FRANKFURT, Nov 8 (Reuters) - Chipmaker Qimonda AG (QI1Ay.DE: Quote, Profile, Research)(QI.N: Quote, Profile, Research) said Thursday its quarterly operating loss widened to a worse-than-expected 258 million euros ($378 million) after prices for standard DRAM memory chips fell to new lows.

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

According to a Reuters poll, nine analysts expected an EBIT (earnings before interest and taxes) loss of 236 million euros on sales of 823 million euros, on average.

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.

"We curtailed our capital expenditures and operating expenses in the fourth quarter even more than originally planned, and on the productivity front, we are confident that we will have more than 50 percent conversion to 80 nanometre and 75 nanometre in December 2007."

U.S. memory-chip rival Micron Technology Inc (MU.N: Quote, Profile, Research) also posted a quarterly loss last month, saying prices for both DRAM and NAND memory chips had fallen about 15 percent from the preceding quarter.

Qimonda is majority owned by German chipmaker Infineon Technologies AG (IFXGn.DE: Quote, Profile, Research), which listed it in New York a year ago. ($1=.6832 Euro) (To read the Reuters poll on Qimonda's fourth-quarter results, please double click on [ID:nL07254560]) (Editing by Jeffrey Benkoe)