Australia\'s biggest lender National Australia Bank (NAB) announced a 15.9 % rise in half-year profits Thursday on lower bad debts and disciplined cost management. The bank booked a profit of Aus$2.43 billion ($2.6 billion) for the six months to March 31 from Aus$2.09 billion a year earlier. Cash earnings, which strips out volatile items, increased 21.7 % to Aus$2.67 billion. NAB said the rise in cash profit was mainly down to market share gains and disciplined margin and cost management, combined with improved asset quality. Charges for bad and doubtful debts fell by 19.7 % to Aus$988 million from a year earlier. The bank declared an interim dividend of 84 cents per share, up from 74 cents a year earlier. \"Further sustainable improvement in NAB\'s shareholder returns remains the core focus of our strategic agenda,\" said chief executive Cameron Clyne. He added that the bank had a relatively positive view on the outlook, saying the Australian economy looked strong and business lending was set to rise. \"I think broadly we still see quite a few positives in the economy,\" he said. NAB\'s market share in the business lending market rose to 23.8 % in the half, up from 20.8 % a year earlier. The bank also increased its share of the personal banking market to 13.8 percent from 12.8 percent.