Germany's economy rebounded last year at its fastest rate since reunification but the contribution of consumers to the recovery remained weak compared to booming corporate investment.

Preliminary Federal Statistics Office data on Wednesday showed gross domestic product (GDP) bounced back from its deepest postwar nadir at a rate of 3.6 percent. In 2009, German GDP shrank by 4.7 percent.

The growth rate exactly hit the mid-range forecast in a Reuters poll of 22 economists.

The public sector deficit came in at 3.5 percent of GDP, a touch higher than expected and compared to 3 percent in 2009.

The breakdown of the numbers provided little sign of the strong upturn in consumer spending that other struggling euro zone economies are hoping for to boost demand in the area's biggest economy for the goods they produce.

Private consumption rose just 0.5 percent compared to a surge of 9.4 percent in equipment investment and 6.4 percent in other investment.

Consumption is still relatively weak, said Gerd Hassel from BHF Bank. Public consumption however rose very strongly because of the fiscal stimulus programmes. Investments grew strongly, also for equipment. Germany is on a good path.

But while exports rose 14.2 percent on the year in 2010, imports also surged 13.0 percent and analysts said consumer spending should pick up strongly this year.

We expect an increase in consumer spending of 2 percent, said Unicredit analyst Andreas Rees. In the first quarter the economy should finally reach its pre-crisis output level and finally have overcome all effects.

Germany's companies are benefiting from the pickup. Of 30 bluechip DAX companies that have reported earnings for the quarter to end-September, 22 beat market expectations, 15 hiked their outlooks and six kept them unchanged.

Siemens , Europe's biggest engineering conglomerate, said this week its first-quarter profit and sales were set to surpass the year-earlier figures, thanks to robust factory demand.

(Reporting by Sakari Suoninen, writing by Annika Breidthardt; editing by Patrick Graham)