According to the proposed settlement documentation released by Detour, it would have resulted in four of nine board members being replaced in the past six weeks, with interim CEO Michael Kenyon stepping down before the next annual general meeting.

Detour had also offered to drop a civil claim against John Paulson. The activist investor owns about 5.4% of Detour.

Paulson & Co in July pressed Detour to call a special shareholder meeting and put forward its own slate of eight nominees for appointment to Detour's board. Instead, Detour appointed three new directors.

"I am disappointed that this latest very reasonable offer was rejected by Marcelo Kim.  Demanding a wholesale change of the board as a condition to negotiating a settlement is neither practical nor responsible," chairman Alex Morrison said.

"Given the critical stage we are at in executing the life of mine plan, now is not the time to throw the company into chaos and start from scratch, especially following the significant changes the board has already made. Our board has decided to keep our reasonable settlement offer open to Paulson."

Detour late in June committed to improve on the operational performance of its flagship Detour Lake mine, in north-eastern Ontario, in response to pressure from Paulson & Co.

Paulson & Co was not immediately able to be reached for comment.