* Fennovoima chooses Pyhajoki in northern Finland
* Construction to start in 2015
* Reactor cost estimated at 4-6 bln euros
* E.ON says nuclear energy competitive
By Terhi Kinnunen
HELSINKI, Oct 5 (Reuters) - Finnish nuclear power consortium Fennovoima said it would build a reactor in Pyhajoki, northern Finland -- the first announcement of a new site anywhere in the world since the March disaster at the Fukushima plant in Japan.
The reactor project, estimated to cost around 4-6 billion euros ($5-8 billion), comes as Finland tries to curb its dependence on Russian energy and help its metals and forestry businesses stay competitive.
Environmentalists oppose the project, citing the area's vulnerable vegetation and wildlife, while proponents of nuclear policies say the Finnish economy cannot afford to phase out nuclear power, as Germany is doing.
Finland's long, cold winters require high energy consumption, and its forest and steel sectors rely on cheap and stable electricity.
The site is due to provide energy to Fennovoima's shareholders including stainless steel maker Outokumpu , retailer Kesko and the local subsidiaries of Swedish metals firm Boliden .
Construction in Pyhajoki, on the Hanhikivi peninsula, is expected to begin in 2015, and Fennovoima's chief executive said the company will choose a supplier in 2012 or 2013. Areva and Toshiba have been invited to bid on the project.
"We will get offers from equipment makers in January. After we have gone through those and chosen the deliverer, we can apply for construction permit from the government," CEO Tapio Saarenpaa told a news conference on Wednesday.
Fennovoima said it picked Pyhajoki over Simo, another municipality that was considered a leading candidate site, because of its lower seismic values and more solid bedrock.
Finland's parliament voted in July 2010 to back the building of two new nuclear reactors by Fennovoima and utility Teollisuuden Voima (TVO), raising Finland's total to seven.
The Fukushima disaster prompted Finland to launch a review of nuclear safety, but there has been little questioning among lawmakers over whether Fennovoima should proceed.
The country's supreme administrative court overruled appeals over Fennovoima's nuclear project on Sept. 21, clearing the way for the site selection.
German utility E.ON has a 34 percent stake in Fennovoima through its Finnish subsidiary, and an official said nuclear energy was a cost-efficient way to produce energy.
"The additional safety measure which may be requested by the authorities after Fukushima will not significantly change the economic competitiveness of nuclear energy," Ralf Gueldner, who heads E.ON's nuclear fleet and is a member of Fennovoima's board, told reporters in Helsinki.
He added Finland was a "rather attractive site" for a nuclear reactor due to strong political support on the national and local level, and from the general public.
But not everybody is enthusiastic. Around 10 people demonstrated outside Wednesday's news conference in Helsinki, carrying plaques saying "E.ON E.OFF - German nuclear power to Finland? No thank you."
Environmentalists, who note the area's rare vegetation and location along a migratory route for birds, have said they will take the case to the European Union.
"The decision conflicts greatly with natural values in the area and shows disregard for environment and also EU legislation," local environmental activist group Pro Hanhikivi said in a statement.