The Fortum decision has provoked resistance from anti-nuclear groups, and Greenpeace last week called a demonstration in an effort to stop the move.

"It wasn't an easy decision, but the problem is that there is no other single large scale solution to increase the energy production capacity, that we all agree is needed," Carola Teir-Lehtinen, Fortum's spokeswoman, told AFP.

The Finnish national energy group is a member of TVO, a non-profit consortium that won parliamentary approval last year to build a new nuclear reactor, supplementing four aging power stations from the 1970s.

TVO said on Monday that interest in the project's 1,600 Mw power-generating capacity had been strong, with Finnish firms wanting to reserve over 2,000 Mw for their future use, but gave no further details.

Believed to be among them are Finnish forestry and paper giants UPM-Kymmene and Stora-Enso, which both hold indirect stakes in TVO, while the City of Helsinki has already said that it will participate in the construction.

Fortum, controlled by the Finnish state with a 61-percent stake, has a stated ambition to become the Nordic region's largest supplier of electricity. Currently it ranks second, supplying some 13 percent of total deliveries.

Following the decision Greenpeace said it would start a campaign targeting Fortum's customers in Scandinavia, where resistance against nuclear power remains strong and the firm has marketed its energy as a "green alternative".

"We will make Fortum's customers in the Nordic countries aware of this, I'm sure that their customers and potential customers in Denmark, Sweden and Norway would like to know about this," Kaisa Kosonen, a campaigner for Greenpeace, said.

Fortum was, however, not worried by any possible boycott threat, Teri-Lehtinen said.

WAR.WIRE