(Repeats story published late on Monday)
PRAGUE July 14 (Reuters) - Czech power group CEZ <
> unveiled a preliminary plan on Monday to build two new units at its Temelin nuclear power plant in a move that could be the largest investment in the central European state.CEZ, ex-communist central Europe's largest company with a market capitalisation of $54 million, said construction should start in 2013 and the first bloc should be completed by 2020.
Czech media have estimated the project could to cost up to 130 billion crowns ($8.16 billion) but a CEZ spokeswoman declined to comment on the price.
The units could reach a combined capacity of up to 3,400 megawatts, adding to the company's current 12,302 megawatts, CEZ said in a presentation on its Web site on Monday.
The company has asked the Environment Ministry for an environmental assessment for the new units, which it said could take two and a half years.
The assessment must precede any decision to build the plant, and the centre-right government, in which the Green Party is a junior member, has pledged not to approve construction of new nuclear power stations before its term ends in 2010.
The Czech Republic is Europe's third largest electricity exporter but shrinking coal reserves, rising demand and an ageing pool of power plants are expected to swing the balance to where it will barely meet domestic demand in about 2015.
CEZ operates two 1,000 megawatt units at the Temelin plant in the southern Czech Republic, near its border with fiercely anti-nuclear neighbour Austria, and has capacity to add another two units of the same size at the site.
It also runs four older units in Dukovany in the southeast, for which it also plans to ask for an environmental impact study to build a new reactor there, CEZ spokeswoman Eva Novakova said.
But she declined to specify when. "It may not take long," Novakova said.
There has been a rising tendency in Europe to push for nuclear power as soaring commodity prices make energy from coal, gas and fuel-oil fired plants more expensive to run.
CEZ has long said it is also interested in investing in nuclear projects in other central and eastern European countries including Romania's Cernavoda, Slovakia's Jaslovske Bohunice, and Bulgaria's Belene.
The vast majority of Czech political parties support building new nuclear plants, but the small Green Party, a coalition ally of the ruling right-wing Civic Democrats, insists the cabinet not push ahead.
Shares in CEZ closed up 0.3 percent at 1,343 crowns, outperforming the main PX index <
> which shed 0.26 percent. (Reporting by Jana Mlcochova)