Sales at US retailers saw an unexpected fall in December, casting uncertainty over the recovery of the US economy.
Retail sales fell by 0.3% compared with November, figures from the US Commerce Department said.
Sales of electrical goods and cars saw some of the biggest falls, though core sales - which exclude cars, fuel and building materials - still fell.
Concerns over job security are expected to continue to restrict spending, with unemployment still at 10%.
Many economists expect unemployment to keep rising until the middle of the year.
December's figures end a tough year for US retailers, with total sales for 2009 down 6.2% on the previous year.
But sales were expected to have been stronger, given the string of retailers reporting positive results for the festive season.
The weaker-than-expected retail figures will add to concerns over the strength of the recovery in the US economy.
In December, the US unexpectedly cut a further 85,000 jobs after seeing some job creation in November.
Economists are still predicting a recovery in 2010, but warn that it will be slow.
"I don't think that portends a new downturn in the economy, but it does serve as a warning that the recovery is going to take some time to put in place here," commented Chris Rupkey, chief financial economist at the Bank of Tokyo-Mitsubishi in New York.