Defying the economic downturn, an Italian white truffle weighing just over 1 kg sold at an international auction today for $200,000.

The prized tuber went for the second year running to Hong Kong-born casino mogul Stanley Ho after an auction held simultaneously in Rome, London, Abu Dhabi and Macau, auction organisers said.

Last December, Ho bought a 1.5-kg specimen -- one of the biggest truffles unearthed in half a century -- for a record $330,000.

The 1.08-kg truffle -- the biggest found in Italy this year -- was flown first class to Macau, with an Italian chef accompanying it, for Saturday's auction after it was picked on Nov. 21 in the central Molise region.

Truffles can vary considerably in size and are prized in Italian cooking for their flavour and aroma.

Output of white truffles -- which are not cultivated and only grow naturally in forests -- has fallen in Italy over the past few years, largely because climate change has brought a damaging mix of drought and torrential rains.

Scarce supply has pushed prices for normal-sized truffles above 4,000 euros for one kg and Italian restaurants have kept purchases to a minimum, although demand from foreign restaurants has remained stable, truffle associations say.