The terms and financial details of the agreement have not been disclosed but people familiar with the process have told Reuters that they anticipated it to be valued at $1.8bn.
WindMW GmbH is a Bremerhaven-based joint-venture between Blackstone and Windland Energieerzeugungs(20%).
It owns the 288MW Meerwind Süd|Ost offshore wind farm located off the German coast in the North Sea.
The windfarm, which was fully commissioned in February last year, produces enough power for about 360,000 households in Germany.
Meerwind’s management team, led by CEO Jens Assheuer, designed, built, commissioned and operated the wind farm in partnership with Blackstone since 2008.
WindMW’s management team will continue to operate the business under China Three Gorges ownership.
Assheuer said: "We look forward to working together with China Three Gorges, with whom we share a strong commitment to developing and operating renewable energy projects globally."
Blackstone senior managing director Sean Klimczak said: "Our team consistently looks for transformative projects that challenge and improve upon the status quo and Meerwind epitomizes that effort. We are pleased that the WindMW team will carry on their impactful work under the new ownership of China Three Gorges."