16 February 2026

Pantheon Resources plc

AGM Arrangements & Corporate Update

Pantheon Resources plc (AIM:PANR, OTCQX: PTHRF) ("Pantheon" or the "Company"), the oil and gas company developing the Kodiak and Ahpun oil fields in close proximity to pipeline and transportation infrastructure on Alaska's North Slope, is pleased to provide the following update.

AGM arrangements

The Company's AGM will be held virtually on Thursday, 12 March 2026 at 3:00 pm GMT. The meeting will be hosted by Computershare and chaired in person from Pantheon's Houston office at 2603 Augusta Drive, Suite 1080, Houston, Texas 77057. Registered shareholders will have full voting functionality.

A separate investor presentation and Q&A to be held as a webinar (details below) will follow at 4:00 pm GMT, open to all shareholders and the wider public.

Further details on the logistics for this year's AGM are set out in the Notice of AGM which will be made available on the Shareholder Documents section of the Company's website and is expected to be posted to registered holders by close of business tomorrow.

Board Update

Following the AGM, David Hobbs will transition from Executive Chair to Non‑Executive Chair, in line with previous guidance.

The Company also announces that Allegra Hosford Scheirer has stepped down from the Board, effective 13 February 2026, and will not seek re‑election. The Board thanks Allegra for her significant contributions, particularly her leadership in subsurface geology.

Commenting on the changes, David Hobbs said: "On behalf of the Board, I would like to express our sincere appreciation to Allegra for her invaluable contribution over the past two and a half years and her foundational contribution to the exploration programme from the early days of Great Bear Petroleum. Her world‑class expertise has been instrumental as we advanced our understanding of the geology. As we shift our focus toward engineering execution, we will continue to align Board composition with the Company's evolving needs.

"As I transition to Non‑Executive Chair, I do so with full confidence in our strong executive team and the exciting pathway ahead."

Operational Update

The Company is pleased to announce that it has formally commenced seismic reprocessing focused on the north west section of the Company's Kodiak project, updip from the Theta West-1 discovery well.  The Theta-West-1 well was previously reported by Wood Mackenzie as being the fourth largest discovery well globally in 2022, and the largest onshore discovery well globally in 2022. The Company is performing preliminary activities for a potential Theta West-2 appraisal well, with timing and execution subject to funding, permitting, and operational considerations.

Additionally, the Company is pleased to report that it will be hosting a booth at the 2026 NAPE (North American Prospect Expo) event from 18 - 20 February. This is a major event in the North American energy industry and Pantheon will have an opportunity to present its projects to a new audience and to network with other industry participants.

Webinar details

The post‑AGM investor webinar presentation and Q&A will be open to all existing and potential shareholders and will be hosted on the Investor Meet Company platform commencing at 4:00pm GMT. Pre‑registration is available at: https://www.investormeetcompany.com/pantheon-resources-plc/register-investor. A copy of the presentation will be made available on the Company's website prior to the meeting.

Shareholders already following Pantheon on the 'Investor Meet Company' platform will receive an automatic invitation.

-ENDS-

Further information:

About Pantheon Resources

Pantheon Resources plc is an AIM listed Oil & Gas company focused on developing its 100% owned Ahpun and Kodiak fields located on State of Alaska land on the North Slope, onshore USA. Independently certified best estimate contingent recoverable resources attributable to these projects currently total c. 1.6 billion barrels of ANS crude and 6.6 Tcf of associated natural gas. The Company owns 100% working interest in c. 259,000 acres.

Pantheon's stated objective is to demonstrate sustainable market recognition of a value of approximately $5 per barrel of recoverable resources. This is based on bringing the Ahpun field to FID and first production into the TAPS main oil line (ANS crude). The Gas Sales Precedent Agreement signed with AGDC provides the potential for Pantheon's natural gas to be produced into the proposed 807mile pipeline from the North Slope to Southcentral Alaska during 2029. The Company intends to apply cashflows from Ahpun to support the FID for the Kodiak field.

A major differentiator to other ANS projects is the close proximity to existing roads and pipelines which offers a significant competitive advantage to Pantheon, allowing for shorter development timeframes, materially lower infrastructure costs and the ability to support the development with a significantly lower pre-cashflow funding requirement than is typical in Alaska. Furthermore, the low CO2 content of the associated gas allows export into the planned natural gas pipeline from the North Slope to Southcentral Alaska without significant pre-treatment.

The Company's project portfolio has been endorsed by world renowned experts. Netherland, Sewell & Associates estimate a 2C contingent recoverable resource in the Kodiak project that total 1,208 mmbbl of ANS crude and 5,396 bcf of natural gas. Cawley Gillespie & Associates estimate 2C contingent recoverable resources for Ahpun's western topset horizons at 282 mmbbl of ANS crude and 803 bcf of natural gas. Lee Keeling & Associates estimated possible reserves and 2C contingent recoverable resources of 79 mmbbl of ANS crude and 424 bcf natural gas.

For more information visit www.pantheonresources.com.