Barrick has committed to invest US$3.31 million (C$4.4 million) to increase its holding by 0.3% from 19.6% previously.
The Midas offering is expected to close around June 19. It entails 33.2 million common shares at C60c, for gross proceeds of about C$19.9 million.
Midas said the funds would help advance its feasibility study and permitting to redevelop and restore the Stibnite site, as well as for general working capital.
Hedge fund Paulson & Co has also indicated its intent, by participating in the offering, to maintain its pro rata interest of 29.11%.
Midas shares are currently trading 42% below the year-earlier price of 62c, having lost 27% since the start of the year. The company is capitalised at $147.12 million.