House prices in the three months to September were 0.5% lower than in the preceding three months, according to the latest Halifax House Price Index.

This compared with a 0.3% decline in August.

House prices fell by 0.4% in September. This was the third consecutive monthly fall. These declines have more than offset the two successive rises in May and June.

Prices have fallen very slightly over the first nine months of 2012. The average UK house price in September 2012 was 0.3% lower than in December 2011, at £159,486.

Prices in the three months to September were 1.2% lower than in the same period a year earlier. This measure of the annual rate has moved outside the narrow range of 0% to -1% for the first time in seven months.

Halifax said that activity remains subdued but stable. Home sales have been very stable in recent months, at between 75,000 and 77,000 per month between May and August. Overall, sales in the three months to August were 3% higher than in the same period last year.

“The generally weak economic climate remains a significant constraint on housing demand,” said Martin Ellis, housing economist at the Halifax.

“The relatively low level of mortgage payments in relation to income, however, continues to provide support for house prices. We expect house prices to be broadly unchanged over the rest of this year and into 2013.”