Vecta Project Update.

17 June 2025

Mosman Oil and Gas Limited

("Mosman" or the "Company")

Vecta Project Update

Mosman Oil and Gas Limited (AIM:MSMN) the helium, hydrogen and hydrocarbon exploration, development and production company, announces an update on the Vecta Project in Colorado, US.

Mosman has negotiated an increase from 20% to 90% interest in the "The Bard" Area of Mutual Interest ("AMI") lease area, in return for funding 100% of the upcoming drilling on the lease. The cost of this well is estimated to be less than US$200,000 and will be funded from existing cash reserves.

The rig crew has returned from break and drilling at The Bard lease area is expected to start shortly.

This increase does not impact the Company's 20% working interest in the remaining Vecta Project prospects in three other AMI areas called Garcia, Treasure Hill and Mona Loa. These areas are part of the current five well drilling campaign.

Andy Carroll, Chief Executive Officer of Mosman, said: "I look forward to the results of each of these wells as they are sound geological prospects in an area that has helium production and access to markets."

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