The South African rand strengthened below 19 to the US dollar for the first time in three weeks on Wednesday, as a weakening greenback and an easing of rolling power cuts, known as loadshedding, boosted the currency.

The rand firmed more than 1% at 18.975 to $1, its strongest level since May 16, before retreating to 19.04 at 12:33 GMT.

The dollar was last trading at 103.940, around 0.14% weaker, against a basket of global currencies.

"Externally, the USD is weaker today... which will be providing a tailwind for the rand," Kieran Siney of research firm ETM Analytics, said.

"News that the nation's power utility Eskom is suspending daytime loadshedding for the time being has provided a boost to investor sentiment."

He added that news reports that South Africa is looking to host the BRICS summit online or in China, to avoid implementing an International Criminal Court arrest warrant for Russian President Vladimir Putin, had boosted sentiment.

The rand lost 7% in May amid record deep power cuts and US allegations that South Africa had supplied arms to Russia last year, pushing it as low as 19.9075 against the greenback last week and leading to fears it would breach 20.

"The fact that the rand has pulled back more against the US dollar than other EM's could be down to the fact that the rand was disproportionally undervalued against its (emerging market) peers and a bit of rebalancing was warranted," said Andre Botha, senior dealer at TreasuryONE.

The country managed 0.4% growth in gross domestic product for the first quarter and dodged a recession, data showed on Tuesday.

Investor outlook mostly remains bleak as the country's rolling blackouts show no signs of fully abating. A business confidence survey published on Wednesday dropped to its lowest level in three years.

Nonetheless, South Africa's international dollar bonds rallied, with some longer dated maturities up more than 0.7 cents in the dollar.

"(It) suggests that there could be some significant portfolio inflows as investors take advantage of the deep discounts and the attractive yields on offer," Siney said.

South Africa's local benchmark 2030 government bond also strengthened, with the yield down 9 basis points at 10.875%.