PRAGUE — In October last year the Czech state power company, CEZ, selected three companies to bid for a contract to expand the Temelin nuclear power plant, in the southern Czech countryside. The companies are now readying themselves to submit detailed proposals that could have major consequences not just for the Czech Republic, but for the future of the nuclear industry in Europe.

CEZ is looking for offers to build not only two new reactors at Temelin, but also as many as three more at other sites that it owns. “In 2007 the decision was made to issue a tender for two nuclear reactors, plus a possible three more,” said Vaclav Bartuska, the Czech ambassador at large for energy security and government commissioner for the completion of the Temelin nuclear complex.

“This is right now the biggest tender in Europe and one of the biggest in the world.” Also, he said, “it’s unique as it is open for both east and west.”

The bidders vying for the deal, estimated to be worth 500 billion korunas, or $25 billion, are Areva, of France; a joint Russian-Czech venture, MIR-1200, in which the Czech nuclear engineering company Skoda JS is working with the Russian companies AtomStroyExport and Gidropress; and the U.S. company Westinghouse.