Johannesburg - Shares of South African e-commerce firm Naspers headed toward their biggest one-day loss in 2-1/2 years on Friday, hit by a sell-off in China's Tencent Holdings, of which Naspers owns over a third.

Investors hammered Tencent after China's central bank ordered a halt to some mobile payment methods used by Internet companies, amid concerns over the security of their verification procedures.

The move is seen as hitting the mobile payment businesses of Tencent, China's largest Internet company, and its smaller rivals.

Shares of Tencent fell as much as 7 percent in Hong Kong before closing down 4.1 percent.

The company's explosive growth in recent years has helped make Naspers the most valuable company with a primary listing in Johannesburg.

Shares of Naspers were down 5.8 percent at 1,211.75 rand at 11:00 SA time, making it the biggest drag on the benchmark Top-40 index and putting the stock on track for its biggest one-day loss since late 2011. - Reuters