Corning has already said it will take a restructuring charge of $550 million to $650 million to account for another round of layoffs.

The writedown and charge will be partly offset by a onetime $400 million aftertax gain from the sale of the company's precision-lens unit to 3M.

Much of the writedown involves intangible assets, whose declining value reflects a severe slump in the telecommunications industry. Corning said it does not expect "any significant growth" in the telecom portion of its business until "late 2004."

Corning said it still has $1.9 billion in intangible assets on its books. Since the start of 2002, the company has taken $2 billion in restructuring and other charges.

On Wednesday, shares of Corning (GLW) fell 27 cents to $4.23.

In the third quarter, Corning reported a net loss of $133 million as revenue plunged 44 percent to $837 million.

In an effort to return to profitability, the company said last month that it will cut another 2,200 jobs, bringing total layoffs this year to 4,600. By early 2003, Corning expects to have 23,500 workers.

"This has been a very difficult year for Corning, our employees, our communities and our shareholders. The long and deep depression in telecommunications industry capital spending has challenged us," said Chief Financial Officer James B. Flaws in a statement.

"Yet we continue to make progress against our goals. Our restructuring should help us achieve profitability in 2003 and we are prepared to do more if necessary," he added.