Sales across the 17-nation single currency area fell 0.4 percent in December from November, well down from the 0.3 percent rise forecast by economists in a Reuters poll, and were down by 1.6 percent on an annual basis, the European Union's statistics office Eurostat said.

That drop was the biggest since December 2008, the beginning of the world's biggest recession since the 1930s, when retail sales also fell 1.6 percent in the month.

European households cannot yet be relied on to help the euro zone pull out of its latest slump. Joblessness reached a euro-era high of 10.4 percent in December, while inflation remains near recent peaks of 3 percent.

Industry data and business surveys suggest the collapse in confidence from the euro zone's two-year sovereign debt saga has largely stabilized and Germany, the bloc's biggest economy, will probably avoid recession in 2012.

But Belgium entered recession territory after two quarters of falling economic output at the end of 2011 and the wider euro zone is expected to struggle through a mild recession this year.

(Reporting By Robin Emmott)

• A Permanent Economic Emergency