Office Depot plunges on small business concern

The office supply chain gets a hefty percentage of its North American business from small customers, who are facing pressure from inflation, frozen credit markets and the nation's economic slowdown.

"We think there's potential that over the next couple of years--2008 and into 2009--that small business growth could be constrained," said Morningstar retail analyst R.J. Hottovy.

Shares of the Delray Beach, Fla.-based retailer sank 85 cents, or 18.8 percent, to close at $3.67 after reaching as low as $3.55 earlier in the day.

Shares haven't traded that low since March 1991.

Earlier in the day, the Federal Reserve and other major central banks from around the world slashed interest rates to prevent a mushrooming financial crisis from becoming a global economic meltdown as anxiety grows about the stability of financial markets.