Rusatom Overseas is a subsidiary of the Russian Rosatom.
According to the agreed schedule, the nuclear plant will produce electricity by 2024.
Fennovoima is due to make the final investment decision about the Pyhäjoki plant at the end of February 2014, when shareholders are to confirm their participation in the project. At the same time, Rosatom will take over a 34 per cent share of Fennovoima.
In November, Fennovoima announced that 45 shareholders were staying on board the project, among them mining company Talvivaara, steel company Outokumpu, dairy company Valio, and several regional power companies.
The price of the nuclear power plant deal has not been disclosed.
The nuclear plant to be constructed in Pyhäjoki is a pressurized water reactor AES-2006. This is a different type of reactor than the one considered when Fennovoima was granted permission for the nuclear plant.