NEW YORK (CNNMoney.com) -- A key gauge of future economic growth fell slightly in July, suggesting the economy may remain cool in the second half of 2006, a private research group said Thursday.

The Index of Leading Indicators slipped 0.1 percent in July to 138.1, below market expectations for a 0.1 percent rise, the Conference Board said. The leading index has decreased in four of the last six months.

The coincident index, a barometer of current economic activity, increased 0.2 percent in July, building on a 0.2 percent rise in June and a 0.2 percent gain in May, the board said.

"What this is telling us is clearly the economy has slowed this summer," said Ken Goldstein, labor economist at the Conference board. But "there's not an indication that the economy is going to get much weaker."

The leading index measures a basket of economic indicators ranging from unemployment benefit claims to building permits which is supposed to forecast economic trends up to six months ahead.

Five of the 10 indicators that make up the index increased in July. The positive contributors were average weekly manufacturing hours, vendor performance, stock prices, index of consumer expectations, and manufacturers' new orders for consumer goods and materials.

The negative contributors were building permits, average weekly initial claims for unemployment insurance, interest rate spread, manufacturers' new orders for nondefense capital goods, and real money supply.

Jobless claims fall by 10,000