UPDATE 1-South African markets fall sharply after S&P downgrade

(Adds Gigaba’s planned briefing, market prices, details)

JOHANNESBURG, April 4 (Reuters) - South Africa’s rand, bonds and banking shares tumbled sharply on Tuesday after S&P Global Ratings cut the country’s credit rating to junk in response to President Jacob Zuma’s move to sack its respected finance minister.

Zuma’s cabinet reshuffle has triggered public criticism from within the ruling African National Congress (ANC) and pressure is likely to mount on the president after the credit agency handed South Africa its first downgrade since 2000.

New Finance Minister Malusi Gigaba is due to hold a news conference later in the day.

Gigaba said on Monday he would pursue “tough and unpopular choices” to oversee a redistribution of wealth to the black majority, a stance echoing recent comments by Zuma. No details of the changes have been made public yet.

The one-notch downgrade to BB+, S&P’s highest non-investment grade, will almost certainly force Africa’s most advanced economy to pay more to borrow its from international markets and possibly and may fall off global investors’ radar screens.

“This sovereign downgrade will lead to a steep erosion of already poor levels of investor confidence,” Cas Coovadia, head of the banking industry lobby group said.

“Negative investor confidence will directly undermine an economy already struggling to achieve the levels of growth needed to meaningfully create jobs or lift our population out of poverty.”

Moody’s also said late on Monday that it was placing South Africa on review for downgrade, and that it would assess the likelihood of changes in key areas of financial and macro-economic policymaking following Zuma’s cabinet changes.

The rand weakened as much as 1.9 percent before recovering to trade 1.2 percent lower at 13.8400 per dollar.

The Johannesburg Securities Exchange’s banking index slumped as much as 4.2 percent, while the yield for the benchmark government bond due in 2026 rose 16 basis points to 9.140 percent. (Reporting by Joe Brock and Tiisetso Motsoeneng; Editing by James Macharia)