JOHANNESBURG--South Africa's competition tribunal approved a takeover of Optimum Coal Holdings Ltd. (OPT.JO) by a consortium comprised of Glencore International PLC (GLEN.LN) and Shanduka Coal, a person familiar with the matter said Thursday.

The next step is for Glencore to make a mandatory offer which could be wrapped up between April and May this year, that person said. Optimum said in a February regulatory filing that the consoritium had confirmed its intention to make a mandatory offer for the remaining shares in Optimum once it had received regulatory approval.

Glencore said in its results in May that it had acquired a 31.2% interest in Optimum Coal for $382 million. By November it had accrued or entered into conditional agreements to own a total effective interest of 65.14% in Optimum.

Optimum Coal is South Africa's sixth-largest coal producer and the fourth-largest exporter. It sold 10.6 million metric tons of coal in fiscal year 2010, of which 52% was sold to South Africa's state-owned Eskom Holdings and the remainder was exported.

-Devon Maylie, Dow Jones Newswires, +44 (0)207 842 9328, devon.maylie@dowjones.com

--Alex MacDonald in London contributed to this story.