Australia, the world's largest shipper of coal, iron ore and wool, forecast the biggest gain in commodity exports in 29 years, driven by demand in China.

Sales may rise 30 percent to a fifth straight record of A$189.1 billion (US$178 billion) in the year ending June 30, 2009, the Canberra-based Australian Bureau of Agricultural and Resource Economics said yesterday.

China's demand is driving Australia's 17th year of economic growth as companies spend a record A$57.9 billion developing mines and oil fields.

Prices for the nation's top five commodity exports, iron ore, coking and thermal coals, gold and crude oil have risen to records this year, stoking earnings at producers including BHP Billiton Ltd.

Wheat production in Australia may almost double to 26 million metric tons in fiscal 2009, the bureau said.