The blue-chip Top-40 index fell 1.09 percent to 29,697.66, extending Tuesday's losses. The market was closed on Wednesday for a public holiday.

The Top-40's break below the key 30,000 level where it has been getting strong support is a negative signal which could herald further decline.

The broader All-share index ended down almost one percent at 33,550.89.

"We are seeing a lowering of risk appetite in the market with concerns out of China particularly and big sell-offs in the metals and resources counters," said Ferdi Heyneke, portfolio manager at Afrifocus Securities.

Oil prices fell more than 2 percent and global stocks retreated as disappointing manufacturing data from China and Europe fuelled worldwide growth concerns.

ArcelorMittal South Africa, a unit of the world's top steelmaker, shed almost 4 percent to 57.63 rand, while Kumba Iron Ore stumbled 3.50 percent, extending its losses from Tuesday of more than 2 percent.

Shoprite was the biggest blue-chip loser on the day with a 5.4 percent tumble after it said would raise up to $1 billion by issuing new shares and convertible bonds, diluting its current shares.

The proceeds from the fundraising will be used to shore up its balance sheet and for potential acquisitions, Shoprite said.

Gold miners bucked the downward trend as a rising dollar knocked South Africa's rand more than one percent weaker. A softer rand benefits domestic gold producers whose costs are mostly counted in the local currency but who earn greenbacks for their product.

Harmony Gold was the biggest gainer among the big bullion producers, adding almost two percent to 84.40 rand.

South Africa accounts for 90 percent of its production, making it much more sensitive to rand movements than bigger rivals AngloGold Ashanti and Gold Fields, which have bigger global footprints.

Decliners outnumbered advancers 182 to 100 with 65 shares unchanged.