The project is being developed by the Blauwwind consortium, comprising Van Oord, oil and gas giant Shell, Dutch developer Eneco, Mitsubishi's European subsidiary Diamond Generating Europe and Swiss investment manager Partners Group.
Prysmian said it would be responsible for the design, manufacture, supply and testing of 175km of inter-array cabling at the site, which is due online by 2021.
Cables will be produced at the company's Pikkala site in Finland.
In March, the cable firm announced a €170 million investment in a new cable-laying vessel, due to enter operation by Q2 2020. It will have deep-water cable-laying capability, increased loading and rotating platforms.
MHI Vestas, announced as the preferred supplier for the project, is set to deliver 77 V164 9.5MW turbines to the site.