U.S. spending on new construction was virtually flat in September, as the first decrease in housing construction outlays since early 2003 offset a slight gain in non-residential building activity, a government report on Monday showed.

The Commerce Department (search) said construction put in place in September ran at a $1.014 trillion annual rate, $136 million lower than in August. The data for August were revised upward slightly, to a 0.9 percent gain from the previously reported 0.8 percent increase.

The September figures were weaker than Wall Street forecasters had been expecting. Analysts polled by Reuters had forecast construction spending to post a 0.5 percent gain in September. The lower-than-expected numbers may also lead to a slightly lower estimate of third-quarter growth.

The decline was led by a 0.2 percent fall in residential construction, the category's first decline since February 2003.

In October, the Commerce Department reported that September housing starts fell 6 percent, likely as a result of the series of hurricanes that swept through the southeast United States.

Non-residential building (search) in September rose 0.3 percent, aided by gains in construction of lodging, manufacturing and religious facilities.