This is the biggest slump recorded by the NAEA in nearly three years – December 2008 was the last time agents reported such a decrease, when FTBs made up just 10% of the market share.
The number of house hunters registering at branches across the country also decreased slightly, with 305 per branch in October compared with 308 in September.
Overall sales remained consistent across the property market in October, with an average of eight per branch. Similarly, supply levels remained in-line with figures in September, with 72 houses available.
NAEA President Wendy Evans-Scott said: "This week’s housing strategy announcement from the Government is welcome news for first-time buyers. But our latest figures show that despite reported increases in mortgage approvals by the larger UK banks over the course of 2011, there is still a lending barrier facing those entering the housing market for the first time.
"To address this Government could ensure that banks are given clearer incentives to offer mortgage finance to the UK’s embattled first-time buyers, and also extend the mortgage guarantee for first-time buyers announced this week beyond just new build homes."
Have your say on this story using the comment section below