By Christopher S. Rugaber

AP Economics Writer

WASHINGTON (AP) — The U.S. economy unexpectedly shrank from October through December for the first time since 2009, hurt by the biggest cut in defense spending in 40 years, fewer exports and sluggish growth in company stockpiles. The drop occurred despite stronger consumer spending and business investment.

The Commerce Department said Wednesday that the economy contracted at an annual rate of 0.1 percent in the fourth quarter. That was a sharp slowdown from the 3.1 percent growth rate in the July-September quarter.

Economists said the drop in gross domestic product wasn’t as bleak as it looked. The weakness was mainly the result of one-time factors. Government spending cuts and slower inventory growth, which can be volatile, subtracted a total of 2.6 percentage points from GDP.

But the fact that the economy shrank at all, combined with much lower consumer confidence reported Tuesday, may raises fears about the economy’s durability in 2013. That’s because deep automatic government spending cuts will cut into domestic and defense programs starting in March unless Congress reaches a deal to avert them.

And Americans are coming to grips with an increase in Social Security taxes that has begun to leave them with less take-home pay.

Still, the government spending cuts and slack inventory growth in the fourth quarter offset a 2.2 percent increase in consumer spending. And business spending on equipment and software rose after shrinking over the summer.

Consumer spending added 1.5 percentage points to GDP, and business investment added 1.1 points — both stronger contributions than in the third quarter.

“Frankly, this is the best-looking contraction in U.S. GDP you’ll ever see,” Paul Ashworth, an economist at Capital Economics, said in a note to clients. “The drag from defense spending and inventories is a one-off. The rest of the report is all encouraging.”

And for all of 2012, the economy expanded 2.2 percent, better than 2011’s growth of 1.8 percent.

Exports fell by the most in nearly four years, likely a result of Europe’s recession and slower growth in China and some other large developing countries.