[3]: 115 Federale Mynbou purchased two small coal mines called Klippoortjie and Koornfontein that were previously owned by FVB.
[1] Needing capital to expand, on 1 June 1958, Sanlam joined the existing shareholders FVB and Bonuskor, acquiring an equal third share in Federale Mynbou.
[6]: 160 Anglo American blocked Mynbou's attempted takeover of Johannesburg Consolidated Investments (JCI) in 1962, which would have given it an interest in diamond, platinum, and copper industries.
[6]: 161 A new jointly own company was formed by Federale Mynbou and Anglo American in 1964 called Main Street Investments.
[9] An announcement was made in June 1965 with Anglo American and Federale Mynbou creating a new joint venture, of equal share, in their Main Street Investments (1965) company.
[3]: 163 In 1980, the merger of the two took place with the merged business named as the General Mining and Union Corporation and eventually renamed as Gencor in 1989.