Aug 13 (Reuters) - A U.S (Other OTC: UBGXF - news) . judge on Thursday found that BP Plc manipulated the natural gas market in 2008, as alleged by the U.S. energy regulator, but did not address a proposed $28 million fine or any other penalties. The administrative law judge's decision upheld the Federal Energy Regulatory Commission's previous charges that BP's trading activities in Texas violated the Natural Gas Act. FERC in August 2013 ordered BP to explain why it should not have to pay the fine and disgorge $800,000 plus interest. BP has disputed FERC's allegations. For a timeline on FERC's BP case and the events leading up to it, see below. 2000-2001 - A power crisis hits California and other western U.S. states, costing customers up to $45 billion along with lost economic activity due in part to power and gas market manipulation. December 2001 - Enron enters bankruptcy amid an accounting scandal and accusations of power and gas market manipulation. 2001-2003 - Numerous energy marketers, such as the former Enron, Mirant, El Paso and Dynegy (NYSE: DYN - news) , exit U.S. power and gas markets due to credit concerns and allegations of market manipulation. April 2003 - U.S. Commodities Futures Trading Commission (CFTC) alleges BP manipulated the propane market in April 2003 and February 2004. August 2003 - Blackout leaves 55 million people in the dark in eight U.S. Northeast and... More