More than 4,500 miles separate a small Wal-Mart Stores Inc. office in Florence, Italy, from the company's dozens of Illinois retail outlets. But thanks to a convoluted tax arrangement, court records show, Wal-Mart's Italian operation has helped the giant retailer cut its state tax bill in Illinois by millions of dollars a year.

Wal-Mart set its affairs so that its Italian outpost is the only operating unit of a real-estate subsidiary that controls billions of dollars of the retailer's property in Illinois and other states.