A fall in the impairment provision offset the drop in net interest income for Westpac New Zealand, thus contributing to an increase in net profit in the nine months to June 2010. Net profit rose to NZ$213 million, up 13 per cent from the same period in 2009. Net interest income fell to NZ$852 million from NZ$1.02 billion a year earlier while impairment provisions more than halved to NZ$234 million from NZ$515 million.Profit growth was stronger in the June 2010 quarter thanks to an improvement in net interest income. A rise in fee and commission income was another contributor to the improved trend in profit.Westpac's balance sheet, however, fell over the latest quarter, with total assets standing at NZ$55.2 billion as of June 2010, down from NZ$56.2 billion in March 2010. Funding from certificates of deposit fell 19 per cent to NZ$1.97 billion over the last quarter. Retail deposits were little changed at NZ$29.9 billion versus NZ$30.1 billion in March.Impaired assets increased slightly to NZ$760 million from NZ$730 million in March, but was down from NZ$832 million last June.