ROANOKE, Va. (AP) _ Coal producer Xinergy Ltd. and more than two dozen subsidiaries have filed for Chapter 11 bankruptcy. Knoxville, Tennessee-based Xinergy filed a Chapter 11 petition last week in U.S. Bankruptcy Court in Roanoke, Virginia. The petition lists zero to $50,000 in assets and about $100 million to $500 million in liabilities. Xinergy produces steam and metallurgical coal at mining operations in Virginia and West Virginia. Xinergy CEO Bernie Mason says in a news release that U.S. coal markets have faced significant challenges in recent years, including declining demand and increased environmental regulations. Mason also says Xinergy’s cash position has been eroded by a harsh winter that affected coal mining and shipments. Xinergy is seeking the court’s approval to obtain debtor-in-possession financing. The company says it will continue operations while it reorganizes.