China failed to overturn a U.S. law targeting unfair trade subsidies on Monday, when the World Trade Organization's Appellate Body said it did not have enough information to uphold China's appeal against an earlier WTO ruling. China had claimed that the U.S. "Public Law 112-99", also known as the GTX legislation, which was signed by President Barack Obama in March 2012, broke world trade rules, but a WTO dispute panel ruled against it in March. The Appellate Body disagreed with…