Suntech Power Holdings Co. filed for chapter 15 protection on Friday in an attempt to stop some bondholders from interfering with professionals who are trying to turn Suntech from the world's former largest solar-panel maker into a seller of solar products, Dow Jones Daily Bankruptcy Review reported today. The filing blocks some unpaid bondholders — part of a group owed about $540 million — from forcing the company into liquidation in a U.S. Bankruptcy Court.