TomCo Energy said chief executive Christopher Brown would stand down to concentrate on his other business interests.
Brown, who holds a 19.57% stake in TomCo Energy, remained supportive of the company and agreed to provide it with an unsecured loan of £100,000.
The loan would incur an interest rate of 8% per annum.
Brown would continue in his current role to allow for sufficient time to appoint a replacement, the company said.
At 8:11am: (LON:TOM) TomCo Energy PLC share price was 0p at 4p