By 1600 GMT the rand had weakened 0.2 percent to 13.3375 per dollar, its weakest since August 15.

The currency is facing selling pressure caused in part by bets on a hawkish Fed, local political fears and signs of a slower recovery of economic growth.

South Africa's central bank is likely to lower its key rate to 6.5 percent on Thursday, according to 17 out of 26 economists polled by Reuters

In fixed income, yields on the benchmark government bond due in 2026 fell 0.5 basis points to 8.43 percent.

On the stock market, the benchmark Top-40 index was up 0.03 percent at 49,751.70 points. The broader All-share index declined 0.07 percent to 56,011.16 points.

Shares of mining company Sibanye-Stillwater Gold plummeted after announcing it would issue convertible bonds worth $450 million to refinance a loan partly used to fund its acquisition of U.S-based Stillwater last year.

Shares in Sibanye, which mines gold and platinum, fell to a seven-week low of 15.70 rand, before recovering to 16.43 rand, down 6.2 percent in the session.

Private education group Curro Holdings was among the gainers after it briefed investors on Tuesday on plans announced on Friday to spin off its tertiary education unit and list it separately.

Curro shares rose 2 percent to 36.20 rand.