offices in both Canada and United Kingdom.

SRK EX has extensive experience of drilling and sampling in unconsolidated materials such as those that may be found in the TSF at Winston, including sampling underwater. Members of the proposed team also have extensive experience in Mineral Resource estimation for tailings for a wide variety of commodities and industrial minerals.

Background

The Winston Tailings Project entails a series of workstreams to quantify, evaluate and permit the contained high-grade gold (Au), gallium (Ga), silver (Ag), zinc (Zn), copper (Cu) and cobalt (Co) and other recoverable minerals located within the historic Winston Lake Mine tailings storage facility. Reprocessing the mine tailings, potentially offers Panther the opportunity to unlock residual metal value and contribute to the long-term environmental rehabilitation of the Winston Project site.^{1, 2}

The Winston Lake Mine was operational from 1988 to 1998, producing approximately 3.3 million tonnes of ore and yielding zinc, copper, silver, and gold. Based on historic recoveries from mining activities in the 1980s and 1990s, it is believed that a significant quantity of valuable material remains in the tailing storage facility.

Source: NI 43-101 Technical Report Feasibility Study for the Superior Zinc and Copper Project, 2021. Site is connected to high-voltage grid power.

Figure 1: Existing Infrastructure at Winston Tailings Storage Facility

References

1.             Panther Metals PLC, announcement, Winston Tailings Assays Confirm Gold, Gallium, Silver, Zinc, Copper & Cobalt, Tailings Sample Assay Results Exceed Expectations, dated 31 July 2025 ( https://polaris.brighterir.com/public/panther_metals/news/rns/story/w00eo6w )

2.             Panther Metals PLC, announcement, Tailings Sampling Programme Underway at Winston Project, dated 15 July 2025 (https://polaris.brighterir.com/public/panther_metals/news/rns/story/w606ngw  )

3.             Panther Metals PLC, announcement, Winston Tailings: Gold & Critical Mineral Reprocessing, Evaluation and Permitting Workstreams Commencing, dated 8 August 2025
(  https://polaris.brighterir.com/public/panther_metals/news/rns/story/rm7movr )

4.             Panther Metals PLC, announcement, Winston Tailings Project Update and Warrant Expiry, Permitting Process Commenced. Warrant Expiry Notice , dated 1 September 2025
( https://polaris.brighterir.com/public/panther_metals/news/rns/story/x20od6r )

5.             Recovery of Minerals Permitting process details available at https://www.ontario.ca/page/recovery-minerals

For further information, please contact:

Panther Metals PLC:

Darren Hazelwood, Chief Executive Officer:            +44(0) 1462 429 743

                                                                                  +44(0) 7971 957 685

Broker:

SI Capital Limited

Nick Emerson                                                             +44(0) 1438 416 500

Winston Project

The Panther Metals Winston Project, located 150km east of Thunder Bay, Ontario, Canada, is an advanced stage polymetallic zinc, copper and precious metal property comprising a high-grade critical mineral mine redevelopment and resource building opportunity. Based on a Feasibility Study published in 2021 the Project is expected to generate average life of mine ("LOM") annual EBITDA of C$67.64 million (M) and have a pre-tax NPV_8% of C$ 175.8 M and IRR of 26%, with further strong exploration potential for defining additional Mineral Resources and Mineral Reserves from the two main deposits as well as additional near-mine volcanogenic massive sulphide ("VMS") exploration targets.

2021 Feasibility Study Headline Metrics

·      NPV_8%:              C$175.8M pre-tax, assuming zinc priced at US$2,700/t, copper at US$7,300/t,                 gold at US$1,635/oz & silver at US$21/oz. At a derisked 6% discount                            
Pre-tax NPV = C$213.2M.

·      IRR:                  26% pre-tax

·      EBITDA :          C$574.9M (gross), C$67.64M (annual). Gross revenue: C$983.3M

·      CAPEX:            C$145.1 M

·      OPEX:              C$65.17/t

·      LOM:              Initial 8.5 year life of mine, with 3.5 year pay-back period. Strong potential to increase LOM.

