A gauge of the U.S. economy's prospects rose marginally as expected in February, pointing to a moderate improvement in economic conditions, a private research group said on Thursday.

The Conference Board said its index of leading economic indicators edged up 0.1 percent, rising for the 11th straight month, after a 0.3 percent increase in January.

Analysts polled by Reuters had expected a 0.1 percent gain in February.

"The indicators point to a slow recovery this summer. Going forward, the big question remains the strength of demand. Without increased consumer demand, job growth will likely be minimal over the next few months," said Ken Goldstein, an economist at the Conference Board.

The coincident index, which measures current economic conditions, edged up 0.1 percent in February after being flat the prior month. The lagging index rose 0.3 percent after dropping 0.2 percent in January.

Meanwhile, factory activity growth in the U.S. Mid-Atlantic region accelerated in March, the Philadelphia Federal Reserve Bank said on Thursday. Business activity index rose to 18.9 in March from 17.6 in February, according to the Fed's survey.

Economists had expected a reading of 18.0, based on the results of a Reuters poll, which ranged from 14.0 to 23.0.

Any reading above zero indicates expansion in the region's manufacturing.

The survey, which covers factories in eastern Pennsylvania, southern New Jersey and Delaware, is seen as one of the first monthly indicators of the health of U.S. manufacturing.