The world's truffle-loving elite are gearing up for what looks set to be a nail-biting bidding war on Saturday when a giant white truffle goes under the hammer at an international auction. Weighing in at 900 grammes, the truffle is not a record breaker but is still expected to fetch thousands of dollars at the auction, which will take place simultaneously in Rome, Moscow, Macao and London via satellite link-up. David and Victoria Beckham are expected to be among celebrity bidders, but observers say the auction of the maxi-truffle is likely to come down to a two-man tussle, for the third year running, between Chinese business magnate Stanley Ho and Sheikh Mansoor Bin Zayed Al Nahyan, the United Arab Emirates race horse enthusiast and power behind Manchester City Football Club.

A couple of unidentified Russian billionaires are also tipped to get in on the action. Two years ago Ho set the world record price for a single truffle, forking out $330,000 for a Tuscan truffle weighing 1.5 kg - one of the largest truffles found in the last 50 years.

Last year he landed the prize again, paying $200,000 for a 1.08 kg specimen dug up in the southern Italian region of Molise. The giant truffle on sale at Saturday's auction again comes from Molise. The auction, explained organiser Giselle Oberti, is aimed at showcasing tubers found across the country rather than in the more famous truffle regions of Piedmont and Tuscany. ''All the various truffle-producing areas in Italy are staking a claim to be recognised," Oberti said. ''There are many premier truffle zones, some very well known like Alba, Aqualagna and San Miniato, while others are only just beginning to enjoy a reputation,'' she said, adding that a total of 16 lots from seven Italian regions will be on sale. The auction will take place at 13.00 GMT at the Westin Excelsior Hotel on Rome's Via Veneto, the Grand Lisboa casino in Macao, the Semifreddo restaurant in Moscow, and celebrity chef Heinz Beck's Apsleys restaurant in London.

TRUFFLE LANDS AND LORE. White truffles are rarer, more pungent and more expensive than black ones. They have a shorter growing season, in the three months around Christmas. Blacks are more common in the centre and south, whites in the north. Nestling in the roots of about 50 trees - mostly oaks but also hazels, poplars, mulberries and willows - truffles are rooted out by specially trained dogs. With demand shooting up over recent years, hunters have become increasingly competitive and there have even been reports of skulduggery such as hamstringing or even poisoning the champion dogs of rivals. Some of the northern and central fields have been exhausted, partly because of poachers who sell their catches on the black market. But new areas are emerging, such as the upper reaches of the Tiber, Abruzzo and the Pollino National Park in Calabria. The biggest white truffle ever found weighed 2.52 kg and was discovered in San Miniato in Tuscany in 1954. Once you've found your truffle, here's what to do with it, according to Italian superchef Annie Feolde: ''Clean it thoroughly with a pointy knife and a little brush, cut it into wafer-thin slivers and heat them up in marinated butter and a little water from boiled vegetables.

''Then spread the mixture over your piping hot tagliolini and you'll see the steam complete the symphony.'' Top Tuscan chef Aldo Fiorelli says ''you can grate your truffle directly onto your pasta. True aficionados use truffles weighing around 100 grammes. Getting your hands dirty isn't frowned on - quite the opposite, in fact. It makes the experience more convivial and orgiastic''.