The number of properties in Great Britain worth at least £1 million has increased by 6% during 2010, but the West Midlands saw a drop in seven-figure homes, research suggested.
An estimated 12,811 homes broke through the seven-figure threshold during the year - the equivalent of 35 a day - to bring the total number of homes worth at least £1 million to 226,344, according to property website Zoopla.co.uk.
The group said one in every 118 homes in Great Britain was now worth at least £1 million, although this is still well down on the one in 97 properties that were worth this amount at the peak of the market in 2007.
But the research uncovered a stark north/south divide, with the number of homes in London, the South East and the East of England worth a seven-figure sum jumping by double digits during the year.
By contrast, the number of million pound properties in Wales and Yorkshire and the Humber has actually halved during the past 12 months.
Nick Leeming, of Zoopla.co.uk, said: "The North versus South wealth divide is now starker than ever. Property values have recovered well at the top end of the property market but the rest of the market and particularly the North have seen a steep decline in high-end property values.
"The prime market in the South has been impacted far less by the mortgage squeeze as a result of the inflow of foreign money and the strength in the City keeping demand for million pound pads at peak levels."
London and the South East now account for four-fifths of all homes worth £1 million, following rises of 12% and 11% respectively in the number of properties valued at seven figures, while in the East the number increased by 15%.
But in Yorkshire and the Humber the number of homes valued at this level dived by 52% during the year, while Wales recorded a 49% drop and in the North East and North West the number of £1 million homes fell by 39% and 36% respectively.
The West Midlands saw a 31% slide in the number of homes in the £1 million price bracket, while the East Midlands recorded a 15% drop, with Scotland seeing a 14% fall.
Wales continues to have the lowest level of homes worth seven figures, at just 578, followed by Yorkshire and Humber at 1,159. At the other end of the scale, there are more than 123,000 million pound homes in London and more than 56,000 in the South East.