The company, however, said Wednesday it expects to report that third-quarter results were within earlier projections. It anticipates a loss of 7 cents to 8 cents a share before one-time items on sales of $830 million to $840 million.

In July, Corning projected a loss of 7 cents to 10 cents a share for the three months ended Sept. 30 on sales of $825 million to $875 million. Analysts surveyed by Thomson First Call were looking for a loss of 8 cents a share.

Its third-quarter results are expected to be released on Oct. 30.

In trading on the New York Stock Exchange, Corning shares gained 11.8 percent, or 13 cents a share, to close Tuesday at $1.23.

The telecommunications industry's alarming slowdown left Corning badly shaken. The world's biggest maker of optical fiber and cable is already cutting 4,400 jobs this year on top of 12,000 last year. That will shrink its worldwide payroll to about 28,000 people.

The fourth quarter appears likely to be hobbled by spending cuts by carriers, bankruptcies and a lack of industry consolidation, said James Flaws, Corning's chief financial officer.

"These events will require us to do more restructuring in the fourth quarter," Flaws said.

Restructuring could mean further job cuts, the sale of non-core businesses, plant closures and consolidation of manufacturing capacity, the company said.

Corning lost $370 million in the second quarter, its fifth quarterly loss in a row, and sales plunged to $896 million from $1.87 billion a year earlier.

The company hinted last month that it will idle its four optical-fiber plants this fall in a repeat of the temporary shutdown last winter. The plants, two in North Carolina and one each in Germany and Australia, are already running at less than 50 percent capacity.