Equinor has bought 41,197,344 shares in Ørsted, giving it a 9.8% stake in the company.
This acquisition makes Equinor the second largest shareholder in Ørsted, following the Danish State, which holds a controlling interest.
Ørsted has a renewable generation capacity of about 10.4 GW and is working towards a goal of 35 to 38 GW by 2030.
The company has around 7GW of offshore wind projects currently in progress.
Equinor’s stake is valued at approximately $2.5 billion (£1.9bn).
Anders Opedal, CEO of Equinor, said: “Equinor has a long-term perspective and will be a supportive owner in Ørsted. This is a counter-cyclical investment in a leading developer, and a premium portfolio of operating offshore wind assets.”