25 June 2025

Mosman Oil and Gas Limited

("Mosman" or the "Company")

Leadership Restructuring

Mosman Oil & Gas Limited (AIM:MSMN), today announces a strategic restructuring of its leadership team to align with its ambitious growth objectives. As part of this initiative Andy Carroll has stepped down from his position as Chief Executive Officer. Howard McLaughlin, currently Head of U.S. Operations, will assume the role of interim CEO during this transition process.

During his nearly two-year tenure as CEO and many years as Technical Director prior to then, Andy Carroll has advanced Mosman's exploration and development projects, particularly in the United States. The Company acknowledges his contributions and wishes him well with his future endeavours. 

Howard McLaughlin, who has been leading Mosman's U.S. operations, is, subject to the completion of customary due diligence, expected to step into the role of interim CEO. In this non-board position, Howard will focus on ensuring continuity and advancing the Company's strategic objectives. 

Mosman has also agreed to settle the options granted to Mr. Carroll under resolution five at the 2024 Annual General Meeting, with the settlement scheduled for completion by 30 June 2025. The Company will update shareholders once a decision is made regarding the appointment of a new Chief Executive.

To support its growth strategy, Mosman is initiating a comprehensive corporate review to strengthen its management team. This review will focus on enhancing the Company's operational presence in the United States, where its core projects are located. The Company aims to build a leadership structure that supports its ambition to capitalise on opportunities in the helium, hydrogen, and hydrocarbon markets, delivering sustainable growth and operational cash flow.

In parallel, Mosman will also conduct a review of its asset portfolio to ensure it is maximising value for shareholders. This assessment will evaluate the Company's projects in the United States, as well as its royalty interests in Australia, to align with its long-term objectives of portfolio expansion, production, and revenue generation.

Mosman Chairman, Carl Dumbrell, commented: "We are grateful for Andy's work over his tenure at Mosman. With Howard, our Head of U.S. Operations, stepping into the role of interim CEO, we are confident in the Company's ability to maintain momentum. I am excited about the opportunities ahead for Mosman and we are committed to expanding our presence in America and optimising our asset portfolio to drive substantial value for shareholders. We deeply appreciate the continued support of our investors and remain dedicated to achieving our ambitious goals."

Market Abuse Regulation (MAR) Disclosure

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 information is now considered to be in the public domain.

Enquiries:

Updates on the Company's activities are regularly posted on its website: www.mosmanoilandgas.com

Notes to editors

Mosman (AIM: MSMN) is a helium, hydrogen and hydrocarbon exploration, development, and production company with projects in the US and Australia. Mosman's strategic objectives remain consistent: to identify opportunities which will provide operating cash flow and have development upside, in conjunction with progressing exploration. The Company has several projects in the US, in addition to exploration projects in the Amadeus Basin in Central Australia.