Former Taoiseach Mr Albert Reynolds will assume the role of executive chairman of Bula Resources.
This follows the resignation today of Bula's chief executive Mr John Hogan.
Commenting on today's board changes, Mr Reynolds said: "The Board regrets that John's appointment did not work out for either side and would like to take this opportunity to acknowledge and thank John Hogan for the contribution he has made to the company."
Mr Enouh Rhee has also resigned as non-executive director of Bula with immediate effect.