* Top-40 and All-share add 0.6 pct
* Afgri falls as corn futures drop
JOHANNESBURG, May 6 (Reuters) - South African stocks extended gains for a third straight session on Monday as oversold mining companies such as Harmony Gold clawed back some of their recent losses.
Financial companies Old Mutual and Investec also gained ahead of earnings results later this month.
The Top-40 index added 0.67 percent to 35,199.18 while the All-share index was 0.6 percent higher at 39,828.96.
“Unless there is any kind of market moving stuff that is going to change things, you expect the momentum to continue to be on the upside,” said Nick Kunze, a trader at Skycastle Investments.
Global markets have been lifted by a brighter outlook for the U.S. economy including a strong payrolls report on Friday.
Harmony Gold, one of the country’s top bullion producers, jumped 5 percent to 40.94 rand after dropping 10 percent in the previous session. Part of this bounce was technical as charts suggested it was oversold and gains in the gold price on Monday also helped.
Sibanye Gold rose 2.5 percent to 8.25 rand after falling nearly 6 percent on Friday.
Johannesburg-listed shares of insurer Old Mutual were the highest gainer on the benchmark index, adding 2.2 percent to 29.60 rand. It is scheduled to issue a trading update on May 9. Investec was nearly 2 percent higher at 67.50 rand.
Grain producer Afgri fell to its lowest point in more than three years as U.S. corn futures slipped following reports of lighter rainfall in the U.S. grain belt eased concerns about planting delays.
Trade was muted as London’s bourse was closed for a holiday. Some 141 million shares were traded, according to preliminary data, with advancers outnumbering decliners 164 to 117. (Reporting by Zandi Shabalala and Benon Oluka; Editing by Ed Stoddard)