1% last month, following a 0.
8% decline in August, Nationwide said, adding that "buyers appear to have a slightly better hand than sellers at the moment".
The average house price now stands at just over £166,757, up from £166,507 a month earlier.
Nationwide said September "proved to be an uneventful month for house prices".
Continue reading the main story Your HomeRenting tips when demand is high Will house prices fall again? How stagnant house prices affect you Higher taxes for holiday homes 'Clear loosening'The quarter-on-quarter rate of change - generally seen as a smoother indicator of recent price trends - fell from 0% in August to -0.
9% in September.
"This represents the first negative reading for the three month rate of change since May 2009 and is consistent with the clear loosening of housing market conditions observed over the summer months," said Martin Gahbauer, Nationwide's chief economist.
"Although the three month rate of change has turned negative, at this stage it is not pointing to a significant pace of decline in property values.
"The annual rate of house price inflation fell from 3.
9% in August to 3.
1% in September.
"The uncertainty over the current direction of house prices was clearly demonstrated with the release of the latest data from the Nationwide Building Society," said Simon Rubinsohn, chief economist at the Royal Institution of Chartered Surveyors.
"Low interest rates will remain a major prop for demand even if accessibility to mortgage finance remains challenging.
Meanwhile, the boost to new instructions following the ending of Home Information Packs is likely to continue to fade.
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