Two leading Swiss electricity companies, Axpo and BKW, have set up a joint company to develop plans for two new nuclear power plants in Switzerland.
The aim is to replace two existing plants at Beznau in canton Aargau and the Mühleberg plant in canton Bern.
The third main nuclear operator, Atel, has been invited to join the project. The partners have agreed on Beznau and Mühleberg as the locations for the two new plants. Commissioning is foreseen after 2020.
Axpo and BKW, which supply about four million people in Switzerland with energy and produce about half the electricity consumed in the country, said they felt "obliged" to offer a solution to a foreseeable power shortfall when old plants reach the end of their life spans.
They said in a statement on Thursday that the establishment of the new company - Resun - was in line with the government's energy policy.
Opponents of nuclear power, who form an alliance called "Stopp Atom", have threatened to fight the plans with a referendum.
They argued that nuclear power presented health dangers and would be too costly without state subsidies. They added that the problem of storing nuclear waste had also not yet been solved.