Disappointing figures from South African firms such as Impala Platinum and investment bank Investec put a dampener on stock prices, dragging the blue-chip top-40 index nearly 1 percent lower on Thursday.

Implats the world's second-largest producer of the precious metal, reported a 12 percent drop in gross platinum production in the first quarter, mostly because of operational issues at third parties, while Investec posted a 2 percent decline in first-half earnings.

The Top-40 index closed 0.86 percent lower at 29,057.13 while the broader All-Share was 0.72 percent weaker at 32,438.05.

Implats closed 4.7 percent lower at 180.15 rand, making it the worst decliner among blue chips. Investec was second with a 3.3 percent drop to 45.80 rand.

Implats dragged down resources after reporting poor production numbers. We sold out of our platinum holdings quite a while back, due to increasing cost pressures, said Kavita Patel, a trader at Sasfin.

Other loses inlcuded Tsogo Sun, which fell over 3 percent to 16.05 rand. The casino and hotel group said first-half profit dipped 4 percent due to a tax charge and weaker demand.

We believe the outlook for the industry remains tough due to depressed demand and oversupply. Overall, occupancy rates remain very high, at around 52 percent, said Patel.

SABMiller, which holds 40 percent of Tsogo stock, was itself down 1.3 percent to 284.40 rand in Johannesburg after narrowly missing forecasts with an 11 percent rise in six-month earnings.

A total 151 counters ended weaker and another 106 gained. Some 182.7 million shares were traded according to bourse statistics at 1512GMT from 230.2 million on Wednesday.