The top five private South African banks - among the continent's biggest - are generally considered well-capitalised, conservative in lending and help drive an otherwise ailing economy.

But inflation, high interest rates and regular power blackouts are taking a toll, leading to defaults.

"Uncertainty... in the regions where we operate remains very high," said Alan Pullinger, CEO of FirstRand.

This will translate into moderate corporate loans and a slowdown in the bank's retail portfolio growth for the next 12 months, he said.

The bank will focus on sectors and on customers who can give assured returns to offset an impending slowdown, he added.

The lender expects its credit loss ratio (CLR) - a measure of bad loans versus total loans - to rise in the current financial year, but to stay within its target range of 80 to 100 basis points, Pullinger said.

It posted a CLR of 78 basis points for the year ended June 30, up from 56 basis points a year earlier.

The bank will be able to maintain its return on equity - a metric that measures profit for each rand of shareholder investment - at between 18% to 22%, the CEO said.

Jacques Celliers, the head of FNB, FirstRand's flagship bank that is primarily local and retail focused, said it would focus on value-added services such as offering mobile connections and e-commerce to gain growth.

FirstRand posted an 11% rise in annual headline earnings per share - a profit measure - to 6.49 rand ($0.3458) for the year and its shares were down over 3% in intraday trading.

($1 = 18.7694 rand)

(Reporting by Promit Mukherjee; editing by Jason Neely and Sharon Singleton)