South African President Jacob Zuma on Thursday said mining taxes will be reviewed in a move likely to renew uncertainty in the key sector hit by wildcat strikes and nationalisation threats. Zuma's announcement is the first clear indication that royalties were up for review in the mining sector -- the bedrock on which Africa's wealthiest economy was built. "Later this year, the minister of finance will be commissioning a study of our current tax policies, to make sure that we have an appropriate revenue base to support public spending," Zuma told the opening of parliament.