WASHINGTON -- General Growth Properties Inc., owner of the Maine Mall, is getting a two-week extension on $900 million in debt that had been scheduled to come due last week as the company works to stave off bankruptcy and negotiate longer-term extensions with lenders.

The mortgages cover two malls, Fashion Show and Palazzo, in Las Vegas, the company said. Shares fell 25 cents, or more than 18 percent, to $1.13 in Monday afternoon trading, mirroring a decline in the broader market.

Chicago-based General Growth Properties, the nation's second-largest shopping mall owner, has been hit hard by the deteriorating U.S. economy and problems at struggling U.S. retailers. Analysts are unsure whether new managers, installed in late October, will be able to keep the company afloat
given its staggering debt load.

"It will be incredibly difficult for General Growth to deal with the
mountain of obligations that are coming due next year," said Benjamin Yang, an analyst at research firm Green Street Advisors, in an e-mail.

General Growth's struggles come amid growing concern about debt tied to commercial properties. Industrywide about $20 billion will be due next year, covering everything from office and condo complexes to hotels and malls.

The retail outlook is particularly bad. Circuit City Stores Inc. and Linens 'n Things have sought bankruptcy protection. Home Depot Inc., Sears Holdings Corp., Ann Taylor Stores Corp. and Foot Locker Inc. are closing stores.

"Many of these loans will become a nightmare as a severely slowing economy, significantly tighter credit requirements, and falling commercial real estate property prices force many borrowers to default over the coming years," JPMorgan Chase & Co. analyst Alan Todd wrote in a research note last week.

General Growth said in a Securities and Exchange Commission filing last month that it faces nearly $3.1 billion in maturing debt next year, and warned that inability to refinance that debt "raises substantial doubts as to our ability to continue as a going concern."