Southern California Edison (SCE) still owns all of its electrical transmission facilities and equipment, but the deregulation of California's electricity market in the late 1990s forced the company to sell many of its power plants, though some were probably sold by choice. In California, SCE retained only its hydroelectric plants, totaling about 1,200 MW, and its 75% share of the 2,150-MW San Onofre Nuclear Generating Station, which has been shut down since January 2012; in June 2013 the company announced its intention to permanently close and decommission the nuclear plant. The utility lost all of its natural gas-fired plants, which provided most of its electrical generation. The large, aging plants were bought by out-of-state companies such as Mirant and Reliant Energy, which allegedly used them to manipulate the California energy market.