Johannesburg - The JSE added to earlier gains in midday trade on Wednesday, as resources counters took the lead again, lifting the broader market.
The local bourse's strong run was in line with global equities, which are rising ahead of the much-anticipated Portuguese bond auction, a trader said.
By 12:02 local time, the JSE all share index was up 1.27%, with resources gaining 2.03%, platinum miners rising 1.33% and gold miners firming 1.08%. Banks climbed 1.24%, industrials picked up 0.63% and financials gained 0.95%.
The rand was trading at 6.83 to the dollar from 6.85 at the JSE's close on Tuesday. Gold was quoted at US$1 383.96 a troy ounce from US$1 375.36/oz at the JSE's previous close, while platinum was at $1 793.00/oz from $1 758/oz before.
"The Portuguese auction could potentially boost the market much more," the trader said, pointing out that China and Japan had indicated they planned to buy euro-zone bonds. This has eased uncertainty about the European sovereign debt crisis.
The US IBD/TIPP Economic Optimism Index came in better than expected yesterday, adding to the positive sentiment, he said.
Dow Jones Newswires reports that European stock markets edged a little higher on Wednesday, with market participants adding limited exposure ahead of an important Portuguese debt auction while finding comfort in reports that the European Union is discussing plans to expand the EUR440bn bailout fund for indebted euro-zone countries to contain the debt crisis.
London's FTSE 100 was last 0.59% higher.
Wednesday's focus is squarely on the Portuguese debt auction, details of which are expected at 10:30 GMT, against a backdrop of recent political tension and a forecast of a contraction of gross domestic product in 2011 by the Bank of Portugal.
The planned sale of EUR750m to EUR1.25bn of Portuguese debt maturing in 2014 and 2020 was likely to attract considerable attention, said CitiFx, although it noted that it was difficult to gauge the extent to which the latest price action in the peripheral bond markets had affected the attractiveness of the government paper.
Asian stock markets were higher on Wednesday, after Wall Street's rise on Tuesday, but investors remained cautious ahead of European bond auctions this week.
Japan's Nikkei Stock Average was flat, while Hong Kong's Hang Seng Index gained 1.54.