National Australia Bank continues to invest in local portfolios of banking businesses in the United States. NAB's subsidiary Great Western Bank announced on Friday that it will buy 32 branches in Nebraska and Iowa from TierOne Bank.Great Western said it will buy about US$1.1 billion in deposits and US$800 million in loans from the Nebraska-based bank. NAB will pay a premium of around US$39 million.TierOne is a loss-making bank and, like a lot of small banks in the US, subject to closer than normal supervision from its regulator.This is the second purchase of customer lists, and deposits and loans, by NAB this year. Earlier in 2009 NAB picked up a branch network in Colorado.The branches in Nebraska and Iowa, like those in Colorado, are mostly in urban centres.So while extending the deposit base, the NAB strategy in the US mid-west is not quite the agribusiness play portrayed by the bank when first announced in late 2007.