PORTLAND, Ore. (AP) -- General Growth Properties, the nation's second-largest mall owner, whose holdings include at least five properties in Oregon, has filed for Chapter 11 bankruptcy protection.

The Chicago-based company is trying to restructure about $27 billion in debt, much of it acquired during aggressive expansion before the recession squashed the real estate boom.

But the company said its malls will operate normally in the meantime.

General Growth owns Clackamas Town Center and Pioneer Place in Portland, the Rogue Valley Mall in Medford, the Gateway Mall in Springfield and the Salem Center.

General Growth owns more than 200 malls across the country.