An index of future economic growth weakened for the second straight month in February, hobbled by sluggish manufacturing and weakness throughout the housing industry.

Industry research group The Conference Board said Thursday that its composite index of leading indicators, which is meant to foreshadow changes in the economy three to six months in advance, slipped 0.5 percent to 137.3 in February after a revised 0.3 percent decline in January.

The drop in February, while expected, was the steepest since February 2006.

Conference Board labor economist Ken Goldstein said in a statement that the index suggests "moderate but choppy growth" with consumers continuing to spend despite swings in energy prices and sagging home values.

The index tracks 10 economic indicators, including stock prices, unemployment claims, homebuilding permits and money supply.

In February, more people filed for unemployment insurance, fewer homebuilders obtained permission to build houses and consumers adopted a more tempered outlook on the economy's future, the Conference Board said.

The coincident index increased 0.3 percent in February after a 0.1 percent decline in January and the lagging index increased 0.2 percent in February after increasing 0.7 percent in December.