At 0650 GMT the rand was 0.42 percent weaker at 12.4975 per dollar, having rallied to 12.40 on Wednesday spurred by a broad emerging market relief rally after Turkey's central bank said it would act to stem a selloff in the lira.

The dollar was up against the euro and other major currencies, while the US 10-year benchmark bond yield edged up past 3.11 percent.

The rand had weakened more than 3.5 percent by Wednesday in an emerging market selloff that has been driven by a strong dollar and rapidly rising US Treasury yields, extending a weakening trend over the past two months.

The relief offered by the Turkish lira stoked a short squeeze as the 12.40/$ level, used as a stop-loss mark by some investors, triggered a brief wave of selling as rand bears weary of a run to 12.20 closed positions.

Focus shifting to US initial jobless claims with little locally on the data front.

South African bonds were weaker, with the benchmark paper due in 2026 yielding 8.51 percent, 4.5 basis points higher.

Stocks opened lower, with the Johannesburg Stock Exchange's Top-40 index down 0.53 percent at 51,831 points.