General Growth Properties Inc., owner of the Maine Mall, may sell off some of the 200 shopping centers it owns nationwide to refinance $4 billion in debt.

Jim Graham, spokesman for the Chicago-based company, said this week that it is “too premature to speculate” which holdings – including the South Portland mall – may be put up for sale.

But, Graham added that leasing at the Maine Mall remains strong. A handful of new national retailers have filled store vacancies this fall.

Meanwhile, John Geddis, Maine Mall general manager, has abruptly resigned from his post to take a job with an unidentified development company in New Orleans. General Growth offered no public announcement when Geddis resigned late this summer after 2 1/2 years running the South Portland mall.

Keith Stone, senior operations manager with the Maine Mall, said Monday that Craig Gorris is the interim general manager.

Gorris is the general manager of Providence Place in Rhode Island, another shopping center owned by General Growth Properties, a nationwide real estate investment trust.

Gorris previously managed the Maine Mall before Geddis was hired, Stone said. Gorris will divide his time between Providence Place and the Maine Mall until a permanent replacement is found.

Geddis left the mall shortly after General Growth Properties disclosed that it was dropping major plans for a redevelopment and expansion of the aging shopping mall. The company had planned for a multi-screen movie theater, more restaurants, an expansion of JC Penney and a second food court.

The decision to drop the expansion followed news that the Maine Mall’s parent company was suffering financially in the difficult economy.

A drop in consumer spending and the tight credit market has hurt General Growth, the nation’s second-largest shopping mall investor. Financial analysts note that General Growth has a high debt-to-asset ratio, making it a credit risk.

More than $1 billion of its debt is due by year-end, and the company is struggling to refinance. Meanwhile, it must pay off $4.3 billion over the next two years, according to Crain’s Chicago Business, which tracks Chicago-based companies.

Standard & Poor’s cut General Growth’s credit rating last week. The ratings agency also placed the rating on review for a possible further downgrade because of its debts.

Several General Growth executives also sold stock in the company last week, including Chief Financial Officer Bernard Freibaum, who unloaded shares worth $31.1 million. The stock price of the publicly traded company has tumbled from $52.80 on Sept. 19, 2007, to $21.42 on Sept. 19, 2008.

The company, in response, announced it may sell some real estate holdings to boost stock values. It declined to identify which assets it may put up for sale. General Growth is the nation’s second-largest mall developer.

General Growth released a statement saying it is pursuing “a comprehensive strategic plan to generate capital.” The company is looking to raise capital from a variety of potential sources, which may include “sales of assets or joint-venture holdings.”

Whether General Growth’s precarious financial situation – or its new strategy for raising cash – will have any effect on the Maine Mall is uncertain.

Graham, the company spokesman, said that General Growth most likely will target “non-core assets” for sale that are not central to its mission of operating shopping centers.

Graham also was upbeat on the Maine Mall.

He noted that Maine’s largest shopping mall has a 93 percent occupancy rate, according to the company’s most recent earnings report. “Our leasing is strong,” Graham said.

Indeed, the Maine Mall has benefited this fall from new retailers moving into the shopping center. The mall has redoubled efforts to fill vacancies since it dropped plans to pursue a major expansion.

New retailers include an Apple computer store and Forever 21, a clothing store that appeals to teenagers and young adults. Both opened this month.

Coldwater Creek and H&M, two national clothing retailers, are scheduled to open next month.

Stone, the mall’s operations manager, said negotiations are under way to bring in additional new retailers early next year. He declined to identify stores that may locate at the mall.

General Growth Properties also is appealing its 2006 South Portland property valuation before the state Board of Property Tax Review. A hearing date has not been set, but it is expected to be in early 2009, according to the city Tax Assessor’s Office.

The company disputes South Portland’s 2006 assessment that valued the mall property at $266 million. The company claims the mall actually is worth $190 million – $76 million less than the city’s valuation.

General Growth bought the mall in 2003 for $270 million, but says the higher price reflected the mall’s name brand, not the value of the property and buildings.

In 2009, the company will make its argument before the state board, composed of attorneys, retired assessors, engineers and others with a background in assessments in Maine. Members are appointed by the governor.

If General Growth loses, it can file an appeal in Superior Court. The case could make it all the way to the Maine Supreme Court.