Wealth management has made a solid contribution to profits at the National Australia Bank, which has announced a 22.8 per cent boost in interim cash earnings to A$2.2 billion for the six months to March.

The NAB's wealth management division reported a 26.2 per cent increase in earnings to A$183 million over the reporting period.

The bank's chief executive, John Stewart, said the wealth management result was driven by "strong sales momentum and improved adviser productivity and higher cross selling."

The division's assets under management increased 13.1 per cent to A$102.4 billion.