BUCHAREST, Oct 9 (Reuters) - U.S. construction and engineering firm AECOM will lead an $8 billion project to add two reactors at Romania's nuclear power plant on the river Danube and refurbish one of its existing units, Romania's Economy Ministry said on Friday.

Romanian Economy Minister Virgil Popescu and U.S. Energy Secretary Dan Brouillette signed a draft intergovernmental cooperation agreement in Washington on Friday for the refurbishment and the building of two new units.

Romanian state-owned nuclear power producer Nuclearelectrica ended talks with China General Nuclear (CGN) about the construction of the two reactors in June after they had dragged on for six years.

The firm currently has two 706 megawatt reactors, which account for roughly a fifth of Romania's power production and which use Candu technology, from Canada's Candu Energy, owned by SNC Lavalin Group.

"This fulfils a strategic mission, identifying partners from NATO states for Units 3 and 4," Minister Popescu said.

"The agreement we signed ... today allows us to have American technology and expertise for Units 3 and 4, but also for refurbishing Unit 1, while keeping Candu 6 technology."

U.S. Ambassador Adrian Zuckerman said AECOM will coordinate the project, which will involve Romanian, Canadian and French companies.

Nuclearelectrica's manager Cosmin Ghita said Friday's draft agreement, which set the main elements of project development and involved parties will be sent to the European Commission for approval. He added CANDU 6 technology will be used for future reactors.

Nuclearelectrica, in which Romania's economy ministry has an 80% stake, has a market capitalisation of 4.95 billion lei ($1.20 billion).

Popescu also said Romania could secure a $7 billion financing package from Exim Bank U.S. for energy and infrastructure projects, including nuclear energy and LNG, roads and railroads and gas deposits. ($1 = 4.1167 lei) (Reporting by Luiza Ilie; Editing by Marguerita Choy)