A company that owns the world's largest pool of plastic shipping pallets embedded with real-time tracking technology has filed for bankruptcy, in part because it lost 1.5 million of its pallets, Reuters reported yesterday. The company, iGPS Co LLC, filed for bankruptcy on Wednesday and plans to sell the business to a group of investors unless it receives better bids at a court-supervised auction. IGPS touts its pallets as stronger and lighter than those made from wood, and they contain built-in radio-frequency identification tags that can report the location of a product during shipment. The leased or rented pallets are used by Kraft Foods Group Inc, Costco Wholesale Corp and Wal-Mart Stores Inc. IGPS, which is based in Orlando, Florida, had revenues of $118.4 million last year, according to court documents. In late 2011 the company found it could not account for 1.5 million of its 10 million pallets, which its lenders alleged was a default under its credit facility, according to court documents.