The Luxembourg-based dredging firm will lay and bury cables connecting the project, 27 kilometres from the UK's east coast, with the onshore substation.
A total of 148 kilometres of cables will be installed for the project, expected online by 2017. In December, NKT Cables was awarded the contract by Dong to supply export cables to the project. The order has been split into two phases, with the first phase set for delivery in 2016.
Jan De Nul will use its newly launched Isaac Newton multipurpose vessel. The company said in "cable-installation mode" the vessel could transport 10,000 tonnes of a single-length cable. Jan De Nul claims it to be the only vessel able to do so.
The contract was signed between the two companies at the EWEA Offshore 2015 conference, taking place in Copenhagen (10-12 March).