The battle for General Growth Properties, a major U.S. mall owner seeking to emerge from bankruptcy protection, is turning into the biggest real estate fight since the sale of Sam Zell's Equity Office Properties Trust. A contest for General Growth's assets has erupted between Simon Property Group and Brookfield Asset Management, and more bidders might emerge for the holdings of the Chicago company, which filed for Chapter 11 protection in April after amassing more than $27 billion in debt. General Growth owns more than 200 U.S. malls, including Tysons Galleria in McLean and Landmark Mall in Alexandria. Its portfolio features some of the most valuable properties in retail real estate, including four of the five U.S. malls with the highest sales per square foot. Plunging commercial real estate values -- down 41 percent since their 2007 peak -- have left landlords reluctant to sell if they don't have to, making General Growth's properties a potentially attractive bargain. "For many years, the investing community failed to understand the real value of high-quality regional malls," said Rich Moore, managing director at RBC Capital Markets in Solon, Ohio. "We've just gone through the worst recession in our history and these things are largely unscathed.