South African shares dipped on Tuesday from a record peak hit a day earlier, depressed by futures-linked selling and uncertainty ahead of a US interest rate decision.
But AngloGold Ashanti bucked the weaker trend as investors bet on merger activity after its parent Anglo American Plc said it would surrender control.
Selling of near-dated stock futures sparked a discount between the futures and the underlying shares, Ryan Wibberley, a trader at Investec Securities said.
"There's certainly been a bit of futures-related basket selling, I give it as much credit as 100 points of the 200 point drop," he said.
"The whole market has also been trading with a view of the (US) rate decision tonight, that's been at the back of everyone's mind."
The blue chip Top-40 index slipped 1.25 percent or 230.64 points to 18,198.97 while the All-share index lost 1.17 percent or 238.33 points to 20,200.15.
So far this year, the Top-40 index has gained 10.7 percent.
The world's second biggest platinum producer Impala Platinum suffered the deepest losses among blue chips, tumbling 5.7 percent to R1,155 after strong gains on Monday.
On Monday, rumours went around that Zimbabwe might withdraw a controversial mining plan to take 51 percent stakes in foreign mining firms, but the word on Tuesday was that no cancellation was on the cards, Wibberley said.
Mining stocks also reacted to news from China that iron ore contract prices are likely to rise by about 10 percent, which was below expectations, he added.
Africa's biggest iron ore producer Kumba Resources , gave up 2.3 percent to 108.40 rand while diversified mining group BHP Billiton , also a major producer, tripped 1.3 percent lower to R109.85.
Swimming against the tide was the world's third biggest gold producer, AngloGold, which added 1.2 percent to R327, making it the biggest winner among blue chips.
AngloGold Chief Executive Bobby Godsell told Reuters on Friday that he would welcome takeover bids after parent Anglo American announced that it was selling part of its 51 percent stake and surrendering control.
"There is a massive amount of speculation as to what kind of corporate action is at play in the coming year," Wibberley said.
Smallcap stock Real Africa Holdings surged 10.8 percent to R5.76 after casino operator Sun International said it was planning a R2,2-million offer for the company at R5.90 a share.
Small gold producer Simmer and Jack Mines flipped 7.9 percent higher to R1.51 after the Johannesburg bourse declined a request by a group of shareholders to suspend the shares.