NEW YORK — The economy contracted in June as factories cut workers' hours and stocks tumbled, a private business group said Monday. It also revised its May figure to show a decline instead of slight growth.

The New York-based Conference Board's forecast of future economic activity fell 0.1 percent, in line with forecasts by Wall Street economists surveyed by Thomson Financial/IFR.

The group also revised May's number downward to a 0.2 percent decrease, from a 0.1 percent increase.

The index has slipped 0.9 percent for the six months ending in June, but the rate of decline has improved since the first quarter.

Downturns in the auto and housing industries have been devastating for the manufacturers that produce everything from spark plugs to vinyl siding. And more job cuts are almost certain: General Motors Corp. said Friday more factories likely will close as it slashes production of trucks and sport utility vehicles by 300,000 by the end of the year.

Manufacturers that make anything related to cars and trucks have been laying off workers, cutting their hours, selling the companies or shutting their doors, said Ralph Hardt, president of Feintool Inc., a Cincinnati component maker.

"The number of auction flyers that come across my desk is back where it was in 2000, 2001, the last recession we had," he said.