The number of properties selling for more than £1m fell by just over a quarter during the first six months of 2005, the Halifax bank has said.
Sales of expensive properties have been waning
Sales of seven-figure homes stood at 1,508 in the first half of the year compared with 2,033 during the same period last year.
London saw by far the biggest fall in £1m-plus property sales followed by the south east, south west and East Anglia.
The fall reflects a general slowdown in the UK property market, Halifax said.
But overall, sales of £1m properties have proved more resilient to the slowing housing market than less expensive property
"Nationally the uppermost sector of the residential property market has held up relatively well with the 26% fall in sales of £1m properties comparing with a 36% decline in total house sales between the first halves of 2004 and 2005," Martin Ellis, chief economist at the Halifax said.
Sales of £1m homes accounted for just 0.4% of all properties that changed hands during the period, and even in the high price London market they accounted for just 2% of total sales.
One out of every three homes that sold for more than £1m was in either Kensington and Chelsea or Westminster during the six months.
Halifax estimates that there are around 53,400 £1m-plus properties across the UK - up from 3,400 in 1995.
In London there are around 33,000 £1m-plus homes, compared with 2,600 in 1995.