Czech state-run power group CEZ said on Monday it had received three bids to build two units at its Temelin nuclear power facility in the southern Czech Republic, as expected.

"Three qualified bidders have placed offers in the largest tender in Czech history," CEZ said, naming France's Areva and groupings led by US giant Westinghouse and Russia's Atomstroiexport.

All three bidders recently signed cooperation deals with Czech partners to sweeten their bids.

The winner of the tender worth an estimated 200-300 billion koruna (7.9-11.8 billion euros, $9.9-14.9 billion) is to be announced at the end of 2013, with the two units to be completed by 2025.

"Today we made another major step towards ensuring reliable energy supplies to Czech customers for dozens of years," said CEZ chairman and chief executive Daniel Benes.

"The Temelin completion is the key pillar of CEZ's strategy and we are glad to have three bids from the most important global nuclear technology suppliers," he added.

The extra capacity will raise the share of nuclear energy in the Czech energy mix to about 50 percent from the current 30 percent produced by Temelin and another CEZ-operated nuclear plant in the southern village of Dukovany.

Temelin, about 120 kilometres (75 miles) south of Prague, but only about 60 kilometres from the Austrian border, has been heavily criticised by Austria which has repeatedly raised safety concerns.

It may also become a thorn in the side of Germany, which has vowed to shut down its nuclear reactors by 2022.

An EU member since 2004, the Czech Republic is betting on nuclear power as its communist-era coal-fired plants are likely facing closure amid tighter regulations on greenhouse gas emissions.

The Czech government, which owns two-thirds of CEZ, has set the condition that the tender winner must already run a comparable nuclear reactor before it gets a go-ahead on the Temelin completion around 2016-17.

"The supplier must already run a model reactor by then. If there's none, it's better to give up," Vaclav Bartuska, government commissioner for energy, said recently.

Planned in the communist era and launched in 2000, the existing Temelin facility includes two Russian-type VVER pressurised-water reactors, each with an output of 1,000 megawatts.