Sales of previously-owned US homes fell 16.7% in December, the National Association of Realtors (NAR) has said.
Sales had risen from September to November as first-time buyers took advantage of tax credits.
The decline in December was expected as buyers rushed to complete deals before the original 30 November deadline.
The first-time buyer tax credit has since been extended until 30 April, and the NAR said there was likely to be another surge in sales in the spring.
December sales fell to a seasonally-adjusted annual rate of 5.45 million from 6.54 million in November, but are 15% higher than the level seen in December 2008.
