The number of Americans filing for first-time unemployment benefits continued to decline last week, even after dropping to a three-and-a-half year low in the previous week. The figure is still below a key threshold for gauging the job market, a sign that the labor market is gaining strength heading into 2012.

There were 364,000 initial jobless claims filed in the week ended Dec. 17, the Labor Department said Thursday. That was down 4,000 from the previous week's revised figure of 368,000. Economists polled by Reuters called for 380,000 initial claims, on a seasonally adjusted basis.

Today's data showed the four-week moving average, considered a less volatile measure of the labor market trends, came in at 380,250, a decrease of 8,000 from the previous week's revised average of 388,250, and the lowest since June 2008.

The general rule of thumb is that when claims fall below 400,000, the economy is adding jobs.

Continuing claims -- which include people filing for the second week of benefits or more -- fell by 79,000 to 3,546,000 in the week ended Dec. 10, the lowest since September 2008.

The continuing claims figure does not include the number of Americans receiving extended benefits under federal programs.

The four-week moving average for ongoing claims fell by 40,000 to 3,631,750 from the preceding week's revised 3,671,750.

Gross domestic product, the broadest measure of the nation's economic output, grew at a revised 1.8 percent annual rate in the third quarter, the Commerce Department said Thursday. That's down from the 2 percent growth reported last month.

Current-dollar GDP -- the market value of the nation's output of goods and services - increased 4.4 percent, or $163.3 billion, in the third quarter to a level of $15,176.1 billion

According to the U.S. Treasury Department, as of Dec. 20, the total U.S. public debt outstanding was $15,132.0 billion, which means U.S. debt to GDP is now 100.29 percent. U.S. now joins countries such as Japan, Greece and Italy in the triple digit debt-to-GDP ratio club.