·    Producing an average 33.40ktpa contained zinc,1.3ktpa contained copper, 698oz recovered gold and 90.8koz recovered silver (after ramp-up), from an onsite processing facility with an annualised 326ktpa capacity.

·    The unit pricing for copper, gold and silver, concentrate payable percentages and exchange rates, are positively different from 2021 in today's dollars, providing scope for additional value uplift.

·      Indicated Resource 2.07 Million Tonnes @ 18% Zn

·      Volcanogenic Massive Sulphide mineralisation well understood by Panther.

·      Panther plans to build value through extending the mine life utilising the Company's strong local exploration network and leveraging institutional, governmental and critical mineral programme support.

·      No name discussions in Canada have indicated strong support for this deal on an asset base previously supported by industry heavyweights, including Sprott.

·      Strong prospects to increase Mineral Resources and Mineral Reserves through exploration down-dip and along strike of the current Resources.

·      Zinc and Copper deemed Critical Minerals in Canada, eligible for enhanced tax-efficient flow-through funding.

·      Positive First Nation engagement.

·      Strong Institutional and Governmental support for future financing options.

·      Existing historical tailings storage facility offers potential for near-term cash-flow subject to further studies.

Highly prospective near mine exploration targets include the Pick Lake Deposit which is not fully constrained and is considered to be open down-plunge; the Winston Lake Deposit where there are strong electromagnetic ("EM") geophysics conductive bodies adjacent to the current Resource; and in the vicinity of historical Zenith deposit.  The wider project area is relatively underexplored and there are several prospective surface zinc targets, including Anderson, Trial and Ciglen, and the VMS hosting horizons along strike strongly warranting geophysical investigation.

The 2021 Feasibility Study¹ for the Winston Project detailed a strong economic case for mine redevelopment for a 1,000 tonnes per day underground operation with a net present value (NPV_8%) of C$171.5M and pre-tax internal rate of return (IRR) of 26% based on an Ore Reserve of 1.96Mt @ 13.9% Zn, 0.6% Cu with significant gold and silver credits (Table 1) producing an expected 69.8 thousand tonnes per year (ktpa) of zinc concentrate and 5.3 ktpa of copper concentrate over an initial 8.5 year mine life. The Project boasts a high-grade CIM compliant Indicated Mineral Resource² of 2.07Mt averaging 17.9% zinc, 0.8% copper, 0.4 g/t gold, and 34 g/t silver plus Inferred 0.27Mt @ 16.2% Zn, 1.0% Cu, 0.3g/t Au & 37.2g/t Ag (Table 2).  Project is located only 20km from the trans-Canada highway and infrastructure including power, tailings storage facility, transport links and underground development are already in place. The previous mining operation closed in February 1999 due to very low zinc prices at the time. In total, 3.4 million tonnes grading 1.0% copper and 16% zinc was mined and processed. The total project area covers approximately 60.4km² and comprises both patented freehold, leased and Crown-land mining claims.

Table 1: Winston Project Mineral Reserve

Notes: JORC (2012) compliant Mineral Reserve effective date 5 July 2019. Ore Reserves are based solely on Indicated Mineral Resources and are reported above an average net smelter return (NSR) cut-off grade of US$98 /t equivalent to 5.2% Zn. ¹

Table 2: Winston Project Mineral Resource Estimate at 3% Zn cut-off grade

Notes: Effective date 15 October 2020. Stated at 3% zinc cut-off grade. Mineral Resource estimate is compliant with the Canadian Institute of Mining, Metallurgy and Petroleum ("CIM"), CIM Standards on Mineral Resources and Reserves, Definitions and Guidelines prepared by the CIM Standing Committee on Reserve Definitions. Mineral resources which are not mineral reserves do not have demonstrated economic viability. There has been insufficient exploration to define the inferred resources tabulated above as an indicated or measured mineral resource, however, it is reasonably expected that the majority of the Inferred Mineral Resources could be upgraded to Indicated Mineral Resources with continued exploration.

Technical References:

1              NI 43-101 Technical Report Feasibility Study for the Superior Zinc and Copper Project, dated 13 October 2021, prepared for Metallum Resources Inc by DRA Global ("DRA").

