Africa's billionaire rankings have taken another dramatic turn, with South African business magnate Nathan Kirsh's fortune increasing by more than $10 billion this year, putting him among the continent's wealthiest persons.

The astonishing gain brings him within touching distance of the exclusive $20 billion club, a feat only a few African billionaires have ever achieved.

The increase comes after Kirsh made one of the most significant business moves of the year.

In March, he agreed to sell Restaurant Depot LLC, one of his flagship enterprises, for an estimated $29 billion.

At the time, The Wall Street Journal reported that Sysco Corp., the largest food distribution company in the United States, was nearing completion of the acquisition.