Under the 20-year contracts, the JV will build and operate two wind farms which will have a total installed capacity of around 265MW.
The National Energy Commission (NCE) has awarded the contracts to Aela under a competitive bidding process that saw 31 companies compete for 1200GWh of energy.
Commenting on the contracts, Aela Energía CEO Sergio del Campo said: "It is an important result and contributes to meeting our goal of delivering 600 megawatts onto the Chilean grid, involving an investment of US$ 1,400 million."
Mainstream will complete development of the projects.
Mainstream Chile general manager Bart Doyle said: "Mainstream brings a portfolio of high quality wind and solar PV projects to Aela Energía.
"Mainstream is delighted to see that our investment over the past seven years in Chile has culminated in this significant win for Aela Energía in what has been a highly competitive tender process."
When operational, the wind farms will supply clean power to regulated customers in Chile’s SIC electricity system starting from 2017.
Aela Energía said that it has a capital fund of $400m to invest in non-conventional renewable energy (NCRE) wind and solar projects.
The company currently owns the 33MW Cuel Wind Farm in the Biobío Region which was developed, built and is being operated by Mainstream.
Actis and Mainstream Renewable own 60% and 40% stake in the JV respectively.
