House prices in England and Wales fell by 0.2% in May, the first monthly fall in values since April 2009, according to the latest figures from the Land Registry.

Both Blaenau Gwent and Denbighshire had the most significant monthly price falls of 3.6%, followed by North Tyneside, where prices dropped by 1.2%, Sheffield by 1.0% and Bedford by 1.2% in May. Overall, the average property value in England and Wales has fallen to £165,314 from £165,596.

According to the Land Registry, across the regions the south-east saw the biggest monthly rise with an increase of 0.9%, followed by London with a 0.7% increase. But properties in Wales fell during the month by 0.8%, in the north-east by 1.9% and in the east Midlands by 3.6%.

Middlesbrough experienced the greatest annual price fall with a drop of 9.2%. But in general year on year, house prices increased by an average of 8.2% in May, with Brighton and Hove once again producing the highest annual price rise of 16.5%.

All regions across England and Wales experienced a rise in average property values during the past year, with London rising by 14.2%, the south-east by 11.3%, and the south-west by 10.7%. In contrast, the north-east rose by just 1.8% and the east Midlands by 3.1%.

London's monthly change of 0.7% marks the capital's third consecutive monthly house price increase, and the average property there is now worth £338,708. London's annual growth continues to overtake that of England and Wales as a whole, where a detached house now costs an average of £258,268 (up 9.6%), a terraced home is worth £126,725 (up 7.6%) and a flat will set you back £155,059.

Property transactions in England and Wales have increased to an average of 50,658 per month in the four months from December 2009 to March 2010 from 32,009 over the same period a year earlier.

The monthly fall in prices echoes the findings of property consultancy Hometrack, which recently claimed prices in England and Wales rose by just 0.1% in June. Hometrack also said that new buyer registrations increased by 0.1% in the month, with demand falling in six out of 10 regions. But the number of new homes coming on to the market continued to increase, rising by 2.9%.

Hometrack's director of research, Richard Donnell, said a combination of the general election, pre-budget talk of austerity measures and the ongoing mortgage shortage had all contributed to uncertainty in the market. "In January price rises were registered across just 7% of the market, rising to 26% in February but falling back to 21% in March," Donnell said.

The amount of time it takes to sell a home remained practically unchanged at 8.4 weeks, while homeowners are getting an average of 94% of their asking price.