Ultra-wealthy people such as the three men -- a 91-year old US billionaire, a jet-setting London property tycoon and a media-shy German industrialist -- are often thought to be at the vanguard of financial innovation, private bankers say.

"They're losing big money and their wealth is disappearing quickly," said David Giampaolo, Chief Executive of Pi Capital, a London-based private equity investment boutique.

Rich investors often held large positions in specific companies or stocks, he said, and they had also often borrowed large amounts of money to boost returns.

"At the time it didn't look irresponsible (but) now they've had double, triple whammy problems," he said.

Hedge funds, still dominated by private investors, are among the players worst hit by the credit crunch, with some analysts predicting their assets will shrink by as much as 80 per cent.

And the scandal around US financier Bernard Madoff -- accused of defrauding rich clients and charities of $50 billion -- is another example of how the very wealthy are not immune to the financial turmoil.

Kerkorian, best known for his ties to the ailing US car industry, this week said he had sold off his remaining shares in Ford Motor, completing a retreat that cost him hundreds of millions of dollars.

Since October, the activist investor has been cutting his losses on a $1 billion investment in Ford that had lost most of its value, capping a two-year period during which he was involved with all three Detroit-based car companies.

Forbes magazine, which tracks the world's richest people, puts Kerkorian's worth at $11.2 billion from investments in casinos and other businesses. His losses made him one of the poorest performers on this year's list, it said.

Iranian-born Tchenguiz draws most attention through newspapers citing his jet-set lifestyle, including an expensive house in an upmarket London district and a sumptuous Louis XIV-style party he is reported to have thrown for his 40th birthday.

His Globe Tenanted Pub Co Ltd, which runs 424 leased pubs across the United Kingdom, said this week it would appoint an external adviser, after narrowly breaching its debt covenants -- early warning signs of financial trouble.

And business publication The Estates Gazette in October said Tchenguiz had dropped off its list of the 500 wealthiest people in UK property after losing 1 billion pounds ($1.45 billion) when Icelandic bank Kaupthing collapsed.

Germany's Merckle, ranked by Forbes among the world's 100 richest people, was caught out by wrong-way bets on shares in Volkswagen, incurring massive losses.

His investment vehicle VEM Vermoegensverwaltung said on Wednesday it would sign an agreement to obtain a bridge loan from banks as it worked on refinancing the group.

Banking sources have said that Merckle's losses were estimated at 400 million euros, forcing Merckle to hold talks on state guarantees from regional governments, although he ultimately opted out of such financing.

But Sebastian Dovey, whose company advises private banks as well as wealthy individuals, still sees a glimmer of hope.

"There is a certain ghoulish interest in covering savage drops in fortunes among other billionaires," said Dovey, a partner at consultancy Scorpio Partnership.