Qimonda AG said its quarterly operating loss widened to a worse-than-expected 258 million euros ($378 million).

Sales in the German company's fiscal fourth quarter fell 4 percent sequentially and 42 percent from a year ago to 711 million euros.

Qimonda said it expected to increase bit production, or the amount of memory it produces, by 5 percent this quarter as it accelerates a planned transition to smaller circuit structures to help cut costs.

Qimonda said average selling prices had been 53 percent lower than a year earlier.

"In light of these difficult market conditions, we have accelerated our efforts to increase productivity and reduce costs," the company said in a statement.