"Uber-prime" real estate still hot in London

Demand for these homes - known as the "super-" or even "uber-prime" slice of the market and typically priced upwards of 20 million pounds - is still far ahead of supply.

And, fuelled by oil and commodity prices which are adding to the wealth of emerging market millionaires, the appetite is showing no sign of slowing under the weight of the credit crunch that is crippling average homeowners, lenders and businesses.

Eliza Leigh, a partner at estate agent Knight Frank, said the company in early July launched a flat for Grosvenor, the firm which manages the Duke of Westminster's property estate.

"In the first 48 hours, we generated 18 viewings for a property with a 25 million pound guide price," she said.

"We achieved that by close of business on Tuesday, having launched at 9 a.m. on Monday, and that purchaser exchanged contracts by Friday."

Analysts expect UK house prices to tumble at least 20 percent from their peak as a decade-long boom turns to bust. The majority of agents say business has ground to a halt and even the so-called "prime" market - roughly, homes between around one million and 10 million pounds - has slowed as once spendthrift bankers and executives draw back.

But "super-prime" is blossoming, helped by London's enduring popularity and - critically - by a lack of properties at the very top end. There are few coveted addresses and even fewer families moving out.

According to estate agent Savills, the number of sales in the 5 million to 10 million pound bracket in the first six months of this year increased only nominally, compared with a 15-20 percent rise for 10 million to 20 million pound deals.

Above 20 million pounds, however, deals are up 200 percent and now represent more than 10 percent of the ultra high-end properties sold - up from just 5 percent a year ago, when demand was concentrated at the lower end of the prime scale.