The drop pushed major indexes to the lowest point since early September.
The Dow Jones industrial average dropped 250 points to 13,095 at midday Tuesday. That's a decline of 1.9 percent.
The Standard & Poor's 500 fell 23 points to 1,410. The Nasdaq composite was off 33 points at 2,984.
The day was shaping up to be among the worst of the year on Wall Street. The Dow's biggest decline was 274 points, on June 1.
3M, which makes everything from Scotch tape to coatings for LCD screens, cut its profit expectations for this year, citing the weak economy. Chemical maker DuPont also slashed its forecast.