A sharp petrol price cut drove the negative move in the
consumer price index, which was substantial enough to overcome
the hefty rise in food prices at the start of the year, Investec
analyst Annabel Bishop said in a note.
Meanwhile, data from Statistics South Africa
showed retail sales fell 0.6% year-on-year in December after rising by a revised 0.8% in November.
Economists polled by Reuters had predicted a 0.1% year-on-year drop in December.
"December is a seasonally significant month for the retail sector; however, consumers remain constrained and continue to grapple with heightened living costs, with many holding back on discretionary purchases," Investec analyst Lara Hodes said in a note.
Business confidence fell in January, with crippling power cuts by state utility Eskom weighing significantly on sentiment, a survey by the South African Chamber of Commerce and Industry (SACCI)
showed .
On the stock market, the Top-40 and the broader all-share indexes lost around 0.5% in afternoon trade. Anglo American Platinum's (Amplats) shares fell to the bottom of the all-share index after the South African miner
announced that Chief Executive Natascha Viljoen will step down next year to become operations chief at U.S.-based Newmont Corporation .
The South African government's benchmark 2030 bond was weaker in afternoon deals, with the yield up 14 basis points at 9.980%. (Reporting by Alexander Winning and Anait Miridzhanian; Editing by Sherry Jacob-Phillips)