A rising number of manufacturers are canceling new investments and putting off new hires because they fear paralysis in Washington will force hundreds of billions in tax increases and budget cuts in January, undermining economic growth in the coming months.

Executives at companies making everything from electrical components and power systems to automotive parts say the fiscal stalemate is prompting them to pull back now, rather than wait for a possible resolution to the deadlock on Capitol Hill…

More than 40 percent of companies surveyed by Morgan Stanley in July cited the fiscal cliff as a major reason for their spending restraint, Mr. Reinhart said. He expects that portion to rise when the poll is repeated this month.

“Economists generally overstate the effects of uncertainty on spending, but in this case it does seem to be significant,” he added. “It’s at the macro- and microeconomic levels.”