Bolivia's rivers have considerable, largely untapped hydroelectric potential, and per capita electric consumption remains low. Partly in an effort to improve services, a controlling interest in the National Electric Company was sold in the 1990s to energy companies in the United States and Spain, and the remaining shares were turned over to a national pension system. Hydroelectric stations generate power in the departments of La Paz and Cochabamba, and thermoelectric plants fueled by natural gas generate power in Santa Cruz and Cochabamba for the integrated national distribution system. Foreign companies have also invested in separate electric systems in Tarija and Trinidad, and the Bolivian government has encouraged plans for the exporting of electricity to Brazil.Bolivia's installed electricity capacity by the mid-1980s had reached 566 megawatts, and government plans in the late 1980s projected growth in domestic demand and significant annual investment in expanding domestic supply into the 1990s. Hydroelectric sources provided approximately 62 percent of the supply of electricity, followed by thermal sources with 25 percent and diesel with 13 percent. The National Electrification Institute (Instituto Nacional de Electrificación), a branch of the Ministry of Energy and Hydrocarbons, provided diesel generators to those outside major cities and beyond the reach of the interconnected electricity system, which linked most major cities for the first time in the 1980s. The National Electricity Company (Empresa Nacional de Electricidad--ENDE), which is a part of the Ministry of Energy and Hydrocarbons, controlled 80 percent of the country's electricity capacity, including five hydroelectric plants. Other producers of electricity included the United States-owned Bolivia Electricity Company (Compañía Boliviana de Energía Eléctrica), serving La Paz and Oruro; the Cochabamba Light and Power Company (Empresa de Luz y Fuerza Eléctrica de Cochabamba); the Rural Electricity Cooperative (Cooperativa Rural de Electrificación), working in rural areas; and Comibol, which generated much of its own electricity, primarily from charcoal and firewood. ENDE established electricity rates, which were often subject to large increases. ENDE, as a consequence of the NPE, negotiated electricity rates with private companies and local city councils. Access to electricity by private citizens was growing in the late 1980s and was available to over 72 percent of urban dwellers. Rural citizens, however, lagged well behind; only about 10 percent had such access, low even by Latin American standards.