Westpac New Zealand said its cash earnings shot up by 22 per cent to $707 million for the 2011-12 year.
The bank said its earnings were supported by strong core earnings growth of 10 per cent and a 21 per cent reduction in bad debt impairment charges.
Westpac said its core earnings were driven by a 7 per cent increase in operating income from balance sheet growth, including strong deposit growth of 11 per cent, improved margins and stronger performances from its wealth and insurance businesses.
Customers with wealth products increased more than 4 percentage points from 19.1 per cent to 23.4 per cent.
Margins increased from 2.64 per cent to 2.72 per cent, mostly from improved mortgage and business lending. Total lending increased by 3 per cent, the bank said.