Abu Dhabi's Masdar bought into German firm E.ON's stake in the massive London Array offshore wind farm project, the companies announced on Thursday.

Masdar will take a 20-percent stake in the project, with E.ON retaining a 30-percent share.

An official with the Abu Dhabi-based firm, which was set up to develop sustainable clean energy, said the stake was "a multi-million dollar" one but declined to provide exact figures.

"Masdar has entered into the London Array scheme through a joint venture agreement with E.ON, which currently owns half of the landmark project," a statement issued by E.ON said.

Denmark based DONG Energy owns the remaining 50 percent stake in the project.

The future of the London Array plan to supply some 750,000 homes with electricity from 341 turbines in the outer Thames Estuary has been in doubt since Royal Dutch Shell pulled out earlier this year, citing escalating costs.

The British government needs wind power to grow rapidly over the next decade to stand any chance of reaching tough European Union renewable energy targets for 2020. - Reuters