As Americans kept spending ravenously during the fourth quarter, the U.S. again imported far more goods than it exported, causing the value of the gap between imported and exported goods to climb to record levels.

The

current account balance

, a measure of the big-picture international trade habits of the U.S., rose to $99.78 billion in the fourth quarter, up 12% from the revised $89.09 billion in the third quarter, the

Commerce Department

reported Wednesday.

The number came as a surprise to Wall Street economists, who had expected the deficit to come in around $95 billion, according to a

Dow Jones

poll. But most said it reinforced the trends shown by other economic measures for the quarter, such as consumer spending, which rose 5.9% for the quarter.

The U.S.' heavy reliance on foreign goods and services is seen as potentially troublesome for the economy at large, because it in turn makes the nation dependent on the inflows of foreign capital through investments. As U.S. markets continue to chalk up heavy returns, foreigners have been eager investors in U.S. stocks and bonds, but any temperance of foreign enthusiasm could spell trouble in the form of a weaker dollar and inflation.

Officials at the

Federal Reserve

have repeatedly communicated their worries about the size of the deficit, and how it could quickly turn sour for the U.S. economy. Recently, the president of the Federal Reserve Bank of New York, William McDonough, said the current account, which is running at around 4% of

gross domestic product

, should be more in the range of 2% to 2.5% of GDP, to mitigate the risks of a foreign flight from U.S. investments.

The deficit, along with historically low unemployment, rising commodity costs and U.S. factories being stretched to their limits, will likely cause Fed policymakers to continue raising interest rates when they meet March 21. Higher interest rates are supposed to make it harder for businesses to borrow and spend, helping to slow growth and minimize the risk of inflation.

The Fed has already raised its benchmark

fed funds rate

by 1 percentage point, to 5.75%, since last June. But the increases have had little effect on consumer spending, which has allowed measures such as the trade deficit to keep growing.

The lion's share of the trade deficit came in the goods and services area, as Americans spent $75.5 billion more on foreign goods than they exported, up from $72.59 billion in the third quarter.

A big surprise to economists was the so-called investment income deficit. The bull market in stocks created a much greater outflow of money from the U.S. Returns on investments in U.S. stocks returned more to foreigners than foreign markets returned to Americans. That shortfall grew to $10.39 billion from $5.29 billion in the third quarter.