Shares of less-than-truckload (LTL) carrier YRC Worldwide Inc. plunged Friday after the company's shareholders at a special meeting approved a huge increase in the number of outstanding shares, sparking investor worries of a significant dilution in the value of the company's equity.

Shareholders voted to increase the number of outstanding YRC shares to about 1.9 billion from 48 million, due largely to the conversion of preferred shares into common shares.

Shortly before the close of trading Sept. 16, YRC stock was down almost 78 percent to seven cents a share.

YRC, based in Overland Park, Kan., announced a major restructuring July 22 that called for the issuance of large amounts of stock in return for the retirement of debt. At the time, YRC warned that the restructuring would dilute the value of existing common shares almost entirely, leaving current shareholders with 2.5 percent of the company.

Separately, the company announced it would plan a "reverse split" for November or December, a move designed to remove shares from the market and boost the share price above $1.00 a share, a level that market regulators said must be maintained in order to keep the company's stock from being delisted from the Nasdaq market system.

If the company enacts a reverse stock split in November or December, it will be the second such action in a little more than a year. Last October, YRC executed a 1-to-25 reverse stock split to boost its shares above $1 and avoid Nasdaq delisting.

In a Sept. 15 internal memo, Greg Reid, YRC's chief marketing officer, said the share issuance and subsequent value dilution were "expected results of the restructuring and do not affect our ability to provide reliable, uninterrupted supply chain solutions" to the company's customers.

Reid added that YRC "expects analysts or competitors to call attention to these developments."