South Africa's rand stumbled on Tuesday as a sharp fall in Chinese imports increased concerns over the shape of the global economy, denting the appeal of emerging market assets.

Government bonds were weaker with subdued appetite for riskier assets, while the bourse opened on the backfoot, with the Top-40 index 0.1 percent lower at 0703 GMT.

Stocks eased despite an 11 percent surge in shares of SAB Miller after the brewer accepted a $104 billion takeover by Anheuser-Busch InBev.

At 0700 GMT the rand slipped 0.15 percent to 13.3500 per dollar, breaking below 13.30 in overnight trade before easing back as momentum fizzled.

READ: Rand firmer after weak U.S. payrolls, stocks up

China's imports fell more than expected, by 20.4 percent in September to record their 11th consecutive month of decline, increasing worries that slack demand from the world's number 2 economy would hurt commodity reliant countries.

"Unfortunately, outlook for international commodity prices remain downbeat and demand for South Africa exports from Northern Hemisphere has not showed much improvement," analysts at NKC African Economists said in a note.

In government bonds, yields were higher across the curve, with the paper maturing in 2026 adding 2.5 basis point to 8.235 percent.