BNN Technology non-executive chairman Harry Keiley and non-executive director Lord Mancroft have resigned with immediate effect.
BNN said non-executive director Mark Hanson had been appointed as non-executive chairman and the board was working with advisers to identify and appoint suitable executive directors to lead the company.
BNN said the board was continuing to talk to potential nominated advisers with a view to appointing one in the near future and examining a number of business opportunities in order to drive the company forward.
Hanson said: 'I am delighted to be taking on this role with the full support of the major shareholders and relish the challenge of helping build BNN into a strong and sustainable business in the longer term.
'We are grateful to Msr Keiley and Lord Mancroft for their hard work and important contributions to BNN and we wish them every success in their future endeavours.
'My Board colleagues and I would also like to thank all of our shareholders for their continued support and look forward to updating them as to our progress as soon as possible.'