By Joe Brock
JOHANNESBURG (Reuters) - Ratings agency Standard & Poor's said on Thursday it had no plans to downgrade South African banks, easing concerns a cut by Moody's on the country's four biggest lenders this week could have a knock-on ratings impact.
Moody's on Tuesday downgraded deposit ratings for Standard Bank, FirstRand, Nedbank and Absa Bank -- Barclays Africa Group's local operation.
The move, which was criticised by South Africa's central bank and some analysts, was the latest blow to Africa's most developed economy and sent banking shares lower.
Some economists said the decision by Moody's could lead to further downgrades but S&P, which cut South Africa's sovereign credit rating in June, said it had no plans to follow suit.
"At the moment they (banks) are on a stable outlook and we've got no plans in the immediate future to change the ratings on institutions outside an economic shock or an industry-wide shock," S&P credit analyst Matthew Pirnie told Reuters.
The decision by Moody's followed the collapse this month of a much smaller lender, African Bank, which needed a $1.6 billion bailout from the South African Reserve Bank (SARB).
The ratings firm said SARB had limited the risk of contagion but showed it was willing to impose loses on creditors.
Pirnie at S&P said it made its ratings decisions on South African banks using a different measure to Moody's.
"In a long time we have not placed government support into the ratings of South African banks because ... the banks are pretty good in comparison to the country they operate in," Pirnie said.
"We don't believe that the African Bank failure poses a systemic risk, therefore we wouldn't move down specifically because of that," he added.