The consumer spending slump and tightening credit markets are unleashing a widening wave of bankruptcies in American retailing, prompting thousands of store closings that are expected to remake suburban malls and downtown shopping districts across the country.

Since last fall, eight mostly midsize chains  as diverse as the furniture store Levitz and the electronics seller Sharper Image  have filed for bankruptcy protection as they staggered under mounting debt and declining sales.

But the troubles are quickly spreading to bigger national companies, like Linens ‘n Things, the bedding and furniture retailer with 500 stores in 47 states. It may file for bankruptcy as early as this week, according to people briefed on the matter.

Even retailers that can avoid bankruptcy are shutting down stores to preserve cash through what could be a long economic downturn. Over the next year, Foot Locker said it would close 140 stores, Ann Taylor will start to shutter 117, and the jeweler Zales will close 100.