The memorandum confirms their interest. It also gives four months to Bulgaria to decide how to restructure the project, a NEK spokeswoman said.

The consortium will invest EUR600 million in the Gorna Arda project was part of an energy deal between Bulgaria and Turkey, signed in 1998.

Initially, the project was to be built by Turkish CCG, part of the Ceylan conglomerate. NEK kept 70% in the joint venture. But construction never got under way as the conglomerate’s Bank Kapital was put under administration in 2000.

Bulgaria will seek to keep a majority stake in the new venture and the partners were yet to decide.

In 2007, CCG has started arbitration proceedings in a Paris commercial court, seeking EUR75 million in damages from NEK over the stalled project.

CCG will withdraw its claim by July 2009 as it has reached an agreement to sell its 30% stake to the EVN-led group.