Japan's biggest trading house Mitsubishi Corporation says its full-year net profit edged down 2.3 per cent due to rising costs and a slump at its Australian unit.
Mitsubishi said net profit was Y453.8 billion ($A5.58 billion) yen in the fiscal year to March, down from 464.5 billion yen a year earlier although the result was better than the firm's forecast of 450 billion yen.
Revenue rose 4.6 per cent from a year earlier to 20.12 trillion yen, while operating profit dropped 14.2 per cent to 271.1 billion yen, the firm said.
The profit fall was partially due to the Caval Ridge coking coal project in Queensland's Bowen Basin that was faced with challenges including labour troubles and poor weather, it said.
The coal mining alliance between Mitsubishi and BHP Billiton is the biggest profit-generating project for the trading house, accounting for roughly 30 per cent of earnings.
Mitsubishi also said sales and general costs grew during the period due "in part to higher expenses in line with increased transactions at consolidated subsidiaries".
Profit from the firm's energy business rose as Japan brings fossil fuel power stations back online and turns off nuclear plants amid public fears about atomic energy following the Fukushima crisis last year.
Mitsubishi also forecasted a sales and profit rise for the current fiscal year to March 2013, projecting group net profit at 500 billion yen on sales of 21 trillion yen.