UPDATE 1-RWE, consortium to build solar plant in Spain

* Plant is one of biggest solar thermal projects worldwide

* Technology comes from Solar Millennium

* Solar Millennium already present in Spanish solar industry

(adds details, share price)

FRANKFURT, July 10 (Reuters) - RWE Innogy (RWEG.DE) and a consortium will build a solar power plant called Andasol 3 in southern Spain, developed by Solar Millennium AG (S2MG.DE), the parties said in a statement on Friday.

It said that Stadwerke Munich, plant builder MAN Ferrostaal, RheinEnergie of Cologne and Eerlangen-based Solar Millennium would form a consortium with RWE Innogy for the unit.

The 50 megawatts (MW) plant is already under construction and will be opened and operated by the project partners in 2011.

"The parabolic trough technology sets new standards for solar power production," said RWE Innogy chief executive Fritz Vahrenholt.

"It is suitable to large-scale applications and thanks to giant thermal salt storages can keep producing after sunset an electricity which is both reliable and absorbable by the transmission grids."