2              NI 43-101 Technical Report on the Mineral Resource Estimation of the Pick Lake and Winston Lake Properties, Ontario, Canada, dated 15 October 2020, prepared for CROPS Inc. (renamed Metallum Resources Inc) by MASSA Geoservices.

Competent Person Statement

Technical information in this announcement has been reviewed by Nicholas O'Reilly BSc (Hons) MSc DIC MIMMM QMR MAusIMM FGS, a director of the Company. Mr O'Reilly is principal geologist and a director of Mining Analyst Consulting Ltd. He has over 20 years' experience in mining, exploration and development across all major commodities. As a qualified geologist, he can act as Competent Person for JORC Code and UK Listing Rules purposes.

Obonga Project - Expanding Canada's Next VMS and Critical Minerals District

Panther Metals' Obonga Project in Ontario continues to demonstrate significant potential as a leading exploration initiative targeting both base and critical minerals. Since acquiring the Obonga Greenstone Belt in July 2021, the Company has rapidly advanced five high-priority targets: Wishbone, Awkward, Survey, Ottertooth, and Silver Rim.

In June 2024, Panther secured a key Exploration Permit for the Wishbone Prospect, valid through 2027, authorizing extensive drilling and geophysical surveys. Previous campaigns confirmed compelling volcanogenic massive sulphide (VMS)-style mineralisation, highlighted by intercepts such as 27.3m of massive sulphide and 51m of sulphide-dominated mineralisation with multiple mineralised lenses. High-grade copper anomalies in lake sediment further enhance the prospectivity of this landmark target.

July 2024 saw Panther awarded an Exploration Permit for Awkward West, supporting an aggressive exploration program including up to 31 drill holes. Historic drilling here revealed notable graphite mineralisation-27.2m at 2.25% Total Graphitic Carbon (TGC) with zones exceeding 5% TGC-alongside promising signs of nickel, copper, and platinum group elements, aligning with Panther's strategic focus on critical minerals.

Additional exploration efforts include high-resolution magnetic geophysical surveys across key prospects, optimizing drill targeting and advancing the geological model. Survey and Ottertooth remain highly prospective, with multiple magnetic and electromagnetic anomalies and historic intercepts of massive sulphides, many targets still largely untested.

Obonga's combination of VMS-style base metals and critical mineral potential, situated in a stable and mining-friendly jurisdiction with strong infrastructure, positions Panther Metals to unlock a district-scale mineral system with significant commercial upside.

Dotted Lake Project - Hemlo-Adjacent Gold Opportunity with Growing Momentum

Panther Metals' Dotted Lake Project, acquired in July 2020, lies just 16km from Barrick Gold's renowned Hemlo Mine, in one of Canada's premier gold-producing regions. The project offers a strategically located and scalable gold exploration play.

Initial soil sampling in 2021 identified numerous gold and base metal targets, and subsequent access improvements facilitated an initial drilling program that confirmed gold mineralisation with anomalous values extending along strike.

In early 2025, Panther completed a follow-up campaign featuring detailed geological mapping, trenching, and targeted diamond drilling. These efforts extended mineralisation both laterally and at depth, identified new structural controls, and reinforced the potential for a broader, high-grade gold system. Multiple zones have been prioritised for expanded drilling, underscoring Dotted Lake's significant upside.

The project's proximity to established infrastructure and Hemlo's extensive mining operations, combined with robust recent results, makes Dotted Lake a key asset in Panther's growth portfolio.

Commercial Strategy - Discovery-Driven Value Creation

Panther Metals is committed to creating substantial shareholder value through focused exploration and disciplined capital management. The Company combines deep geological expertise with an understanding of market and financing dynamics to advance high-potential projects efficiently.

With access to a global network of industry leaders and a rigorous operational focus on drilling, Panther prioritises activities that directly contribute to discovery and resource growth. The drill hole remains the ultimate validation in mineral exploration, and Panther's strategy is to fast-track world-class targets into drill-ready assets - delivering tangible results that underpin long-term value creation for shareholders.