A key gauge on the future direction of the U.S. economy fell in April for the fourth straight month, suggesting the economy is losing steam, a private research group said Thursday.

The New York-based Conference Board (search) said its index of leading indicators fell 0.2 percent to 114.5 in April after a downwardly revised 0.6 percent decline in March.

Five of the 10 indicators in the index decreased in April -- consumer expectations, real money supply, interest rate spread, stock prices and vendor performance.

"A decline in the leading index indicates that the economy is losing some steam heading into the second half of the year," Conference Board economist Ken Goldstein said in a statement.

The leading index has declined at a 1.0 percent annual rate over the last six months, and there have been more weaknesses than strengths among the components in recent months, the board noted.

The coincident index of current economic activity rose 0.2 percent in April, matching its March increase. The index of lagging indicators, a measure of past economic activity, rose 0.4 percent after a 0.2 percent decline in March.