Winston Project Update

Panther Metals Plc (LSE: PALM), the exploration company focused on mineral projects in Canada, is pleased to confirm a variation to the Option and Sale and Purchase Agreement with Frontier Energy Ltd ("Frontier"), announced 17 June 2025. Under the variation agreement the Option Period is extended to 29th October 2025, with all other terms unchanged. The agreement with First Quantum Minerals Ltd is separate and not affected.1

References

• Panther Metals PLC, announcement, Winston High-Grade Brownfield Critical Minerals Project, Panther Metals Secures Feasibility Study Stage Multi Element VMS Opportunity, dated 17 June 2025

( https://polaris.brighterir.com/public/panther_metals/news/rns/story/x4204pr )

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$67.64 million (M) and have a pre-tax NPV8% of C$ 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

• NPV8%: 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 (NPV8%) 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.

Commercial Strategy - Discovery-Driven Value Creation