China’s one-time solar-power giant Suntech Power Holdings Co. plans to file for bankruptcy protection in U.S. court as its leaders negotiate with the holders of more than $500 million in U.S. convertible bonds, the Wall Street Journal reported on Saturday. Suntech Power Holdings, which was once the world’s largest solar panel maker, defaulted on its U.S. debt in March, and financial professionals in the Cayman Islands — where the holding company is incorporated — have been trying to negotiate a repayment plan with bondholders. Suntech plans to file for chapter 15 protection. If recognized by a U.S. judge, the solar panel maker will receive the benefits of U.S. bankruptcy law, including the so-called automatic stay that halts lawsuits and prevents creditors from seizing assets. The filing is expected by Feb. 21.