The country's four biggest lenders - Absa, Standard Bank, Nedbank and FirstRand - told Reuters it was hard to access the skills they need to rapidly digitise - a response to growing demand for online and mobile banking and the arrival of a host of digital-only banks trying to steal their customers with slick apps and cut-price fees.

All four said they had taken a number of measures to address the shortage, including changing their hiring strategies, implementing for example 'speed dating' style events where large numbers of candidates undergo short interviews in one go, and developing training programmes.

But in some cases lenders said it still took months to hire and they were paying ever-rising salaries to win talent.

The problem is particularly acute for positions that did not exist just a few years ago, such as cloud engineers, said Standard Bank Group Chief Information Officer Alpheus Mangale.

In September last year, he said the bank wanted to hire 12 such engineers to make sure its cloud systems were up and running and look after their day-to-day upkeep.

"We are probably at about 40 percent of that, because the skills just don't exist ... in the market," he said.

Banks can expect to pay a 20-30% premium when they do find such skills, he added.

Specialist recruitment agency Acuity Consultants said salaries for software developers had also leapt by up to 30% over the past year.

Thando Lukhele, a divisional executive in Nedbank's group technology division, also said it could take months to fill roles and the bank paid extra for new hirings. Absa and FirstRand's retail unit cited similar problems.

The banks' issues highlight how the skills shortage is complicating some of South Africa's largest companies' ability to compete, making adapting to technological and market changes more time-consuming and costly.

Such skills are in short supply globally, and McKinsey has estimated demand for technological skills will rise by 55% by 2030 based on analysis focusing on the United States and Western Europe.

But Yossi Hasson, a co-founder at non-profit technology school WeThinkCode_, said the issue was magnified in South Africa by problems in public education, limited access to the internet and computers and the fact that those with skills are often taken overseas by global companies.

The banks, many of which sponsor WeThinkCode_ alongside companies ranging from news organisations to Nandos, have tried a range of other steps to attract or develop talent.

Standard Bank's Mangale said it had created training programmes with Amazon and Microsoft, as well as internal programmes and partnerships with universities or technical schools and initiatives to retrain existing staff.

The bank, he said, had decided it should not rely on other institutions to create skills whose presence was increasingly becoming make or break for companies of all sectors:

"The use of technology, and how you leverage all the emerging tech ... is really at the heart of how organisations will win or lose in the market."

(Editing by Mark Potter)

By Emma Rumney and Naledi Mashishi