The company that owns the Steeplegate Mall - Concord's largest taxpayer - may be on the cusp of bankruptcy. Despite corporate assurances that the mall will remain open and "vibrant" through the holidays, city leaders are keeping a close watch on a linchpin of the local economy.

In addition to paying $1.5 million in taxes for 2007, the mall holds dozens of shops that employ hundreds of people. Its 52 acres are part of a sprawling retail campus on the Heights. City Manager Tom Aspell says the city hasn't heard directly from General Growth Properties Inc., but his office is aware of the company's troubles.

On Monday, the company's shares fell sharply after it reported it may file for bankruptcy if it can't cover $1 billion in debt due next month.

Aspell routinely keeps watch on financial happenings that affect major taxpayers. General Growth became a cause of concern a few months ago when the company sold property in Las Vegas and, later, in Maine.

"We've been following this all along," he said. "There's a lot going on. . . . Myself and the assessors really keep track of anything that involves Concord taxpayers to try and stay out in front of it."

General Growth took over the mall in 1996 and made a series of upgrades and expansions. In 2007, the mall had six anchor stores and 56 smaller shops; it was valued at $83.5 million. It is current on its tax bill, although the mall and the city have squabbled in recent years about how much the mall should pay.

General Growth Properties is a publicly traded real estate investment trust based in Chicago. According to its website, the company and its predecessors have been operating shopping centers for 50 years. It employs 4,200 people nationwide. It's the second largest mall owner in the country and operates several well-known properties, including Boston's Faneuil Hall.

This fall, it has struggled to find financing in a tricky global credit market. Earlier this week, the Associated Press reported that General Growth is trying to sell properties and cut costs. Dividends have been suspended, and top executives have been replaced.

The company is working with advisers to boost capital and is considering joint ventures and other options. In the meantime, a spokesman said yesterday, it's business as usual at malls across the country, including Steeplegate.

"There's really no impact on the mall," said David Keating. "Regardless of what we're going through at the corporate level, Steeplegate is going to remain open, remain vibrant, and we're looking forward to a great holiday season."

Material from the Associated Press was used in this report.