Botswana is proposing a law that will ask mining companies, once granted a licence, to sell a 24% stake in mines to locals if the government does not exercise its option to acquire the shareholding, a draft bill seen by Reuters on Tuesday shows. The current Mines and Minerals Act allows the government of Botswana, the world’s top diamond producer by value and an emerging copper mining hotspot, to buy a 15% shareholding in any mining project upon being licensed. The existing law gives the government an option to negotiate higher stakes in diamond mines.