North Sea Energy (NSE) Chairman and CEO J. Craig Anderson and CFO Petya Popova are leaving the company with immediate effect, to pursue other interests.
Anderson has been the CEO of NSE for the last 10 years, since founding the company, and its chairman for the past two and a half years.
Anderson oversaw the exploration, appraisal and development of the Jacky field, discovery of the Polly field and recently the drilling of the Bagpuss well that encountered a large amount of hydrocarbons in the UK North Sea.
Popova has been the CFO of NSE for the past six and a half years.
Ian Lambert, a director of NSE and former CEO of Trade Winds Ventures, will assume the role of Interim CEO and CFO.
Lambert said: "NSE would like to thank Mr Anderson and Ms Popova for their tremendous dedication to the shareholders of NSE through very difficult market conditions. We wish them well in their future endeavors."
As a result of the management changes, C. Brent Austin and Larry Leblanc, directors of NSE, have resigned effective immediately.
The company plans to continue its efforts with respect to the Bagpuss and Blofeld prospects and will work together with its JV partners to attract farm-in partners.
The UK's Oil and Gas Authority has approved a license renewal for the Bagpuss and Blofeld License P.1943 into a second, four-year term.
Maersk Oil North Sea UK has now dropped out of the license, with its 25% interest being reassigned to the remaining partners, including North Sea Energy, now holding 20%, Encounter, holding 17.67%, Groliffe 8.83%, and Reach Halibut 53.5%.
Maersk's move follows UK independent Premier Oil resigning as operator on the Bagpuss joint venture, late 2016.
Premier said it would sell its 40.1% interest to newly formed firm, Aberdeen-based Reach Halibut, subject to approval by the joint venture partners.
Premier announced drilling results from the Bagpuss well in August 2016. The well, 13/25-1, was drilled using the Ocean Valiant semisubmersible drilling rig on the Halibut Horst in the Outer Moray Firth, in the North Sea.
The well encountered 41ft of hydrocarbon-bearing sands within a 68ft hydrocarbon column, which Premier Oil said was in line with its pre-drill estimates.