Chinese state nuclear company CNNC has confirmed it is interested in the project, which is on the Danube river.

Energy Minister Temenuzhka Petkova has said the Balkan country plans to launch a tender by the end of the year to pick a strategic investor for the plant, which is estimated to cost at least 10 billion euros (8.8 billion pounds).

She has invited France's Framatome, majority controlled by EDF, to take part. The European Investment Bank has also said it would look into the project.

Bulgaria cancelled the project in 2012 after failing to find investors. The country also faced of pressure from the United States and the European Union to limit its energy dependence on Russia, which was under contract to build the nuclear plant.

Bulgaria had to pay more than 620 million euros to Russia's Rosatom for cancelling the project, but also received nuclear parts for two 1,000 megawatt reactors. As a result, the country has to decide what to do with the equipment.

Sofia says it has already spent 3 billion levs ($1.82 billion) on Belene, which has a licensed site and equipment. But the government does not want to commit more public money, extend state guarantees for a possible loan, or sign any long-term electricity supply deals for the plant.

"If there is no interest at the market, there are two options for the project - the sale of the equipment, which cannot be done under favourable conditions or the installation of one of the reactors at the Kozloduy plant," Deputy Prime Minister Tomislav Donchev told a news conference.

Bulgaria already has two 1,000 megawatt Soviet-made nuclear reactors at its Kozloduy plant, which at present provide about 30 percent of the country's electricity.

Critics of the Belene project say that the investment does not justify the benefits and that the project as been a source of corrupt practices for decades.

Martin Vladimirov, an analyst with the Centre for the Study of the Democracy, said Belene was type of a "zombie" project that cannot die because powerful lobbies are looking to cash in on lucrative procurement orders.

(Reporting by Angel Krasimirov and Tsvetelia Tsolova; editing by Jason Neely and Jane Merriman)