Statistics South Africa said quarter-on-quarter growth on an annualised basis jumped to 4.9 percent after slowing to a 6-1/2 year low of 2.1 percent in the first quarter, when an electricity crunch briefly shut down mining and some factories.

Comparing activity with the weak performance of the previous quarter may have exaggerated second quarter growth but unadjusted year-on-year expansion remained solid at 4.5 percent.

The strong headline growth masked weakness in some sectors. These included real estate and retail sales, suggesting households are still struggling under tighter monetary policy.

"The expectation would be that going into the third quarter these numbers would slow down quite a lot," said Stanlib economist Kevin Lings.

"There would be no interpretation of this being a trend. This is just literally an electricity effect from the first quarter into second quarter. As far as I can see, the consumer side of the economy (is) slowing."

The rand appreciated to 7.74 against the dollar soon after the release of the data from 7.78 previously, before wiping out its gains.

The data may help growth beat expectations for the year, although it is still unlikely to meet last year's 5.1 percent.

"South African GDP for Q2 was higher than expected ... not a bad print at all given how gloomy everyone has been about growth," said Razia Khan, head of regional research for Africa at Standard Chartered in London.

"Growth was always going to be favourable, given that it reflected recovery from an exceptionally weak first quarter."

The power crisis and higher interest rates have led many analysts to cut their 2008 growth forecasts and question whether growth will reach the Treasury's 4.0 percent forecast. Growth has averaged around 5 percent for the past four years.

MANUFACTURING REBOUND

The near-collapse of electricity utility Eskom's grid earlier this year saw mining contract 25.1 percent in the first quarter and also hit manufacturing, which accounts for 17 percent of GDP, the economy's second biggest sector.

Manufacturing bounced back in the second quarter to post its strongest growth in 12 years, while mining expanded by 15.6 percent quarter-on-quarter and annualised.

"The strong growth of 4.9 percent was mostly caused by a rebound in the manufacturing industry which grew at 14.5 percent," Joe de Beer, Stats S.A. executive manager, said.

"Both mining and manufacturing recorded high annual numbers because of a high base effect."

However, the wholesale and retail sector contracted 2.2 percent, its worst performance since the last quarter of 1991, and finance and real estate growth eased to 2.3 percent from 4.9 percent.

Analysts said rate rises were having an effect. The central bank has raised its repo rate by 500 basis points to 12 percent since June 2006 to try tame soaring inflation, but kept it unchanged last week on growth concerns and a better inflation outlook.

Construction also slowed but remained relatively strong at 10.6 percent growth, supported by huge government infrastructure projects to boost energy and transport capacity and for preparations for the 2010 soccer World Cup.