The oil exploration firm said it acquired an additional 30.83% interest in the project for a cash consideration of US$35,760, taking its total ownership of the project to 46.83% from 16% previously.
READ: Mosman O&G reports near 47% rise in net attributable production for the six months to 31 December
Following the purchase, Mosman said it would become operator of the project.
John W Barr, chairman of Mosman, said the company maintained the objective of increasing production at its project, with technical work carried out at the Challenger project “encouraging”.
"The next step for Challenger is to make final technical decisions on the wells to be drilled and then consider the various funding alternatives that are available", Barr added.
In late-morning trading Thursday, Mosman shares were steady at 0.25p.