In September they signed a letter of intent, which they have now extended, to share the estimated 30 billion zlotys ($9.75 billion) to 50 billion zlotys cost of building the station.

Poland wants to develop nuclear power to reduce its dependence on highly polluting coal, but top utility PGE , which is managing the project, cannot fund the project alone.

The four firms which include Tauron and Enea are state-controlled.

The largest eastern member of the European Union aims to launch a 3 gigawatt nuclear plant by 2023 and double that capacity by 2030.

Center>Copyright Reuters, 2012