Australia\'s biggest bank, the Commonwealth, on Wednesday posted a 13 percent rise in full-year profit, but warned that global volatility could push up funding costs. The country\'s top home lender said net profit for 2010/11 was Aus$6.39 billion (US$6.61 billion), up from Aus$5.66 billion the year before.Cash profit topped Aus$6.83 billion, up 12 percent. Cash earnings per share jumped 11 percent to Aus$4.38 while cash return on equity was 19.5 percent, up 80 basis points. \"The result was achieved in a challenging environment where the impact of the global financial crisis continues to linger,\" the bank said. \"Credit growth remains at historic lows, business and consumer confidence is fragile and there is significant uncertainty in global markets.\"Chief executive Ralph Norris, who retires in November to be replaced by fellow New Zealander Ian Narev, said the bank continued to be affected by economic turmoil overseas, with a danger that this may force up funding.\"On-going offshore instability continues to impact the domestic economy and has the potential to place further upward pressure on wholesale funding costs for domestic banks,\" he said.Nevertheless, he called the result \"solid\" with all of the bank\'s businesses performing well. \"We have maintained our conservative business and financial settings which has enabled us to support our customers in an uncertain economic environment which remains challenging for many,\" said Norris.Looking ahead, he said the 2012 financial year was shaping up to be similar to 2011 -- subdued system credit growth and intense competition.\"At this stage there is nothing to suggest that the 2012 financial year will see any material improvement on this front,\" he said.\"Nor is it clear what the catalyst will be for a meaningful revival in consumer and corporate confidence which is prerequisite to stronger demand for credit.\"However, chief financial officer David Craig said he bank was well-placed to weather the current market instability, sparked by last week\'s United States debt downgrade. \"We didn\'t necessarily expect that but we are absolutely prepared for it,\" he said. \"We are absolutely in a fortress balance sheet position.\" The bank declared a final dividend of Aus$1.88 per share - an increase of 11 percent.