Stuard Detmer is to step down from his position as chief executive of Aminex, the Irish listed oil company, “to pursue other business interests”.

Aminex chairman Brian Hall will take on the role of executive chairman, assuming all related duties “with immediate effect”.

“Stuard Detmer initiated the important strategic process of divesting non-core assets in order that the company could focus on its core African activities, a process in which we have made significant progress and which the company expects to continue. We wish him every success in his future endeavours,” Mr Hall said.

Last year Aminex, which has exploration and development assets in the emerging hydrocarbon province of East Africa, delayed the sale of three of its sites in the US.