Peabody Energy has long been the king of coal. The world's largest private-sector coal producer, Peabody owns stakes in 26 mines (25 majority owned) and processing facilities in the US and Australia. It sells about 228.8 million tons of coal annually and maintains 6.3 billion tons of proved and probable reserves. US customers, primarily power companies, account for most of Peabody's sales, and its coal fuels more than 40% of US power. Its operations include coal trading and brokering, coalbed methane production, transportation-related services, and development of coal-based generating plants. Facing regulatory pressure and a down market, Peabody sought Chapter 11 bankruptcy protection in 2016.