Residential and buy-to-let mortgage sales increased by 8.7% last month from August 2015, reaching £15.25 billion, according to Equifax Touchstone analysis of the intermediary marketplace.

However, the firm said this was a slower post-summer bounce back than last year when overall mortgage sales rose by 13% between August and September.

The highest growth region for residential and buy-to-let sales in percentage terms was the North West, where sales were up by 13.28% (£69.1 million), followed by the home counties with growth of 10.6% (£324.6 million) month-on-month. The region which reported the lowest increase last month was the North East, up by only 0.15% (£1.35 million).

Overall mortgage sales from January to September this year were 19.2% stronger than for the same period in 2014, reporting a total increase of £20.38 billion. Year-to-date residential mortgage sales were up 16.0% year-on-year to £97.4 billion and buy-to-let sales rose by 31.4% to £29.3 billion.

The data from Equifax Touchstone, which it claims covers 92% of the intermediated lending market, shows that the average value of a residential mortgage in September was £184,900 (September 2014: £170,131) and £157,658 for buy-to-let (September 2014: £144,797).

Iain Hill, relationship manager at Equifax Touchstone, said: “The residential and buy-to-let market has been affected by the recent uncertainty around the slowdown in economic growth which has hindered buyer confidence. After the traditional drop in mortgage sales over the summer, reflecting the holiday slowdown, sales failed to bounce back in September 2015. However, the somewhat disappointing figures reported last month may just be a slight setback ahead of a strong end to the year.

“Looking ahead, we expect the market to recover and continue to follow an upward trend in the last quarter of 2015, with regions such as London and the South of England leading the way and reporting the strongest figures.”