"We do not expect to deliver double-digit income growth over the next couple of years, given various pressures, not least (South) Korea," says Peter Sands, Standard Chartered's chief executive, in a statement in March.

But even in South Korea, banks are expanding, although in other areas. Hana Financial Group, for example, says it plans to merge its two credit card services to make them more profitable.

Banks in Asia are expanding among the rich and the less affluent.

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Banks eye offering opportunities

At one end of the financial scale, banks are looking to expand among the growing population of the region's wealthy.

Some time this year, the Asia Pacific will become home to the largest concentration of high-net-worth individuals in the world. The number of rich people in the region has grown by about a third since 2007, much faster than the rest of the world, according to RBC Wealth Management, a Canadian bank.

There are around 4 million HNWIs in the Asia Pacific who, by next year, should control almost $16 trillion in assets.

Around half of the region's total is estimated to be in Japan; more than 160,000 are in South Korea; China is moving toward three quarters of a million.

Banks are also looking to expand on the other end of the affluence scale.

Asian banks are reaching out to the 600 million people around the region that do not have access to banking services. According to the World Bank, which did a huge global study of access to financial services in 2012, 45 percent of adults in the region says they did not have a bank account.

The numbers vary a lot from country to country. The Global Financial Inclusion Indicators suggest only 4 percent of adults in Cambodia have a bank account, while more than 60 percent have one in Malaysia and the Chinese mainland.

The unserved market of hundreds of millions of people is a powerful incentive for banks to expand.

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