WASHINGTON (MarketWatch) - The U.S. current account deficit widened to $183.1 billion in the second quarter, or 5.1% of gross domestic product, the Commerce Department reported Wednesday.

The increase in the deficit was accounted for by a decrease in the surplus on income and an increase in the deficit on goods. Read the full report.

The current account is the broadest measure of international flows of goods, services and capital in and out of the United States. In essence, the current account deficit measures how much Americans need to borrow from or sell to foreigners to fund their consumption and investment. The figures are not adjusted for price changes.

The current account deficit has narrowed in the past year, largely because imports have fallen and exports have increased as the dollar weakened. It was as high as 6.6% of GDP a year ago.

The dollar depreciated 2% in the second quarter against seven major currencies.

Few economists believe a current account deficit of 5% of GDP is sustainable. Global economic policymakers have said the U.S. current account deficit (and corresponding surpluses in China and elsewhere) represent a major threat to global growth.

In a separate report, the Commerce Department said housing building weakened again in August, with permits for single-family homes falling to a 26-year low. See full story.

Quarterly details of current account

The deficit on goods and services trade increased to $180.6 billion from $177.1 billion. The deficit on goods trade rose to $216.3 billion from $211 billion. The surplus on services trade increased to $35.8 billion from $33.9 billion.

The trade figures had been reported earlier in monthly reports.

The surplus on income decreased to $27.3 billion from $33.2 billion. U.S. investment income from assets owned abroad fell to $194.1 billion from $199.1 billion. Foreign investment income from assets owned in the United States rose to $165 billion from $164.1 billion.

Net financial inflows dropped to $136.7 billion in the second quarter from $190.4 billion as acquisitions of U.S. financial assets by foreigners fell sharply.

Foreign acquisitions of U.S. assets increased by $26.3 billion after $459 billion in the second quarter. Foreign direct investment in the United States increased $93.8 billion compared with an increase of $80.4 billion in the previous quarter.

U.S. acquisitions of foreign assets decreased by $110.4 billion after increasing by $260.6 billion in the third quarter.