The deal is for 23 GW87 1.5MW turbines for the Negrete Cuel development in central Chile. It follows on from Mainstream's deal with Goldwind to co-develop the 109MW Shady Oaks project in the US.
Finance has been provided by China Development Bank with Mainstream maintaining 100% ownership of the project.
Speaking about the deal, Mainstream chief executive Eddie O'Connor said: "Our goal is to deliver low cost, high quality projects and by partnering with Goldwind and the China Development Bank we can achieve this. We’re developing over 15,000MW of projects across four continents and working with Chinese partners is very much central to our strategy. Earlier this year we established our office in Beijing and we’re fully committed to these relationships for the long term."
There are a number of projects in the pipeline in Chile. Vestas is currently developing the country's largest project, the 100MW Talinay Oriente wind farm in Limari province.
Negrete Cuel is Goldwind's second project in South America. In August, it has signed a deal with Ecuador's electricity corporation (CELEC) to build the country's first wind farm.